Download Birmingham`s Climate Portfolio

Birmingham’s Climate Portfolio
Birmingham’s Climate Portfolio
Contents
Page
1.0 Introduction: Baseline Climate of the West Midlands
1.1 Temperature
1.2 Precipitation
2.0 Significant weather events
3.0 Climate Change
3.1 Scenarios and Probabilities
3.2 Climate Projections for Birmingham
3.3 Risks to Birmingham
4.0 Urban Heat Island (UHI) of Birmingham
5.0 Impacts
5.1 Energy impacts
5.2 Health Impacts
6.0 Opportunities from Climate Change
7.0 Mitigation/Adaptation
8.0 Reference
2
3
4
6
7
9
10
12
14
17
17
17
19
19
20
Page 1
Birmingham’s Climate Portfolio
1.0 Introduction: Baseline Climate of the West Midlands
The UK experiences a great variety of air masses both in origin and trajectory (Chandler and Gregory,
1976). These can be broadly classified into the following categories: Maritime Polar, Maritime
Tropical, Continental Tropical, Continental Polar, Maritime Artic and Returning Polar Maritime. The
UK experiences a predominantly westerly air mass influence, bringing depressions with their
associated wind and rain. Thus the UK is classified as having a temperate maritime climate. Generally
the UK experiences milder winters and cooler summers than continental Europe.
Figure 1 Characteristics of Air Masses across the UK (Met Office Fact Sheet 10, 2010)
Shifting air masses are what gives the UK its transient climate. Gregory (1976) classified the UK
regions into groups based on their length of growing season and rainfall (both magnitude and
seasonality). The Midlands is assigned ‘BD2’ which translates to:
A growing season of 7-8 months.
A probability greater than 0.3 of annual rainfall being below 750mm.
Rainfall predominantly falling in the winter half of the year.
Gregory (1976) compares the climate of the Midlands to that of north eastern coastal areas,
Shropshire, Lincoln and around Dublin. The prevailing air mass is essentially what controls the
climatology of the Midlands. Influencing this and leading to air mass modification is the landlocked
nature of the Midlands, the topography and the urban conurbations.
The Midlands has arguably one of the longest and best kept meteorological records in the UK. As far
back as 1733 Thomas Barker created a weather journal backed by early instrumentation. For
Birmingham the Lunar Society commenced weather observations in April 1793 (Giles and Kings,
1997). Various other organisations continued measurements for Birmingham through the 19th and
20th Century with data collection for the city now located at the Winterbourne station (University of
Birmingham). Collectively this gives over a 200 year temperature and rainfall series for Birmingham.
Page 2
Birmingham’s Climate Portfolio
The Birmingham temperature series contains more data (mean maximum, mean minimum, mean
monthly, highest maximum and lowest minimum) compared with the central England temperature
series (mean monthly only) (Giles and Kings, 1996). The rainfall series also consists of frequency of
precipitation which other series have not captured.
Figure 2 Location of climate stations in the Midlands (Met Office, 2010)
Birmingham is located on top of the Midlands Plateau, an area 100 – 250m above sea level, made
predominantly of sedimentary rocks (English Nature, 2005). Of the West Midlands, 70% of the land is
agricultural. Urbanization in the region has been focused mainly upon the Birmingham plateau
(Anderson et al., 2003).
1.1 Temperature
Due to the inland location of the Midlands, temperatures are more continental and are governed by
the prevailing air mass (Figure 1) and the radiation balance. This gives the Midlands a large annual
range in temperatures with observed lows of -26.1oC at Newport on 10th January 1982 and highs of
37.1oC at Cheltenham on 3rd August 1990 (Giles and Kings, 1997). The low temperature at Newport
still stands as the lowest ever measured temperature in the UK. Temperatures were only recently
Page 3
Birmingham’s Climate Portfolio
recorded higher than Cheltenham for the UK during the heat wave of August 2003 when Faversham,
Kent recorded 38.5oC (Met Office, 2010). Birmingham exhibits less of an extreme range, perhaps
moderated by its urban influence (Figure 3). Birmingham had a mean daily temperature of 9.4oC
(1961-1990) which has now risen to 10oC (1991-2007).
