EU:ONE OF the world's leading climate scientists is warning that the EU and its international partners must urgently rethink targets for cutting carbon dioxide in the atmosphere because of fears they have grossly underestimated the scale of the problem.
In a startling reappraisal of the threat, James Hansen, head of the Nasa Goddard Institute for Space Studies in New York, calls for a sharp reduction in C02 limits.
Dr Hansen says the EU target of 550 parts per million (ppm) of C02 - the most stringent in the world - should be slashed to 350ppm. He argues the cut is needed if "humanity wishes to preserve a planet similar to that on which civilisation developed".
Instead of using theoretical models to estimate the sensitivity of the climate, Dr Hansen's team turned to evidence from the earth's history, which they contend is more accurate. The team studied cores taken from the bottom of the ocean, which allow C02 levels to be tracked millions of years ago. They show that when the world began to glaciate at the start of the Ice Age around 35 million years ago, the concentration of carbon dioxide in the atmosphere stood at about 450ppm.
"If you leave us at 450ppm for long enough it will probably melt all the ice - that's a sea rise of 75 metres. What we have found is that the target we have all been aiming for is a disaster - a guaranteed disaster," Dr Hansen said.
At levels as high as 550ppm the world would warm by six degrees, the paper finds. Previous estimates suggested three degrees.
- (Guardian service)