Warming threat underestimated

Canberra Times
Friday 18/4/2008 Page: 1

Climate change expert Nicholas Stern says he underestimated the threat from global warming in a report 18 months ago when he compared the economic risk to the Great Depression of the 1930s. The latest climate science showed global emissions of planet-heating gases were rising faster and upsetting the climate more than previously thought, Lord Stern said in an interview yesterday. 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.

"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. Lord 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 his climate change report - the Stern Review - as a blueprint for urgent climate action.

The report predicted that, on current trends, average global temperatures would rise by 2-3 degrees in the next 50 years or so and could reduce global consumption per head by tip to 20 per cent, with the poorest nations feeling the most pain. Some academics said he had overplayed the costs of potential future damage from global warming at up to 20 times the cost of fighting the problem now, such as by replacing fossil fuels with more costly renewable power.

Lord Stern said increasing evidence of the threat from climate change had vindicated his report, published in October 2006. "People who said I was scaremongering were profoundly wrong," he told a climate change conference organised by industry information provider IHS. A UN panel of scientists, the Intergovernmental Panel on Climate Change, writes regular summaries on climate science and shared the Nobel Peace Prize last year with former US vice-president Al Gore for raising awareness.

Its latest report in 2007 had not taken detailed account of some dangerous threats, including the falling ability of the world's oceans to absorb CO2, because scientists had to be cautious and that evidence was just emerging, the former World Bank chief economist said. "The IPCC has done a tremendous job but things are moving on," he said.

"The IPCC's [cautious] approach to this is entirely understandable and sensible, but if you're looking ahead and asking about the risk then you do have to go beyond." Lord Stern said global greenhouse gas emissions should halve by mid-century to minimise the risks of dangerous climate change. The US should cut its emissions by tip to 90 per cent by then. He spoke before a senior White House official, speaking on the condition of anonymity, said US President George W. Bush planned to call for a halting of growth in US greenhouse gas emissions by 2025.