Download Climate Change and Agriculture: the nature and scale of the problem

Climate Change and
Agriculture:
the nature and scale
of the problem
Geoff Hawtin
Kew - Wakehurst Place
23 Nov 2015
Overview
• The challenges
• Climate change
• Crop genetic
improvement
• Genetic diversity
• Conserving and
using genetic
diversity
The situation today
• 870 million of the world’s
7.2 billion people are
undernourished
• 98% of these live in
developing countries:
15% of the population
undernourished
• Poor nutrition is a major
factor in at least 50% of
the 10.9 million child
deaths annually
FAO 2012
Food security at risk
In order to
meet global
demands, we
will need
60-70%
more food
by 2050.
World population 1950 - 2050
FEEDING THE WORLD in face of changing food habits
Per capita consumption of livestock products
One third of the world’s
cereal supply is used for
livestock feed
Land degradation
Increasing pressure on land
Urbanization
Alternative uses e.g. biofuel
…and climate change
World Resources Institute, 2013
o
o
•
2 - 4 C rise from 1990-2000 levels  significant decrease in
global agricultural productivity
•
Major losers: Southern Africa, Mediterranean, and Southern Asia
•
Winners: Northern Europe, North America, East Asia …,
“What is an abnormally
hot dry year now will be
considered an abnormally
cold and wet year in
2100”
…although it not necessarily all bad, e.g.
Rosenthal et al.
(2012) report ~100
% increases in root
yield under elevated
CO2 and optimal
management
and the recent report: Carbon Dioxide – The good news
I.M. Gloklany. Global Warning Policy Foundation, 2015
There is evidence that yields losses are occurring already:
Estimated yields relative to those that would have occurred
without climate change over the period 1980 - 2008
Lobell et al., Science, 2011
“….. the prevalence of crop pests will
change and the frequency of shock pest
events will increase,…
Smith, 2015
Plant pests
moving polewards
2.7 km per year (Bebber et al. 2013)
By 2050 …
• Potato tuber moth
• additional 2.5 million ha
• >4 generations per year
Kroschel et al 2013
Natural Catastrophes Worldwide
Climatological events (extreme temperature, drought, forest fire)
Hydrological events (flood, mass water movement)
Meteorological events (storm)
Geophysical events (earthquake, tsunami ….)
and agriculture itself is a major source of GHG
Agriculture’s contribution to GHG emissions per country - 30% on average
• 42 countries ≥ 50%
• 89 countries ≥ 20%
(CCAFS 2015)
and what does this mean for future food production?
Common beans in a +2ºC world
Adapting to climate change through
crop genetic improvement
•
>70% increase in global food production and
>90% of UK cereal yield increases over past
25 years associated with better crop varieties
•
Improved varieties: a good option for
smallholders
•
higher yields and greater resilience
•
adapted to changing climates and weather
extremes: drought, heat, cold, waterlogging, salinity, etc…
•
able to tolerate or resist new pests and
diseases
•
use inputs more efficiently
•
more nutritious
and breeding varieties to help
mitigate climate change through:
• capturing more carbon:
– e.g. perennial varieties; larger root systems
• reducing nitrogen fertilizer needs (1/3 agric. GHG)
– e.g. greater NUE; nitrogen-fixing cereals …
• reducing CH4 emissions from paddy fields
(accounts for 10% of total global emissions)
– e.g. reduced flooding requirement
• reducing CH4 emissions from cattle
- e.g. lower fibre/higher polyphenol fodder
• biofuel (“two-edged sword”)
but much is possible with a large, diverse genepool
(a) Historical
(b) Future (no adaptation) (c) Future (+3 ºC adapted)
Potential of tepary bean (P. acutifolius) x common bean (P. Vulgaris)
in E. Africa. Steve Beebe, pers. comm.
Genetic diversity:
the basis of crop improvement
Traditionally plant breeding has
depended largely on intra-specific
genetic diversity; the hundreds of
thousands of varieties developed
over thousands of years by
farmers and plant breeders…
.. and increasingly, crop wild relatives:
•
60-70,000 CWR species (20% of all plant spp.)
•
Becoming increasingly valuable as a result of modern genomic,
molecular, cytogenetic and other techniques, as a
source of new genes/traits
• potato: insect resistance
(hairs) from S. berthaltii
• rice: drought tolerance
from O. longistaminata
• Chickpea: heat tolerance
from C. reticulatum
but genetic diversity is threatened:
on farmer’ fields as:
– farmers switch to fewer
crops and new varieties
– consumer demands change
Varieties lost in US since 1900:
cabbage 95%, maize 91%,
pea 94%, apple 86%,
tomato 81%
and in the wild as habitats are
degraded or lost
•
•
19% Moncots threatened
with extinction
14% of legumes threated
with extinction
Plants under pressure – a global
assessment. IUCN Sampled Red List
Index for Plants. Royal Botanic
Gardens, Kew, UK. 2012
What can we do about it?
A continuum of conservation approaches:
• In situ (crop wild relatives):
– wild protected areas
– special management regimes
• on-farm management of farmer
varieties/landraces
• ex situ
– seed genebanks
– field gene banks
– in-vitro tissue culture banks
– pollen, DNA libraries etc.
•
•
Integrated/complementary approaches are vital.
Ex situ collections are increasingly important for identifying
and sequencing genes for specific traits …
The International Agricultural Research Centres
of the CGIAR
Work in >150 countries
7,500 scientists
Total 2014 budget: approx US$ 1 bn
CGIAR collections, 2013
(number of samples per crop)
–
–
–
–
–
–
–
–
–
Banana: Bioversity
1,500
Barley: ICARDA
27,000
Beans: CIAT
36,000
Chickpea: ICARDA + ICRISAT
34,000
Forages: CIAT + ICARDA + ILRI 66,000
Maize: CIMMYT +IITA
28,000
Potato: CIP
7,000
Rice: AfricaRice + IRRI
129,000
Wheat: CIMMYT + ICARDA
167,000
TOTAL for all crops
approx. 780,000
• >100,000 samples distributed per year
• Samples are freely available upon request
Millennium Seed Bank Partnership
•
Opened 2000, Wakehurst Place
•
Maximizes inter-specific rather than intra-specific
genetic diversity
•
With partners in >80 countries, seeds from >13%
of the world's plant species already conserved
•
As of August, 2015: 36,333 plant species and
>2.1 billion seeds in storage
•
2020 target: 25% of all bankable flowering plant
species (70,000 spp.) safely conserved
•
Conservation and research critical for
conservation and use of CWR
Cornflower: Centaurea cyanus
Svalbard Global Seed Vault
• International safety back-up facility
• Norwegian government initiative - with
Global Crop Diversity Trust
• On Spitsbergen, Svalbard Archipelago:
78°N latitude, 700 miles from N. Pole
• In permafrost, cooled to -18°C
Global
Crop
Diversity
Trust
Svalbard
cont…
Global
Crop
Diversity
Trust
• Tunnel: 95 m. into the mountain
• 3 vaults, each 10 x 6 x 27 m.
• Capacity 4.5 m. samples (500 seeds/sample)
• Currently >860,000 accessions of >4,500 spp.
stored
Arguably the world’s best insurance policy!
Conclusions
•
Feeding the world in face of
climate change is a key challenge
for 21st Century
•
Crop genetic improvement offers
one of the best hopes for meeting
these challenges
•
Plant breeding depends on genetic
diversity; increasingly that found in
wild relatives
•
But this diversity is threatened and
important efforts are underway to
conserve it - for use today and
long into the future
Many thanks for
your attention