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CSG 15
MINISTRY OF AGRICULTURE, FISHERIES AND FOOD
Research and Development
Final Project Report
(Not to be used for LINK projects)
Two hard copies of this form should be returned to:
Research Policy and International Division, Final Reports Unit
MAFF, Area 6/01
1A Page Street, London SW1P 4PQ
An electronic version should be e-mailed to [email protected]
Project title
Identifying and costing agricultural responses under climate change
scenarios (ICARUS)
MAFF project code
CC0357
Contractor organisation
and location
Dr Jo Hossell
ADAS
Woodthorne
Wergs Road
Wolverhampton
WV6 8TQ
Total MAFF project costs
Project start date
£ 50, 450 +VAT
15/05/00
Project end date
31/01/02
Executive summary (maximum 2 sides A4)
This project has identified key adapations that may be necessary to be offset the impacts of climate change in the agricultural industry.
It has focussed on the responses for single crops, which have been chosen to represent economically important production systems in
England and Wales. The commodities are wheat, potatoes, cauliflowers, grass for dairy enterprises, greenhouse tomatoes and indoor
and outdoor pig production.
The research has reviewed the effects of climate change on the commodities and identified the most important impacts. Information
on impacts has been gathered from both research and expert consultation. Where possible impacts have been quantified and related to
the levels of change under the UKCIP98 scenarios. Adaptations to the main impacts have been identified and these have been related
to the level of the industry most likely to initiate or fund the change, e.g. grower, commercial interests, government/levy body. Where
quantitative information is available on impact levels, the economics of selected key adaptations have been analysed using cost
benefit analysis. These costings have been set within two alternative economic scenarios, one using the current policy situation and
the other assuming a more liberal structure without commodity support mechanisms. Current prices have been assumed throughout.
The adaptations with a net benefit have been ranked according to their net present value to provide an indication of the priority that
should be given to adopting the change.
The majority of the adaptations identified rely on growers to change their production methods or timing of operations. Also some
adaptations are effective against a range of potential impacts, whilst others are alternative strategies in dealing with the same impact.
Such adaptations, although mitigating the same impact, may still occur in parallel, since different aspects of the agricultural industry
may implement them on different timescales. Many of the measures identified are likely to be adopted in parallel with changes in
other aspects of the industry. For example, farmers changing harvesting practices for cauliflower production, whilst the industry
develops new cultivars to reduce variation in maturation rates.
Investment in extra wheat breeding to overcome yield losses through increased temperatures provides the highest net value of all the
adaptations costed (£1,527 million). This is largely due to the area covered by the crop in England and Wales. By contrast,
improving application of additional nitrogen fertiliser in cauliflowers provides a clear Benefit: cost of 21.7 but the net value of the
benefit is only £19,000. Previous work has suggested that farmers are reluctant to make changes for relatively small monetary
CSG 15 (Rev. 12/99)
1
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
benefits (Hossell, et al., 2001), so low value benefits may not be realised immediately. Many of the adaptations will need to be
adopted in parallel in order to offset the effects of climate change.
Adaptations such as shifts in cropping areas may require early consideration by the industry, since they may only be viable if the
savings made through not renewing existing equipment in current production areas are balanced against potential moving costs.
A number of adaptations are currently economically unviable, e.g. changes to the storage and handling of pig slurry. However, such
changes in practice may still be necessary to reduce environmental damage such as N pollution. Hence government assistance may be
needed to encourage the uptake of such adaptations.
The different costs and breakeven points of the various adaptations suggest that some will be adopted more rapidly than others.
Comparing the relative merits of the different adaptations with results from MAFF funded cc0333 suggests that adaptations
responding to crop yield changes and animal housing conditions, and changes in timing/frequency of operations such as pesticide
applications may need to in place by the 2020s in southern areas of England and Wales. Other changes, such buffer feeding in dairy
systems in summer may be delayed until the 2050s.
The significance of non-costed adaptations, i.e. those for which quantitative information is not readily available, should not be
ignored. Some of these changes such as changing cultivars may be crucial to ensure the adaptation of crop production to climate
change. Moreover, some of the adaptations will need to be adjusted as climate changes and hence will require repeated adaptation
measures over a number of years, for example changing cultivars and changes to grazing silage ratios.
Key conclusions and priority adaptations summarised by commodity are:
Wheat
 Climate change may have important implications for yields. Some of these effects may be offset by the introduction of new
cultivars, so additional plant breeding research and investment is considered critical to the future productivity of the industry.
The development of new cultivars, potentially has a long lead-time before results are available to the market, so it is important
that steps are taken in the near future to adopt this adaptation.
 Other adaptations to yield loss such as irrigation are unlikely to be cost effective, unless irrigation is already installed on the farm.
Substitution of grain maize for wheat is unlikely to occur unless the yield of maize increases greatly under climate change or
wheat yields decline greatly.
Potatoes

Whilst losses may be partially offset by the adoption of an alternative crop, production in areas such as Cornwall, which provide
the earliest potatoes may not be able to adapt to the longer growing season.
 For main crop potatoes, grower level adaptations are likely to be readily adopted as they provide considerable benefit (e.g.
increase storage refrigeration) or are easy to fit into the production cycle (additional spraying), but information on the timing of
such changes needs to be considered.
Cauliflower

The cauliflower production industry is a dynamic market orientated sector, which is likely to respond rapidly to the new situation
generated by climate change. However, the effect of loss of early potato production in Cornwall, where winter cauliflower
provides the other part of the rotation could be significant. It is unlikely that cauliflower production in this area would survive
the loss of the early potato crop.
 The greatest net benefit in terms of cost is given by increasing the number of passes of the crop at harvest. However, the need for
this adaptation is also likely to be highly variable, since it is a response to uneven maturation of the curds due to warmer and
more variable conditions. The uptake of this adaptation, hence, may be delayed for several years as climate changes until the
effect on the evenness of maturation rate becomes clear.
 The adaptations that are likely to be most readily adopted by growers are the increase in nitrogen applications and the increased
spraying for aphids, since both have reasonable benefit:costs ratio with only a small change in yield (1-2%).
Grass

Modern dairy systems are very flexible, and are likely to adapt readily to the new opportunities provided by climate change. The
main effects of climate change on grass growth and dairying will be positive because of increases in grass yields. The challenge
lies in utilising the grass efficiently, but there are many techniques, which are already used in dairy systems to promote
utilisation. These include buffer grazing, extended grazing, zero grazing, storage feeding etc and they are likely to be readily
adopted by farmers.
 The reduction N input through an increase in legume use is likely to be readily adopted as it assists with compliance with existing
N reduction policies.
 However, the economic context of the future adaptations is crucial, since the value of the increased grass dry matter production
for dairying depends dramatically on whether economic policies and conditions are conducive to increased milk production, or
whether the adaptation adopted will merely displace land to relatively unprofitable alternative uses.
Tomatoes

The tomato industry is already under severe competitive pressure from foreign producers. This is forcing a reduction in the size
of the production area, but an increase in yields to maintain volume. Some of the most cost effective adaptations (e.g. shade
screens) require significant investment in new equipment or greenhouse housing. The yield penalty of this adaptation is high
(15%) and the level climate change will be only slowly realised. Hence this adaptation is unlikely to be widely adopted. But
producers need to be aware of the potential need when considering upgrading of existing greenhouse stock.
CSG 15 (1/00)
2
Project
title

Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
By contrast, reduction of heating costs will be rapidly adopted, since it requires no additional costs and may be automatically
achieved as required. However the reduced need for winter heating may affect the benefit:cost of investing in Combined heat and
power (CHP) or other waste heat supplies. Similarly faster picking rates may be rapidly adopted since it is justified by a
relatively small saving in yield.
Pigs

There is greater difficulty in estimating the impacts of climate change on pigs than for crops because of the scarcity of data on the
impact of the environment on animal performance under the conditions of commercial livestock management. The two subsectors of pigs out of doors and indoors are very different in terms of the impacts and the adaptations that are appropriate.
Over all commodities, grower based adaptations dominate those identified as critical to countering climate change impacts. The most
effective adaptations involve actions that can be taken by the farmer without assistance from the industry. But where no new
investment or know-how is needed, growers will take advantage of an adaptation only if they are aware of the likely persistence of the
warmer conditions year on year. To this end information on the level of climate change impacts, their persistence (for mean changes)
or return frequency for extreme events is needed.
Information on climate change impacts and potential adaptations also need to be readily available within the industry. Government
knowledge transfer projects should help with this process, but it is important also to involve the industry as well as the growers, since
some changes may also require assistance/adaptation within other parts of the industry. For example the loss of early potato
production will affect buyer’s sourcing of the product. Changes in the distribution of the crop will also change transport costs for the
processing side of the industry.
CSG 15 (1/00)
3
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Scientific report (maximum 20 sides A4)
Aims and objectives
This study has focussed on the costs and benefits of climate change to single crops. The crops chosen represent economically
important production within the UK (Wheat, Potatoes, Cauliflowers, Grass (for dairy enterprises), Greenhouse Tomatoes, Pigs Indoor and Outdoor).
The project aimed to:
1. To review existing knowledge and literature on the possible agricultural impacts and adaptations of climate change in each of the
sectors in England and Wales, considering, where appropriate, other countries techniques and adaptation responses.
2. Prioritise the key impacts, which can or need an adaptation response.
3. Prioritise the possible adaptation strategies based on their practicality, impact and cost effectiveness
4. For the leading adaptive measures, examine in more detail how they may be applied, their effect and the timescale over which
they should be introduced.
5. Hold a workshop to review the responses within the industry to the project findings and to assist in summarising the results by
enterprise type.
6. Produce a final report highlighting the key findings and identifying areas where adaptations options offer no benefit or do not
exist and where more research is needed
Layout of this report
This report provides a brief background to the type of climate change expected in Britain as projected by the UKCIP98 scenarios
(Hulme and Jenkins 1998). The principles of costing adaptations to climate change are then discussed in a methodology section. The
results for each commodity are divided into 4 sections:
1. a brief assessment of the assumptions used in the assessments, including the economic scenarios.
2. the impacts and adaptations - For each commodity a literature review on the main impacts of climate change on both the crop and
its production was undertaken. A summary of these reviews is provided in Appendix 1. Where possible effects have not been
quantified in previous studies, and where the means to do this were readily available, changes have been calculated using the
climate data for the 2050s Low and High UKCIP98 scenarios. Based on the review and these impact values, a list of key impacts
was drawn up and tabulated. Expert opinion has been used to suggest possible adaptations to them at a farm, industry and policy
level. The likelihood of uptake of these adaptations is discussed and the adaptations costed.
3. A summary provides the cost benefit of each adaptation for each commodity and the likely sources of funding for each adaptation
are also identified.
4. Conclusions for the study are discussed in the final section, and further research requirements are identified.
Climate change scenarios
Where possible the project has used the four UKCIP98 scenarios (see Table 1) (Hulme and Jenkins 1998) to relate climate change
impacts in the literature to the costed future adaptations. Actual data from the UKCIP98 baseline and climate change scenarios
datasets have also been used where impacts have been calculated as part of the project. Where the impacts for different scenarios are
available, the costings have been based on both the 2050s High and Low scenarios in order to indicate the range of costs and benefits
that may be realised.
Climate impact
Longer growing season
Fewer frost days:
Days with max. 25°C:
More winter rain:
Less summer rain:
Higher summer PET:
Higher CO2 levels
Change in winter light levels (Dec-Mch)
2050s Low – High scenario changes
+40%
-70%
x3
+9 to +13%
0 to –20%
+6 to +17%
+66%
-6 -0%
Table 1: Key changes in climate for agriculture from the UKCIP98 2050s Low and High senarios in England and Wales.
Methodology
Principles of Costing Climate Change Adaptation
The method used is one of cost benefit analysis that explores the relative cost of the adaptation against the value of the benefit. The
result is specified as a cost to benefit ratio, with values of less than one indicating a net cost (or negative benefit). As with all
techniques that provides a monetary value on a change, there is the need to also consider effects that cannot be costed, such as
environmental benefit or personal preference. Such influences may outweigh the monetary effects. Previous work has suggested that
farmers are quicker to respond to a drop in farm income than they are to a possible increase that would require some adaptation to
achieve (Hossell et al., 2001). Hence policy may need to be weighted to ensure uptake of beneficial adaptations rather than
adaptations to avoid negative effects.
CSG 15 (1/00)
4
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Each of the adaptations involves investments and subsequent positive annual net cash flows. The calculations have been done for the
climate predicted in year 2050. Since the climate change is gradual the benefit of the adaptations gradually increases and it is hard to
predict the point at which the investments would be made. When looking at the industry as a whole the investments would take place
over many years with those with the high rate of return being made earlier than those where the rate of return is more marginal.
Benefits and costs in 2050 are described in terms of their net present value using standard discount rates of 6%. The value using the
2% rate is also shown in the costings tables in Appendix 3.
Assumptions made
The approach taken in this study is to specify a limited number of economic, policy and climate scenarios to illustrate the changing
context within which climate adaptations might take place (see Table 2). The choice of scenarios is made on the following basis:
1. A limited number of scenarios are essential to avoid large numbers of combinations, which become too cumbersome to work
with.
2. Simple assumptions were chosen to assist clarity
3. A range of scenarios were chosen to illustrate the extremes
Type of assumption
Future climate*
Economic
Farming type
Future prices
Rate of change
Assumption/ information source
UKCIP98 scenarios have been used where available and contrasts made with either the 2050 High and Low
scenarios where possible
Current agricultural policy
Liberalised agricultural policy
Conventional full time farm enterprises
No change from present day
Linear change to 2050 and occurring uniformly across England and Wales
Table 2: Assumptions made about the future climate and economics of agriculture in the cost-benefit analysis. (*where values
relating to the 2 different scenarios are available.)
Economic scenarios
The study examines possible climate change adaptation in the context of two policy scenarios (see Table 2 and Appendix 3 for the
other assumptions used). One scenario is that present day policies remain unchanged, and the other is that a liberalised regime is
adopted. The unchanged policy scenario could be criticised on the grounds that it is unlikely. However this scenario has two major
advantages; since it already exists, it can be clearly discerned in all its detail and it is of great interest to those driving policy change
now. The immediate relevance of current policy stems from the fact that the non-market mechanisms create rigidities that constrain
the adaptation of the industry. Although adaptations to climate change are not likely to be a major driver of policy change, working
out how current policy and climate change adaptations interact increases the likelihood that policy makers will consider the issue.
The liberalised scenario assumes that existing structures of production controls and farm product price supports and subsidies are
removed, and rewards for production come solely from the marketplace at prices that approximate to current world prices. The
difference between the current policy and the liberalised policy can be large (e.g. wheat), or small (e.g. potatoes). Where the
differences are very small or nil, the two scenarios converge or collapse into a single scenario. For example, with potatoes there is no
price support and restrictions on trade are confined mainly to trade in seed potatoes for reasons connected with plant health. Here
only the one economic scenario is explored.
Adaptations by Commodity
Wheat
Economic scenarios
Current Policy
The current policy takes account of all announced decisions for example those agreed under Agenda 2000. Hence the situation
examined is that projected to exist from 2002. The Arable Area Payments Schemes allows farmers to claim a payment of £234 per
hectare for wheat grown on eligible land, provided they have 10% of their land set-aside (SAS). On this SAS they also receive a
payment of £234 per hectare. The areas of eligible land on each farm are registered, based on land that was in the arable rotation in
December 1991. The support arrangements for other combinable crops are also important since these crops are easily substituted one
for another.
Liberalised Policy - Winter Wheat
In this scenario it is assumed that there is no area payment for producers of wheat, so the price received is close to the world price.
These prices for the liberalised and current policy are so close that it has been judged appropriate to use a wheat price of £62 in both
instances. However the liberalised scenario is very different from the current policy scenario because of the absence of direct
payments, constraints on IACS eligible land, and set-aside requirement.
Climate Change impacts
Establishing thresholds
Appendix 1 provides a summary of the literature review undertaken to determine the key effects of climate change on wheat
production. Table 3 lists the adaptations costed in this study and the impacts against which they are targeted. All costings assume a
total wheat area of 1,969,700 ha.
5
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
Project
title
Adaptation Type
Adaptation
Change of cropping mix
1
Irrigation
Extra aphicide application in winter
Fewer aphicide applications in
summer
Movement of wheat to more
favourable areas of England or Wales
2
Increase in wheat breeding
investment
MAFF
project code
CC0357
Impact
Change in yield
Change in grain-fill period due to higher temperatures
Increase in yield from higher CO2 levels
Loss of quality for bread-making
Change in yield
Increased incidence of aphid infestation and higher population levels
over winter
Reduction in aphid infestation in drier summer conditions
Change in yield
Change in grain-fill period due to higher temperatures
Increase in yield from higher CO2 levels
Loss of quality for bread-making
Change in yield
Change in grain-fill period due to higher temperatures
Increase in yield from higher CO2 levels
Loss of quality for bread-making
Table 3: Possible adaptive actions and the climate change impact to which they are responding. Type 1 adaptations are within
business, Type 2 are across the agricultural industry (see section on Uncertainty in the prediction of future adaptations).
Future wheat yields
Appendix 1 includes a discussion on the potential future yields of wheat within the literature review of impacts. In an experimental
study, yield losses between 0 and 1.6 t ha-1 per degree Celsius rise in temperature for varieties of winter wheat grown in polytunnels
have been reported (Batts et al., 1998). But studies of CO2 effects show an increase in yields of 20-30% by 2080 given no rise in
temperature Ministry of Agriculture Fisheries and Food (MAFF) 2000). Given the wide discrepancy between studies on the overall
effects of climate change on wheat yields, two impacts have been examined for this commodity. The first assumes a steady increase
in grain yields without any special adaptation to existing breeding programmes, with varieties changing every five years, current
breeding practice may generate the changes needed over ten generations of varieties to maintain existing yield increase trends. Hence,
the increase used is based on the current trend in growth of average yields of 0.13t/ha/year (Scott and Sylvester-Bradley, 1998). This
would mean yields would rise from the 8.12t/ha of 2000 to 14.62t/ha by 2050. This trend may be seen if a low level of climate
change mean that CO2 fertilisation exactly balances yield losses from increased temperature, hence allowing the current rate of
technological yield increase to continue unabated. Such a response is likely to be linked to a low level of temperature increase such as
in the Low 2050s UKCIP98 scenario and hence is referred to in this report as the Low scenario. The cost benefit analysis for the Low
scenario explores the balance between the benefit of increased yield and the increased costs of production that this produces.
Examining the more severe climate change impact, such as that the might be experienced under the High 2050s UKCIP98 scenario
(referred to in this report as the High scenario), the assumption is that the yield impact will be halve the yield rise described above i.e.,
the yield would only increase to 11.37t/ha by 2050. Additional breeding investment would therefore be needed to offset this yield
loss. The analysis for the additional adaptation scenario explores the economic implications of investing in new cultivars to offset a
potential yield loss of 3.35 t/ha as compared to the no adaptation scenario
Adaptations
Additional plant breeding investment
Varietal development would address a number of the potential impacts of climate change on wheat production:
1. Lower photoperiod requirements allowing earlier start of reproductive growth in spring to take advantage of lower frost risk
2. Generally slower development to maintain duration of phases so that carbon is not lost.
3. Increased stem storage of readily remobilisable reserves to maintain grain filling in early droughts and to increase contribution of
pre-anthesis growth to grain filling
4. Development of breadmaking varieties with increased uptake and storage of nitrogen.
The comparison of the yield and adaptation responses is presented in Table 3.1 in Appendix 3. Current breeding investment costs are
assumed to be £1.5 million per year. The current and liberalised policy scenarios have the same net benefits under this analysis. The
main difference in this instance is that growers continue to receive the area payments, and it is assumed that these are not to be
affected by the adaptation response to breeding. The net present value of the additional yield at 6% (i.e. Low climate change impact)
is £1,527 million for the no adaptation scenario. Under the high climate change impact, with the additional breeding expenditure the
benefit is £757 million. Hence the benefit of the additional yield alone is 5.6 times the increased production costs (i.e. a Benefit: cost
ratio of 5.6), whilst the benefit of the additional breeding is 5.4 times its cost.
Additional insecticide spraying
Figure 1.1 in Appendix 1 shows the change in number of aphid generations overwinter for baseline and climate change scenarios.
The calculations suggest that an aphicide application will be need in autumn under climate change. This would be offset by the need
for one less treatment in spring on 20% of the crop. Appendix 2 provides more detail on how the impacts of no adaptation would
affect yields. If these assumptions are applied to the total area of wheat then the cost would be £35.5 million per annum or £349
million at a net present value at 6% (See Table 3.2 in Appendix 3). However, the cost benefit of applying the pesticide would be
6
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
Project
title
MAFF
project code
CC0357
repaid 2.9 times over when calculated for the High scenario. The benefit ratio increases to 3.7 under the Low scenario because of the
greater rate of yield increase under this scenario.
Movement of Wheat to More Favourable Parts of England or Wales
A parallel and complementary adaptation to a change in cultivar in existing wheat growing areas is the shift of wheat to alternative
areas of the country. A considerable amount of wheat is grown on relatively drought prone soils such as Cotswold brash and thin
clays over chalk. Heavier soils in the wetter West and North could have the potential to produce better yields under the climate
change scenarios. Wheat could either move there through displacing less profitable crops in the arable rotation (for example barley,
oats, oilseed rape or grass leys) or through new land brought into the arable rotation. Most of this new land is likely to currently be in
long term grass or permanent pasture.
Under the current policy scenario this adaptation is highly unlikely since if the result of climate change were to shift the best areas for
wheat production westwards, the rigidities of the Integrated Administration and Control System (IACS) and the rules about eligible
land would constrain the changes that farmers could make. Currently the wheat and arable area is concentrated in the South and East
of England. In 2000 the area of wheat was approximately 43% of the area of arable land (MAFF, June Agricultural Census, 2000).
