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Global climate change may impact food production across a
range of pathways (Figure 17): 1) By changing overall growing
conditions (general rainfall distribution, temperature regime
and carbon); 2) By inducing more extreme weather such as
floods, drought and storms; and 3) By increasing extent, type
and frequency of infestations, including that of invasive alien
species (dealt with in a separate section).
IMPACTS OF CLIMATE CHANGE ON YIELD
The estimated impacts of changes in the general climate re-
gime vary with the different models in the short to mid-term
(2030–2050), but after 2050 an increasing number of models
agree on rising negative impacts (IPCC, 2007; Schmidhuber
and Tubiello, 2007). Many models have projected that the po-
tential for global food production may rise with increases in
local average temperature over a range of 1–3ºC (before 2050),
Global temperature increase (relative to pre-industrial)
0°C
+1°C
+2°C
+3°C
+4°C
+5°C
+6°C
0°C
+1°C
+2°C
+3°C
+4°C
+5°C
+6°C
Projected impacts of climate change
Food
Water
Ecosystems
Extreme weather events
Risk of abrupt and major irreversible changes
Falling crop yields in many areas, particulary developing regions
Possible rising yields in some high latitude regions
Small mountain glaciers disappear,
impacts on water supplies
Significant decreases in water availability in many
areas, including Mediterranean and Southern Africa
Sea level rise threatens major cities
Extensive damage to coral reefs
Rising number of species face extinction
Rising intensity of storms, forest fires, droughts, flooding and heat waves
Increasing risk of dangerous feedbacks and abrupt, large-scale shifts in the climate system
Falling yields in many developed regions
Figure 17: Projected impacts of climate change.
(Source: Stern Review, 2008).