Lowest minimum
Highest minimum
Temperature (oC)
-13.6
20.4
Date
8th February 1895
5th August 1975
Lowest maximum
Highest maximum
-6.5
34.8
12th January 1987
3rd August 1990
Figure 3 Winterbourne daily temperature extremes (1881-2006) (CARG, University of Birmingham)
Figure 4 Mean monthly temperature, decade normals (Data from Birmingham Temperature
Series, Giles and Kings 1996)
1.2 Precipitation
The average annual precipitation for the Midlands ranges between 600 and 850mm. The driest areas
in the midlands are found in the lower lying areas to the east. The maximum totals are found on high
ground such as the Peak District and the Welsh borders (Giles and Kings, 1997). The Welsh
mountains also act as a rain shadow over much of the West Midlands resulting in rainfall totals that
are less than areas of equivalent altitude to the north or south. Birmingham, located on a plateau
(100-300m) in the centre of the Midlands acts to increase rainfall totals compared with the
comparative surrounding dryness.
Page 4
Birmingham’s Climate Portfolio
Figure 5 Birmingham Rainfall Series, decade normals (Data from Giles and Kings 1996)
There is a tendency for a winter bias in precipitation. Summer rainfall falls over a fewer number of
days but with a greater intensity. Birmingham has an average precipitation 767mm (1961-1990).
However it must be noted that rainfall has increased to an average annual of 821mm in later years
(1991-2007) (LCLIP, 2008).
Figure 6 Precipitation distribution in the Midlands (Met Office, 2010)
Page 5
Birmingham’s Climate Portfolio
2.0 Significant weather events
A significant weather event can be broadly defined as ‘an event that is rare within its statistical
reference distribution at a particular place,’ (IPCC, 2007). The definition of a significant weather
event will vary from place to place and can be defined by magnitude, rarity, return period, impact
and loss. Note extreme impacts / losses are not always due to the most extreme weather. The
World Meteorological Organisation (WMO, 2004) defines significant weather to be:
‘a hazardous meteorological or hydro-meteorological phenomenon, of varying but short duration
(minutes, hours, days to a couple of weeks) and of varying geographical extent, with risk of causing
major damage, serious social disruption and loss of human life, requiring measures for minimizing
loss, mitigation and avoidance, and requiring detailed information about the phenomenon (location,
area or region affected, time, duration, intensity and evolution) to be distributed as soon as possible
to the responsible authorities and to the public.”
Throughout the years Birmingham has been susceptible to weather events ranging from floods to
tornadoes. A study over the past decade, Birmingham’s Local Climate Impacts Profile (LCLIP, 2008)
set out to find the most significant events. A ranking system was derived using the weather intensity,
impacts and return period. Over the period 1998-2008, 81 significant weather events were found in
Birmingham. 16 events found in Birmingham were -5 or -6 (Figure 7) and 31 events were C or D
(Figure 8).
Significant Weather
Scale
Return Period
Good
2
Monthly
Fine
1
Weekly
Average
0
Daily
Poor
-1
Weekly
Bad
-2
Monthly
Adverse
-3
Seasonal
Severe
-4
Annual
Extreme
-5
Decades
Catastrophic
-6
Centuries
Figure 7 Scale of return of significant weather (LCLIP, 2009)
Page 6
Birmingham’s Climate Portfolio
A
Warnings issued by organisations (e.g. Police, AA and Environment Agency).
B
Disruption to services, with perhaps some additional warnings issued.
C
Disruption to services and structural damage - natural and built environment.
D
Disruption to services, structural damage - natural and built environment and injury/death to
individual(s).
Figure 8 Scale of impacts of significant weather
Figure 9 Number of significant weather events reported per year (LCLIP, 2008)
The LCLIP study found the number of significant weather events to increase from 1998. However this
can be considered subjective as analyses is based on reported events within the media. Heavy rain
and flooding were found to cause the most problems for Birmingham followed by thunderstorms
then snow and ice.
The most notable impacts over the last 10 years for Birmingham have been a Tornado in July 2005, a
heat wave in July 2006 and flooding in summer 2007. The Birmingham tornado was estimated to
cause both £50 million damage (LCLIP, 2008) and injure 19 people, 3 seriously.
3.0 Climate Change
In order to prepare for the likeliness of extreme weather returning the future climate of Birmingham
needs to be explored. The UK Climate Projections (UKCP09) model predicts a 5.2oC temperature rise
in the summer daily maximum temperature for the West Midlands by 2080 using a medium
emissions scenario. This will put the population of the West Midlands above the threshold zone for
human comfort and health. Annual precipitation is not expected to change. However the
distribution will shift, with wetter winters and drier summers, with potential increased risk of
flooding and water shortages respectively.