This is approximately equivalent to the whole IACS eligible area. Substitution of arable crops (including leys) by wheat could take
place but the production of wheat on ineligible would be financially unviable. The section on grass indicates the returns of
introducing barley onto livestock farms. This is not viable even with AAPS payments. Hossell, et al, (2001) showed no significant
increase in wheat production on non-arable farms under a medium High 2050s scenario as it was not cost effective. Hence this option
has not been costed.
Irrigation
Irrigation can be discarded as an adaptation mechanism. This applies to both the current and liberalised policy scenarios. It seems
clear that irrigation of wheat is not commercially viable. Not only is it very rarely practised, but research has shown that with the
price of wheat then at between £80/t and £100/t and with the capital costs and grant rates and water charges then ruling, irrigation of
wheat was not economic (ADAS, 1977). The cost side of this equation (capital costs, net of grant, and water charges) have increased
dramatically since 1977 but the price of wheat is now lower. The figures given in Appendix 2 suggest that irrigation of wheat is not
economic at any prospective wheat price. The only exceptions are on farms where irrigation facilities exist because of other higher
value crops such as potatoes or sugar beet, and spare capacity is sometimes utilised for wheat earlier in the season before these crops
can use the water.
Change of Cropping Mix
This adaptation strategy has already been touched upon in the discussion of the movement of the wheat crop. At the individual farm
level (but not necessarily at the national level) this implies changes in cropping mix. Another possibility is that crops not now
commercially viable in England and Wales might become worth growing. Since the wheat crop covers a large area, the candidate
crops to displace a significant amount of wheat from farms need in themselves to occupy significant areas. Grain maize is the crop
most commonly cited as a suitable replacement for wheat in parts of England and Wales (Parry, 1990; Hossell et al., 1994; Holman &
Loveland, 2001). See Appendix 3 for a fuller discussion of the adaptation assumptions used.
Table 3.3 in Appendix 3 compares the gross margins of grain maize and wheat production under the 2050s High and low Scenarios.
The competitiveness of the Gross Margin depends the yield impact of climate change on wheat. The Benefit: costs vary between 0.91
for the 2050s High scenario to 0.44 for the 2050s Low scenario, i.e., any benefits are outweighed by the costs of the adaptation. The
costs of the change at 6% NPV would be £385 million and £3,353 million respectively for England and Wales.
The implication is that only if wheat yields are significantly reduced by climate change (below the High scenario reduction given
here) or grain maize yields reach more than 10.7/ha for the High 2050s scenario or more 14t/ha for the Low 2050s scenario would it
be economic to produce grain maize as an alternative to wheat. The potential for grain maize yields to increase through technological
improvements has not been considered in this assessment. It may be realistic to conclude that grain maize may be substituted for
wheat under the High 2050s scenario but not under the lesser warming of the Low 2050s scenario.
Potatoes
Appendix 1 provides a summary of the literature review undertaken to determine the key effects of climate change on potato
production. Table 4 lists the adaptations costed in this study and the impacts against which they are targeted. The different types of
potato production can be separated by identifying the time of year in which they are planted and harvested. These fall into three main
categories first earlies, second earlies and main crop. Each of these classes can be further divided into the market sectors for which
they are destined. These are ware for general consumption, salads and processing potatoes, which are used for manufactured potato
products. For the purposes of this analysis the potato crop is divided into its early and maincrop elements. In these calculations the
price of earlies is assumed to be £145/t and £89/t for main crops
Adaptation Type
1
2
Adaptation
Additional aphicide application
Conversion of ambient storage to refrigerated stores
Increased need for cutworm control
Increased irrigation of maincrop potatoes
Additional aphicide application
Loss of early potato production advantage in Cornwall and shift to
alternative crop
Eastward shift of early potato production
7
Impact
Increase in peach potato aphid populations
Increase in mean and maximum temperatures
Increase in cutworm damage
Drier summer conditions
Increase in peach potato aphid populations
Reduction in frost days
Reduction in frost days
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
Adaptation Type
Adaptation
Loss of early crop production nationally
MAFF
project code
CC0357
Impact
Increase in growing season length
Table 4: Possible adaptive actions and the climate change impact to which they are responding for early and maincrop potatoes.
Type 1 adaptations are within business, Type 2 are across the agricultural industry (see section on Uncertainty in the prediction of
future adaptations).
Economic scenarios
There is no EU regime for potatoes. The current potato market is a free market, the current policy and a liberalised policy can be
regarded as synonymous.
Future potato yields
Measuring increases in yield at a commercial level as a result of genetic gain is difficult as genetic progress is affected at a
commercial level by climatic conditions. For example the poor harvesting conditions in the autumn of 2000 prevented crops from
being lifted thus reducing the average yields.
The yield of early potatoes depends critically on the timing of harvest. An examination of recent yields shows a 7.5% decline over the
1990s. Yet, without investigating lifting patterns it would be dangerous to assume that major changes in yields of crops harvested at a
given date are taking place. Similarly the assumption that yields of potatoes would change with changed climate is not clear cut.
Some research shows an increase in tuber numbers with elevated CO 2 (MAFF, 2000) but for earlies the earlier start to the growing
season could reduce yields, since it would encourage growth during periods of low solar radiation. Hence for the purpose of these
analyses, the yields for earlies have been assumed to remain at current levels.
For maincrops the longer growing season could increase yields by between 5 and 10% however, this would only be realised if
harvesting conditions allow the gathering of the whole crop and if yield is unaffected by reduced moisture availability. Yields for
maincrops have also been assumed to remain at today’s level except for the purposes of examining the cost benefit of irrigation.
Adaptations
Early Crops
In reality these adaptations may well partially operate in parallel, with some increase in imported earlies from areas of France, Spain
and the Channel Islands, a shift of production eastwards and some switching out of potatoes into alternative crops.
National Economic Loss of the Early Crop
As the growth of early potatoes is controlled by solar radiation, countries with at more southerly latitudes will have greater solar
radiation earlier in the year. If those countries experience fewer frost days earlier in the year then they will be able to advance their
potato planting yet obtain a higher yield in proportion to growers in Southern England. A scenario where 50% of the crop is no longer
grown in England and Wales due to competition from abroad has been calculated. It is assumed within the calculation that potato
processing capacity is not lost from the UK as a result and therefore the economic benefit to the country from that processing capacity
remains. The economic loss to the country would be in excess of £42 million annually at 6% (See Table 3.4 in Appendix 3). This has
a Benefit:cost of 0.56. It is likely that growers would switch to alternative crops in this situation (see below).
Producers grow alternative crops
Where producers cannot continue to grow early potatoes the crop may be substituted for an alternative crop. The chosen crop will
depend on the rotational practice the farm operates and the effect of climate change on the crops, which are within the rotation. In
Cornwall for example early potatoes follow winter cauliflower which may also be affected by climate change. As Cornwall is a
special case, the cost of early potato loss from this county has been calculated separately.
With the loss of the early potatoes it is expected that an alternative crop would be grown possibly a cereal, such as spring barley, as
potatoes generally follow an autumn harvested crop unless on a specialist vegetable farm such as is found in Lincolnshire. The
benefit from growing this crop is expected to generate a return under a liberalised economic scenario (i.e. without arable area
payments) of between £1.3 million pounds (Table 3.5 in Appendix 3). Under the current policy with arable area payments still
available then the return rises to between £2.79 million pounds annually. But when the loss of potato production is also considered
the net cost is £29.06 million at 6% under a current policy scenario. Without the benefit of arable area payments the cost rises to
£35.87million. These have Benefit:cost of 0.71 and 0.64 respectively.
Economic Loss to Cornwall
The key area of early production that would be hit by climate change is Cornwall, where timing of potato production is linked with
production of winter cauliflowers. The county grew approximately 2,700 ha of early potatoes in 1997, more than a quarter of the
country’s production. The cost of losing this crop to the region would be £3.5million, (Table 3.6 in Appendix 3), which at 6% net
present value is £14.90million. This has a benefit: cost of 0.22. An alternative crop to replace the early potatoes has not been
factored in as the crop in Cornwall is grown at a specific time of the year and fits in with the winter cauliflower crop, so it would be
difficult to find an alternative crop to grow.
8
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Effect of climate change on Main crop potatoes
The four counties in England that grow the greatest area of potatoes, over 10,000 ha in each county, are Lincolnshire, North
Yorkshire, Norfolk and Cambridgeshire. These counties lend themselves to potato production due mainly to their soil type and where
economics of scale in potato production can be achieved.
The extended growing season through a reduction in frost days will enable crops to develop earlier and increase yields. By planting
earlier it may be possibly to make use of early season rainfall to produce yields early in the season, which reflect current production
levels before drought conditions are experienced. However, the drier conditions and the potential yield growth may alternatively
increase the water requirements of the crop and the subsequent need for irrigation especially on lighter soils.
Economic value of additional irrigation to England and Wales
Potatoes respond well to irrigation and produce an economic response from it. See Appendix 2 for a discussion of the current and
prospective costs of irrigation. The figures indicate that irrigation of potatoes is economic with the exception of cases were the cost of
installing irrigation facilities is very high and the price received for potatoes is low.
An increase in the length of the growing season, reductions in rainfall and increases in temperature will increase the total water
requirement of the crop due to higher rates of evapotranspiration. To assess the potential increase in irrigation requirements irrigation
models were run that identified irrigation requirements for two different sites, one in Norfolk, the other in North Yorkshire. The
models were run for current climate conditions and the 2050 Low and High scenarios including increased evapotranspiration. Table
3.7 in Appendix 3 identifies the increase in irrigation requirements over those that exist at present.
The table above indicates that irrigation requirements are expected to rise from current level to between 9 and 48 mm of irrigation
water per hectare of maincrop per year. This is the equivalent of 0.72 and 3.84 tonnes a hectare of potatoes based on a yield response
from irrigation of 0.08t/ha per mm of water applied (Bailey, 1990). As the average area of maincrop potatoes in England and Wales
was 75,000 ha between 1993 and 1997. The national reduction in yield would therefore be between 54,000 and 288,000 tonnes if
additional irrigation were not provided. If it were not to be provided then the area of potatoes grown would either have to increase by
between 1,200 and 6,400 ha to compensate for the yield reduction or the equivalent yield imported. The net benefit at 6% has been
calculated (see Table 3.8, Appendix 3) for the low and high 2050s scenarios as £9.48 million and £-48.4 million respectively,
providing Benefit:costs of 1.7 and 0.7. As irrigation contributes to tuber quality as well as size it must be recognised that failure to
provide additional irrigation for the potato crop will result in a reduction in the overall quality of the national crop.
Pests
The increase in pests, cutworms and peach potato aphids is expected to require an additional application of insecticide for both pests.
The timing of the additional aphicide spray is not critical and therefore could be incorporated into a spray for potato blight. Therefore
the only additional cost would be that of the pesticide (£70 K).
The point at which cutworms can be economically controlled is more critical and would require growers to subscribe to a cutworm
monitoring and alert service. The additional cost to the industry that grows 120,000 ha annually is expected to be over £3.8 million
annually (Table 3.9, Appendix 3). If this were to protect 10% of the crop then the value of the crop would be £373 million and with
the cost of the pest control at £3.8 million, the Benefit:cost ratio is 9.83. This provides a net present value to 2050 at 6% of £156.6
million.
Storage Costs
Once potatoes have been “cured” period their storage temperature needs to be reduced rapidly to a holding temperature of between 4
and 10°C for ware potatoes, depending on the market for which they are destined. With the predicted increase in temperatures the
level of crop cooling required is likely to increase. With a rise in temperature it is envisaged that the demand will increase for
refrigerated stores. Upgrading existing stores will require installation of additional insulation, refrigerated plants and an increase in
electricity usage. (see Appendix 3 for details of these assumptions). No records are kept of the proportion of the crop that is stored in
refrigerated, as opposed to ambient conditions. It is, therefore, calculated that an eighth of the storage capacity needs to be upgraded
to refrigeration to enable the ware crop to be successfully stored until new crop potatoes became available. If the cost of installing
and running the additional refrigeration plant was phased over time in direct proportion to the climatic change then the average annual
cost would be £1.37 million, which if discounted over 50 years would range from £6.4 to £18.5 million at discount rates of 6% and
2%. The benefit of investing in additional storage is that it will enable the potato crop to be stored until new crop potatoes become
available. The value of these potatoes is £44.5 million. With an annual cost of £1.37 million in additional storage the benefit to cost
ratio is 32.5.
Cauliflower
The cauliflower industry is a specialised market orientated sector with professional growers who are quick to respond to market
signals. The main growing areas are Lincolnshire, where holdings are relatively large and Cornwall where the production is based on
smaller holdings. The consumer, shopping primarily in the large multiple retailers, expect year round supply and are now receiving it
with imported production filling the periods of the calendar when UK production is not available or in limited supply. Average
imports have risen from 40,180 tonnes in 89/90 to 93/4, to 97,460 tonnes between 95/5 and 99/00. Imports to UK are mainly from
Spain, Italy and France and they provide continuity of supply from November to May. With this lengthy season, cauliflower has lost
some of its status as the preferred vegetable for important meals (e.g. Sunday lunches).
9
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
One important aspect of the industry should not be overlooked. Cauliflower production does not take place in isolation. A wide
range of crops use the pack-houses and transport to the main markets in the cities, thus improving capital utilisation and reducing unit
costs. If one of these crops is lost because it can no longer be produced competitively, it adversely affects the profitability of all the
other crops. Lower total throughput increases the costs of getting the other crops to market. The existence and efficient utilisation of
the marketing chain is as important as the physical conditions in which the cauliflower crop is grown, in determining where
production takes place.
Given the steady decline in home grown cauliflowers over the last 10 years, the value for the area of the crop has been taken from
1999/2000 values, since an average of the last 5 or 10 years values would overestimate current production levels. Yields have been
fairly consistent over the last 5 years and have averaged 14.0 t/ha. The total area of the crop has been taken as 11,968,000 ha, with the
crop worth £228/tonne (average value between 1989/90 and 1999/2000)
Economic Policy
For all practical purposes the current and liberal policy regimes within the UK are the same
Climate Change Impacts
Cauliflower production for the modern market is based upon continuity programming, with the aim of supplying crop to the market,
to satisfy the market’s demand, throughout the season. Programming is carried out using knowledge of varietal performance and long
term average weather conditions. There are always difficulties in achieving perfect continuity of production through the season, since
crop growth and harvest will be adversely affected by any period when temperature differs from the long term average.
The effect of extreme temperatures, either high or low, will depend upon which phase a crop is in at the time. Three sequential
plantings in the same field, all receiving the same conditions, could conceivably be in different phases of development at a given point
in time. The first planting may have just initiated curd and is in the cropping phase, the second planting is in the vernalisation phase
and the third planting is coming towards the end of the juvenile phase. A period of high daily average temperatures would therefore
have the effect of accelerating the first planting towards maturity while delaying curd initiation in the second planting due to its
inability to collect any cold. The third planting would also speed up until it reached the end of the juvenile phase, when it would also
enter the vernalisation phase. Following the warm period plantings 2 and 3 will both start to collect cold and, given a period of
relative cold, could both initiate curd at the same time and therefore crop together. The harvest pattern for these 3 crops would
therefore be for planting 1 to come in ahead of schedule, planting 2 considerably behind schedule and planting 3 on schedule. This
could mean production levels on target initially as planting 1 harvests, then a period with little or no production and finally a glut due
to plantings 2 and 3 cropping together.
The above pattern of production is currently seen at some stage in virtually every year, although the degree of the peaks and troughs
of production depend on variations in temperature. During years when there are more extreme or prolonged variations from the norm,
continuity can be destroyed, with resultant problems for both the fresh and processing markets.
The general effect of an increase in average daily temperature would therefore be to reduce the length of the juvenile phase, increase
the length of the vernalisation phase and reduce the length of the cropping phase. The size of any changes to the 3 phases from a
comparable temperature increase will vary considerably through the year, with the effect likely to be greatest on early crops and least
on summer crops.
Adaptation Type
1
Adaptation
Develop new markets
More frequent spraying for aphids
New pesticides
Improved pesticide application/delivery methods
Improved seed and crop hygiene
Additional top N fertiliser dressing
Irrigation provision
More passes per crop
Move crop production to cooler areas
2
Change grading rules
Change cultivar
Climate Change Impact
Reduced marketable yields
Increase in aphids
Increase in aphids
Increase in diamond back moth
Increase in aphids
Increase in diamond back moth
Increased risk of Xanthomonas
Increased N leaching
Reduced summer rainfall
Extended harvesting period
Reduced marketable yield
Soil erosion
Post harvest breakdown (wetter conditions)
Increased disease risk
Crop spoilage at harvest (wetter conditions)
Reduced marketable yields
Increased risk of post harvest breakdown
Reduced marketable yield
Increase in post harvest losses
Changes in timing of harvest
Table 5: Possible adaptive actions and the climate change impact to which they are responding for cauliflowers. Type 1 adaptations
are within business, Type 2 are across the agricultural industry (see section on Uncertainty in the prediction of future adaptations).
Adaptations for Climate Change
10
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Develop new markets
If it were possible to develop new markets for cauliflowers, such as an alternative outlet for small or discoloured curds, the
consequences of variable curds would be reduced. Market demand is the main driver of change in production with retailers and their
main suppliers being the chief innovators. Some development of new market requirements have been achieved, for example spear
size calabrese. However, it is assumed that this is not a realistic adaptation.
More frequent spraying for aphids
In summer crops, spraying for aphids typically happens twice. With the greater risk of aphids this would increase to spraying about
four times. The additional cost of the chemical would be £25/ha. per application and for high volume spraying, an extra £13.5/ha. to
apply (see Table 3.11 in Appendix 3). In winter crops the current single spray might increase to two aphid sprays. The total
additional cost is £ 0.7 million is outweighed even if the % of yield protected is only 2%, with a benefit:cost of 2.7 and a net present
value at 6% of £3.3 million. It is likely therefore to be a readily adopted adaptations.
New pesticides
New pesticides are only developed for major crops such as wheat, rice and potatoes, because the cost is high and can only be justified
for large potential markets. The vegetable crops have to depend on the use of pesticides developed for these major crops. Hence it is
unlikely that additional expenditure would be incurred, although new pesticides may come into use on the cauliflower crop.
Improved application/delivery methods
Since the pesticides used in vegetables are not developed for this use, their effectiveness is often limited and accurate delivery is very
important. Most new application methods are likely to be the application of methods developed for vegetables in general, but some
work specific to cauliflowers may be required. A recent example of the development of a new delivery method would be the use of
module drenches to control cabbage root fly. The cost of this investment was about £100,000 (See Table 3.12, Appendix 3).
Allowing for the development of two new application methods specific to cauliflowers, the annual cost if discounted at 6% over 20
years is only about £17,400 (net present value to 2050 at 6% of £81,160). With a saving in marketable yield of 1%, this provides a
Benefit:cost of 1.91.
Improved seed and crop hygiene
The cost of improved seed hygiene would be borne by the seed companies but recovered from growers in the cost of their seed.
Improved crop hygiene involves thorough debris disposal from crops, ploughing down etc. and longer intervals between growing
successive crops of cauliflowers - rotation. The cost of the latter could be very high in intensive cauliflower areas where annual
cropping is common, for example Cornwall and Lincolnshire.
Additional top N fertiliser dressing
Increased rainfall in winter will lead to leaching of nitrogen fertiliser. This may create the need to apply less fertiliser as a base
dressing and more as top dressings. Two top dressings are common at present and one more might be required. The total amount of
fertiliser applied would not change but an additional spreading cost of about £7.35 per ha would be incurred. The application has a
positive benefit provided the yield saving is greater than 0.25%. The net benefit at 6% is £3.9 million with a benefit:cost ratio of 21.7
(See Table 3.13 in Appendix 3).
Irrigation
The main cauliflower growing areas of Lincolnshire are on very deep silt soils and rely on soil moisture reserves during dry spells, not
irrigation. Irrigation is barely used in the area and has been ruled out as an effective adaptation measure. The low-lying topography
and proximity to the sea make salt water intrusion a problem for borehole, surface storage areas so it is unlikely that the areas
irrigation capacity could be increased in the future (see Appendix 3 for more details on this issue).
Change programmes to include different cultivars
The changing of programmes by planting of different cultivars depends on the predictability of the climate after climate change. If
the climate becomes more unpredictable with more extreme events, which cannot be accurately forecast, it will limit the impact of this
approach. The costs are primarily those of the seed industry in providing a range of genetic potential suited to growth in the new
climate created by climate change. The issues are discussed in the section on changes to cultivars below.
More passes per crop at harvest
Where any increased variation in the crop is created by changed conditions, the average number of passes to harvest the crop may
have to increase. Changes can be programmed in provided that temperature is reasonably uniform year on year (no worse than
currently) but increased variation in temperature will cause increased disruption. Moreover, variation in crop maturation is likely to
increase dramatically for any crop where a greater degree of variation has been introduced due to pest and disease or husbandry
problems. A reasonable estimate of the impact is an increase in summer, from 3, to 4 passes at harvest and in winter of on increase
from 6 to 7. If the yield harvested at each pass is proportional to the number of passes done the cost benefit for summer is 2 but only
1.14 for winter. The total benefit calculated at 6% is £13.3 million, with a benefit:cost for summer of 2.0 and for winter of 1.14 (See
Table 3.14 in Appendix 3). However, the extra pass would only be of net benefit if the yield saved by the extra pass were greater than
12.5%. The wet autumn and winter of 2000/1 affected the number of passes that could be made in Cornwall by 1 or 2 and caused a
loss of yield of 10-15% (ADAS, 2001).
Change cultivars
Virtually all cauliflowers grown in UK are hybrids. None are bred in the UK. There are about five multinational companies who
supply cauliflower seed. For UK production the breeding companies cross a temperature tolerant line with another parent line to give
11
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
them the characteristics they need for the UK market. Over the very long time scales of climate change, and from the large stock of
genetic material each company controls, it is reasonable to assume that the varietal selection programmes of the companies will
accommodate the changes needed to cope with climate change without any additional investment in the UK.
