Review

There is near unanimous scientific consensus that the rising atmospheric concentration of greenhouse gases due to human actions will cause warming (and other climatic changes) at Earth’s surface. The Inter-governmental Panel on Climate Change (IPCC), drawing on the published results of leading modelling groups around the world, forecasts an increase in world average temperature by 2100 within the range 1·4–5·8ºC.1 The increase will be greater at higher latitudes and over land. Global average annual rainfall will increase, although many mid latitude and lower latitude land regions will become drier, whereas elsewhere precipitation events (and flooding) could become more severe. Climate variability is expected to increase in a warmer world