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 group,based at the Grantham Research Institute on Climate Change at the London Schoolof Economics. It 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.
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.
The group worked out how much carbon the EU, US and China – if they keep their promises – would then be putting into the atmosphere by 2030 and concluded that they would, in total, be emitting 21-22bn tonnes a year. By contrast, the rest of the world – which includes growing economies such as Brazil and India – are likely to be emitting around 34bn tonnes, according to figures supplied by the International Energy Agency. In total, this gives a likely carbon emissions output of 55-56bn tonnes a year by 2030.
However, the maximum emissions target that has a reasonable chance of curtailing temperatures at 2C has been calculated as having a median value of about 36bn tonnes. In short, the world will still be emitting far too much carbon – an excess of some 20bn tonnes a year – to give the planet a reasonable chance of holding back the heat to a manageable level.