Move cropping to cooler areas
See Appendix 3 for discussion of this adaptation. There is good reason to believe that production would be quickly shifted to
alternative or new growing areas if there were competitive advantage from so doing. Predicting how production would be relocated is
very hard but there is already some infrastructure in cooler areas (e.g. Yorkshire, Lancashire and East of Scotland) and the need to reequip production facilities and packing lines would exist even if there were no change of location, so the cost of funding capital
investments to support cauliflower production in new areas would not all be additional expenditure. However, we have assumed that
the costs and benefits of moving production balance at an industry level. A major reason for taking this approach is that the new
opportunities for production to displace a product from warmer areas of Europe, though hard to quantify, should be considerable.
Change grading rules
The official grading rules for cauliflowers are set by the EU. If climate change were causing widespread problems to producers
throughout Europe, there is a chance that the rules might be changed, but if the difficulty was mainly in the UK, it is very unlikely that
changes would be agreed. Within the UK the EU grading regulations now assume a secondary role because the major retailer
specifications (specifying size, colour, shape, quality, packaging etc.) are generally above legal requirements, even though they still
have to label according to the EU regulations. JAMES GOT TO HERE BY WEDNESDAY EVENING!!
Grass
The implication of changes in grass yield can only be properly understood in the context of particular grazing livestock systems. The
authors have chosen here to concentrate on dairy systems because this is the commodity of greatest value produced from the grassland
of England and Wales. Beef and sheep are the next two most important commodities produced by grazing animals, but these are less
well documented and generally take place in systems that do not fully exploit the productive potential of grassland in England and
Wales - and are hence less sensitive to changes in grass growth.
The principle effect on grass based systems of climate change is the effect on the timing and yield of the commodity. Total annual
grass production can be expected to increase as a result of the higher temperatures, higher early and late season rainfall and increased
carbon dioxide concentration in the atmosphere. However, mid summer production may fall due to drought restricting grass growth
in drier areas of England (Hossell et al., 2001; Holman and Loveland, 2001). No change in grass species, from the currently used
perennial ryegrass, Italian ryegrass and white clover, is envisaged for England and Wales as a result of climate change. The
calculations assume only current economic policies.
Economic scenarios
In Table 6 below, some of the interactions between agricultural policy scenarios and how increased grass dry matter production may
be utilised in dairy systems are explored.
Method Of Utilising Increased Grass Dry
Matter Yields in the Dairy System
1a. Increased stocking rate leading to more
cows on the same grass area
1b. Reduced area of forage and land released
to alternative enterprise
2 Reduced feed purchases
Policy Scenarios
Existing Policy (with quotas)
Liberalised Policy (no quotas)
Less likely
More likely
More likely
Less likely
Unlikely
Unlikely
Table 6: Policy Scenarios and Routes to Exploitation Of Increased Grass Dry Matter Yields in Dairy Systems.
Current Policy
In practise, the situation is further complicated by the trading of quota which (under current policy) allows the lowest cost dairy
producers to acquire additional quota and increase production, but the scheme in the matrix above is helpful in analysing the main
ways in which dairy producers will react to increased grass dry matter yields from climate change. In mid 2001 with quota prices and
leasing costs very low, the issue of quotas is much less significant than in recent years. With low milk prices (largely due to strong
sterling) the current scenario is very much what one might have constructed as a liberalised one just a few years ago. For this reason
the Cost Benefit Analysis in this section has been carried out on the current policy scenario only, rather than repeated at some yet
lower liberalised milk price.
Liberalised Policy
In the liberalised policy scenario where quotas do not constrain production, extra cows may be kept by increasing the stocking rate,
and thus producing more milk. However, in practise, land is rarely the most limiting factor in dairying systems. Modern dairying
hinges more on the competitive utilisation of expensive fixed investment in cows, buildings (accommodation, feed storage, slurry
systems), milking systems and the labour force, as much as land. Hence, even under the liberalised policy scenario, some of the
impact of higher grass dry matter yields will be the release of land from dairying systems into the next most profitable enterprise. On
many mixed farms this would be cereal production, although on livestock farms it would be beef or sheep enterprises. Looking ahead
to 2020 and 2050 under a liberalised scenario the size of the UK dairy production industry will depend mainly on how competitive the
farm to retail dairy production and marketing chain has been, and the proportion of the UK market for milk and milk products which
it continues to command.
12
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Future Grass Yields
The source of grass dry matter yield data used in this analysis of climate change adaptations in MAFF Project CC0333 (The
timescale of potential farm level responses and adaptations to climate change in England and Wales). The scenarios are for the
Medium High UKCIP98 scenario. The modelled results for grass are for grazing, or a two cut silage system followed by grazing.
The silage cuts take place on 15 May and 20 July and grazing is assumed to restart four weeks after the second silage cut. This gives
the information in Table 7 for modelled grass yields for a farm, which is based on good growing conditions in East Lancashire.
Baseline
(t/ha)
11.189
8.629
Grazing
Silage/grazing
2020/Baseline
2.19
.9
Change (t/ha)
2050/Baseline
2
1.51
2020s
19.6
10.5
Change (%)
2050s
17.9
17.5
Table 7: Grass Dry Matter Yield Changes for farm in East Lancashire (After Hossell et al., 2001)
Although the Lancashire site is a good example of conditions in the wetter and cooler North West, it does not reflect the type of
climate of dairy farms in the South and East. For the latter we have used the results for a site at Andover (Table 8).
Baseline
(t/ha)
7.358
6.787
Grazing
Silage/grazing
2020/Baseline
.72
.34
Change (t/ha)
2050/Baseline
.39
.23
2020s
9.7
5
Change (%)
2050s
5.3
3.4
Table 8: Grass Dry Matter Yield Changes for a farm in Andover (After Hossell et al., 2001)
Adaptations
Adaptation type
Adaptation
Balance of grazing and cutting
Climate Change Impact
Increased spring and autumn yield
Decreased summer yield
Increase in silage yields
Increased spring and autumn yield
Increased poaching risk in spring and autumn
Decreased summer yield
Increase in silage yields
Increase in yields of fodder crops
Decreased summer yield
Increase in silage yields
Increased poaching risk in spring and autumn
Increase in yields of fodder crops
Increased spring and autumn yield
Increased in nutrient leaching in high rainfall
conditions.
Decreased summer yield
Decreased summer yield
Increased spring and autumn yield
Increased spring and autumn yield
Increased poaching risk in spring and autumn
Use of extended grazing
Buffer grazing
1
Storage feeding
Zero grazing
Increased use of legumes
Irrigation
More frequent reseeding
Change of seed mixture
Increased drainage
Table 9: Possible adaptive actions and the climate change impact to which they are responding
The key adaptation responses to climate change are thus to make best use of the increased grass yield available in spring and autumn
and to the reduced summer yields. All adaptations are based at the farm level and are type 1 adaptations (Table 9).
Exploitation of Increased Grass Growth in Dairying Systems
The exploitation of greater grass growth depends on being able to utilise the additional yield (see Tables 7 & 8 above)
An increase in grass dry matter yield could be exploited in a number of different ways:1. Increased stocking rate leading to: a) More cows on the same area or b) Same number of cows on reduced grassland area, and
expanded alternative enterprise
2. Reduced purchased feeds.
Since substituting grass dry matter for concentrates often reduces milk yield, this option was not costed. Instead options 1a) and 1b)
were considered in relation to the current policy and quota system. The scope for exploiting higher grass dry matter production
depends on the performance of the cows in the baseline system. If the milk yield per cow is high there may be very little, or no, scope
to increase it through feeding extra grass dry matter. In general, increases in yield per cow through feeding more forage are difficult
to achieve, especially when yields are already high, because of the lower energy concentration in forages compared to concentrates.
Most dairy cows in England are fed grass dry-matter to appetite, and additional grass dry-matter can only be utilised by reducing
concentrate use or keeping more cows. Higher milk production per hectare is more achievable than higher milk production per cow.
The higher milk production may come from a higher stocking rate (1 (a) above), or the area of forage may be reduced permitting land
to be transferred to an alternative enterprise (1 (b) above). Substituting grass dry matter for concentrates (2 above) will often result in
13
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
a reduction in milk yield per cow, making this route to greater grassland utilisation more difficult to budget, and less likely to be profit
maximising because of the physical and economic consequences of reduced milk yields per cow.
Five possible adaptations in the list above (changed grazing and cutting ratios, extended grazing, buffer feeding, storage feeding and
zero grazing) are primarily about the manner in which grass is produced and utilised. Appendix 3 provides more details on how each
of these techniques may be used. It was considered unrealistic to cost separately these measures that a farmer would adopt
collectively. Hence costings for grazing/feeding adaptations were calculated together. Five further adaptations are about how the
production function can be altered in the new situations of the climate change scenarios (for example increased use of legumes
reducing inputs, or irrigation raising outputs).
Change of Grazing and Cutting Ratios
A likely response to reduction in summer grass growth in drier areas is to reduce the area cut for second cut silage to allow the cows
to graze a larger area when the grass supplies are reduced. Tables 4.16 and 4.17 in Appendix 3 illustrate that this could maintain
summer grazing without reducing grass available for silage. Table 10 shows a summary of the possible changes in the grazing/silage
area ratio that would achieve this aim.
Table 10: Yields achieved with different summer grazing and silage area ratios for East Lancashire. These are based on total grass
yields modelled in CC0333 (Hossell, et al., 2001).
Baseline
2050 with adaptation
96/4
Grazing/silage ratio for second cut 60/40
Total silage (t/ha DM)
2.41
2.53
Summer Grazing (t/ha DM)
0.91
0.91
Extended grazing
Extended grazing is the grazing of dairy cows earlier in spring and later in autumn than has been usual practice in recent years (see
Appendix 3 for more details). It can both reduce labour and machinery costs due to less silage & muck and utilise more grass growth
occurring early and late in the year.
Buffer Feeding
Buffer feeding is the feeding of forage-based feeds for a restricted time to grazing animals as a supplement to grazed grass. The role
of buffer feeding is to help optimise output from grazed grass and minimise waste; ensuring an adequate supply of high quality
grazing material for as long a grazing season as possible. It is appropriate where supplies of grass for grazing are not adequate. It is a
grazing management tool, by reducing pressure to give grass a chance to recover and so allow additional grass to accumulate. (MDC
2000)
Storage Feeding
Storage feeding refers to the practice of feeding dairy cows on silage throughout the year. Even through the grazing season, silage is
fed to housed cows. In intermediate situations, it is hard to distinguish between storage feeding and buffer feeding.
Zero Grazing
Zero grazing refers to the practice of harvesting forage crops and feeding them while fresh to housed (or yarded) livestock. While
zero grazing can refer to a situation where livestock are never grazed at any point in the year, common parlance is to refer to it as a
more limited feeding method which may only last for a few days.
Cost/Benefit calculations for combined adaptations
The possible adaptations to climate change described above are all related to utilisation. Some reduce costs (extended grazing) while
others tend to increase costs (zero grazing and storage feeding). In the calculation in Table 3.15, Appendix 3 the extra total annual
grass dry matter for the 2050 scenario is all assumed to lead to a change of stocking rate. Table 3.18, Appendix 3 provides the
benefits of these changes to stocking rates. The net present value of the benefits at 6% is £250 million and £70.1 million for East
Lancashire and Andover respectively.
The logic here is that the production of milk is fixed, whether by quota or market constraints and hence the greater stock carrying
capacity of the grassland goes into keeping the herd on fewer acres. This releases land to an alternative use. The assumption has been
made that the land released may not good enough to support more profitable cereals such as wheat (a survey of grassland suggested
that the majority was imperfectly or badly drained, MAFF, 2000). Furthermore the results of a previous MAFF funded work
(CC0333, Hossell et al., 2001) suggest that barley production would increase on dairy farms rather than wheat. Hence, Table 3.19 in
Appendix 3 provides a conservative estimate of the possible benefits of using this additional land for barley production. Examining
the average value of the two sites, with current policy in place there would be a small negative net present value at 6% of £-13.4
million if stocking rates increased and the released land were used to grow barley and set aside. However, the UK’s rebate under the
Fontainbleu agreement is critical to this result and if the effect of the EU’s rebate were excluded the impact would be positive, giving
a net present value of £59.6 million, with a benefit:cost of 1.5. This demonstrates how critical general policy can be in relation to the
EU budget in determining the outcome of the balance of costs and benefits in some scenarios.
Increased Use of Legumes
Climate change would take the conditions in England and Wales much closer to those experienced in New Zealand where clover is a
very important source of nitrogen and grassland management is designed to make good use of the potential of clover. With grassland
soils warming earlier due to climate change in 2050, mixed perennial rye grass/white clover swards will be able to support the level of
animal production, which currently requires 220 kg/ha. of N (Nix, 2000). At an average price of 33 pence per kg this would reduce
14
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
forage costs by £66 per ha. The net present benefit of this saving at 6% is £512.1 million (Table 3.20 in Appendix 3). This also
suggests that organic grassland may become more productive under climate change.
Irrigation
Increased irrigation is one possible adaptation to reduce the impact of reduced summer grass yields due to drought. However the
calculations in Appendix 2 show that irrigation is not economic for dairying in the baseline period.
The average response of 0.018 t/ha mm is less than the response required for break-even at the lowest water cost and highest dairy
gross margin (0.040 t/ha. mm) - the most favourable combination of circumstances for irrigation to be economic. The price of milk
would need to rise by 3.8 pence per litre before irrigation under current conditions would be profitable.
Reseed More Often
It is possible that with a more certain reseeding opportunity in mid summer in drier areas, more reseeding will prove worthwhile. The
key cost associated with reseeding is the lost grassland production while reseeding takes place, but if grass growth is reduced in mid
summer by drought in the drier areas, this cost may diminish.
Changed seed mixtures
Changes in seed mixtures towards more use of Italian, hybrid and early perennial ryegrasses may also be anticipated. The good early
and late season growth of these mixtures fit well with extended grazing systems. Increased use of legumes is considered separately
below.
Increased drainage
In the context of climate change adaptation, it is the potential of drainage to improve utilisation of grass, rather than to improve grass
dry matter yields, which would be most important. Climate change will increase total seasonal grass yields, but more will come early
and late in the season when it is difficult to utilise. Written off at 6% over 20 years the capital charge of increasing drainage would be
about £12,180 or £61 per cow (see Appendix 3 for more details). This cost implies that it is unlikely that grassland drainage would be
a cost effective adaptation to improve utilisation.
Tomatoes - Heated Glasshouse Production
The magnitude of any climate change impacts and subsequent adaptations (see table 10) must be judged against the strong economic
and technological driving forces existing at present in the industry. The problems of estimating the size of the English heated glass
house tomato industry in 2050 are large. It has been assumed that the industry might have halved its cropped area to 130 ha.
Adaptation type
1
Main Adaptations
Shade screens
Climate change impact
Faster ripening
Reduced yield due to reduction in leaf size and vigour
Reduced yield due to reduction in leaf size and vigour
Reduced yield due to reduction in leaf size and vigour
Reduced yield due to lower winter solar radiation
Increased yield due to higher CO2 levels
Increased yield due to higher CO2 levels
Reduced winter heat needs
Faster ripening
Increase in pest populations/introduction of new pests
Reduced yield due to poor set
Increased yield due to higher CO2 levels
Reduced yield due to reduction in leaf size and vigour
Cooling air systems
Totally Controlled Environment
Artificial lighting
Reduce CO2 input
Purge air at end of day to reduce CO2
Reduce heating input
Faster picking
Changes to pest control
Change cultivars
2
New Glasshouse Designs
Table 10: Summary of the key impacts and adaptations derived from the literature review (See Appendix 1).
Economic Scenarios
The liberalised scenario and the current one are regarded as broadly the same.
Adaptations
Shade screens
Above 30 °C there is a reduction in the size and vigour of tomato leaves. This produces a reduction in yield of 10-20%. So the
savings in yield of 37,500 need to be offset against the annual running and repair costs of £3,000 and the capital investment cost offset
at 6% over 20 years of £4,350/year. This provides a benefit:cost of 5.1 with the net present value to 2050 at 6% for the whole
industry of £18.28 million (see Table 3.21 in Appendix 3).
Cooling air systems
In addition to the new glass house design features the installation of cooling air systems is also a reasonable adaptation. In principle
air conditioning could be used but there might be more cost effective ways of introducing cooling air. This sort of adaptation would
need more development and it is not currently possible to demonstrate its economic benefit.
Totally controlled environment
It is possible to change tomato production from glasshouses to totally controlled environments (TCE). TCE buildings use artificial
lighting. Some development work has been carried out in Israel and the USA. TCE is uneconomic at present and would probably so
remain within the time frame of up to fifty years and the climate change scenarios under consideration here, which will allow
continued production in glass houses and outside.
15
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Artificial lighting
Reduced winter solar radiation in the period December to March reduces the yield of long season tomato crops. A one percent
reduction in radiation will lead to the same reduction in yield. ADAS analysis of changes of radiation levels in 2050 compared to the
base period was –1.8 to - 0.9 % in the South East and +0.9 to +1.8 % in Yorkshire (see Figure 1.3 in Appendix 1). A 1% reduction in
yield will cost £2500. The Benefit: cost ratio is only 0.02 (See Table 3.22 in Appendix 3) and the net present value at 6% for the
whole industry is £-80.48 million.
Reduce CO2 input
Higher levels of CO2 in the atmosphere will reduce the need for CO2 enrichment. Where CO2 is supplied as pure CO2 there will be a
cost saving of about £8000 per ha. However it is unlikely that any growers will be using pure CO2 in 2050. They would be more
likely to be using gas/Combined Heat and Power (CHP) plants (Drakes, 2001). Nurseries with CHP plants have access to effectively
free CO2. These plants (which supply power to the electricity grid) were installed on a number of large nurseries at a time when it
was in the interests of electricity companies to pay for the investment to meet their Non-fossil Fuel Obligations. The situation has
now changed and these investments have come to a halt. Where nurseries do pay for CO2, this adaptation will give small savings and
the change in crop management is so straightforward that growers can be expected to reap the benefits without any investment or need
for new information.
Purge Air at end of day to reduce CO2
This is sometimes carried out at present. The CO2 level is allowed to fall at the end of the day to reduce night-time levels which arise
from respiration of the crop. There is little associated cost.
Reduced winter heat input
Higher winter temperatures will reduce the heat needed in winter to maintain the glasshouses at the required temperature regime.
Figure 1.2 in Appendix 1 illustrates the level of reduction possible under the UKCIP98 High scenario for 2050. The saving produced
provide a net present value to 2050 of £4.41 million at 6%. The reduced heat input figures have been calculated as savings on current
usage and expenditure, although use of waste heat and combined heat and power (CHP) might be much more common in the future.
These latter will require much new investment and although the heat sources are cheaper it is not clear that the real cost of heating
(including the cost of capital) will be much lower in 2050.
Faster picking
Increased rate of ripening due to warmer sunnier conditions, especially in the South of England will lead to a shorter window for
picking. (Drakes, 2001). The need to get the fruit into the cold chain more quickly may lead to the need to start picking earlier. The
need to increase the frequency of picking might be accompanied by a need to start picking earlier.
A 15 % increase would be about £4,400 per ha, which for the industry as a whole is £2.67 million at 6% (see Table 3.24 in Appendix
3). The benefit would be the avoidance of some increased level of rejection by multiple retailers when tomato deliveries were not up
to specification. It is difficult to quantify the level of yield saved but the additional picking cost would be justified by a yield saving
of 1.75% or more.
Adaptation to bio-controls and more pesticide use.
The main potential pest threats for glasshouse tomatoes are glasshouse whitefly, tobacco whitefly (Bemissia tobaci) and liriomyza.
These threats would be particularly severe if the pests were able to overwinter outside glasshouses. For example tobacco whitefly
lives in many areas of the world where minimum temperatures go down to 5 or 6 degrees centigrade for short periods. However the
climate change scenarios for 2050 show increases of temperature of the order of only + 1 or 2 °C. This would not be a large enough
climate change to allow tobacco whitefly to over winter in the UK. (Buxton, pers comm. 2002)
Within glasshouses these pests will thrive from higher temperatures, placing pressures on existing pest control methods. While there
are chemical control methods available, these are becoming less acceptable to retailers. But a great deal of glasshouse tomato
production takes place in hotter climates than England and Wales. There seems a good chance that advances in our knowledge of the
biology of the pests, especially from research carried out in glasshouse cropping areas with hotter climates than the UK, will allow the
industry to adapt without significant cost increases.
Change cultivar
A change of cultivar provides a means to reduce the impact of poor set, reduction in leaf size and vigour, high CO 2 levels and faster
ripening (see appendix 1 on climate change impacts). It is likely that the European seed companies that supply the tomato industry
would accommodate these modified requirements for tomato varieties. As climatic conditions change their selection procedures will
find lines that perform as required. It is likely that the change in requirements will be accommodated without major additional
expenditure on tomato breeding. Protected tomatoes are commonly grown in hotter climatic conditions than the UK, and the required
genetic characteristics will be available within the range of plant material held by the seed companies. The benefits of new cultivars
(see Table 3.25 in Appendix 3) has been calculated as saving of the 15% loss from reduction in leaf size and vigour, combined with a
saving of the 20% yield loss due to poor fruit set. The net present value at 6%of the savings to 2050 would be £0.37 million.
New glasshouse designs
Other changes in glasshouse design are possible but have yet to be fully developed. These could include changes to the nature of the
glass, or the thermal properties of the structure. These possible adaptations would need development so it is difficult to cost them or
demonstrate an economic benefit. A broad estimate is that instead of a cost of £300,000/ha for conventional glasshouses with shade
screens, other new cooler designs might cost about £400,000/ha. If so, shade screens would still give a better return on investment.
16
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Pigs
Little research has been conducted on the direct effect of climate change on pig production. Turnpenny, et al., (2000) examined the
implications for indoor pig production, but not for outdoor systems. Hence many of the adaptation assessments presented below are
qualitative rather than quantitative (see table 11). Further work is needed to quantify the impacts of climate change on pig production
and to disentangle the effects of climate from those of different production methods/housing systems.
