Page 183 - Climate Change and Food Systems

chapter 5: climate change impact on key crops in africa: using crop models and general equilibrium models to bound the predictions
figure 10
Rainfed maize areas (ha) for West Africa, 2000
< 1 ha
1 to 10 ha
10 to 30 ha
30 to 100 ha 100 to 500 ha 500 to 3 000 ha > 3 000 ha
Sources: SPAM (Spatial Production Allocation Model)
(You and Wood, 2006; You, Wood, and Wood-Sichra, 2006, 2009)
Note: ha = hectare
climate change in the region. All models confirm that rainfed rice will improve in productivity. Results for all other crops are mixed; rainfed maize and groundnuts will increase in productivity under climate change, while irrigated wheat will decline in productivity.
Any negative impact of climate change on irrigated crops is attributable to temperature increases. Yield reductions for rainfed crops could be attributed, depending upon the particular crop, to either rainfall reductions or temperature increases. For East Africa, most models show steady or increased annual rainfall; however, in some areas, growing season rainfall might decline despite rising annual rainfall.
figure 11
Change (%) in rainfed maize yield for West Africa due to climate change, 2050, A1B Scenario
Source: Authors
Notes: Top to bottom: results for the CNRM, CSIRO, ECHAM, and MIROC GCMs
Baseline area lost
Yield lost > 25% of baseline
Yield lost 5% to 25% of baseline Yield change within 5% of baseline Yield gain 5% to 25% of baseline Yield gain > 25% of baseline
New area gained
163