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omies, the scarcity of capital for adaptation measures, their
warmer baseline climates and heightened exposure to extreme
events (Tubiello and Fischer, 2006; Brown and Funk, 2008).
This will aggravate inequalities in food production among re-
gions (Parry
et al
., 2005).
Regional impacts will be strongest across Africa and Western
Asia where yields of the dominant regional crops may fall by
15–35% once temperatures rise by 3 or 4º C (Stern Review,
2006). Sub-Saharan Africa is expected to be worst affected,
meaning the poorest and most food insecure region is also
expected to suffer the largest contraction of agricultural pro-
duction and income. Despite the uncertainties regarding
short-term effects, models do point to many cases where food
security is clearly threatened by climate change by 2030, with
losses in major crops by this time (Lobell
et al
., 2008).
There is wide variation in how individual species in different
regions respond to a warming climate and Lobell
et al
. (2008)
identified 3 general classes of crop responses to climate
change projections: 1) Consistently negative, for example,
Southern African maize; 2) Large uncertainties ranging from
substantially positive to substantially negative, for example,
South Asian groundnut; and 3) Relatively unchanged, for ex-
ample, West African wheat. Adaptation to climate change by
switching from highly vulnerable to less vulnerable crops may
be viable, and is recommended particularly for South Asia
and South Africa where the case for adaptation is particularly
robust (Lobell
et al
., 2008).
The impacts on crops are also highly variable in different re-
gions and on different types of crops. For example, in Southern
Africa, declines in production of 15% for wheat and 27% for