Economic Policy
Current Policy
The pig meat sector is not heavily supported under the Common Agricultural Policy. In common with the poultry sector, protection
has been designed to only compensate for the difference between cereal prices inside the EU and on the World Market. The only
intervention within the EU’s market has been the use of aid to fund private storage of pigmeat as a temporary measure to remove
pigmeat from the market at times of oversupply. There are no direct aid payments associated with pig production. During 2000 and
2001 there was a Pig Industry Restructuring Scheme (‘outgoers’ and ‘ongoers’) which made payments to those leaving the industry
and committing not to re-enter pig production within ten years (outgoers), and an interest rate subsidy to those reduced capacity by 16
% and continued in pig production (ongoers). The Pig Industry Restructuring Scheme was a short term reaction to exceptional market
conditions of depressed prices rather than a long term instrument.
Liberalised Policy
With further liberalisation of the CAP the price of pigmeat would probably be slightly lowered to reflect reductions in cereal prices
and hence pig concentrate prices within the EU.
Adaptations
Pig production type
Adaptation
type
Indoor
1
Outdoor
1
Adaptation
Climate change impact
Increase in autumn winter labour
Change in slurry storage/handling systems
Change in housing/ventilation systems
Change in breeding practices
Increased rainfall leading to increased slurry volume
Increased rainfall leading to increased slurry volume
Increased annual temperatures
Increased summer heat stress reducing boar libido/sow
fertility
Wetter conditions leading to greater time needed for animal
management
Increased labour demand in autumn/winter
Table 11: Summary of the key impacts and adaptations derived from the literature review (See Appendix 1).
Indoor Pigs
Increased Autumn/Winter labour requirement
On Breeding/Finishing units, the large majority of slurry output is produced by finishing pigs, particularly those on liquid feeding
systems. Appendix 1 provides an indication of the possible implications of climate change for labour requirements. However, lack of
quantified research on the effects means it is difficult to cost the adaptations that may be necessary. On a anecdotal basis, one 250
sow breeding-to-finish producer with 4 staff, including himself, revealed that one member of staff spent 75 % of his time carting
slurry during normal weather conditions, and 120% of his time during unusually wet conditions i.e. extra 20% overtime at premium
rate.
Change in slurry handling/storage
Increased autumn/winter rainfall will affect the water content of slurry and hence the volume needed to be stored. Possible
adaptations to such conditions are listed in Appendix 3. Table 3.26 in Appendix 3 shows the cost of one possible adaptation to the
increased volume, that of a covered slurry store, combined with increased separation of rainfall from dirty water. This provides a cost
benefit ratios of 0.32, with a net present value for the industry of 350,000 sows of £-5.33 million at 6%. This would not be an
attractive adaptation to producers
Changes to housing; ventilation/heating
Increased temperatures can change the need for ventilation and heating in housed systems. Unless adaptations are made higher
temperatures may reduce the appetite of pigs. A number of adaptations are possible (See Appendix 1) but given the variation in age
and sophistication of existing housing its is difficult to cost a number of these. The adaptations likely to offset these impacts would
involve increasing fans, higher running speeds, water showers, and increased water usage. The capital cost of installing 4 additional
fans and a shower system would be £9000. Discounting over 20 years would result in an annual cost of £783 at 6%. Hence when
annual running costs are also included the cost benefit is 8.2 at 6%. The net present values are £47 million at 6%. This adaptation is
highly profitable and would attract farmer investment.
Outdoor Production
Reputedly 25% of the National herd is based outdoors. Over the last 3 years, the National herd has contracted by 33% as a result of
price pressures, largely fuelled by strength of sterling relative to the Euro. Home production has therefore struggled to remain
competitive, also taking on additional capital costs such as the need to house sows in alternative group housing systems, following the
UK Stall and Tether ban in Jan 1999. During this time, cereal prices have fallen dramatically, with arable producers with suitable
land now either looking for alternative higher value cropping options or to add value back into what has become a cheap commodity
by feeding their own cereals through a pig unit. Costs of building indoor units are becoming prohibitive, for example a modestly
17
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
sized new indoor 220 sow breeding to finish unit has cost £0.75m. Planning permission for this unit took 2 years to achieve. It is
likely, therefore, that any form of expansion could well involve outdoor production, probably contracted with specialist large pig
production companies supplying all labour, stock and equipment on rented arable farmland.
If this trend develops, as outlined, clearly a greater proportion of the National Herd are likely to be based outdoors. Therefore any
climatic change (most likely to impact on outdoor production) will have a correspondingly larger effect.
Change in breeding practices
If for a 650 sow unit, the £10,725 in lost farrowing rates and additional rearing costs can be overcome by the use of insulated arcs, AI
and serving tents, then the total costs of the adaptation (annual running costs of £659.8 plus the annulised capital cost of serving tents
and insulating new arcs of £5,407.5) of £6,067.3/year produces a benefit:cost of 1.78. The net present value for the whole industry at
6% is £4.53 million (see Table 3.28 in Appendix 3). It seems likely that producers would be prepared to invest in this adaptation.
Increased Autumn/Winter-labour demand
There is a shortage of information on costings for outdoor production particularly. Exeter University costings 1996-1997 reported a
labour cost of £96 per sow, based on 16 hours for average herds, and a figure of £88 per sow based on 14 hours for top 6 herds. PIC
in their handbook "Outdoor Pig Production”(1992) suggest one man can look after 200 sows and progeny to 30kg (equivalent to £80
per sow for an annual wage of £16,000,however additional help is needed for straw carting, moving site, holiday cover, sickness etc.
Typically, contractors can be brought in to help move site/erect fencing/mend arcs, although this will of course add to overall labour
costs. If sites had to be moved more frequently, due to adverse weather/ground conditions, clearly this would result in higher labour
costs though without exact data, this might have to be estimated on a percentage rise basis. BOCM “Outdoor Pig Production”
suggests a similar figure of £90 per sow. Actual farm data from a 680 sow herd in the on agency supplied staff, reveals for 2000/2001
a paid labour charge of £104/sow, together with a contract charge for site moving/fencing/remedial work/straw carting/arc mending)
of £27 per sow.
It is not possible to realistically quantify the additional labour costs created by changing climate. Further work is needed to quantify
the level of the changes needed under different climate conditions.
Summary of results
The table 12 shows the cost benefits for the different enterprises and adaptations and the likely funder.
Commodity
Wheat
Potatoes
Cauliflower
Grass
Adaptation
Change in cultivars
Aphid spraying
Change in crop location
Irrigation
Change in crop mix
Loss of early crop
Change from earlies to other crops
Loss of earlies to Cornwall
Irrigation of maincrops
Additional Pest control measures
Change in storage equipment
Develop new markets
More frequent sprays
New pesticides
Improved pesticide application
Improved crop/seed hygiene
Additional N application
Irrigation
More passes/crop
Change cultivars
Move cropping to cooler areas
Change in grading rules
Changes in cutting/grazing ratios
Extended grazing
Buffer feeding
Storage feeding
Zero grazing
Use of additional land for barley
Increase in legumes
Reseeding
Changes in seed mixtures
Increased drainage
Installation of shade screens
Cost benefit (high/low scenario where
used)
5.6/5.4
2.9/3.7
Not costed
Not costed
0.91/0.44
0.48
0.71
0.13
1.7/0.7
98.3
32.5
Not costed
2.7
Not costed
95.5
Not costed
21.7
Not costed
1.14 (winter), 2 (summer)
Not costed
Not costed
Not costed
No costs involved
No costs involved
No costs involved
No costs involved
No costs involved
0.82 (current policy) 1.5 (liberalised) policy
No costs involved
Not costed
Not costed
No savings calculated
5.1
18
Priority rank
within a
commodity
(industry wide)
1 (1)
2 (3)
2 (14)
1 (4)
3 (16)
3 (19)
2 (15)
4 (22)
1 (12)
=2 (=5)
=2 (=5)
=2 (=5)
=2 (=5)
=2 (=5)
1 (2)
1 (13)
Likely funder
Commerce
Growers
Growers/Government
Growers
Growers
Growers/Commerce
Growers/Government
Growers/Commerce
Growers
Growers
Growers
Growers/Commerce
Growers
Commerce
Commerce/Government
Commerce/Growers
Growers
Growers
Growers
Commerce
Commerce/Growers
Commerce/government
Grower
Grower
Grower
Grower
Grower
Grower
Grower
Grower
Commerce
Grower
Commerce/Grower
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
Commodity
Tomatoes
Pigs
Adaptation
Additional cooling systems
Controlled environment
Artificial lighting
Lower CO2 input
Purge CO2 at night
Reduced winter heating costs
Faster picking
Bio control of pests
Change cultivars
New greenhouse design
Changes in slurry handling
Changes to housing/ventilation
Change in breeding practices
Cost benefit (high/low scenario where
used)
Not costed
Not costed
0.02
Not costed
Not costed
No costs involved
Savings not calculated
Not costed
No costs involved
Not costed
0.32
8.2
1.78
MAFF
project code
Priority rank
within a
commodity
(industry wide)
2 (18)
3 (20)
4 (21)
1 (11)
2 (17)
CC0357
Likely funder
Commerce/Grower
Commerce/Grower
Grower
Grower
Grower
Grower
Grower
Grower
Commerce
Commerce
Grower
Grower
Grower
Table 12: A summary of the adaptations suggested in this report, their benefit cost ratios, where calculated and an indication of the
likely funder of the adaptation (the government funding source may also include levy bodies). Values in bold in the benefit:cost
column indicate positive effects of the adaptations. Priority ranking is based on size of positive net present values.
Uncertainty in the prediction of future adaptation
In interpreting the costing results is important to bear in mind the constraints within which the analyses have been undertaken. In
terms of adaptation two types of change has been envisaged:
1. changes within an existing farm, which produces a commodity now and will continue to do so under climate change, and
2. changes that take place because farms abandon or take up the production of a commodity.
For ease of reference these may be termed type 1 adaptation (within business) and type 2 adaptation (movement of production
between geographic areas). The first situation can be tackled with some confidence at the micro-level with good knowledge of
farming systems and the shape of the production functions (although the lack of reliable macro-economic price forecasts will always
be a weakness). The latter situation is much harder to forecast because there is no simple connection between the shifts of
comparative advantage and the decisions of individual firms. For example winter cauliflower (locally known as broccoli) in the far
west of Cornwall has a clear climatic advantage over the main summer cauliflower production area of Lincolnshire; this may be
eroded under climate change. But climate and soil are only two factors among many that drive the decisions of individual farm
businesses. Soil and climate provide the ultimate determinants of what can be grown but the knowledge and skills of individual
producers, the collective knowledge of farmers in a locality and the educational, extension, marketing and contracting resources all
play a part. The nature of the fixed capital investments and whether profitability is sufficient to renew them are often crucial. Even
when all these very real factors are taken into account there remains “serendipity”, which makes accurate forecasting hazardous. If
climate change moves the ideal locations for summer cauliflower production North from Lincolnshire, models of economics and
production may suggest that farmers should change their crops but not which ones will do so. This is much harder than anticipating
what the summer cauliflower producers in Lincolnshire might do to stay in business, and the likely limitations of their adaptations.
Hence the research findings are likely to be more accurate in exploring the type 1, rather than type 2 adaptation. Given also that
farmers respond more quickly to avoid a loss than to obtain a profit, type 1 adaptations are likely to be those that are adopted first as
climate changes.
In looking at these single commodities it is important to also consider the context within which they are grown (largely multi crop
enterprises) and the influences that affect production off the farm. The horizon for the climate changes anticipated over the next
twenty five or fifty years is a much longer time frame than that with which farm business specialists and agricultural economists
normally work. In even twenty five years the world will be different place from the world of today. By 2020 the world’s population
is expected to increase by thirty percent (Pinstrup-Anderson et al., 2000). Agricultural production in Europe will be operating within
the context of an agricultural policy that will have changed, and the structure of the industry in terms of the size of farm businesses,
and their enterprise mix will also have changed. This latter point is important for those crops such as wheat and grass where
production does not, in the main, take place in businesses that produce a single commodity. Here it is important to consider typical
businesses, such as specialist cereal farms or dairy farms, and understand the adaptation to climate change that will be required within
the context of the whole farm. For other commodities such as heated glasshouse tomatoes, production does tend to be highly
specialised, and the business context is effectively mono-culture.
The difficulty of examining climate change is compounded because of the long timescales involved. Over 25 or 50 years not only do
the technical relationships affecting the production of each business change at the micro-level, but at the macro-level changes in
demand and supply are likely to move prices of inputs and outputs significantly.
A number of general conclusions can be drawn from this summary:
 Investment in extra wheat breeding to overcome yield losses through increased temperatures provides the highest net value of all
the adaptations costed (£1,527 million). This is largely due to the large area covered by the crop in England and Wales. By
contrast, improving application of additional nitrogen fertiliser in cauliflowers provides a clear Benefit: cost of 21.7 but the net
value of the benefit is only £19,000. Previous work has suggested that farmers are reluctant to make changes for relatively small
19
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
monetary benefits (Hossell, et al., 2001), so low value benefits may not be realised immediately. Many of the adaptations will
need to be adopted in parallel in order to offset the effects of climate change.
 The different costs and breakeven points of the various adaptations suggest that some will be adopted more rapidly than others.
Also some adaptations are effective against a range of potential impacts, whilst others are alternative strategies in dealing with the
same impact. Such adaptations, although mitigating the same impact, may still occur in parallel, since different aspects of the
agricultural industry may implement them on different timescales. For example, a farmer’s response to a change in potential
wheat yield may be to adjust the cropping mix. This is likely to be a relatively rapid response to actual yield changes. The same
impact may encourage wheat breeders to increase investment in wheat breeding to provide better-adapted cultivars. This is a
longer term-response due to the need for the new variety to be trialled and the delay in uptake of the cultivars by farmers.
 The significance of non costed adaptations, i.e. those for which quantitative information is not readily available, should not be
ignored. Some of these changes such as changing cultivars may be crucial to ensure the adaptation of crop production to climate
change.
 Adaptations such as shifts in cropping areas may require early consideration by the industry, since they may only be viable if the
savings made through not renewing existing equipment in current production areas are balanced against potential moving costs.
 A number of adaptations are currently economically unviable, e.g. changes to the storage and handling of pig slurry. However,
such changes in practice may still be necessary to reduce environmental damage such as N pollution. Hence government
assistance may be needed to encourage the uptake of such adaptations.
 Comparing the relative merits of the different adaptations with results from MAFF funded cc0333 suggests that adaptations
responding to crop yield changes and animal housing conditions, and changes in timing/frequency of operations such as pesticide
applications may need to in place by the 2020s in southern areas of England and Wales. Other changes, such buffer feeding in
dairy systems in summer may be delayed until the 2050s.
 Some of the adaptations will need to be adjusted as climate changes, for example changing cultivars and reducing heating
demand in glasshouses.
Key uncertainties and information gaps
The key uncertainties in this work include:
 The effect of different GCM climate change predictions on the calculations – Only the UKCIP98 scenarios have been used.
 The impact of climate change on other sectors that influence agriculture, such as water use and supply and changing public
demand for different food types under warmer/wetter conditions.
 The level of future climate change, particularly rainfall patterns and intensities, on timing of farm operations and nitrogen
leaching
 Future economic and policy environment for both agricultural production and agri-environmental measures. The calculations
have shown that differences in liberal versus current policies can affect sign and magnitude of the cost benefit analyses
 Changes in the production of crops outside of England and Wales in response to climate change. These have been ignored in the
calculations
 Future technological improvements in yield. This has been excluded from calculations
 Physiological maximum yields for crops, since the climate change impacts do not consider potential upper limits to yields
 The effects of sea level rise on the availability of agricultural land in eastern and south eastern coastal areas.
General research needs
A number of general further research themes have been identified:
 The assessments have not considered how technological improvements in yield may interact with changes due to future climate
conditions. Nor has consideration been given to the potential plateauing of yield values as maximum achievable values are
reached. Both scenarios also need to be incorporated to provide a full picture of the value of plant breeding in adapting to climate
change.
 Liberalised regimes can reduce both the sign and magnitude of the benefits of adaptation. Further work is needed to put the cost
of future changes into the context of the EU/global food market. Past work has suggested that changes in supply of crops outside
England and Wales can more than offset the impacts of climate change on that commodity within the country (Hossell, et al..,
1994).
 The costings are based on changes in average climate conditions, the costs of rare events or of changing frequency of extreme
events has not been considered.
 The effects of climate change on crops has focussed largely on yield and production issues, there is less information in the
literature about the implications for quality, particularly for potatoes and cauliflower and for the protein levels in grain and grass.
Whilst new cultivars/different sward mixes may offset some of the climate change impacts, more work is needed to understand
the implications for production practices e.g. the importance of irrigation or timing of harvest on quality.
 The implications of climate change for changes in weed growth and possible changes to the timing and means of weed control are
not yet understood for most crops. This impact may affect yields as well as the economics of production, the efficacy of existing
herbicides and the need to develop new ones.
 The implications of climate change for organic production have not been well studied. The range of adaptations and their relative
costs and benefits are likely to be different than for conventional farming. For example the increased use of legumes in grass
land may make organic dairy production more efficient.
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Project
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Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357

The timescale over which changes need to be made needs further analysis, particularly to consider how extreme events may
“bring forward” certain adaptation needs, for example the need for increased ventilation in pig housing units. Whilst
infrastructure and breeding programme investments are clearly long-term adaptations, most farm level changes in timing or
pattern of production may need to be introduced only once key thresholds have been reached. Further work is needed on the
timescale for these transient adaptations.
Research needs have also been identified for specific commodities/adaptation types:
Wheat
Further research is needed to investigate the potential for climate change impacts on yields to be offset by the development of new
cultivars and or a shift in the main centre of production to cooler areas.
 Potatoes
The general rise in temperatures means that increasing areas may be suitable for early potato production, providing a crop at the same
time of year as current early production but in more northerly and easterly areas. However the mere fact of being able to increase the
early potato area will affect the value of the crop, since the price advantage achieved by earlies is dependent upon their “novelty
value”. The feasibility of increasing area of early potato production in terms of the most likely areas and the effect of increases in
total production on the value of the crop need further research.
The longer growing season should also allow early potato production in existing areas to be moved forward in the year. However this
will push production into periods of the year with lower solar radiation. The effect of reduced solar radiation on yield of current early
varieties needs to be investigated. The aim of these studies would be to establish if earlier production requires varieties with slower
development to produce a reasonable yield.
 Cauliflower
The implications of climate change for the variability of cauliflower maturation has not been fully explored. Development models for
the crop exist based on simple temperature sums. Since it may have serious implications for harvestable yield, quality and continuity
of supply, further research is needed to quantify the effects of increased and or variable temperatures on the maturation rates of first,
second and third plantings.
 Grass production for dairy cows
Fifty three percent of cows were in herds of more than 100 cows. There has been a long standing trend to larger herd sizes and this
will certainly increase by 2020 and even more by 2050. Some adaptations for climate change, such as extended grazing, may be
harder to implement with large herds, for example due to poaching in gateways with large groups of animals. But larger herds often
have the potential to group cows more effectively, and this can assist utilisation. For example there may be groups of stale milkers
(perhaps being milked once per day) and dry cows, which can access more distant pastures and be grazed more tightly etc. Further
research is needed to examine the different costs of implementing different grass production systems on different size farms.
The change in consumption levels of cattle under different climate conditions and their utilisation rate of this food needs further
investigation. This also needs to be considered in conjunction with possible effects of climate change on grass protein content.
 Tomatoes
Further work is needed to identify the potential threat of introduced pest and diseases to tomato production and the types of controls
that may need to be introduced.
 Pigs
The impact of climate change for pig production has not been well quantified. Whilst the adaptations suggested are relatively low
technology solutions, further research on the commercial practices adopted in other climates will provide a clear guide as to both
impacts and alternative adaptations.
Conclusions
Key conclusions and priority adaptations are summarised by commodity:
Wheat

Climate change may have important implications for yields. Some of these effects may be offset by the introduction of new
cultivars, so additional plant breeding research and investment is considered critical to the future productivity of the industry.
The development of new cultivars, potentially has a long lead time before results are available to the market, so it is important
that steps are taken in the near future to adopt this adaptation.
 Other adaptations to yield loss such as irrigation are unlikely to be cost effective, unless irrigation is already installed on the farm.
Changes in the distribution of the crop across the country may also counter yield losses, but these costs cannot be calculated
without a full economic analysis of the UK and global market.
 Substitution of grain maize for wheat is unlikely to occur unless the yield of maize increases greatly under climate change or
wheat yields decline greatly.
Potatoes

Whilst losses may be partially offset by the adoption of an alternative crop, production in areas such as Cornwall, which provide
the earliest potatoes may not be able to adapt to the longer growing season. Farmers in this area should be encourage to diversify
their operations to increase off-farm income.
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Project
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Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357

Potato production in England and Wales may suffer from changing market advantage elsewhere in Europe and abroad. Further
work is needed to clarify the change in production and the level and success of adaptation to climate change in competing
production areas abroad.
 For main crop potatoes, grower level adaptations are likely to be readily adopted as they provide considerable benefit (e.g.
increase storage refrigeration) or are easy to fit into the production cycle (additional spraying), but information on the timing of
such changes needs to be considered.
Cauliflower

The cauliflower production industry is a dynamic market orientated sector, which is likely to respond rapidly to the new situation
generated by climate change. However, the effect of loss of early potato production in Cornwall, where winter cauliflower
provides the other part of the rotation could be significant. It is unlikely that cauliflower production in this area would survive
the loss of the early potato crop.
 The greatest net benefit in terms of cost is given by increasing the number of passes of the crop at harvest. However, the need for
this adaptation is also likely to be highly variable, since it is a response to uneven maturation of the curds due to warmer and
more variable conditions. The uptake of this adaptation, hence, may be delayed for several years as climate changes until the
effect on the evenness of maturation rate becomes clear.
