Opinion A renowned global-warming scientist says the problem of global warming is much more serious than previously estimated. However, he also hints that there may be no need to fear catastrophic carbon-driven climate upheaval, as mankind will run out fossil fuels much sooner than presently estimated.
James Hansen, chief of NASA's Goddard Institute for Space Studies, was one of the first to warn about global warming decades ago. Until relatively recently, he believed that a target of 450 parts per million atmospheric CO2 would be sufficient to stave off disaster. Now, however, he thinks that this figure should revised downward to 350ppm.
"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," Hansen told the Guardian over the weekend.
The new assessment is based on research carried out by Hansen and his colleagues in recent years using ocean-floor samples and satellite imagery. This reveals, according to his analysis, that comparatively low levels of atmospheric CO2 were enough to cause the glaciers to retreat in prehistoric times - and that today's polar ice may vanish much faster than anyone thinks.
Regarding solutions, Hansen himself has said "a 350ppm target is only achievable by phasing out coal use", at present one of humanity's main power sources. He believes the missing coal energy could be easily replaced by better-insulated buildings, more efficient transport, etc. (An abstract of Hansen's thoughts can be read here in pdf.)
That said, the EU, with the strictest carbon policy in the world, is only aiming for a 550ppm quota. No other major industrial bloc is even as close as this. A global cap at 350ppm would appear wildly unrealistic in diplomatic and political terms.
But Hansen offers some hope, telling the Guardian that fossil fuels will soon run out anyway, so forcing the human race to find alternative power sources. ®