Page 186 - Climate Change and Food Systems

climate change and food systems: global assessments and implications for food security and trade
variation); where the “no climate change” results are relative to the “climate change” results; whether there is great variation between economic- demographic scenarios; and whether values change very much through time.
East Africa
Figure 12 shows that, on average, maize yield
will increase by around 60 percent between 2010 and 2050, although there is fairly large variation between the “good” climate model and the “bad” climate model. Very little variation is seen between economic-demographic scenarios. Climate change seems to be mostly favourable for yields of maize in East Africa, given that the X’s for the no climate change scenario are located at the bottom range of the bars on the yield graph.
Harvested areas appear to rise slightly and then fall slightly, denoting that the impact on production is predictable – that is, with production increasing rapidly in the early years, then tapering off.
Southern Africa
Yield is projected to increase by around
50 percent between 2010 and 2050 in
Southern Africa (Figure 13), which is not significantly different than the 60 percent projected for East Africa. However, the range
of yields over all climate models is very small compared to those observed for East Africa. A slightly steeper decline in harvested area devoted to maize was also noted, which would result in production actually falling slightly, on average, after 2040.
West Africa
Figure 14 shows the projections for maize production in West Africa. Yield changes are remarkably similar to those of the other two regions, with yields over the period growing between 50 and 60 percent. Similar to the case for East Africa, the harvested area appears to rise and then fall, both ever so slightly. This results in a production level that is relatively flat after 2040.
4.2 Sorghum
For sorghum, biophysical changes in yield and area attributable to climate change are based on the percentage changes for maize, since sorghum and maize are very similar crops, and since the sorghum model in DSSAT had not been run globally in time for the results to be included in IMPACT.
East Africa
In Figure 15, sorghum yields under climate change are projected to rise around 90 percent between 2010 and 2050. Unlike in the case of maize, the areas expand steadily by around 30 percent. The yields and area changes will result in sorghum production changes of around 150 percent.
Sorghum prices, unlike those for maize, are projected to be relatively flat, with a modest increase of 20 percent. Still, the climate-impacted prices will be higher than the prices without climate change.
Southern Africa
Sorghum yields more than doubled in Southern Africa which is even greater than the gains expected in East Africa. There is little variation in yield among climate models and between models with or without climate change in Southern Africa. On the other hand, a fairly high variation in yield was noted between climate models in East Africa.
Harvested area is projected to rise by around 30 percent in Southern Africa. The end result would be almost a tripling in production between 2010 and 2050.
West Africa
In Figure 17, sorghum in West Africa is between the projected levels for East Africa and Southern Africa. The yield almost doubles, with a small
to moderate variation between climate models. Harvested area expands by around 20 percent, with total production rising by close to 150 percent.
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