Climate change will affect production potential differently in different parts of the world. In broad terms it is likely to deepen global
inequities. While some developed countries in middle and especially northerly latitudes may make net gains, many developing countries in the tropics may suffer increased climaterelated difficulties and increased variability of rainfall (Fischer and others 2002b).
The IIASA study suggests that, taken as a whole, developing countries might lose 11 per cent of currently suitable land for rainfed cereals (Fischer and others 2002b). Not all developing areas will lose out. Given a 3°C temperature rise and unchanged rainfall, China would make net gains in potential rainfed cereal land, as would Central Asia and West Asia. But there would be very significant losses of 31 per cent in Southern Africa and 20 per cent in South America, with losses ranging from 11 per cent
to 13.5 per cent in the rest of sub-Saharan Africa, and in Central America, South and South-East Asia (Figure 5). Projected losses increase progressively as temperatures increase.
Increased rainfall improves the situation for some regions, but worsens it for others, with the overall loss in developing countries remaining at the same level. Calculated at country level under the Hadley Centre’s CM2 climate model, 38 developing countries, with a projected year 2080 population of 3 300 million, would lose more than 5 per cent of their rainfed cereal production, losing a total potential production of 273 million tonnes. Figure 6 shows
country-level gains and losses under another Hadley climate model, CM3-A1F1.