Page 7
Birmingham’s Climate Portfolio
“The scientific evidence is now overwhelming: climate change presents very serious global risks,
and it demands an urgent global response”
Sir Nicholas Stern, 'The Stern Review' on economics of climate change, October 2006
Since the industrial revolution CO2 concentrations have risen from ~280ppm to ~390ppm (parts per
million) currently. Between 1995 and 2005 atmospheric CO2 rose by 19ppm, the highest decadal rise
since measurements began.
Figure 10 Greenhouse gas concentrations from 0 to 2005 (IPCC, 2007)
The forcing component through increased amounts of greenhouse gases in the atmosphere from
anthropogenic emissions far outweighs any natural changes, for example solar irradiance. When
examining the difference in climate scenarios with and without anthropogenic forcing since the
industrial revolution, it is clear of the impact this has on temperatures.
Black line = Actual Temperature
anomaly
Red Line = Temperature anomaly
with Natural and Anthropogenic
Forcing
Blue Line = Temperature anomaly
with Natural Forcing Only
Figure 11 Difference in temperatures since 1900 with and without anthropogenic forcing (IPCC, 2007)
Page 8
Birmingham’s Climate Portfolio
Climate change is now widely accepted as one of the greatest challenges of the 21st Century. If
climate change is not addressed, it is estimated that the cost to the world’s economy will be greater
than the 20th Century world wars and the Great Depression of the 1930’s combined. The Stern
Report (2006) estimates that taking action now would cost 1% of global gross domestic product
where as acting in the future would cost anywhere between 5 and 20%.
In order to adapt Birmingham to climate change it is important to understand what the likely
predictions are. These need to be interpreted with a prior lay knowledge of the local area
highlighted in the LCLIP report mentioned above. By doing this, the knowledge of climate change will
become more applied to Birmingham and provide a more practical means of adapting.
3.1 Scenarios and Probabilities
The UKCP09 uses three emissions scenarios – low, medium and high which are developed on the
IPCC Special Report on Emissions Scenarios (SRES, 2000). The emissions associated with the
scenarios are based on demographic, social, economic and rate and development of technological
change. Based on the current socio-economic situation it is agreed that the world emissions are
currently equivalent to a medium to high emissions scenario. The low emissions scenario
demonstrates what emissions could be if more sustainable energy usage and mitigating policies to
climate change were adopted. If all emissions were stopped today there would still be a 0.6oC
warming from a lag effect.
Example of Socio-Economic areas covered for UPCP09 emission scenarios (UKCIP, 2001)
- Values and Policy
- Economic Development
- Settlement and Planning
- Agriculture
- Water
- Biodiversity
- Coastal Zone Management
- Built Environment
A1F1 – High Emissions Scenario
A1B – Medium Emissions Scenario
B1 – Low Emissions Scenario
Very rapid economic growth, a global population
that peaks in mid–21st Century and thereafter
declines. The scenario also envisages increased
cultural and social interaction, with a
convergence of regional per capita income.
Focuses on the idea that there will be extensive
fossil fuel use with little use of renewable energy
sources.
A balance emphasis on all energy sources –
where balanced is defined as not relying too
heavily on one particular energy source, on the
assumption that similar improvement rates
apply to all energy supply and end use
technologies.
The same population dynamics as A1, but a
transition toward service and information
Page 9
Birmingham’s Climate Portfolio
economies, with lower material consumption
and widespread introduction of clean and
efficient technologies.
For each emission scenario there is a range of probabilities. ‘The probabilities are a measure of the
degree to which a particular level of future climate change is consistent with the evidence
considered,’ (UKCP09). By using cumulative probabilities, this enables predictions giving a range of
values which decrease in likelihood from the central estimate:
-
Very likely to be greater than/ very unlikely to be less than (lower estimated limit) = 10%
Central Estimate = 50%
Very likely to be less than/very unlikely to be greater than (upper estimated limit)= 90%
For example, under a medium emissions scenario, temperature change on the warmest day of
summer 2060 is likely to be 2.5oC (central estimate). The temperature change is unlikely to be less
than -1.5oC (10%) and more than 6.5oC higher (90%).
The climate change variables: mean, maximum and minimum temperature, precipitation, humidity
and cloud cover were calculated for the three emissions scenarios and probability levels. It must be
noted that humidity and cloud cover predictions have large amounts of uncertainty in the findings,
so they are not presented here.
3.2 Climate Projections for Birmingham
The user interface on the UKCP09 climate projections website (http://ukcp09.defra.gov.uk) provides
estimates to a 25km2 resolution.
