Robin McKie writes: Pledges at this year’s climate summit to cut carbon emissions are likely to fall far short of the targets needed to avoid heating the planet by more than 2C. That is the stark conclusion of a report by a team led by British economist Nicholas Stern.

The group, based at the Grantham Research Institute on Climate Change at the London School of Economics, concludes that action planned by countries – in particular the European Union, the US and China – will still leave the world emitting 10bn tonnes of carbon a year in excess of levels needed to prevent global warming from having devastating consequences.

“Intended national contributions will not be consistent with the international goal of limiting the rise in global mean surface temperature to no more than 2C,” states the report, whose publication follows Saturday’s climate action march in London which organisers say was attended by 20,000 people.

Scientists say 2C is the maximum increase in temperature the world can tolerate without risking environmental mayhem – which could include rises in sea level, melting of the ice caps, drought in Africa, America and Asia, storms and ocean acidification. Loss of ice caps would lead to less solar energy being reflected back into space, while thawing tundra would release more methane and other greenhouse gases currently frozen in polar regions . Both processes could lead to even greater temperature rises. [Continue reading…]