Climate change threatens the basic elements of life for people around the world – access to water, food, health, and use of land and the environment. On current trends, average global temperatures could rise by 2 - 3°C within the next fifty years or so,1 leading to many severe impacts, often mediated by water, including more frequent droughts and floods (Table 3.1).

• Melting glaciers will increase flood risk during the wet season and strongly reduce dry-season water supplies to one-sixth of the world’s population, predominantly in the Indian sub-continent, parts of China, and the Andes in South America.
• Declining crop yields, especially in Africa, are likely to leave hundreds of millions without the ability to produce or purchase sufficient food - particularly if the carbon fertilisation effect is weaker than previously thought, as some recent studies suggest. At mid to high latitudes, crop yields may increase for moderate temperature rises (2 – 3°C), but then decline with greater amounts of warming.
• Ocean acidification, a direct result of rising carbon dioxide

More information from STERN REVIEW: The Economics of Climate Change