Temperature – The annual average temperature in Birmingham has increased by 0.6oC , from 9.4oC
(1961 – 1999) and 10oC (1991 – 2007). This rise in temperature for Birmingham also relates to a
warming trend found in the Central England Temperature series (CET, Figure 12).
The UKCP09 projections show that Birmingham will experience hotter summers and milder winters. This is highlighted
for the three emission scenarios and for the range between the 10% and 90% probabilities in Figure 13.
Figure 12 CET Annual Temperature Series 1971 - 2009
Page 10
Birmingham’s Climate Portfolio
2030
Probability (%)
Mean summer
temperature (°C)
Change on hottest day (°C)
Change in summer mean
maximum temperature
(°C)
Change in mean winter
temp (°C)
2050
2080
10
16
16
16
-1.5
-1.5
-1.5
1
1
1
50
17
17
17
2
2
2.5
2
2.5
2.5
90
18.5
18.5
19
6
6
6.5
4
4.5
4.5
10
16
16.5
16.5
-1.5
-1.5
-1.5
1
1
1.5
50
17.5
18
18
2.5
2.5
3.5
3
3.5
4
90
19.5
20
21
7.5
7.5
9
5.5
6
7
10
16.5
17
17
-2
-2
-1.5
1
2
3
50
18
19
20
2.5
3
4
4
5
6
90
20
21
22.5
8
9.5
12
7
9
11
4.5
4.5
4.5
5.25
5.25
5.25
6.25
6.25
6.25
4.5
5
5.5
5.5
6
6
6.5
7
7.5
5
5
6
6
6.5
7
7.5
8
8.5
Figure 13 Temperature Change in Birmingham
Key
Low emissions
Medium emissions
High emissions
Precipitation - The annual mean rainfall for Birmingham has already increased by 53mm from
767mm, 1961-1990 to 821mm, 1991-2007. Precipitation patterns are expected to shift in the 21st
Century, with winter months experiencing greater mean totals whilst summer will become drier. By
2020 winter precipitation is could increase by up to 14.5% (90% probability level). However annual
precipitation totals are not expected to change much from current levels.
2030
Probability (%)
Mean winter precipitation
change
Winter %change in
precipitation on the
wettest day
Mean summer
precipitation change %
Summer %change in
precipitation on the
wettest day
10
-2
-2
-1
-8
-6.5
-9.5
-24
-27
-27
-14
-14
-16
50
7.5
8.5
8.5
8
6.5
4.5
-12
-8
-7
2.5
2.5
1.5
2050
90
19.5
21
21
26
21
20
12
12
11
24.5
24
21.5
10
1
2
2
-6
-4.5
-4.5
-33
-36
-38
-16
-18
-18
50
12
15
16.5
9
10
11
-12
-17
-17
2
0.5
0.5
2080
90
26
31
35
26
27
30
13
7
7
24
23
24
10
3
3
6
-4
-3.5
-1
-34
-43
-50
-16
-18
-20
50
16
19.5
26
13.5
15
19.5
-13
-20
-25
-1
-1
-3
90
35
44
57
28
33
35
11
5
5
25
25
29
Figure 14 Precipitation change in Birmingham
Page 11
Birmingham’s Climate Portfolio
Summary of likely changes for Birmingham
•
•
•
•
•
Summer mean temperature rise of 2.8oC (Low emissions scenario) to 4.7oC (High) by 2080.
Summer mean daily maximum will rise by 3.9oC (Low) to 6.6oC (High) by 2080.
August 2003 heat wave will be a typical summer towards the end of the century.
Precipitation totals will remain constant. However a shift in seasonality towards a winter
bias is expected.
Summer precipitation will happen over fewer days but will become more intense.
3.3 Risks to Birmingham
A transient climate, with a shifting mean and variance (distribution) will force the climate of
Birmingham towards the extremes. What climate change projections provide us with is the longterm average. However on a day to day basis, the weather is likely to show a much greater
distribution in the number and magnitude of significant weather events. The significant weather
events that have already affected Birmingham, above, are likely to become a more recurrent
feature, with increased severity towards the end of the Century.
Page 12
Birmingham’s Climate Portfolio
Heatwaves for Birmingham are defined as two consecutive days over 30oC with night time
temperatures not falling below 14oC. The resilience to heatwaves varies throughout the UK (Figure
16).