 The adaptations that are likely to be most readily adopted by growers are the increase in nitrogen applications and the increased
spraying for aphids, since both have reasonable benefit:costs ratio with only a small change in yield (1-2%).
 By contrast the development of new application/delivery methods may take longer to be realised as it requires a high level of
initial investment to be made within the industry and there will be a time lag between development and equipment production.
The cost of purchase of the new equipment has also not been costed.
Grass

Modern dairy systems are very flexible, and are likely to adapt readily to the new opportunities provided by climate change. The
main effects of climate change on grass growth and dairying will be positive because of increases in grass yields. The challenge
lies in utilising the grass efficiently, but there are many techniques, which are already used in dairy systems to promote
utilisation. These include buffer grazing, extended grazing, zero grazing, storage feeding etc and they are likely to be readily
adopted by farmers.
 The reduction N input through an increase in legume use is likely to be readily adopted as it assists with compliance of existing N
reduction policies.
 Drainage and irrigation also seem less likely adaptations on the grounds of capital cost.
 However, for dairying the economic context of the future adaptations is crucial, since the value of the increased grass dry matter
production for dairying depends dramatically on whether economic policies and conditions are conducive to increased milk
production, or whether the adaptation adopted will merely displace land to relatively unprofitable alternative uses.
Tomatoes
 The tomato industry is already under severe competitive pressure from foreign producers. This is forcing a reduction in the size
of the production area, but an increase in yields to maintain volume. Some of the most cost effective adaptations (e.g. shade
screens) require significant investment in new equipment or greenhouse housing. The yield penalty of this adaptation is high
(15%) and the level climate change will be only slowly realised. Hence this adaptation is unlikely to be widely adopted. But
producers need to be aware of the potential need when considering upgrading of existing greenhouse stock.
 By contrast, reduction of heating costs will be rapidly adopted, since it requires no additional costs and may be automatically
achieved as required. However the reduced need for winter heating may affect the benefit:cost of investing in Combined heat and
power (CHP) or other waste heat supplies. Similarly faster picking rates may be rapidly adopted since it is justified by a
relatively small saving in yield.
Pigs

There is greater difficulty in estimating the impacts of climate change on pigs than for crops because of the scarcity of data on the
impact of the environment on animal performance under the conditions of commercial livestock management. The two subsectors of pigs out of doors and indoors are very different in terms of the impacts and the adaptations that are appropriate.
Though the adaptations suggested are relatively low technology options they still involve some considerable capital investment.
Farmers may need convincing of the need for such investment, since the direct impact of climate change on pig production is not
always clear.
Overall commodities, grower based adaptations dominate those identified as critical to countering climate change impacts. The most
effective adaptations involve actions that can be taken by the farmer without assistance from the industry. But where no new
investment or know-how is needed, growers will take advantage of an adaptation only if they are aware of the likely persistence of the
warmer conditions year on year. To this end information on the level of climate change impacts, their persistence (for mean changes)
or return frequency for extreme events is needed.
Information on climate change impacts and potential adaptations also need to be readily available within the industry. Government
knowledge transfer projects should help with this process, but it is important also to involve the industry as well as the growers, since
some changes may also require assistance/adaptation within other parts of the industry. For example the loss of early potato
production will affect buyer’s sourcing of the product. Changes in the distribution of the crop will also change transport costs for the
processing side of the industry.
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Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
23
MAFF
project code
CC0357
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
References
ADAS (1977), Economics of Irrigation, Report of ADAS Working Party, ADAS
ADAS (1995) Gross Margin Budgets 1995 : Vegetable Crops, ADAS, Oxford, Unpublished.
ADAS (2001). A review of the impact of the wet autumn of 2000 on the main agricultural and horticultural enterprises in England and
Wales. Shepherd, MA (ed), Final report to Department of Environment, Food and Rural Affairs for Project CC0372, ADAS. 151pp.
Ahmadi A, Baker DA. 2001. The effect of water stress on grain filling processes in wheat. Journal of Agricultural Science,
Cambridge, 136, 257-269.
Bailey, R (1980). Irrigation of Potatoes. In: Management of irrigation, ADAS: 62-87.
Batts GR, Ellis RH, Morison JIL, Nkema PN, Gregory PJ, Hadley P. 1998. Yield and partitioning in crops of contrasting cultivars of
winter wheat in response to CO2 and temperature in field studies using temperature gradient tunnels. Journal of Agricultural Science,
Cambridge, 130, 17-27.
Booij, R. (1987). Environmental factors in curd initiation and curd growth of cauliflowers in the field. Netherlands Journal of
Agricultural Science, 35, 435 – 445.
Brooks RJ Semenov MA. 2000. Modelling climate change impacts on wheat in central England. pp157-177 in Downing TE,
Harrison PA, Butterfield RE, Lonsdale KG eds, Climate change, climatic variability and agriculture in Europe. Research Report no
21, Environmental Change Institute, University of Oxford.
Brown RA, Rosenberg NJ. 1999. Climate change impacts on the potential productivity of corn and winter wheat in the primary
United States growing regions. Climate Change, 41, 73-107.
Butterfield RE, Harrison, PA, Orr JL, Gawith MJ, Lonsdale KG. 2000. Modelling climate change impacts on wheat, potato and
grapevine in Great Britain. pp265-287 in Downing TE, Harrison PA, Butterfield RE and Lonsdale KG eds, Climate change, climatic
variability and agriculture in Europe. Research Report no 21, Environmental Change Institute, University of Oxford.
Calderini DF, Abeledo LG, Savin R, Slafer GA. 1999. Final grain weight in wheat as affected by short periods of high temperature
during pre- and post-anthesis under field conditions. Australian Journal of Plant Physiology, 26, 453-8.
Cavan G, Cussans J, Moss SR. 2000. Modelling different cultivation and herbicide strategies for their effect on herbicide resistance
in Alopercurus myosuroides. Weed Research 40, 561-8.
Chauvel B, Guillemin JP, Colbach N, Gasquez J. 2001. Evaluation of cropping systems for management of herbicide-resistant
populations of blackgrass (Alopercurus myosuroides Huds). Crop protection 20, 127-137.
Christ RA, Korner, C. 1995. Responses of shoot and root gas exchange, leaf blade expansion and biomass production to pulses of
elevated CO2 in hydroponic wheat. Journal of Experimental Botany, 46, 1661-1667.
Davies, A, Shzao, J, Jenkins, T, Carson, I, Pike, A, Pollock, CJ and Parry, ML (1997). Mapping the geographic and economic
response of agricultural systems in England and Wales to climate change. Report on contract No CSAA2524, MAFF, London.
Delecolle R, Ruget F, Ripoche D, Gosse G. 1995. Possible effects of climate change on wheat and maize crops in France. pp 241257 in Climate change and agricultural analysis of potential impacts. ASA special publication no. 59, American Society of
Agronomy, Madison, Wisconsin, USA.
Ewert F and Pleijel H. 1999. Phenological development, leaf emergence, tillering and leaf area index, and duration of spring wheat
across Europe in response to CO2 and ozone. European Journal of Agronomy 10 171-184.
Fangmeier A, De Temmerman L, Mortensen L, Kemp K, Burke J, Mitchell R, van Oijen M, Wiegel H-J. 1999. Effects on nutrients
and on grain quality in spring wheat crops grown under elevated CO 2 concentrations and stress conditions in the European multiplesite experiment ‘ESPACE-wheat’. European Journal of Agronomy, 10, 215-229.
Ferris R, Wheeler TR, Ellis RH, Hadley P, Wollenweber B, Porter JR, Karacostas TS, Papadopoulos MN, Schellberg J. 2000. Effects
of high temperature extremes on wheat. pp31-55 in Downing TE, Harrison PA, Butterfield RE and Lonsdale KG eds, Climate
change, climatic variability and agriculture in Europe. Research Report no 21, Environmental Change Institute, University of Oxford.
Foulkes , Scott RK. 1998. Varietal Responses to Drought Part 1 in Project report 174, Exploitation of Varieties for UK cereal
production, Volume 2. Home-Grown Cereals Authority, London.
Hakala K. 1998. Growth and yield potential of spring wheat in a simulated changed climate with increased CO2 and higher
temperature. European Journal of Agronomy, 9, 41-52
Hakala K, Helio R, Tuhkanen E, Kaukoranta T. 1999. Photosynthesis and Rubisco kinetics in spring wheat and meadow fescue under
conditions of simulated climate change with elevated CO2 and increased temperatures. Agricultural and Food Science in Finland. 8,
441-457
Harrison, PA, Butterfield RE, Orr JL. 2000. Modelling climate change impacts on wheat, potato and grapevine in Europe. pp367390 in Downing TE, Harrison PA, Butterfield RE and Lonsdale KG eds, Climate change, climatic variability and agriculture in
Europe. Research Report no 21, Environmental Change Institute, University of Oxford.
Holman, I and Loveland, P (2001). Regional climate change impact and response studies in East Anglia and North West England
(RegIS). cc0337, Final report to MAFF, Soil survey and Land Research Centre, Cranfield.
Hossell, JE (1994). The implications of global climate change for biodiversity. Sandy, Bedfordshire, RSPB.
Hossell, JE, Ramsden, SJ, Gibbons, J, Harris, D, Pooley, J and Clarke, J (2001). Timescale of farmlevel adaptations and responses to
climate change. ADAS Final report to MAFF for project cc0333.
Hulme, M and Jenkins, G (1998). Climate change scenarios for the United Kingdom. Technical Report No 1, Scientific Report, UK
Climate Impacts Programme, Norwich. 60.
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Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Li AG, Hou YS, Wall GW, Trent A, Kimball BA, Pinter PJ. (2000) Free-air CO2 enrichment and drought stress effects on grain filling
rate and duration in spring wheat. Crop Science 40, 1263-70.
Mayes, JC (1998). "United Kingdom summer weather over 50 years - continuity or change?" Weather 53: 2-11.
Ministry of Agriculture Fisheries and Food (MAFF) (2000). Climate change and agriculture in the United Kingdom. MAFF, London.
65.
Mitchell RAC, Mitchell VJ, Driscoll SP, Franklin J, Lawlor DW. 1993. Effects of increased CO 2 Concentration and temperature on
growth and yield of winter wheat at two levels of nitrogen application. Plant cell and Environment 16, 521-9.
Moss SR, Clarke J. 1994. Guidelines for the prevention and control of herbicide resistant blackgrass (Alopercurus myosuroides).
Crop protection 13, 230-4.
Nix, J (2002). Farm management pocketbook: 32nd Edition. University of London, Wye College.
Parry, ML (1990). Climate change and world agriculture. London, Earthscan.
Parsons, DJ, Armstrong, AC, Turnpenny, JR, Matthews, AM, Cooper, K and Clark, JA (2001). "Integrated models of livestock
systems for climate change studies. 1. Grazing systems." Global Change Biology 7: 93-112.
Pettitt TR, Parry DW Polley RW. 1996. Effect of temperature on the incidence of nodal foot rot symptoms in winter wheat crops in
England and Wales caused by Fusarium culmorum and Microdochium nivale. Agricultural and Forest Meteorology 79, 233-42
Plowman AB, Richards AJ, Termayne MA. 1999. Environmental effects on the fitness of triazine-resistant and triazine-susceptible
Brassica rapa and Chenopodium album in the absence of herbicide. New Phytologist 141, 471-485.
Oakely, J. et al (2002)
Riedo, M, Gyalistras, D, Grub, A, Rosset, M and Fuhrer, J (1997). "Modelling grassland responses to climate change and elevated
CO2." Acta Oecologica-International Journal of Ecology 18(3): 305-311.
Rogers GS, Milham PJ, Gillings M, Conroy JP. 1996. Sink strength may be the key to growth and nitrogen responses in N-deficient
Wheat at elevated CO2. Australian Journal of Plant Physiology 23 253-64
Scott RK, Sylvester-Bradley R 1998. Crop physiology, assessment and management. pp 2.1-2.14 in Management through
understanding: Research into practice. Proceedings of the sixth HGCA R&D conference on cereals and oilseeds. Home-Grown
Cereals Authority, London.
Slafer GA and Rawson HM. 1994. Sensitivity of wheat phasic development to major environmental factors: A re-examination of
some assumptions made by physiologists and modellers. Australian Journal of Plant Physiology, 21 393-426.
Storkey J, Cussans J W. 2000. Relationship between temperature and the early growth of Triticum aestivum and three weed species.
Weed Science 48, 467-473.
Thornley, JHM and Cannell, MGR (1997). "Temperate grassland responses to climate change: an analysis using the Hurley pasture
model." Annals of Botany 80(2): 205-221.
Topp, CFE and Doyle, CJ (1996). "Simulating the impact of global warming on milk and forage production in Scotland .1. The effects
on dry-matter yield of grass and grass white clover swards." Agricultural Systems 52(2-3): 213-242.
Turnpenny, J.R., Parsons, DJ, Armstrong, AC, Clark, JA, Cooper, K, Matthews, AM (2000) Integrated models of livestock systems
for climate change studies. 2 Intensive systems, Global Change Biology, 7, p 163-170
van Oijen M, Eweert F. 1999. The effects of climatic variation in Europe on the yield response of spring wheat cv Minaret to elevated
CO2 and O3: an analysis of open topped chamber experiments by means of two crop growth simulation models. European Journal of
Agronomy 10, 249-264.
Wass, S and Barrie, I (1984). "Application of a model for calculating glasshouse enefgy requirements." Energy in Agriculture 3: 99108.
Wassenaar T, Lagacherie, P. Legros, J-P and Rounsevell, MDA,.1999. Modelling wheat yield responses to soil and climate
variability at the regional scale. Climate Research 11, 209-220.
Weir AH. 1988. Estimating losses in the yield of winter wheat as a result of drought, in England and Wales. Soil use and
management 4, 33-40.
Williams,JR, Chambers, B, Smith,K & Ellis,S (1999)
Wolf J, Semenov MA, Eckerstern H, Evans LG, Iglesias, Porter JR. 1995. Modelling the effects of climate change and climatic
variability on crops at the site scale: Effects on winter wheat; A comparison of five models pp 231-280 in Climate change and
agriculture, Assessment of impacts and adaptations, eds. Harrison PA, Butterfield, RE and Downing TE. Research Report 9,
Environmental Change Unit, University of Oxford.
Worland AJ Appendino ML Sayers EJ. 1994. The distribution in European winter wheats of genes that influence ecoclimatic
adaptability whilst determining photoperiodic insensitivity and plant height. Euphytica 80 219-228.
Worland AJ. 1996. The influence of flowering time genes on environmental adaptability in European wheats. Euphytica 89 49-57.
Wurr, D.C.E., Fellows, J.R. and Hambridge, A.J. (1995) The potential impact of global warming on summer/autumn cauliflower
growth in the UK. Agriculture and Forest Meteorology, 72, , 181-193
Wurr, D.C.E., & Fellows, J.R. (2000) Temperature influences on the plant development of different maturity types of cauliflower.
Acta Horticulturae , 539 , 69-74.
25
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Appendix 1 – Climate change Impacts
Impacts on Wheat
Changing yields
The principal impacts of climate change on wheat are through the photoperiodic and temperature related controls that adapt varieties
to a wide range of climatic conditions (Slafer and Rawson 1994). In UK conditions these controls suppress reproductive growth in
winter when frost would damage the developing ear, and they optimise the flowering time of crops sown on various dates. The
majority of crop growth occurs once visible reproductive development has been triggered and the duration of each subsequent
developmental stage is inversely proportional to temperature. A consequence of this is that as temperatures rise under climate change
each growth phase will become shorter and thus less solar radiation will be received leading to reduced growth (Mitchell et al., 1993).
Thus, if current varieties are used it is expected that generally both growth and yield will be reduced.
In an experimental study, yield losses between 0 and 1.6 t ha-1 per degree Celsius rise in temperature for varieties of winter wheat
grown in polytunnels have been reported (Batts et al., 1998). These values encompass those given in another experimental study in
spring wheat using a single variety of 0.4 t ha-1 per degree Celsius rise in temperature (Hakala, 1998). Some modelling studies also
have values in similar ranges ( 0.4 t ha-1 per degree Celsius, Wolf et al., 1995; and either 0.47 or 0.33 t ha -1 per degree Celsius
depending on the model used, van Oijen and Ewert 1999). Greater losses are also possible as grain filling is inhibited by temperatures
above 25 C during the pre and post anthesis phases (Calderini et al., 1999). At temperatures above 30 C near anthesis severe losses of
1% of yield for every hour above 30 C have also been reported (Ferris et al., 2000), but this is unlikely to affect a significant
proportion of the UK crop, or to occur regularly by 2050.
There are no direct effects of CO2 on development that would compensate for the shorter duration of phases at increased temperature.
(Ewert and Pleijel, 1999). However, some compensation is likely thorough higher crop photosynthesis (Hakala et al., 1999), although
this may be offset by higher night temperatures leading to increased respiratory losses (Delecolle et al., 1995) and the increased
respiration levels associated with higher CO2 (Christ and Korner, 1995). It may be possible that increasing CO 2 will be able to offset
decreases in yield but the exact relation depends on the relation between the increases in CO2 and temperature (Brooks and Semenov,
2000). There may also be regional differences in these responses, with the highest increases in yield in south-western and the lowest
increases in the north-eastern regions of the UK (Butterfield et al., 2000). Similar responses will occur over Europe with the greatest
increases in yields in southern Europe (Harrison et al., 2000).
Increases in growth are also likely as a result of higher leaf area index early in the season (Ewert and Pleijel, 1999) resulting from the
increased tiller production at higher CO2 (Christ and Korner, 1995). Also if summer rainfall is significantly reduced then there will be
an increased risk of truncation of grain filling by drought. This effect can be quantified from the relation between loss of yield in non
irrigated crops, compared with fully irrigated crops and the amount of water applied to avoid soil drying on a soil of low water
holding capacity (Foulkes and Scott, 1998), as a yield loss of 1 t ha-1 for every 40 mm of rainfall lost.
A strong relation between soil water holding capacity and yield of wheat under climate change in areas subject to summer droughts
has been demonstrated in a modelling study (Wassenaar et al., 1999). The majority of these effects are through reduced
photosynthesis (Li et al., 2000) but direct inhibition of grain filling by water stress has recently been demonstrated (Ahamadi and
Baker, 2001). It is also well established that much of the UK wheat production area is on soil types can potentially suffer from yield
reducing droughts under present climatic conditions (Weir, 1988). However, when the variability of the UK climate is taken into
account in estimates of the range of water limited yield under climate change studies suggest no change under current CO2 levels and
increases in yields under higher CO2 levels (Harrison et al., 2000).
At the higher CO2 expected with climate change there is a general expectation of reduced nitrogen uptake by the vegetative organs by
about 3.5% per 100 ppm change from the nitrogen concentration at 350 ppm (Rogers et al., 1996, Fangmeier et al., 1999). This may
lead to a smaller supply of nitrogen that can be remobilised to the developing grain, resulting in reduced grain protein concentration,
with the consequent reduction in breadmaking quality (Fangmeier et al., 1999). Overcoming this would require selection for varieties
with a higher nitrogen uptake, with the particular aim of increasing the amount of nitrogen taken up and transferred directly to stem
storage.
However, studies on spring wheat have shown significant interactions with temperature, which suggest that temperature effects in the
opposite direction may be larger (Hakala, 1998).
Since winter rainfall is expected to increase, a move to earlier sowings with the consequences of increasing requirements for disease
and weed control is likely with perhaps an extra requirement for autumn or overwinter spraying. The shorter window available for
sowing may also have consequences for the amount of labour and machinery required (Hossell, et al., 2001). Because of increasing
winter rainfall the risk of loss of nitrogen by leaching is higher, and thus fertiliser strategies should aim for minimum overwinter
levels.
Weed Control
As winter temperatures rise the balance between weed and crop growth is likely to change as they have different critical temperatures
for the start of growth (Storkey and Cussans, 2000). Detailed work is required to assess the magnitude of this effect and also to
explore if any of the weeds occurring in warmer regions are likely to become a greater threat under the warmer conditions expected.
There is also the possibility of an interaction of increased temperature with the rates of evolution of characters such as herbicide
resistance (Plowman et al., 1999). This possibility has been shown for a number of weed species (MAFF, 2000) thus under climate
change increasing emphasis may be required on strategies that reduce the development of herbicide resistance (Cavan et al., 2000,
Chauvel et al., 2001, Moss and Clarke, 1994)
26
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Pest and Disease Control
The warmer wetter winters are likely to lead to earlier outbreaks of pests and diseases, incidence of many of which are proportional to
temperature (e.g. nodal foot rot, Pettitt et al., 1999) and to result in changes in the spectrum of problems. A potential adaptation to
this would be to test pest and disease resistance of new varieties in more southerly regions where the spectrum of problems will be to
be similar to those expected under climate change.
Increase spraying
Figure 1.1: The number of generations of aphids between baseline and 2050s for the High and Low UKCIP98 scenarios.
The predicted climate changes are expected to encourage aphids. Where wheat has emerged by the end of September in the southern
and western counties there may be as many as 8 generation by the end of March. The severity of the infection depends on when the
crop is planted and the weather conditions, late planting and heavy frosts help to reduce the number of aphids.
The calculation used in Figure 1 assumes 176 days above a daily temperature of 3°C is needed for an aphid to reach reproductive
maturity reproduction (Williams 1987, Williams & Wratten 1987, Oakley 2000). An initial emergence date of 21st September is
assumed as this coincides with the average first occurrence of aphids on winter wheat crops.
Other factors
In understanding the impact of climate change on wheat an important consideration is the effects on other producing regions since this
will significantly affect world prices. It has been suggested that it may significantly reduce production in the USA (Brown and
Rosenberg, 1999) and Mediterranean regions of France (Delecolle et al., 1995) whilst having smaller effects in central France, and
increases in production in southern Europe (Harrison et al., 2000).
