Science - May 17, 2010

Earth's temperature rising by one degree too much

CO2 emissions are still rising substantially. Limiting global warming is not realistic.

The current agreements on CO 2 emissions mean the earth's temperature is set to increase by more than two degrees. That is the opinion of a team of scientists, which includes ESG visiting researcher Michiel Schaeffer, as presented in an article in Nature at the end of April.
Schaeffer and his colleagues at the Potsdam Institute for Climate Impact Research worked out what the effect on global warming would be of the current promises regarding CO 2 emissions in 2020. These promises were made following Copenhagen. As at the start of April, 76 countries representing 80 per cent of global CO 2 emissions had made public their emissions targets. Schaeffer and his colleagues are not impressed by their intentions. 'The lack of ambition expressed in these promises is amazing', they write in Nature, with all due respect for the positive examples - in this case Japan and Norway.

Three degrees
According to the scientists, the current promises will lead to levels of emissions in 2020 ten to twenty per cent higher than at present. In other words, we will be producing more CO 2 , not less. As a consequence, the aim of limiting global warming to two degrees by the end of the century is unrealistic.
Based on the current promises, there is even a large chance (fifty per cent) that the earth's temperature will have risen by three degrees in 2100. That is why the scientists are advocating rapid, drastic steps to reduce CO 2 emissions. As an illustration: even if emissions are halved by 2050, there is still a fifty per cent chance of global temperatures rising by two degrees.