http://www.timesonline.co.uk/tol/news/environment/article6939942.ece

Preventing runaway global warming may be twice as expensive as previously thought and Britain will have to incur billions of pounds of additional debt to cover its share of the cost, according to the world’s most influential climate change economist.

Lord Stern of Brentford said that future generations would find it easier to pay off the debt than to cope with the consequences of climate change.
He called for air passengers to pay a significant proportion of the cost through a new global tax on flights, and shipping should also contribute through a new tax on bunker fuel.
The author of the 2006 Stern review on the cost of tackling global warming admitted that the latest science indicated that he had been too optimistic in that report. Cuts in CO2 emissions would have to be deeper and made more quickly to have a 50-50 chance of keeping global temperatures from rising more than 2C (3.6F) above pre-industrial levels.
Lord Stern said that Britain should pay about $3 billion (£1.8 billion) a year by 2015 to a global fund of $50 billion a year to help poor countries to adapt to climate change. He called on Alistair Darling, the Chancellor, to “make financial commitments to the developing world” in next week’s Pre-Budget Report.
He also urged the European Union to make an unconditional commitment to cutting its CO2 emissions by 30 per cent on 1990 levels by 2020.
The EU has committed only to a 20 per cent cut and said that it would increase this to 30 per cent on condition that other countries made comparable efforts. Speaking yesterday at the London School of Economics, Lord Stern said that the Copenhagen climate change summit was “the most important international gathering since the Second World War”.
He said that the oceans were absorbing less of the CO2 from fossil fuels than he had assumed in 2006. In addition, the effects of CO2 on the climate were “coming through more quickly than we thought”.
Lord Stern’s 2006 report estimated that the cost of tackling climate change, including investment in renewable energy and other low-carbon technology, would amount to 1 per cent of global GDP. His latest analysis estimates the cost to be closer to 2 per cent, and possibly reaching 5 per cent. He concluded: “This may turn out to cost more and we should be prepared to pay that. If it costs us 3 or 4 or 5 per cent [of GDP], it would still be a good deal.”
The report says that if emissions continued rising at the present rate, there would be a “significant probability” of global temperature rising by 5C or more by the end of the century.
“The human species has only been around for 200,000 years at most and has no experience of trying to survive under such conditions,” he said.
“It is highly likely that there would be massive movements of people, probably hundreds of millions, with the risk of conflict that would be severe, prolonged and global.”
Lord Stern’s report recommends that the concentration of CO2 equivalent gases in the atmosphere should be capped at 500 parts per million (ppm) and, over time, fall well below 450ppm. His 2006 review said that 550ppm would be acceptable.
He says that total emissions of CO2 equivalent should fall from 47 billion tonnes this year to 44 billion tonnes by 2020 and to well below 20 billion tonnes by 2050.
Lord Stern urged Britain and other rich countries not to use the present strain on public finances as an excuse for delaying meeting their responsibilities to developing nations. “If there have ever been credible reasons for borrowing and public debt, this is surely one of the strongest,” he said. A spokesman for the Department of Energy and Climate Change said that Britain would “pay its fair share” towards a global fund to help poor countries adapt to climate change.
Lord Stern accused climate sceptics of undermining efforts to tackle climate change by using leaked e-mails from scientists to spread doubts about man-made global warming. He said that the e-mails, which sceptics have suggested show temperature data was manipulated, did not alter the “overwhelming evidence that has built up over nearly 200 years” that human activities were causing climate change.
“I think it is very important that those with any kind of views on the science or economics have their say — that does not mean that unscientific muddle also has the right to be recognised as searing insight.”
The director of a research unit at the centre of a row over leaked e-mails said that he would stand down from the post while an independent review took place.
Phil Jones, director of the University of East Anglia’s Climatic Research Unit, said that he “absolutely” stood by the science produced by the centre and that suggestions of a conspiracy to alter evidence to support a theory of man-made global warming were “complete rubbish”.
Professor Jones said that he would stand aside as director until the completion of the independent review.