Page 170 - Climate Change and Food Systems

climate change and food systems: global assessments and implications for food security and trade
and conclusions for 2050. In particular, projections for population, GDP and levels of agricultural production are presented. Then methodologies
for climate models are presented, followed
by the crop model results for climate change impacts and IMPACT model results. Key policy recommendations are then briefly presented in the conclusions.
1.1 Population
Table 1 presents regional summaries of population growth, which is one of the leading drivers of food demand, along with data for leading countries in each region.
East Africa is projected to have the fastest population growth, with the median variant projected to grow at around 2.0 percent annually. This is followed by West Africa, with the median variant projected to grow at around 1.8 percent annually, and Southern Africa, projected to grow at 1.4 percent annually.
The reason Southern Africa is projected
to grow more slowly is largely because South Africa, which in 2008 made up slightly more than one-third of the region in terms of population, is projected to grow at only 0.4 percent annually. Its low variant scenario actually projects a negative population growth rate.
Nigeria’s population represents more than half of the population of West Africa, and almost 20 percent of the population of all three regions, so it has a large influence on all of the regional statistics presented for West Africa.
With such large population growth rates projected across the three regions, demographic changes will present formidable challenges
to policy-makers in the areas of employment, housing, water, health and issues of food security. These challenges will be in addition to any challenges presented by climate change.
1.2 Income
The second key driver of food demand is measured as GDP per capita. Table 2 shows
that the GDP per capita for Southern Africa is approximately six times higher than West Africa. East Africa and West Africa have similar GDP per capita values, though West Africa’s is around 13 percent higher than in East Africa. However, the projected growth rates of GDP per capita suggest that they will even out, with West Africa having the highest projected growth, followed by East Africa and then Southern Africa.
1.3 Agriculture
The most important crops for each region, based on crop area harvested, are presented in Table 3. Maize, sorghum and millet occupy the highest
crop areas for all of Africa, but with considerable variation across regions. Maize is the most significant crop in Southern Africa, and ranks fourth in West Africa. Sorghum ranks a close second, although it is of relatively low importance (fifth) in Southern Africa. Millet is ranked third – in first place in West Africa but fourth in Southern Africa.
Only Southern Africa is dominated by a single crop, maize, which occupies almost twice the area as the second through fifth ranked crops. Both East Africa and West Africa have more diverse cropping areas, although maize and sorghum together form a significant portion of crop area for East Africa.
2. Climate and climate models
2.1 Precipitation
Figure 2 shows mean annual precipitation for
the 1950 to 2000 period. Steep declines in precipitation are seen moving northwards through the Sahelian zone towards the Sahara in North
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