The world has already produced around one third of the total amount of CO2 that could be emitted between 2000 and 2050 without the global temperature rising more than 2°C, according to the report published in Nature. CO2 emissions are currently increasing by three per cent annually, and within 20 years, the world will have exceeded its total limit of a trillion tonnes of CO2, which is 20 years earlier than planned by international agreements.

‘If we continue burning fossil fuels as we do, we will have exhausted the carbon budget in merely 20 years, and global warming will go well beyond 2°C,’ said Malte Meinshausen of the Potsdam Institute for Climate Impact Research in Germany, lead author of the report.

For the climate to stay at a temperature considered safe by most scientists – less than 2°C above preindustrial levels – the report states that CO2 emissions
need to be cut by half. And even then, there would still be a one-in-four risk that temperatures could rise by more than 2°C.

July 2009