In view of all of these factors it becomes difficult to predict the exact effects of climate change on growth and yield of wheat. Thus it
is not surprising that in direct experimentation, where climate change conditions have been mimicked, contrasting results between
varieties have been seen (Batts et al., 1998). This is an important result because it strongly suggests that the development and
selection of appropriate varieties will be an important mechanism in coping with the impacts of climate change. Most simulations of
crop response assume a change in variety will be allowed, in this project the implications of that assumption are examined through
costing the required changes to existing crop breeding in order to cope with changed climate conditions.
Impacts on Potatoes
Changes in timing of production
Early crops differ from maincrop potatoes as their maturation is controlled by thermal time and consequently have a finite life, while
maincrops would keep growing if they were not controlled by frost. Early potatoes are grown in the South and Western parts of
Britain, predominantly Cornwall and South Wales. These areas benefit from an early growing season, which allow early planting and
harvesting avoiding frosts.
The impacts of climate change on potato are principally a consequence of the increased temperature on growth and development of
the crop. After planting emergence is proportional to temperature, depth of planting and the degree of sprouting (Allen and Scott,
2001). Subsequent canopy production is usually proportional to temperature in the absence of water deficits. Once canopy production
is complete the gain in tuber dry weight (and thus fresh weight, the economic product) is proportional to the amount of solar radiation
27
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
intercepted with a strong possibility of reductions in yield from potentials if water deficits develop. Potato yields for both early and
maincrops are at their optimum at or just below current temperatures with losses of 4 t ha-1 fresh weight per degree Celsius rise in
temperature above this (if a dry matter content of 25% is assumed) for both irrigated and unirrigated crops (Wolf, 2000a). It is not
expected that there will be major increases in growth of potato caused by increasing CO 2, but current evidence is conflicting
(Rosenzweig et al., 1996). It has been suggested in a modelling study that increasing CO 2 will result in an increase in yield of 1 t ha-1
fresh weight for every 22 ppm increase in CO2 (Wolf, 2000a)
Thus in the determinate early crop the higher temperatures under climate change will allow earlier leaf growth, but the growth cycle
will be completed earlier ending in earlier senescence. Because at the time of year early potatoes are sown (typically before 1 March)
solar radiation is rising rapidly (see diagram below) the earlier leaf growth and senescence will result in less solar radiation
interception and lower yields, a result that has been confirmed experimentally by growing the same varieties in different climatic
zones (Kooman et al., 1996). Generally the timing of production will be earlier because of the higher temperatures and the area of the
country suitable for early potato production is likely to rise (Davies et al., 1997). Taken together these factors may result in
significant changes in the availability and price of this crop.
In the maincrop the principal changes will be an increased length of the growing season, which will tend to increase yields. However,
in models where a the crop has a given duration in thermal time a shortening of the growing season reduces yields, with greater
reductions in hotter climate change scenarios (Butterfield et al., 2000). Thus an important assessment of suitability of potato under
climate change would be to see if current maincrop varieties are truly indeterminate or only appear so. In current conditions it has
been shown that a important cause of variability of potato yields is delays in canopy production caused by premature sowing of
maincrop varieties when temperatures are too low (Allen and Scott, 2001). This should be considerably reduced under the warmer
spring conditions expected under climate change. Similar conclusions on the advantages of early planting under climate change have
been reached from modelling studies (Wolf, 2000a). A less favourable change may be the increasing growth restriction due to
drought when unirrigated leading to an increasing irrigation needs and costs. A modelling study has indicated that yields at Oxford
are not likely to change greatly under climate change but the conclusions are sensitive to the exact model used (Wolf, 2000b). Also
the warmer conditions may lead to an increased storage costs.
Pests and Disease
The general impacts of climate change on pests and diseases of potato will be analogous to those for wheat. Particularly for potato it
has been estimated that the risk of infestations of Colorado beetle and leaf mining flies will increase (Baker et al 1996).
Impacts on Cauliflowers
Impacts on quality and timing of harvest
The UK cauliflower crop is divided into three main types (see Table 1), each with its own range of varieties bred for conditions
prevalent during the cropping period. Most growers produce a continuity of crops that allow them to supply the market throughout
the season, with plantings being carried out to a regular programme through the season. A large producer will plant cauliflower every
week from mid March through to mid July, weather permitting.
It is because of the need for seasonal production levels to match demand that factors influencing the rate of development and quality
of the crop can be just as important as the actual yield produced. Whilst there is also a processing market which is less demanding in
terms of quality, the industry primarily aims at the fresh market which requires undamaged curds of a uniform size, shape and colour.
On average, only 65 - 70% of the plants set produce marketable curds. Of the remainder, many may be of the required quality, but,
because of variation in growth within the crop, will be uneconomic to cut (too early or too late). Others will be too large or too small,
or will have suffered pest or disease damage or other factors influencing the shape, structure or colour of the curd.
Other than pest and disease, all of these faults are likely to be caused by lack of uniformity of growing conditions (soil conditions,
nutrients, water or climate). However, the climate during production is the single most influential factor in the success of a crop.
Early summer, late autumn and winter crops are particularly sensitive to extremes of temperature, both high and low, and excess or
insufficient rainfall (Booij, 1987; Wurr & Fellows, 2000). It is not unusual for some of these crops to have no curds harvested due to
extreme conditions. Conversely, during the summer months, when conditions may be far more uniform, cuts of over 90% can be
achieved, although cuts can also be severely reduced during periods of extreme summer weather. In order to appreciate the potential
influence of climate extremes on cauliflower growth it is necessary to understand how these might disrupt the normal growth cycle of
the plant.
Planting period
Optimal 1
vernalisation
temperatures (ºC)
Cropping period
Main UK
production areas
Characteristics
Early summer types
February-March
9-13
(2-24)
May-June
10
(9-21)
June-December
Lincolnshire,
Lancashire, West
Midlands
Rapid maturing,
small headed, few
leaves
As above, plus East
Scotland
Take 60-120 days to
mature
Summer-autumn types
March-July
28
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
Planting period
Optimal 1
vernalisation
temperatures (ºC)
Cropping period
Main UK
production areas
November-March
Cornwall, East
Kent, South Wales
MAFF
project code
CC0357
Characteristics
Winter types
(a) True winter types
June-August
13-14
(5-23)
Mature in 14-28
weeks
(b) Winter-hardy types
August
March-May
Lincolnshire,
Lancashire
1Range
(min-max) in parentheses
Table 1.1 Main features of cauliflower production in the UK
Modelling has been used to predict the effect of rises in mean temperature ranging from 0.3ºC to 3.0ºC
(Wurr et al., 1995). Increases in average temperature have different effects on the 3 phases of growth,
with duration of phases 1 and 3 being reduced while phase 2, vernalisation, increases. For early
emerging crops (1 and 15 February and 1March) the duration of all three phases of growth were either
reduced or remained unchanged by all increases in average temperature. For phases 1 and 3 this would
be expected since growth in both periods is directly linked to temperature. The reduction in the
vernalisation phase was due to the increased temperatures being closer to the optimum figures for
vernalisation to occur. The greatest impact of the temperature increases was on phase 1, juvenility.
The overall effect of increased temperatures on these crops was to reduce the cropping period by up to
20 days.
For all crops emerging after 1 March, increased temperatures continued to reduce the duration of
phases 1 and 3 but increased the duration of the vernalisation phase. The increased length of phase 2
was most marked at higher temperatures, as would be expected, with the change being sufficient to
nullify the reductions in phase 1 and 3 for crops emerging after 10 May at the 3.0ºc increase, producing
an increased overall cropping period. The effect on vernalisation at lower temperatures was less
marked and was generally cancelled out by reductions in duration of phases 1 and 3.
These results suggest that, with experience of current varieties, cropping programmes should be able to
be amended to allow for changes to crop duration caused by temperature increases. However, this
work also showed that while the variability in crop growth during curd development (phase 3) was
reduced at increased temperatures, that during vernalisation (phase 2) was increased, resulting in a less
uniform crop and consequent harvesting problems. Should any future increases in temperature also be
of a variable nature rather than across the board, this is also likely to have a further effect on crop
uniformity. Periods of extreme high temperatures will also have a further negative effect on crop
uniformity and programming since vernalisation does not occur at all at average temperatures above
about 23ºC.
Impacts on Tomatoes
Changing yields
There have been few studies of the impact of climate change on tomato production, but conclusions may be drawn about the effects of
changing temperature and light levels on the yield and production of the crop.
High temperature reduces set because of its effect on pollen tube formation. Above 32 degrees centigrade pollen may be sterile or
pollen tube growth impaired. Fruit may be smaller or absent as a result. This leads to crop yield losses in the range of 10 –50%, but
typically 20% (UK Tomato Manual, 1973). Above 30°C there is also a reduction in the size and vigour of tomato leaves. This
produces a reduction in yield of 10-20% (UK Tomato Manual, 1973). Higher temperatures also mean tomatoes need to be handled
faster into the cold chain.
However, increases in CO2 levels increase yields of tomatoes and this is already widely used in the industry. Increases in daytime
CO2 to 800 parts per million by volume (ppm) may give a yield increase of 15-20% on current yields (Hand, 1984). Between 350
ppm and 800 ppm there is a linear increase in yield with CO2 increase. Higher levels of CO2 in the atmosphere will reduce the need
for CO2 enrichment. But increased night time CO2 levels may cause stomata to close and delay development (UK Tomato Manual,
1973).
Higher winter temperatures will reduce the heat needed in winter to maintain the glasshouses at the required temperature regime. No
new investment or know how is needed and growers will take advantage of this impact without a need for any new knowledge.
Heating costs of long season tomatoes are about £52,000 per ha. per year so there is scope for considerable savings. A 14-18%
reduction in heating costs has been calculated using the UKCIP98 2050 High Scenario (Figure 1.2.
Reduced winter solar radiation in the period December to March reduces the yield of long season tomato crops. A one percent
reduction in radiation will lead to the same reduction in yield (UK Tomato Manual, 1973). By contrast sunnier summer conditions
will speed up rates of ripening, which will mean picking rates will need to increase to avoid spoilage.
29
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Pests and Diseases
It is likely that warmer winters may also favour the arrival and survival of glasshouse pests from abroad (Drakes, pers comm), but
further research is needed to determine the potential impacts of such arrivals and the adaptations to them.
Figure 1.2: Reduction in heating need for greenhouse tomatoes by 2050 as compared to the 1961-90 baseline. Calculations are based
on Wass and Barrie, 1984.
Figure 1.3: Mean monthly difference in radiation levels (W/m2) between the UKCIP98 baseline and the 2050 High scenario.
30
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Impacts on Grass production
There have been few studies on the impact of climate change on livestock systems (e.g Parsons et al. 2001), but assessments have
been made of the impact in grass yields. Armstrong (1996) showed that increases in temperature were more important than increases
in rainfall in increasing the yield of grass. Total annual grass production may increase as a result of the higher temperatures, higher
early and late season rainfall and the increased carbon dioxide concentration in the atmosphere (MAFF, 2000; Davies et al. 1997,).
However, changes can be very site specific (Thornley and Cannell 1997, Riedo et al., 1997). Mid summer production may fall due to
drought restricting grass growth in drier areas of England (Hossell et al., 2001). No major change in grass species used in agriculture
from the current perennial ryegrass, Italian ryegrass and white clover is envisaged for England and Wales as a result of climate
change, but changes in species mix may be introduced as white clover benefits greatly from higher atmospheric CO 2 (Topp and Doyle
1996).
However, the impact of climate change on grass production systems needs to extend beyond the effects on the crop itself
(MAFF,2000). Although grass yields may increase, the length of the grazing season may be constrained substantially by an increase
in rainfall, as waterlogged conditions in the early part of the year restrict the accessibility of the land for grazing. The predicted
increase in grass growth due to climate change is likely to be greatest at times when efficient utilisation may prove difficult to
achieve.
Disease and nutrient leaching impacts were not considered to be critical (Davis, pers comm) and thus adaptations to these effects have
not been costed. There is some evidence that increased CO2 may affect the protein content of some grass sward species, but this
needs further work before the implications and possible adaptations can be costed.
Pigs
There has been little or no consideration of the impacts of climate change on pig production. Discussions with ADAS pig consultants
has indicated that the main implications of climate change are the effects of rainfall on quantities of slurry in indoor systems and on
the welfare and management of outdoor pigs. Temperature may be expected to affect food consumption and fertility in both systems.
These impacts will require adaptations to housing, breeding practices and labour requirements but the levels of the change have not
been fully quantified.
Labour requirements in indoor systems
There are more developments with multi-site production now, where different stages of production are carried out on separate sites
e.g. breeding on one site, nursery pigs on another, and finishing pigs on another different site, all based on all-in/all-out production.
This would certainly have implications for the amounts of slurry produced on each site, and therefore the labour requirement in
dealing with it. For example, nursery production sites involving typically dry -fed pigs from 7 to 18 kg would produce significantly
less slurry than specialist finishing sites where pigs might all be wet-fed.
Implications for labour might include:
a) More time spent emptying slurry tanks from buildings which are slatted but completely or partly exposed e.g. weaner kennels,
kennel verandas, finishing accommodation with outside slatted runs, strawed outside yards with dirty water drainage into below
ground tanks, dirty outside yard areas
b) More time emptying below ground tanks and transferring to lagoons or central above-ground slurry/dirty water tank
c) More time emptying lagoons or above-ground tank and carting slurry to suitable ground nearby
d) Potentially further distances to cart slurry to, once nearby ground is unsuitable/saturated already i.e. longer round trips, therefore
more time spent away from the farm
e) Additional labour demand to keep up with slurry carting in wet weather may mean taking away skilled staff from actually
managing the pigs, potentially lowering production efficiency/output
Slurry disposal in indoor systems
It has been estimated that annually 10.4m tonnes of pig manure, as 5m tonnes solid muck, 5.4m tonnes slurry, are handled annually in
the UK (J R Williams, B Chambers, K Smith, S Ellis, 1999). Just taking slurry alone, some 5m tonnes of the slurry fraction is water.
In periods of unusually high Autumn/Winter rainfall, it is apparent many farm slurry handling systems just cannot cope with the extra
volumes. Significant changes to farm storage/handling systems would need to be made if pollution was to be prevented under wetter
conditions of climate change.
The key problems are insufficient storage capacity, and land area available of suitable land in close proximity within suitable crop
rotations on which to spread slurry e.g. can’t spread neat slurry on some growing crops without risk of crop scorch. There is also a
risk of run-off from overflowing stores into water courses and of slurry levels rising above slats, giving health and safety risks to pigs
and staff. In addition, lagoon sides may give way or seep through degraded sides into nearby watercourses.
Impacts of increased temperature in housed systems
Consistently higher temperatures during the year with existing buildings/equipment would lead to higher ventilation rates (maximum
and minimum) throughout all housing systems but also a lower need for heat input, particularly in flat deck weaner accommodation,
but also for creep heating systems in farrowing houses. There is also a risk of lower appetite/lower feed intakes in naturally ventilated
buildings where there was insufficient capacity to increase ventilation rate and a increased risk of dirty pens where either ventilation
rate is insufficient or where higher ventilation create uncontrolled air patterns i.e. draughts.
Costs of electricity usage in fan controlled ventilation systems would be expected to rise. There is considerable year on year
variability in electricity costs for indoor production units, which could be exaggerated by other variables, such as switches in the type
of production e.g. home-mixing feed uses more electric than buying in compound feeds. The sample could also be skewed with
higher numbers of outdoor units, in successive years, where electric costs are minimal. Individual farm survey/records would be
31
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
needed to more accurately establish typical electric costs for given situations. Again, individual farm data would be needed to
establish what proportion of electric is used for heating purposes and what is used for ventilation.
In response to these impacts the following adaptations would be likely to be made to pig housing:
 Buildings insulated to higher standard
 Use of sprays/showers for more effective cooling than using air cooling via higher ventilation rate
 More accurate linkage of heating/ventilation system to optimise efficiency of energy use/prevent system “hunting” i.e. fans
chasing higher temperatures created by heating system
 Temperature control of critical areas which might not have been temperature-controlled before e.g. service areas
Impact on breeding rates in outdoor systems
Heat stress can have a significant effect on boar libido. These impacts include reduced semen viability in hot weather (directly as hot
sun on scrotal sac, or indirectly through higher body temperature as a consequence of heat stress), reduced inclination to serve sows
(loss in libido). Sow fertility may also be affected with higher embryo loss, and a drop in farrowing rates. These effects are
aggravated if the stock is overweight at the end of spring. This is normally shown by fewer farrowings in late November, December
and occasionally beyond this time into January, if for example there has been unusually warm autumn weather. Sows with sunburnt
skin may also not stand for boars. Sunburn also causes inflammation resulting in the production of prostaglandins, which in turn can
cause abortions. High temperatures also reduce appetite, further increasing abortion rates or reducing milk output.
The sows also leave the arc in hot weather to drink more and seek shade/wallows give fewer suckling opportunities for the newly
born, left behind in the farrowing arcs. Piglets are therefore weaned at lighter weights. This has been shown to be a severe
disadvantage to the piglets immune system, making the piglet more prone to effects of PMWS (Wasting disease) also leading to
reduced growth rate throughout the growing/finishing phase. MLC Stotfold research has suggested that an improvement of 0.1 kg
weaning weight is worth a reduction of 1 day in finishing time.
In addition, weaner/grower pigs may have reduced appetites (10% reduction in feed intakes would be considered commonplace,
though there is no national recorded information to back this up, although individual farm records could substantiate it). Lower feed
intakes would directly result in lower growth rates, shown as lighter carcase weight sold.
Anecdotal evidence on the impacts of high temperatures exists for some herds. For example, Range Farm, Rendlesham Estate,
Suffolk, a 580 specialist breeder unit reported in June 1996 that Heat stress reduced farrowing rates by up to 12% and average piglet
weaning weights by 0.9kg. Unfortunately, fewer pig breeding herds are recording with National Recording Systems, such as Signet
Pigplan (formerly MLC). 1990 had a warm autumn conditions that may have reduced the number of litters/sow in the October-March
91 period (MLC, 1991)
Wet autumn and winter conditions also increase piglet mortality. This is caused by cold, wet conditions increasing wind chill and
causing lethargy in piglets to suckle, resulting in eventual death/higher predisposition to disease/attack by predators. There is also a
higher incidence of lameness in both sows and boars, caused by more strain on leg muscles, together with hoof tissue being constantly
soft while constantly immersed in mud. Any abrasions to feet will therefore more likely lead to infection/arthritic conditions.
Damage to boars' legs/feet would lead to fewer boars being available for work. This means uneven boar usage, and therefore resulting
in lower fertility through overuse of boars with reduced semen count. In addition, lame sows not feeding produce less milk to suckle
their young.
However, other factors come into play, besides just seasonal weather effects. Economics also influences production. For example,
during periods of low prices, producers might save costs by not buying in new stock, and continue to produce from their older herd.
As sows get older, they become less productive. Similarly disease can affect fertility. Generally, this factor can produce variable
effects across the country, some herds badly hit with diseases which can affect fertility such as PRRS (Blue Ear Virus), Swine flu,
Leptospirosis. Other herds, sometimes in areas of lower pig density, may not be as greatly affected. Finally, larger pig companies
tend to run larger specialist units with specialist managers that may (sometimes but not always) be more efficient than say a smaller
unit that is based on a multi-enterprise farm.
Several changes could be made to housing/living conditions to reduce the impacts of heat stress. These include insulating farrowing
arcs, increasing the draught and shade provided for sows and over dunning/loafing areas in weaner kennels. Provision of wallows,
regularly replenished and ready for periods of hot weather, suitably large enough for all sows to gain access and sit in would help
reduce overheating. But water pressure may need to be increased to ensure water supply or header tanks used where water pressure
drops during hot weather. Also a reduction in farrowing paddock size would mean sows don’t have to walk as far to water troughs, so
they would not be as far away from the piglets.
Daily work patterns e.g. feeding, moving and serving in cooler parts of the day e.g. early morning, could also be made to counter
effects of heat stress and to suit boars who are less inclined to work in hot weather. A reduction in boar libido could be countered by
a greater use of artificial insemination (AI) to supplement natural service or by switching to undercover service tents/portable
accommodation enabling greater degree of mating supervision, and making it easier for carrying out AI. Changes could be made in
the planning of incoming gilts, for example, increased numbers could be introduced in the spring to compensate for lower sow fertility
during hot weather.
Tented service areas and an increase in AI would also counter breeding problems associated with wetter autumn and winter
conditions. In addition, a reduction in the number of animals per paddock would reduce competition for food.
Impacts of wet conditions on labour in outdoor systems
Typically, wet Autumn/Winter conditions will result in increased demands on labour. These demands would be on additional time
needed for:
32
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code

CC0357
Strawing down farrowing arcs/front of arcs to maintain dry conditions within and around front of the arc. Typical straw usage for
an outdoor unit would be 600kg/sow. This could increase perhaps by up to 40% if prolonged wet winters became the norm
(straw use in the summer months is very much reduced to prevent sows becoming too hot in their arcs and seeking cooler
conditions outside).
 General management tasks such as feeding (travelling conditions much worse therefore the need to feed stock on alternate sides
of the paddock, wherever and whenever possible, to reduce ground poaching.
 Feeding of sows with feed in bags in extreme conditions, when it is not possible to gain access to certain sites with bulk feed
carriers
 Gathering up stock and moving around paddocks
 Moving arcs more frequently from more boggy areas of the field to less boggy areas
 Remedial field work, such as dragging, subsoiling/panbusting to override compaction and assist drainage.
Adaptations to these impacts are likely to involve:
1) More careful selection of sites/fields, more suited to specific purposes e.g. more use of gently sloping free-draining ground for all
stages except farrowing where a level site is necessary for piglets to be protected within the arcs. Last winter, ground which would
normally be considered as ideal for outdoor pig keeping, such as the Breckland soils in East Anglia (Low rainfall area,normally),
became excessively poached following extraordinary high rainfall in a short space of time.
2) Change in paddock layout to more use of long rectangular paddocks than radial paddocks (more prone to poaching in the corner
segments where there is maximum stock movement). Long rectangular paddocks also have the benefit of 2 long sides along which
feeding can be alternated in wet weather to reduce poaching.
