Since the 1970s, average global temperatures over land have increased by around 0.7 oC. The Intergovernmental Panel on Climate Change (IPCC) projects a future rise of between 0.7 oC and 1 oC by the end of this century (IPCC, 2007a). Temperature has already increased almost everywhere on the planet with the largest warming over the northern continents (e.g. UK), where in a few places it already exceeds 20C. However, unlike temperature, precipitation increases in some parts of the world and decreases in others (Archer and Rahmstorf, 2010).