The effects of climate change pose a major threat to global prosperity and security. A few years ago, the UK Government funded the Stern Review on the economics of climate change. Its findings were stark: climate change will pose dramatic challenges to human well-being, including the risk of losing the equivalent of 5-20% of global GDP each year.

2009 is a landmark year for climate change. In Copenhagen in December, the world will come together at the United Nations conference to agree a new international agreement to tackle climate change. The current international agreement, the Kyoto Protocol, will expire in 2012. Copenhagen, in effect, will create its successor.

Climate change also threatens the future development of poor countries. Rising sea levels, floods, droughts, increased climate shocks, and lower farm yields will jeopardise hard-won progress in the battle against poverty. Regions like sub-Saharan Africa, which are least responsible for the problem, will suffer most.