IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group II: Impacts, Adaptation and Vulnerability

5.6 Costs and other socio-economic aspects, including food supply and security

5.6.1 Global costs to agriculture

Fischer et al. (2002b) quantify the impact of climate change on global agricultural GDP by 2080 as between -1.5% and +2.6%, with considerable regional variation. Overall, mid- to high-latitudes agriculture stands to benefit, while agriculture in low latitudes will be adversely affected. However, Fischer et al. (2002b) suggest that, taking into account economic adjustment, global cereal production by 2080 falls within a 2% boundary of the no-climate change reference production.

Impacts of climate change on world food prices are summarised in Figure 5.3. Overall, the effects of higher global mean temperatures (GMTs) on food prices follow the expected changes in crop and livestock production. Higher output associated with a moderate increase in the GMT likely results in a small decline in real world food (cereals) prices, while GMT changes in the range of 5.5°C or more could lead to a pronounced increase in food prices of, on average, 30%.

Figure 5.3

Figure 5.3. Cereal prices (percent of baseline) versus global mean temperature change for major modelling studies. Prices interpolated from point estimates of temperature effects.