Sir John Houghton argues that drought is the biggest climate change threat in the developing world:

“It’s the extremes of water which are going to provide the biggest threat to the developing world from climate change,” he said.

“Without being able to be too specific about exactly where, droughts will tend to be longer, and that’s very bad news. Extreme droughts currently cover about 2% of the world’s land area, and that is going to spread to about 10% by 2050.”