The UK Government has published a study by Sir Nicholas Stern into the possible economic consequences of climate change, the first major contribution to the global warming debate by an economist, rather than a scientist. It suggests that climate change could shrink the global economy by a fifth unless drastic action is taken - including a move towards renewable energy sources..

KEY POINTS

• Taking action now would cost about 1% of global gross domestic product.
• Without action up to 200 million people could become refugees through drought or flood.
• Unless the world, including USA and China, tackles climate change it is heading for the worst global recession ever seen.
• 1% of global gross domestic product (GDP) must be spent on tackling climate change immediately.
• If no action is taken, floods could displace up to 100 million people, melting glaciers could cause water shortages for 1 in 6 of the world's population, 40% of species could become extinct, droughts may create tens or even hundreds of millions of refugees.
• Failure to act early could cost 5% to 20% of global GDP and render large parts of the planet uninhabitable with poor nations, especially in Africa, hit worst.
• Switching to cleaner energy sources, like wind and solar, can help avoid the worst of the damage.
• Support for energy R+D should at least double and support for deployment should increase five-fold.
• Green taxes and changing behaviour will help - but schemes must be international.
• If the UK shut down all of its power stations tomorrow, the reduction in global emissions would be wiped out in just over a year by increased emissions from China.
• Action now will still take 30 yrs to show benefit.

The full report is available from the UK Treasury at http://www.hm-treasury.gov.uk/independent_reviews/stern_review_economics_climate_change/stern_review_report.cfm
with a summary at http://www.hm-treasury.gov.uk/media/8AC/F7/Executive_Summary.pdf