Climate change expert Nicholas Stern says he under-estimated the threat from global warming in a major report 18 months ago when he compared the economic risk to the Great Depression of the 1930s.
Latest climate science showed global emissions of planet-heating gases were rising faster and upsetting the climate more than previously thought, Mr Stern said in a Reuters interview today.
For example, evidence was growing that the planet's oceans - an important "sink" - were increasingly saturated and couldn't absorb as much as previously of the main greenhouse gas carbon dioxide (CO2), he said.
"Emissions are growing much faster than we'd thought, the absorptive capacity of the planet is less than we'd thought, the risks of greenhouse gases are potentially bigger than more cautious estimates, and the speed of climate change seems to be faster," he said at a conference in London.
Stern said that increasing commitments from some countries such as the European Union to curb greenhouse gases now needed to be translated into action. Policymakers, businesses and environmental pressure groups frequently cite the Stern Reviewas a blueprint for urgent climate action.
The report predicted that, on current trends, average global temperatures will rise by 2-3 degrees centigrade in the next 50 years or so and could reduce global consumption per head by up to 20 percent, with the poorest nations feeling the most pain.
Some academics said he had over-played the costs of potential future damage from global warming at up to twenty times the cost of fighting the problem now, such as by replacing fossil fuels with more costly renewable power.
Stern said on Wednesday that increasing evidence of the threat from climate change had vindicated his report, published in October 2006.