In 2006, Lord Stern produced an influential document on global warming, "Stern Review on the Economics of Climate Change". The report assumed that if nothing was done to counter climate change, global temperatures would rise between 2C and 3C by the end of the century and would cost about 20 percent of the GDP.

Lord Stern says now new research shows temperatures could raise by 4C to 7C by 2100 and would produce conditions not seen on Earth for more than 30 million years. The revised estimated costs would be 50 percent higher than predicted in 2006 - risking a third of the world's wealth.

Lord Stern warned, "The costs of delay are very deep." Climate change will cause sea levels to rise by 50 meters, increase occurrence of hurricanes and cause widespread desertification. Hundreds of millions of people would be forced to relocate and social conflict would follow.