3) Alternate trackways to avoid excessive travelling damage in wet weather.
4) Higher stocking areas for sows, therefore higher rental costs per sow on rented land. These are variable but one farm's results
reveal this figure to be between £25 and £30 per sow.
5) Increased use of electric taped gateways and paddock sides, enabling low-ground pressure vehicles to enter paddocks at different
points when strawing down to minimise poaching.
6) Having surplus field space available to move sows across to should paddocks become too boggy. Again, this pushes up the field
area requirement and therefore rental costs.
7) Possibly more reliance on agency staff. As it becomes more difficult to find specialist labour to work in wet, difficult conditions, it
may be necessary to offset unforeseen labour loss due to sickness/flu (often reported by outdoor producers in wet winter weather)with
hired-in agency labour. This again would push up labour costs.
8) A rethink on nose ringing of sows. Some producers, following the wet conditions of last year, decided to reinstate nose ringing to
prevent soil damage, leading to excessively boggy ground conditions after periods of unusually high rainfall, often in a short space of
time. This is a controversial point since many high welfare pig supply contracts require outdoor sows not to be nose ringed.
Appendix 2 – Irrigation Adaptations
The main reference used in analysing the potential of irrigation as an adaptation to Climate Change has been Economics of Irrigation,
Report of ADAS Working Party 1977 (reference ADAS 1977)
The key information in this document has been brought up to date using current figures for costs and returns (Nix 2000).
The key table in the ADAs report is one showing the breakeven yield response compared to the average yield response summarised
from experimental evidence. In the 1977 report the price of applied water varied from £1 per ha mm to £5 per ha mm. In bringing
this table up to date there were a number of changes which became evident comparing the situation in 2001 with that which had
existed 24 years earlier: Grants are no longer available in general for irrigation investment
 Although the 1977 report wrote off fixed investments in sourceworks etc. at 12%, 8% now seems a more realistic cost of capital
at the start of the 21 st century. This is a 33% reduction.
 The areas irrigated have increased from the 12 - 36 ha considered in the 1977 report to 20 - 60 hectares common now.
 The cost of mobile irrigators has changed little in actual terms - £7,500 for a machine to irrigate 36 ha in 1977 to about £10,800
for a machine to irrigate a similar area today.
The result of bringing the calculations up to date is to only change the cost of irrigation from a range of £1 - £5 per ha. mm. to the new
range of £2 - £6 per ha. mm.
Table 3.1: Break-even Relationship Between Crop Response, Water and Product Price (figures in bold are deficits)
Irrigation Cost (£/ha/mm)
Average Yield
Response
2
3
4
5
6
Price (£/t)
(t/ha/mm)
376 0.048
0.072
0.096
0.120
0.144
Grass
0.018
493 0.037
0.055
0.073
0.091
0.110
Potatoes
598
0.030
0.045
0.060
0.075
0.090
70
0.029
0.043
0.057
0.071
0.086
90
0.022
0.033
0.044
0.056
0.067
110
0.018
0.027
0.036
0.045
0.055
33
0.080
Project
title
Wheat
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
130
0.015
0.023
0.031
0.038
0.046
50
0.040
0.060
0.080
0.100
0.120
60
0.033
0.050
0.067
0.083
0.100
70
0.029
0.043
0.057
0.071
0.086
MAFF
project code
CC0357
0.025
Appendix 3 - Costings
Wheat
Additional wheat breeding
Change in cultivar
The widest range of responses is likely to be focused on adapting to or offsetting changes in crop yield. The literature review showed
that there is a wide range of projected yields and that both the magnitude and the sign vary. There is also a trend in increasing wheat
yields that has been attributed to technological improvements in cultivars. However, it is difficult to divorce the improvements in
yield experienced over the last 50 years from climate changes (e.g. Mayes 1998) already seen over the same period.
Plant breeding provides an obvious means to adapt to the threat of reduced yields under climate change. This assumes that plant
breeding could reduce climate change impacts, since is that the length of developmental phases is under genetic control and exhibits
considerable variability in European wheat (Worland, 1996). More emphasis would need to be given to measuring of the length of
and growth in developmental phases of the crop to allow identification of material that will be appropriate under the changed
conditions. Much plant breeding is carried out by multinational companies, which already supply producers in a range of climates
greater than the changes predicted for climate change. Hence they do have the ability to select appropriate varieties for gradually
changing climate conditions without any new investment in genetic diversity or processes for screening their promising lines.
Typically it is eight years from selection to marketing of a commercial variety and then a commercial life of about five years (Roger
Sylvester Bradley, pers comm). It could be argued that such yield improvements could occur through the usual cycles of breeding.
However, whilst this may partially offset any losses due to climate change, it does not always result in selection of the most
appropriate developmental controls, as demonstrated for German varieties (Worland et al., 1994). Also, to be successful under a
changed climate it may require a use of a wider genetic pool and, when comparing varieties in trials, weighting may be required to
place greater emphasis on those years and sites that are closer to the conditions anticipated under climate change.
Table 3.1 shows the economics of this adaptation investment.
Table 3.1: The costs associated with the yield increases with and without the additional breeding adaptation.
Benefit/Cost (£Million)
Low yield impact High yield impact –
no additional
with additional
adaptation costs
breeding adaptation
Value of extra production @£62/tonne
398.1
199.1
Cost of additional breeding
0
1.5
Additional harvesting cost@£4/ tonne
25.7
12.8
Additional marketing and transport costs
32.1
16.0
@£5/tonne
Additional drying costs @£2/ tonne
12.85
6.4
Total Benefit/Cost
327.5
162.2
Cost Benefit ratio
5.6
5.4
Net Present value by 2050 at 6%
1527.4
757
Net Present value at by 2050 at 2%
4413.0
2186
Additional insecticed spray
Table 3.2: The cost benefit of changing the number of pesticide sprays in response to the changing phenology of aphids.
Extra insecticide spray
Low scenario High scenario
Wheat areas (ha)
1,969,700
1,969,700
Yield protected (t/ha)
1.08
0.84
Value of yield protected (£) @£62/t
131,891,112
102,581,976
Additional pesticide (£/ha) @£19/ha (less £5/ha saved on
18
18
summer treatment on 20% of crop)
Total cost of pesticide application (£)
35,454,600
35,454,600
Cost Benefit ratio
3.72
2.89
Total Benefit/Cost (£)
96,436,512
67,127,376
449,816,994
313,107,907
Net Present value at 6% discount to 2050s
1,299,547,953
904,587,300
Net Present value at 2% discount to 2050s
34
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
The calculations presented in Figure 3.1 suggest that at least an extra generation of aphids may be expected between September 21 st
and March 31st over the majority of the wheat growing areas of the country by 2020s High. This rises to at least 2 extra generations
under the 2050 High scenario.
The yield loss is not linearly related to the percentage of infection as the earlier in a plants’ life the infection occurs the greater the
yield loss. With 10% of the plants infected (approximately at the start of the 2 nd generation) the yield loss under current climate is
0.6t/ha (Oakley et al., 2002). If the percentage of plants infected and proportion of yield lost remains constant as crop yields increase,
then the corresponding yield loss under the High scenario would be 0.81t/ha and 1.02 t/ha under the Low scenario. Normal practice
would be to spray every two generations, so that 8 generations would require 4 sprays. Although the increase in generations is greater
in the south than the north, the assumption has been made that an additional aphicide will be required in the autumn across the winter
wheat crop.
A seed treatment at £19/ha provides protection for approximately 2 aphid generations so follow up sprays would still needed in the
worst situations. Climate change is expected to mean that an additional aphicide control measure in the autumn is required but one
less would be needed in the spring on 20% of the crop. This additional cost is offset by a reduction in the amount of spring/summer
sprays required which could cost £5/ha. But the saving would only occur on 20% of the crop, the equivalent of £1/ha across the
wheat area.
Switch to maize production
Table 3.3: Gross margins for wheat and grain maize in the 2050s
High Scenario
Wheat Grain
Maize
11.37
62
45
88
118
2
452
Low Scenario
Wheat
Grain Maize
Yield produced (t/ha)
10
14.62
8
Value of yield (£/ha)
61
62
61
Seed Costs (£/ha)
125
45
125
Fertiliser (£/ha)
45
88
45
Sprays (£/ha)
20
118
20
Drying (£/ha)
10
2
10
Gross margin (£/ha)
410
653
288
Benefit: cost of changing to grain
0.91
0.44
maize
Net Present Value by 2050 at 6%
£-385,872,421
£-3,353,415,088.48
Net Present Value by 2050 at 2%
£-1,114,808,293
£-9,688,214,924.63
In 2000, only a limited area of Grain Maize was produced in England (~200 ha, Nix, 2000) with an average yield of 4-5t/ha. Under
climate change it would be reasonable to expect this to increase to the level achieved in central France (8-10 t/ha, Nix, 2000).
However, not all of the country would be warm enough to allow production.
Earlier work on the impacts of climate change have suggested that the yield of maize may not increase greatly under climate change
(Hossell et al., 2001) and the crop would not be substituted in for wheat. However, this work used the cooler Medium High UKCIP98
scenario, which did not greatly increase grain maize yields in England and Wales (maximum of 4.71 t/ha).
Potatoes
Loss of production due to increased exports
As the growth of early potatoes is controlled by solar radiation, countries with at more southerly latitudes will have greater solar
radiation earlier in the year. If those countries experience fewer frost days earlier in the year then they will be able to advance their
potato planting yet obtain a higher yield in proportion to growers in Southern England. This additional yield would allow them to
produce potatoes at lower cost and therefore enable them to export them to England. Annual imports of early potatoes vary between
160,000 and 210,000 tonnes which come from Cyprus, Spain, Brittany, Jersey and sometimes from Egypt. This compares with early
production in Great Britain of between 314,000 and 360,000 tonnes annually.
Table 3.4: Economic loss from a 50% reduction in the early crop area
Output
£
Area (ha) @ 50% of 12,468ha
6,234
Yield (t/ha)
22.5
Price £/t
145
Value
20,338,425
Costs saved
Variable costs
9,662,700
Labour and machinery
1,652,010
11,314,710
Total costs saved
9,023,715
Economic loss from a 50% reduction in the early crop area
Cost: Benefit
0.56
Net Present Value at 2050 at 6%
£42,090,078.44
35
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Net Present Value at 2050 at 2%
£121,600,730.99
Switch to spring barley
As early potatoes are predominantly planted on lighter land it is likely that a direct substitution of early potatoes with a spring cereal,
possibly spring barley, would take place.
Table 3.5 Economic gain from growing a cereal crop
Proportion of Early potato crop
50% reduction
50% reduction
(current policy)
(liberalised policy)
Area (ha)
6,234
6,234
Yield (t/ha)
5.5
5.5
£/t
68
68
Grain income
2,331,516
2,331,516
Total variable costs @ £160/ha
997,440
997,440
1,334,076
1,334,076
Gross margin before AAPS
Arable Area payments @ £234/ha
1,458,756
0
1,334,076
Total gross margin
2,792,832
20,338,425
20,338,425
Loss of potato crop (£ million)
Total costs saved from potato production
11,314,710
11,314,710
6,230,883
7,689,639
Net loss (£ million)
Benefit:cost
0.71
0.64
Net Present Value @ 6% discount rate (£)
£-29,063,235.51
£-35,867,434.71
Net Present Value @ 2% discount rate (£)
£-83,965,409.76
£-103,623,144.51
Loss of early potatoes in Cornwall
Earlier potatoes from abroad would encourage the earlier planting in the UK aided also by the extension of the growing season as a
result of climate change. However, the areas in west Cornwall that grow the earliest crops have traditionally grown winter
cauliflowers which are harvested late in the year with early potatoes being planted soon after the crops are lifted, sometimes in
December. Unless climatic conditions change rotational practise to either advance the harvest of winter cauliflower crop or replace it
with another crop which allows potatoes to be planted earlier it is likely that one of the two crops will be dropped from the rotation.
As the early potato crop is predicted to yield less as a result of earlier planting and lower solar radiation then it is likely that it would
be uneconomic to grow.
The predicted climate change is expected to result in wetter winters and drier summers. The wetter winters could cause difficulties in
establishing a seed bed in which to plant the advanced early crop, especially on heavier land. This in itself is unlikely to prevent early
potato production being economic on its own, however, it may contribute to lower returns through not being able to plant and harvest
crops as early as they potentially could be. Planting potatoes into an imperfect seedbed would not be an option as it would result in a
reduction in the quality of potatoes produced. Again the southwest of England, with its already high winter rainfall totals would be at
a disadvantage by comparison with the rest of the UK. If the predicted climatic change took place and it was no longer economic to
grow potatoes in Cornwall then the economic loss to the county would be significant.
Table 3.6: Costs/benefits of the loss of early potatoes in Cornwall
Economic loss to Cornwall
£
Early Potatoes Gross Margin / ha
1448
Less fuel and repairs / ha
265
Margin/ha to pay remaining fixed costs and return on investment
1183
Economic loss to the county by loosing early potato production @ 2700 ha
3,510,000
Benefit:cost
0.22
Net Present Value for 2050 at 6%
£-14,898,511.26
Net Present Value at 2050 2%
£-43,042,681.96
Additional irrigation on maincrop potatoes
To protect yield alone potato crops are normally irrigated when the soil moisture deficit reaches a pre-determined level. This varies
from 30 mm for sandy soils to120 mm for deep fen peat. However irrigating when these deficits are reached will only protect yield, it
will not protect crop quality. Irrigation is used to protect the crop against common scab, which affects the tubers skin quality. To
protect skin quality by preventing common scab crops need to be irrigated with 12 mm of water when the soil moisture deficit reaches
15 mm for a period of at least 4 weeks after tuber initiation. Table 3.7 shows the increase in irrigation needed under climate change
Table 3.7 Increase in irrigation requirements under climate change
North Norfolk
North Yorkshire
Baseline
2050 Low
2050 High Baseline
2050 Low
2050 High
Annual average demand
1.31
1.45
1.79
1.70
1.79
1.89
million litres /ha
36
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
Baseline
Increase in irrigation
mm/ha
North Norfolk
2050 Low
2050 High
14
48
Baseline
MAFF
project code
CC0357
North Yorkshire
2050 Low
2050 High
9
19
The cost benefit for this additional irrigation is shown in Table 3.8
Table 3.8 The economic implications of additional irrigation
Low Scenario
High Scenario
Yield penalty – England & Wales (t)
54,000
288,000
Crop value (£) @ £89/t
4,806,000
25,632,000
Irrigation cost (£)
2,774,000
36,000,000
Annual national economic benefit of irrigation (£)
2,032,000
-10,368,000
Benefit: Cost Ratio of irrigation
1.7
0.7
Net Present Value by 2050 at 6%
£9,478,029.77
-£48,360,340.86
Net Present Value by 2050 at 2%
£27,382,589.70 -£139,715,890.73
To protect yield alone potato crops are normally irrigated when the soil moisture deficit reaches a pre-determined level. This varies
from 30 mm for sandy soils to120 mm for deep fen peat. However irrigating when these deficits are reached will only protect yield, it
will not protect crop quality. Irrigation is used to protect the crop against common scab, which affects the tubers skin quality. To
protect skin quality by preventing common scab crops need to be irrigated with 12 mm of water when the soil moisture deficit reaches
15 mm for a period of at least 4 weeks after tuber initiation.
Additional pest control
Table 3.9: Industry cost of Climate Change on pest control in 2050.
National yield @ 120 000 ha x 35t/ha (t)
4200000
10% of National crop value @ £89/t (£)
373,800,000
Membership of a cutworm prediction service per grower. (£)
280
Number of potato growers in England and Wales
8080
National cost of Cutworm prediction service (£)
2,262,400
National cost of pesticide (£)
420,000
National cost of application (£)
1,050,000
National cost of additional aphicide (£)
70,000
Total additional cost of pest control in England and Wales (£)
3,802,400
Benifit: Cost Ratio
9.83
Net Present Value by 2050 at 6%
£156,618,844.64
Net Present Value by 2050 at 2%
£452,481,123.89
Additional refrigerated storage
Good potato storage practice allows potatoes to undergo a “curing period” once they have been loaded into store. This is a period
where the temperature is maintained at between 13° and 18°C for 10 to 20 days. The warm temperature combined with a high relative
humidity enables the crop to form a layer of corky cells over wounds caused by harvesting and loading into store. This protects the
crop from excessive moisture loss and entry of diseases in the remainder of the storage period. However these conditions are also
ideal for development of storage diseases and therefore once the curing period has finished the temperature needs to be reduced
rapidly to a holding temperature of between 4 and 10°C for ware potatoes depending on the market for which they are destined.
Provided that temperatures in autumn do not rise significantly then ambient stores will be able to reduce the temperature to a stable
position although it is likely to take longer than at present. In good harvesting conditions this is not expected to result in a significant
loss in crop quality. However, in poor harvesting conditions where the crop is loaded into store damaged and wet, losses due to
disease could be significant.
If the temperature in spring rises then difficulty will be experienced in holding the temperature of ambient stores low enough towards
the end of the storage season when ambient temperatures are rising. Additional refrigerated storage may be needed under climate
change and the cost of such adaptation is provided in Table 3.10.
Ventilation in both ambient and refrigerated stores will need to increase. It is not predicted that the volume of storage required will
increase therefore the additional cost will primarily be seen in the need to upgrade stores which are ambient to refrigerated.
Additional power will be needed to operate fans and refrigeration plants to control temperatures. Under present conditions the power
required per tonne of potatoes stored in ambient conditions varies between 5 and 20 kWh depending on weather conditions, the
condition of the potatoes as they enter the store, the condition of the store itself and the length of storage. The power required for
refrigerated stores varies between 40 and 100 kWh per tonne stored depending on the same factors noted above.
To convert an ambient store to a refrigerated would require investment in refrigeration plant and control systems. To convert a 2000
tonne ambient store would cost approximately £60,000 depending on the level of automation. Many stores would need upgrading of
insulation to make best use of the refrigerated conditions. In many situation this could add a further £10,000 to the cost.
In identifying the degree to which ambient stores may need to be converted to refrigerated it is assumed that the stored crop is used at
a constant rate throughout the winter and spring period. No records are kept of the volume of crop that is stored in refrigerated
37
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
conditions. Discussions with the BPC identified that of a potential 6 million tonne crop harvested in the autumn of which 4 million
tonnes are ware crop. It is, therefore, calculated that an eighth of the storage capacity needs to be upgraded to refrigeration to enable
the ware crop to be successfully stored until new crop potatoes became available. This is the equivalent of 500,000 tonnes of
potatoes. The cost of refrigeration equipment and additional insulation would therefore be £17,500,000.
In assessing the additional power required to run the refrigeration plant the difference between the ambient and refrigerated energy
requirement has been taken as 75% of the total power requirement.
Table 3.10 Cost to the industry on enhancing cold storage for potatoes
Cost/Benefit
£
Cost of upgrade for 2000t store
70000
Cost of upgrading for 500,000t of crop (0.125 of national capacity)
17,500,000.00
Additional power required per year @ 60 KW/t @ £0.066 /KW
2,000,000.00
Average power cost if 5 units phased in per year over 50 years
£1,020,000.00
Cost of upgrading 5 units
350,000.00
Average total cost per year @ 5 units /year
£1,370,000.00
6% NPV for 2050
£6,390,207.08
2% NPV for 2050
£18,461,686.95
Value of potatoes @ £89/t
£44,500,000.00
Cost :Benefit
32.5
Cauliflower
Additional aphid sprays
Table 3.11: Cost to the industry of additional aphid sprays
Cost Benefit
Total cost of additional spray (£25/ha) and
application (£13.5/ha)
Cost of increasing summer application from 2 to
4 sprays
Cost of increasing winter application from 1 to 2
sprays
Total cost of additional spraying
NPV for 2050 at 6%
NPV for 2050 at 2%
Benefit in terms of yield protected @5% of
national crop
Cost: benefit
Value (£)
38.5
492,800.00
214,368.00
707,168.00
3,298,503.62
9,529,572.44
1,910,115.65
2.7
Development of new spray mechanisms
Table 3.12: Cost of development of new spray application methods
Cost/Benefit
Cost of new application development
Investment cost per year at 6% discount
Total cost of development of two applications
NPV by 2050 at 6%
NPV by 2050 at 2%
Value of crop saved at 1% of national crop
Benefit:cost
Additional N dressing
Table 3.13: Cost of additional N dressing
Cost/Benefit
Cost of extra application
Total application cost
Value of crop saved at 5% of national winter crop
NPV by 2050 at 6%
NPV by 2050 at 2%
Benefit:cost
Value (£)
7.35
40,924.80
888,663.43
3,954,179.12
11,423,857.81
21.7
38
Value (£)
100,000
8,7000
17,400
81,160.29
234,476.90
382,023.13
1.91
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Irrigation
During the early 1980’s, there was interest in bringing irrigation to the Lincolnshire area, with some initial thinking done by Severn
Trent Water Board and the drainage boards. The idea was to transfer water from the river Severn to the river Trent and from the Trent
pump into drainage canals to flow South and reach S. Lincolnshire. The plan was to flush salt water out of the drainage canals so that
they could be used for irrigation supplies. The salt water comes from residual soil deposits and tidal ingress. A small area in New
Fen was treated in this way using water from the river Witham (but is not cauliflower land). The cost west to east water grid was
considered to be too high because of the need make good all the seawalls and outfalls around the Wash. (There is a little irrigation
carried out in Lincolnshire by growers of other crops situated next to big drains using float intakes since fresh water is less dense - but
the risks of salt contamination are high.). Boreholes are not possible in Lincolnshire because of the depth at which the rock lies.
Another possibility is winter storage, but drainage canals are sometimes contaminated with salt water in winter when tidal outflows
become jammed (or are propped) open. It is not certain that it would be possible to get sufficient land to build reservoirs, or that the
network of pipelines to the crop would be economic - cauliflowers are an extensive crop compared to other vegetables.