Threshold temperatures
Region
Day max (°C)
Night min (°C)
North East England
28
15
North West England
30
15
Yorkshire & Humber
29
15
East Midlands
30
15
West Midlands
30
15
East of England
30
15
South East England
31
16
London
32
18
South West England
30
15
Wales
30
15
Figure 16 Threshold temperatures for the UK based on regions (Met Office, 2010,
http://www.metoffice.gov.uk/weather/uk/heathealth/ )
By the 2080s Birmingham could have an average of 3 heatwaves during July and 2 during August
(medium emissions). Under a high emissions scenario this will rise to 4 and 3 respectively. These
heatwaves are also likely to become longer and more severe throughout the 21st Century. This could
result in an 11% increase in all cause mortality in summers as a result of higher temperatures by
2080 Elderly and already vulnerable residents will be particularly at risk. The rise in temperatures
could also Increase the number of ozone pollution episodes. It is estimated there will be 53% more
deaths by the 2020s than 2003 (Health Effects of Climate Change in the West Midlands, 2010). The
increase in summer temperatures combined with a decrease in summer precipitation could lead to
the increase in number of droughts and their duration.
An increase in precipitation in winter will lead to more flooding. However whilst summer
precipitation totals will decrease, when precipitation does occur, it is likely to be more intense thus
rising the risk of surface flooding. The return period of significant rainfall events is likely to decrease.
Flooding causes both damage to properties, loss of life and psychological stress to those affected.
Other affects of climate change include secondary impacts such as high temperatures triggering
storms and changes in air quality are expected. It is also important to consider that global issues will
affect Birmingham. For example supply chains will be affected and Birmingham could become a hub
for refugees fleeing from conflict or displacement arising from climate change.
A shift in precipitation patterns will lead to more frequent winter flooding for Birmingham. Reduced
summer precipitation combined with an expected rise in temperatures will lead to an increase of
heat waves and droughts. The magnitude of the events is also likely to increase and secondary
impacts of these changes such as high temperatures triggering storms and changes in air quality
Page 13
Birmingham’s Climate Portfolio
expected to occur. This will put increasing pressure on both the population and local services to
manage.
4.0 Urban Heat Island (UHI) of Birmingham
The layer of atmosphere between the Earth’s surface and the top of the buildings is the area in
which people live and work. This is known as the urban canopy layer and much like a mountainous
environment has its own climate. Urban areas in essence modify the climate through un-natural
modifications to the environment. The urban fabric modifies temperatures, precipitation run-off and
wind flows. The resulting consequence is coined the urban heat island (UHI). The physical processes
responsible for this effect whereby urban areas are significantly warmer than the surrounding rural
areas are highlighted as following.
UHI Causes (Oke, 1987; Grimmond, 2007)
Reduced sky view factor (SVF)
Decrease in long wave radiation loss: radiation trapping
Slower wind speeds
Decrease in total turbulent heat loss
Building materials
Thermal properties: increased heat capacities and conductivities
Radiative properties: albedo and emissivity changes
Anthropogenic heat flux
Energy consumption and resulting heat from buildings, vehicles and people
Air Pollution
Absorption and re-emission of long-wave radiation in the air
Lack of Vegetation
Decreased evapotranspiration: less cooling from latent heat flux
Increased surface area
Higher short-wave absorption
Figure 17 UHI Transect showing the typical temperature profile across a city
(Oke, 1987)
Thus urbanisation has lead to the modification of the surface and atmospheric energy budgets
across vast areas of the Earth’s surface. The effect of the built environment alters the radiative,
thermal, moisture and thermodynamic balances (Oke, 1987). At present over half the worlds
population live in urban areas and with a predicted urbanised population of 5 billion by 2030
Page 14
Birmingham’s Climate Portfolio
(UN,2010) this makes quantifying the urban heat island a pressing issue. Birmingham, UK (52oN,
1.5oW) has a population exceeding one million over an area of 267 km2 at an altitude of around
140m. It has a well defined urban heat island, yet has not been properly investigated since the
1980s.
Unwin (1980) compared daily maximum and minimum temperatures at two sites: Edgbaston,
representative of the city and Elmdon of rural areas. Over the study period (1965-74) Edgbaston
was found to be 0.27k warmer than Elmdon. However on analyses, the mean maximum was cooler
at Edgbaston and the overall heat island effect was due to a significantly higher (1.02K) night time
minimum at Edgbaston (Figure 18). These suggest a day time cool island across Birmingham.
