Human-induced warming is causing glaciers and permafrost to melt. Image: US Global Change Research Program

A scientist who has for years been warning about climate change, said on Thursday that global warming talks in Copenhagen next week were based on such flawed proposals that he hoped they failed. James Hansen, the director of NASA's Goddard Institute for Space Studies since 1981, said attempts to agree a new global deal on cutting emissions after the Kyoto treaty expires were based on a "fundamentally wrong" approach. Meanwhile, conference officials have said cash commitments from rich countries are vital to get China and India to agree to a deal.

"I would rather it not happen if people accept that as being the right track because it's a disaster track," he told the UK's Guardian newspaper ahead of the December 7-18 summit.

Hansen is highly sceptical about a favoured measure of cutting greenhouse gas emissions, a cap-and-trade system under which a progressively stricter 'right to pollute' is exchanged in a carbon market.

The scientist favours a direct tax on fossil fuels as the only realistic way to achieve the necessary cuts.

"The approach that's been talked about is so fundamentally wrong that it is better to reassess the situation," Hansen told the paper.

"I think it's just as well that we not have a substantive treaty, because if it is going to be the Kyoto-type thing, and people agree to that, then they'll spend years trying to determine exactly what that means and what is a commitment, what are the mechanisms.

"The whole idea that you have goals which you're supposed to meet and that you have outs, with offsets (sold through the carbon market), means you know it's an attempt to continue business as usual."

The newspaper says Hansen, in repeated appearances before Congress beginning in 1989, has done more than any other scientist to educate politicians about the causes of global warming and to prod them into action to avoid its most catastrophic consequences. But he is vehemently opposed to the carbon market schemes - - in which permits to pollute are bought and sold - - which are seen by the EU and other governments as the most efficient way to cut emissions and move to a new clean energy economy.

He compared the current approach to the Catholic Church's use of indulgences in the Middle Ages, saying sinners paid the bishops to give them redemption, a system that was patently absurd but suited both sides.

"We've got the developed countries who want to continue more or less business as usual and then these developing countries who want money and that is what they can get through offsets," Hansen said.

However, he insisted there was still hope, telling the Guardian: "I find it screwy that people say you passed a tipping point so it's too late.

"In that case what are you thinking: that we are going to abandon the planet? You want to minimise the damage."

Mars terrain captured by NASA's Mars Exploration Rover Spirit. The study provides clues to astrobiologists on planetary habitability. Image: NASA.

This week, the Financial Times reported that China at 48%, has been the beneficiary of the UN's Clean Development Mechanism, or CDM carbon credits, which allows developed countries to meet part of their carbon emission reduction targets under the Kyoto Protocol, through investing in clean-energy projects in developing countries. The system however, is very difficult to police.

On Thursday, Connie Hedegaard, the Danish environment minister, European climate change commissioner-designate and next week's climate change conference chairwoman, said commitments from rich countries to fund climate change measures are crucial to persuading developing countries such as China and India to formalise their domestic commitments to curb emissions.

However, given the fragility of the US economy, President Obama would risk a firestorm if he offered cash help to China for example, which has currency reserves of over $2.4 trillion.

Yvo de Boer, the UN’s principal climate change official, said rich nations could pledge an overall sum for the funding they would collectively deliver by 2020. “I think they will be able to agree on the fact that a longer-term $100bn (€66bn, £60bn) a year will be needed and will have an agreement on the short-term funding [for the next three to five years],” he said. “A more difficult question is how that $100bn bill should be shared out among individual countries. It will be very difficult to reach agreement on that exact long-term cost sharing at Copenhagen, to get that precise,” he added.