Moving cropping to cooler areas
This industry is very market focused and quickly adapts to meet the requirements of its major customers. A typical large grower with
a base and pack house in Lincolnshire sources product from Cornwall, Norfolk and Essex through contract growing giving them
management control over the crop. Swapping products amongst growers in Lincolnshire is common and use of product from
Scotland and sometimes Lancashire is also practised to fill production gaps. There is good reason to believe that production would be
quickly shifted to alternative or new growing areas if there were competitive advantage from so doing. Predicting how production
would be relocated is very hard but there is already some infrastructure in cooler areas (e.g. Yorkshire, Lancashire and East of
Scotland) and the need to re-equip production facilities and packing lines would exist even if there were no change of location, so the
cost of funding capital investments to support cauliflower production in new areas would not all be additional expenditure.
It would be easy to over estimate the adaptation costs with production moving to new areas because in this situation it is easier to
foresee the threats to existing production patterns that climate change will create, than the new opportunities which it will also bring.
The market focused and entrepreneurial culture of cauliflower producers is more likely to exploit these opportunities than, for
example, the more tradition bound culture of some sectors such as beef production. There is also the possibility that new export
market opportunities could arise as competing production areas in southern Europe suffer from climate changes, which will pose even
more significant difficulties for their industries.
With the movement of production, one area’s loss is another’s gain. For example if cauliflower production moves from Lincolnshire
to Eastern Scotland, there is a positive employment effect there. The ADAS figures for labour requirements averaged 278.5 hours per
hectare in 1995. Assuming an 8 hour day and 200 days of work per person per year, this is equivalent over 11,968 ha. to 2,083 full
time job equivalents (ADAS, 1995). Some of these jobs are carried out by local people from the rural areas and some are carried out
by more distant work forces. For example, the gangs engaged in cauliflower production might be mini-bussed from large cities such
as Sheffield, but also include people from Eastern Europe.
Additional passes at harvest
Table 3.14: Cost of additional passes
Cost/Benefits
£
Cost of additional passes /ha
400
Cost over summer Cauliflower area @ 6400 ha
2,560,000
Cost over winter Cauliflower area @ 5,568 ha
2,227,200
Value of summer crop if 25% of yield is harvested for each
5,107,261.09
pass
Value of winter crop if 14.3% of yield is harvested for each
2,539,038.37
pass
Total benefit
2,859,099.46
NPV by 2050 at 6%
13,335,939.87
NPV by 2050 at 2%
179,710,910.20
Benefit:cost summer/winter
2.0/1.14
Grass
Utilising additional grass production
It is assumed that all the additional grass dry matter in Spring and Autumn is used at the current efficiency of utilisation to provide
additional grass dry matter (DM) in summer for buffer grazing (where there is a shortfall), and then to raise the stocking rate.
The changes in stocking rate assume some combination of five adaptations (change in cutting/grazing ratios, buffer feeding, zero
grazing, extended grazing, and storage feeding) are employed and that the overall efficiency of forage utilisation does not change. In
the case of the East Lancashire dairying site there is no shortfall in Summer DM yields for grazing so buffer feeding is not anticipated
(See Tables 4.15 and 4.17). In the case of Andover in Table 3.16 below, a decrease in summer grass DM is anticipated and so buffer
feeding is likely to be required.
Table 3.15: Assumptions and yield values used in the calculation of stocking rate effect by 2050 if buffer Feeding and Extended
Grazing Maintain Grassland Utilisation Efficiency.
39
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
East Lancs
Andover
Additional dry matter (DM) per year, 2050 yield – baseline (kg/ha)
1262
254
Buffer feeding adaptation
no
Yes
Additional Grass Dry Matter per year needed for Buffer feeding
344
(kg DM/ha)
Baseline grass DM yield t/ha
10
7.12
Stocking Rate Change – Grazing Livestock Units/ha
0.252
0.072
Changing grazing/silage ratios
The extra dry matter produced under a warmer climate uses the relative splits between grazing and silage shown Tables 4.16 and 4.17.
T his more extreme grazing/silage ratio change adaptation would be difficult for large dairy units where silage ground is remote from
milking facilities and cows could not walk to the more distant fields. The larger changes in grazing and cutting areas required for
adaptation in 2050 would involve costs on a significant number of farms but they would be introduced only gradually as climate
changes. There are also alternative techniques such as zero grazing and storage feeding.
The calculations below assume a typical dairy farm that over the long time-scales of climate change they can be implemented in a cost
neutral manner. The typical current system is for a dairy cow yielding 6,350 litres of milk per year and consuming 1,745 kg of
concentrate per year, stocked at 2.0 per hectare (Nix, 2000).
Table 3.16: Changing silage and grazing areas in Andover and the effect on dry matter availability. Yields are in t/ha (Based on
results from Hossell, et al.,2001)
No Adaptation Baseline
Grazing/silage at first cut 40/60
40/60 then 60/40
Spring
Summer
Autumn
Total
Yield from grazings
1.42
0.91
2.37
4.7
Yield from silage
2.09
0.32
0
2.41
3.51
1.23
2.37
7.11
Totals
With Adaptation – 2050
Grazing/silage at first cut 96/4
40/60 then 62/38
Spring
Summer
Autumn
Yield from grazings
1.85
0.91
2.19
4.95
Yield from silage
2.51
0.02
0
2.53
4.36
0.93
2.19
7.48
Totals
Table 3.17: As Table 3.16 but for a site in East Lancashire
No Adaptation Baseline
Grazing/silage at first cut 40/60
40/60 then 6040
Spring
Summer
Autumn
Yield from grazings
1.05
3.95
2.29
7.29
Yield from silage
1.15
1.59
0
2.74
2.2
5.54
2.29
10.03
Totals
No Adaptation – 2050
Grazing/silage at first cut 40/60
40/60 then 60/40
Spring
Summer
Autumn
Yield from grazings
1.36
4.3
2.98
8.64
Yield from silage
1.04
1.62
0
2.66
2.4
5.92
2.98
11.3
Totals
Extended Grazing
The key elements of an extended grazing system (MDC, 2000) are:
 A reserve of grass is built up in late summer and early autumn to extend autumn grazing.
 Cows are managed at grazing to minimise poaching (short grazing periods of 3/4 hours, small blocks of grazing, front and back
fences and cows walk from the gateway over ungrazed grass)
 A well maintained road network to and from the paddocks.
40
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
In the last five years as milk prices have fallen there has been considerable interest in extended grazing as a way of reducing the costs
of milk production. However, extending the grazing period into the spring is currently unreliable due to unpredictable spring
temperatures. As springs become warmer, the onset of grass growth will commence earlier in the season giving farmers more
confidence in planning for earlier turnout dates.
Buffer feeding
With extended grazing and buffer feeding it seems appropriate to cost them together because grazing, conservation, and feeding of
conserved grass are all parts of the solution to a single problem, matching the pattern of available grass growth to the more constant
nutritional needs of the utilising livestock.
With climate change, buffer feeding, a practice only used on a minority of dairy farms at present, would be useful in augmenting the
grazing of grass during the longer summer droughts. Although with climate change, production in the drier South and East falls in
Summer due to drought, it increases in Spring and Autumn. Some of this increased production could be conserved to provide a buffer
feed, and some would be utilised by extended grazing. Under some climate change scenarios, greater consumption levels might be
required and expected, but further work is needed to quantify these.
Storage feeding
Storage feeding has the advantage that higher levels of utilisation are achievable in silage making than from grazing. The
conservation of the grass growth makes it easy to match grass supply to the nutritional needs of the cow. The disadvantage of storage
feeding is that it requires the expense of conserving all grass production. In addition, the feeding and muck disposal costs are higher
where cows are housed throughout the year, rather than grazed for at least part of it. At current milk prices (about 18.5 p.p.l.) the
emphasis is on reducing costs by extending the grazing season and hence interest in storage feeding is low. However at higher milk
prices it has the potential to match the grass production and utilisation equation in a more radical way than buffer feeding, extended
grazing, and even zero grazing.
Zero grazing
It is not uncommon for this technique to be used for a few days when rainfall would result in damage to grass swards if cows were
allowed to graze. It is one of the range of techniques which along with storage feeding etc. allow dairy farmers to match feed supply
to animal needs whilst minimising sward damage. The cost of completely zero grazed dairy production are considerable because of
the labour, machinery and muck disposal costs of housed cattle. However large dairy herds are increasingly accommodated in sleep
feed facilities on farms with the equipment to zero graze if needed, and so it is an important part of the flexibility which may be
needed to utilise the early and late grass growth expected with climate change.
Table 3.18 provides a costing of the effects of adaptations to increased grass production on stocking densities.
Table 3.18: Benefits of increased stocking densities at two sites in England
E Lancs
Andover
Total Dairy Herd England, 1999, Million Cows
2.495
2.495
Typical stocking rate (cows/ha)
2
2
New stocking rate (cows/ha)
2.252
2.072
New dairy cow population
2.809
2.584
Additional cows - million head
0.314
0.089
Typical Net Margin/cow
171
171
Net Annual benefit in 2050 (£)
53,694,000
15,219,000
Net Present Value at 6% years 0-50
250,449,474
70,987,271
Net Present Value at 2% years 0-50
723,563,372
205,086,433
Table 3.19: Net Social Benefits in 2050 with Grassland Released for Barley/SAS, Based on Modelled Grassland Yield Changes at
Two Sites.
E Lancs
Andover
Average value
tal Dairy herd (Million cows)
2.495
2.495
2.495
pical stocking rate (cows/ha)
2
2
2
w stocking rate (cows/ha)
2.252
2.072
2.162
d area for dairy cows (million/ha)
1.248
1.248
1.248
w area for dairy cows
1.107904085
1.204150579
1.156027332
nd released (Million ha)
0.140095915
0.043849421
0.091972668
oss Margin on winter barley/SAS @£429/ha (£)
60,101,147
18,811,402
39,456,274
ange in fixed costs of barley production @ £290/ha (£)
40,627,815
12,716,332
26,672,074
rease in Net Margin/year (£)
19,473,332
6,095,069
12,784,201
crease in EU rebate at 71% of additional AAPS payments
23,536,114
10,523,861
15,672,143
240/ha)
t Social Benefits/cost /year in 2050
-4,062,782
-1,376,872
-2,887,942
nefit:cost
0.82
0.82
0.82
t Present Value at 6% years 0-50
-18,950,376
-6,422,260
-13,470,471
41
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
E Lancs
Andover
Average value
t Present Value at 2% years 0-50
-54,748,760
-18,554,289
-38,916,990
Increased use of Legumes
Most grazing swards in the UK do contain white clover but the reliance on this as a source of nitrogen is low. In current UK
conditions, the slow growth of white clover early in the season leads many farmers to apply fertiliser N to stimulate grass growth and
the fertiliser N then inhibits the role of clover. With grassland soils warming earlier due to climate change in 2050, mixed PRG/white
clover swards will be able to support the level of animal production, which currently requires 220 kg/ha. of N (Nix, 2000).
Table 3.20: Savings in Fertiliser and Application Costs from Climate Change Adaptation of More Legumes, 2050.
Cost/Benefit
Value
Area of forage for cows (million ha)
1.248
N cost (£/kg)
0.33
Change in N use (kg/ha)
200
Savings/ha (£)
66
Total England saving in N use (£)
82,300,000
Average number of applications/year
3
Application cost (£/application/ha)
7.35
Application cost (£/ha/yr)
22.05
Savings in England application cost (£)
27,500,000
Net social benefits in 2050 (£/yr)
109,800,000
Net Present Value at 6% years 0-50
512,149,443
Net Present Value at 2% years 0-50
1,479,630,093
Increased drainage
The economics of grassland drainage was reviewed in the late 1980’s. (Temple and Parker 1987) The importance of grant rates, tax
allowances and marginal tax rates in determining the after grant and tax net cost of irrigation was emphasised. Both factors have
become much less favourable since the drainage of grassland in the 1970’s was commonplace, and have brought investment in
grassland drainage to a virtual halt.
Much dairying takes place on heavy soils, which are difficult to drain. The spacing of drains on clay soils needs to be very close if the
soil is to rapidly return after rainfall events to a moisture content which will reduce the plasticity of the soil to the point that it can bear
the weight of a dairy cow on the small surface area of its hooves without poaching. Drainage costs with 20 m laterals and permeable
backfill are in the range £1,400 to £1,600 per hectare. Recurrent costs result from the need to mole across the lateral drains at regular
intervals (Nix, 2000). For a herd of 200 cows, the capital cost of drainage could be about £140,000 (based on 200 cows on 100 ha.).
Tomatoes
Shade screens
There are a variety of glass house design features that can be used to reduce temperature and one of these is shade screens, which can
reduce glasshouse temperatures by up to 5°C. The cost of shade screen installation is about £50,000 per hectare. It is realistic to
assume that all the yield loss would be removed by installation of shade screens.
Table 3.21: Costs and Returns on the Use of Shade Screens
Cost/ Benefit
Value/ha/year
Capital Cost: investment in shade screens
50000
Cost per year at 6% over 20 years
4,350
Annual operating cost (repairs, servicing and electricity) at 6% of original cost
3,000
Total Annual Costs
7,350
15% yield reduction avoided, crop output £250,000 per ha.
37,500
Net benefit from shade screens over whole industry @130ha
3,919,500
Benefit:Cost
5.10
NPV to 2050 at 6%
18,282,056
NPV to 2050 at 2%
52,817,943
Artificial lighting
Artificial lighting has been developed in Sweden and Norway and is also used under thermal screens in Holland. Lights cost about
£60,000 per ha to install and have running costs (mainly electricity) of about £130,000/ha/year. If the capital cost of the lights is
discounted over 20 years at 6%, the cost is £5,220/year, the total annual cost of the lighting is £135,220/ha.
Table 3.22: The costs and returns on the use of artificial lighting in greenhouses
Cost/ Benefit
Value
Capital cost (£/ha)
60000
Yield saved at 1%
2500
Cost of running lights/year
130000
42
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
Capital cost /year @6%
CC0357
5220
Total annual costs
Industry cost@130ha
MAFF
project code
135220
17578600
Net benefit
-17,253,600
Benefit:Cost
0.01848839
NPV to 2050 at 6%
-80,477,428
NPV to 2050 at 2%
-232,504,060
Reduction in winter heating
Calculating the cost of winter heating use under the UKCIP98 2050 High scenario, using the formula provided by Wass and Barrie,
1984, provides an estimated future reduction in heating needs of 14-18% across the main tomato growing areas of SE England and
Yorkshire (See Figure 1.2 in Appendix 1). Heating costs of long season tomatoes are about £52,000 per ha. per year so savings of
between £7,200 and £9,360/ha/yr may be possible in the future in an average year.
Table 3.23: The costs and returns on reduced heating needs in glasshouse
Cost/Benefit
Value
Cost of long season heating (£ million)
52,000
Saving by 2050 @14% of annual costs (£)
7,280
Saving by 2050 @18% of annual costs (£)
9,360
Industry saving @14% (£)
946,400
Industry saving @18% (£)
1,216,800
NPV at 6% (£)
4,414,374
NPV at 2% (£)
12,753,387
Faster picking
The pattern of harvesting tomatoes is that at peak yield, which tends to coincide with high temperatures in the glass houses, picking is
carried out daily, say from June to August. Earlier and later in the season picking may be once every two or three days. With climate
change the period of daily picking might extend to May to September.
An earlier start to picking (say 5.00 am) may require higher pay rates to compensate pickers for the socially disruptive consequences
of the job. This could increase wage rates by up to 30%. A 15 % increase in cost has been taken as the most likely case. Typical
labour requirement for harvesting is 4,900 hours per ha at about £6 per hour, or a labour cost per ha of £29,400.
Table 3.25: The costs and returns from faster picking of glasshouse tomatoes
Cost/Benefit
1.1.1.1.1.1.1.V
a
l
u
e
Time taken to harvest (hrs/ha)
4,900
Increase picking time needed @15% of total (hrs/ha)
735
Cost of additional picking time @ £6/hr (£)
4,410
Labour cost/ha (£)
29,400
Industry cost @130ha (£)
573,300
NPV at 6% (£)
2,674,092
NPV at 2% (£)
7,725,610
Break even point (% of yield saved)
1.764
Change in cultivars grown
Table 3.25: The costs and returns from a change in cultivar
Cost/Benefit
Value/ha/year
Yield in 2050 absence of climate
500
change (t/ha)
Yield lost due to poor fruit set (t/ha)
100
Yield loss due to poor leaf
60
43
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
MAFF
project code
CC0357
Cost/Benefit
Value/ha/year
size/vigour in 2050 (t/ha)
Value of lost yield @£500/ha over
80,000
130ha
Net present value to 2050 at 6% (£) 373,151
Net present value to 2050 at 2% (£) 5,028,462
Pigs
Changes in slurry handling/storage
Possible adaptations include
1) The need to avoid rainwater entering dirty water/slurry stores, thereby increasing volumes of dirty water requiring to be disposed
of. This would include covering open yard areas, outside slatted runs, better differentiation of clean and dirty water collection,
including remedial work to gutterings, covering above ground tanks, slurry lagoons
2) Switch to irrigation disposal systems for dirty water/low dry matter slurry, involving less traffic on land
3) Increase in on-farm storage capacity, allowing slurry disposal to take place when ground conditions are suitable rather than having
to get slurry out on to land, whatever the ground conditions
4) Switch to larger capacity tankers with low ground pressure tyres, tractors able to travel further at higher speed (Fastrac vehicles)
5) Adopt on farm measures to take water out of slurry
With the exception of option 1, the other adaptations are interlinked and are only effective in combination.
The costing is based on a 600-sow breeding to finisher unit, with grower/finisher pigs on slurry and sows on a scraped yard system of
385m². The Grower/finisher buildings have 1 month slurry storage within, and 3 months storage in an above ground slurry store,
typically 3862m³. With 300mm additional rainfall December to March, the additional rainfall entering tank over 4 months is 207m³
and the rainfall on the dirty yard area is 103m³. Total additional slurry from rainfall addition is therefore 310m³ in 4 months. With a
typical tanker size of 1500 galls (6.8m³) capacity, this relates to 46 extra trips per winter slurry spreading. In an average trip of 1
hour, costs @£20 per hour for tractor and spreader (Nix, 2002) the total cost of the additional winter and autumn rainfall is
£911.76/year
Table 3.26: Costs and returns of providing covered slurry storage and separating off rainwater.
Cost/benefit
Value
Capital cost of cover (£)
18000
Cost of separating water from a dirty yard (£)
15000
Total capital outlay (£)
33000
Annual investment cost at 6% discount rate
(£/yr)
Additional rainfall in tanks (m3)
Additional runoff from yard (m3)
Number of trips to spread slurry assuming
6.8m3 spreader
Total cost of spreading @£20/trip (£)
Benefit cost
2871
207
103
45.58
911.76
0.32
Net present value for industry at 6% (£)
-642,387
Net present value for industry at 2% (£)
-1,142,887
This cost may be offset against the capital costs for a covered slurry store, which is estimated at £18,000, and remedial work to
separate clean water away from dirty yard water estimated at £15,000; a total capital outlay of £33,000. It is assumed that these
investments return the quantity of slurry produced to that before the climate change takes place. The capital investment is written off
over 20 years, the cost is £2871/year at 6%.
Increased ventilation, water use and use of water showers
Assuming a drop in fed intake/growth rate of up to 10% with the consequence, therefore, of a lower carcass weight sold. A 10%
lower growth rate means 10 days more fattening time are required to reach slaughter weight, or 10 days less growth i.e. 5kg less
carcass. With a net loss kg carcass @£1.03/kg x 5 i.e. £5.15 less the saving in feed (5kg liveweight gain x 2.9 feed conversion rate
and feed@£129/tonne =£1.87 ) i.e. £3.28 per pig. The total cost to 600 sow breeding herd to finish £19,677 per year (assuming higher
temp in summer only, i.e. 50% of year)
Table 3.27: Costs and returns on measures to reduce temperatures in housed pig systems
Cost/benefit
Value
Final weight lost (kg)
5
Feed conversion rate
2.9
Food saving (£)
1.8705
44
Project
title
Identifying and costing agricultural responses under climate
change scenarios (ICARUS)
Cost of lighter carcass @1.03/kg (£)
MAFF
project code
CC0357
5.15
Total loss (£)
19,677
Capital cost of fans + shower (£)
9,000
Running costs in electricity @.2/pig (£)
1,200
Water costs at £0.07/pig (£)
420
Cost per year of investment discounted over 20 years at 6%
amortisation (£) + running costs
Cost per year of investment discounted over 20 years at 2%
amortisation (£) +running costs
Cost benefit at 6%
2,403
2,169
8.19
Cost Benefit at 2%
9.07
Net Cost over industry of 350000 pigs @6% (£)
10,076,500
Net Cost over industry of 350000 pigs @2% (£)
10,213,000
Net Present value @6% (£)
47,000,673
Net Present value @2% (£)
137,627,160
Changes in breeding practices
Table 3.28: Costs and returns on measures to reduce the impact of high temperatures on breeding rates in outdoor pig systems.
Benefit:cost
Value
Reduction in farrowing rate from heat stress (%)
12.00
Reduction in litters/sow/year (no pigs)
0.27
Reduction in pigs reared @58 litters/summer (no.pigs) for 650 sow
unit
Total cost of weaner reduction @£10/weaner (£)
Extra cost of keeping low weight weaner (0.9kg lighter) until reaches
35kg weight @0.25/pig/day (£)
Net cost of lost output £/yr
527.0
5,270.0
5,005.0
10,275.0
Additional AI @15% extra/month of £683 over 4 months (£)
409.8
Cost of additional straw for serving tents (£)
250.0
Cost of 5 additional serving tents @4500
22,500.0
Insulation of 150 farrowing arcs @£250
37,500.0
Trade in value for 150 old arcs @£50/arc
7,500.0
Cost of capital investment/year discounted over 15 years at 6%
5,407.5
Benefit:cost
1.78
Net benefit of adaptation
4,207.70
Total benefit for whole industry
971,007.69
Net Present value @6%
4,529,153.5
Net Present value @2%
13,084,992.7
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45