Overall mean
Mean Maximum
Mean minimum
Edgbaston (City)
9.49
12.41
6.56
Elmdon (Rural)
9.22
12.90
5.54
UHI Intensity (Tu-r)
0.27
-0.49
1.02
o
Figure 18 Mean Temperatures ( C) in Birmingham 1965-74 (Unwin, 1980)
Unwin (1980) recorded a maximum UHI intensity of 10oC. The largest UHI intensity was found during
the spring and autumn. The city was found to be on average 0.59k cooler than rural areas during the
summer. To investigate Birmingham’s UHI further Unwin (1980) classified the temperature
differences based on Lamb’s (1950) airflow types. Unwin (1980) found anticyclonic conditions to give
rise to an average 2.26k difference in the mean minimum temperatures (Figure 19). Cyclonic
conditions were found to have the least pronounced UHI effect in the mean minimum temperatures.
The maximum day time cool island was found under unsettled westerly and cyclonic conditions.
Airflow type
Occurrence (%)
Anticyclonic
Unclassified
South-east
Southerly
Northerly
Westerly
South-west
North-west
Easterly
North-east
Cyclonic
18.4
5.3
3.1
5.8
8.5
22.3
3.9
7.8
7.4
2.8
14.7
UHI intensity of mean
minimum
2.26
1.39
1.32
1.14
0.84
0.67
0.67
0.63
0.63
0.51
0.49
UHI intensity of mean
maximum
-0.23
-0.42
-0.41
-0.44
-0.53
-0.61
-0.58
-0.62
-0.41
-0.44
-0.61
Figure 19 Occurrence of Lamb’s air flow type and their associated UHI
Unwin (1980) also analysed the distribution of UHI events. It was found that for Birmingham, urban
heat islands were predominantly in the summer half of the year. On analysing the strongest heat
islands that developed in the study period, 71% of these were associated with anticyclonic
conditions.
Johnson (1985) adopted a different strategy to Unwin (1980) through investigating the heating and
cooling rates of the UHI. Johnson (1985) states the rationale for this being the exact time that the
urban and rural surfaces display different characteristics can be established. By traversing a 20km
route across the city centre using a psychrometer attached to a car roof over 8 sample days in July
Page 15
Birmingham’s Climate Portfolio
1982. As the UHI is most pronounced under anticyclonic (calm, clear sky) conditions, only when
these prevailed did measurements take place. To compliment the study thermograph records from
Edgbaton and Elmdon were also used to calculate heating/cooling rates.
Johnson (1985) found that range of heating/cooling rates decreased with proximity to the city
centre. Strong temporal variations were found with the greatest heating/cooling rates at
sunrise/sunset. There was also a large variation in rates at the rural/urban boundary and between
different rural surfaces.
Figure 20 Top: UHI Intensity. Bottom: average heating / cooling rates for urban
and rural Birmingham.
The UHI intensity for Birmingham was found to grow early afternoon and remain a fairly constant
4.5k throughout the night. Johnson (1985) found the centre of Birmingham to be on average 0.1k
warmer than the rural areas. However Unwin (1980) found the city centre to exhibit an urban cool
island. It must be noted that the Edgbaston site used by Unwin (1980) is approximately two miles
out of the city centre and the Elmdon site is situated next to Birmingham international airport. Thus
the two sites used by Unwin (1980) cannot be considered truly representative of urban/rural
characteristics.
Johnson (1985) also started some early work into the relationship between the sky view factor (SVF)
and the maximum cooling rates. Johnson (1985) found that the cooling rates decreased with a
decrease in SVF (r = -0.83). Thus Birmingham was found to heat up and cool down slower than the
surrounding rural areas.
Page 16
Birmingham’s Climate Portfolio
5.0 Impacts
Potential Impacts of Climate Change in the West Midlands (Anderson et al. 2003)
The capability of Birmingham’s urban drainage system to increased Winter precipitation and
flooding
Increased risk of building subsidence
Increased demand for summer irrigation systems due to decreased summer rainfall
Reduction in agricultural yields due to summer droughts
Increased energy demand for cooling (section 6.1) and transport to cooler areas
Increase in storm frequency
Increase demand for rural living (Rural areas in the West Midlands population increased by
20% and urban areas declined by 5.7% (1993 – 2003)
Tarmac melting / railways buckling
5.1 Energy impacts
Hadley et al. (2006) studied the impacts of energy change in the USA in response to climate change.
A general circulation model (GCM) was coupled with an energy use model for a low (1.2oc) and high
(3.4oC) temperature scenario for 2025 in response to atmospheric CO2 doubling. Hadley et al. (2006)
found the most relevant impact to be changes in heating/cooling requirements in residential and
commercial buildings. Cooling is less efficient than heating thus Hadley et al. (2006) state the offset
in reduced winter heating due to climate change is more than outweighed by the increase in
summer energy demands for cooling. Hadley et al. (2006) also state the increased electricity
production from fossil fuels to cope with the increased demands would increase carbon emissions.
5.2 Health Impacts
Tol (2002) states that for every 1oC rise in temperature 350,000 worldwide could die from
cardiovascular and respiratory problems. The summer 2003 heat wave across West Europe claimed
an estimated 35,000 lives. The UK Office for National Statistics estimates there were 2045 deaths
above the national average for England and Wales between the 4th and 13th August. Stedman (2004)
using a dose-response function analysed the August 2003 heat wave finding 21 – 38% of the
associated deaths to be caused by increased atmospheric loadings of ozone (Figure 24) and PM10.
The problem lies that unlike any other significant weather event, heat is not treated as an
atmospheric hazard. Heat and the influence of the UHI have impacts for the wellbeing of the young,
old (Figure 23) and those already with underlying illnesses. It also affects residents, especially those
of lower income in old, high density housing which have little or no surrounding vegetation (Coutts
et al. 2008).
The UHI of Birmingham is likely to exacerbate future heat waves. Tan et al. (2010) found the UHI of
Shanghai, China to create additional heat wave days that were not found in surrounding rural areas.
Page 17
Birmingham’s Climate Portfolio
How climate change affects human health (Tol, 2002)
Heat stress mortality
Detrimental air quality
Floods and storms
Water supply and agriculture
Influencing vectors of infectious disease (e.g. malaria)
Figure 21 Average annual heat-related deaths by age for the US: 1979 -1999 (Rate - per million people) (CDC, 2002)
Air pollution is a major environmental risk to health. Exposure to air pollutants is mainly beyond the
control of individuals thus requires action at higher levels. Unfavorable air quality is estimated to
cause around 2 millions premature deaths worldwide per year (WHO, 2003). Within cities there is
considerable risk from exposure to pollutants, particularly ozone and particulate matter. Reducing
PM10 concentrations from 70 to 20ugm-3 has been shown to reduce air quality related deaths by
15% (WHO, 2003)
Climate plays an influence on air quality. Temperatures affect reaction rates and natural emissions.
The amount of precipitation affects deposition rates and wind speeds affect the horizontal
dispersion. As a consequence of warming, more windows will be open to allow for ventilation, thus
indoor concentrations of pollutants will become higher.
Page 18
Birmingham’s Climate Portfolio
Figure 22 Distribution of ozone using 76 monitoring stations on 6th August 2003 (Lee et al. 2006). High
pressure, low wind speeds and sustained high temperatures lead to ozone concentrations greater than
-3
110ppbV (220 ugm ) for a five day period within the heat wave period. The maximum daily 8 hour mean
-3
for ozone set out by the EU directive: 2008/50/EC (and 2002/3/EC) is 120 ugm .
6.0 Opportunities from Climate Change
Potential Opportunities of Climate Change in the West Midlands (Anderson et al. 2003)
Longer growing season
Solar power feasibility
Reduced snow/ice damage, reducing amount of grit used
Less heating required in winter
Decrease in winter deaths
7.0 Mitigation/Adaptation
Various strategies into reducing the impact of the UHI have been put forward. These are available on
a range of different scales from individual to neighbourhood and new development to retrofitting
existing buildings (Grimmond, 2007). In order to adapt and ensure the appropriate strategy is used
the UHI of Birmingham needs to be understood and modelled. The strategies outlined as following
should alter the surface energy balance (section 6.0) of the urban environment and reduced the UHI
effect. Akbari et al. (2001) estimate that through a large-scale implementation of mitigation
measures, 20% of the US energy demand for cooling could be saved.
Page 19
Birmingham’s Climate Portfolio
Current strategies to UHI Mitigation/Adaptation
Increase albedo of buildings: new development in highly reflective materials mean buildings
do not necessarily need to be white (Grimmond, 2007)
Increase spacing between buildings
Green infrastructure: vegetation reduces ambient air temperatures through increased
evapotranspiration and provides shading
Cool pavements: Akbari et al. (2001) found a 10oC decrease in pavement temperature for a
0.25 increase in albedo
Ensure ventilation in old, high density housing
Heat wave action plans and heat awareness
Page 20
Birmingham’s Climate Portfolio
8.0 References
Akbari H., Pomerantz M., Taha H., 2001. Cool Surfaces and shade trees to reduce energy use and
improve air quality in urban areas. Solar Energy 70: 295 - 310
Anderson M., Dann S., Hughes C., Kersey, J., Chapman L., Kings L., Thornes J., Hunt, A. and Taylor T.
2003. Sustainability in the West Midlands. The Potential Impacts of Climate Change in the West
Midlands. Technical Report, Entec UK limited, UK Climate Impacts Programme.
Centers for Disease Control and Prevention. Heat-related deaths – four states, July–August 2001,
and United States, 1979–1999. Morbidity and Mortality Weekly Report, 2002, 51:567–570.
Council Directive 2008/50/EC on ambient air quality and cleaner air for Europe and 2002/3/EC of
the European Parliament and of the Council relating to ozone in ambient air.
Coutts A.M., beringer J., Tapper N.J., 2008., 2008. Investigating the climatic impact of urban planning
strategies of regional climate modelling: a case study for Melbourne, Australia. International Journal
of Climatology, 28: 1943 – 1957.
Giles, B.D. and Kings, J. 1996. Chapter 8. Birmingham Weather Through Two Centuries. In: Gerrard,
A.J. ans Slater T.R. 1996. Managing a Conurbation: Birmingham and its Region, Brewin Books,
Studley, Warwichshire, 101 – 114 pp.
Giles, B.D. and Kings J. 1997. Chapter 5. The Midlands. In: Wheeler, D. 1997. Regional Climates of
the British Isles, Routledg, London, 111 – 129 pp.
Grimmond S., 2007. Urbanization and global environmental change: local effects of urban warming.
The Royal Geographical Society 83 – 88.
Hadley W., Erickson D.J., Henandez J.L., Broniak C.T., Blasing T.J., 2006. Responses of energy use to
climate change: A climate modeling study. Geophysical Research Letters 22: 1-4
Health Effects of Climate Change in the West Midlands:
Technical Document and Summary Report available on the WMPHO website:
www.wmpho.org.uk/topics/climatechangeandhealth.aspx
Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller, 2007.
Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel
on Climate Change, 2007, Cambridge University Press
Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)
Masson V., 2005. Urban surface modeling and the meso-scale impact of cities. Theor. Appl. Climatol.
84: 35 – 45.
McGregor G.R., Ferro C.A.T., Stephenson D.B., 2005. Projected Changes in Extreme Weather and
Climate Events in Europe. In Kirch B., Menne B., Bertollini R., Extreme Weather Events and Public
Health Responses, Springer.
Page 21
Birmingham’s Climate Portfolio
Met Office Fact Sheets: http://www.metoffice.gov.uk/corporate/library/factsheets.html
Met Office Regional Climate Mapped Averages:
http://www.metoffice.gov.uk/climate/uk/averages/regmapavge.html#
Met Office, Threshold temperatures for the UK based on regions:
http://www.metoffice.gov.uk/weather/uk/heathealth/
Oke T.R., 1987. Boundary layer Climates, 2nd Ed. Methuen, London.
Smith C., Lindley S., Levermore G., 2009. Estimating spatial and temporal patterns of urban
anthropogenic heat fluxes for UK cities: the case of Manchester. Theor. Appl. Climatol. 98: 19 – 35.
Stedman J.D., 2004. The predicted number of air pollution related deaths in the UK during the
August 2003 heatwave. Atmospheric Environment 38: 1087 – 1090.
Stevenson D. Eulerian modelling of TORCH: EMEP4UK simulations of surface ozone during the 2003
heat-wave. PP Presentation. http://www.airquality.co.uk/reports/cat11/0903300937_Eulerianmodelling-of-TORCH-David-Stevenson.pdf
Tan J., Zheng Y., Tang X., Guo C., Li L., Song G., Zhen X., Yuan D., Kalkstein A.UJ., Li F., Chen H., 2010.
The urban heat island and its impact on heat waves and human health in Shanghai. Int. J.
Biometeorol. 54: 75 – 84.
UKCP09: UK Climate Impacts Programme: http://ukcp09.defra.gov.uk/
UK Office for National Statistics: http://www.statistics.gov.uk/hub/index.html
Winterbourne Climate Station, Climate and Research Group Weather Facility, University of
Birmingham. 2010. http://kermit.bham.ac.uk/~kidd/.
WHO (2003). Air Quality and Health. World Health Organisation. Factsheet Number 313. Accessible
via: http://www.who.int/mediacentre/factsheets/fs313/en/index.html
World Meteorological Organization, 2004 Workshop on Severe and Extreme Events Forecasting,
Toulouse, 26-29 October 2004
Page 22