LONDON - Respect and legal responsibility for human rights must be at the heart of any new deal to tackle climate change, aid group Oxfam said on Tuesday noting that rich nations had to bear the greatest share of the cost.

Oxfam said in a report "Climate Wrongs and Human Rights" the world's richest nations had caused most of the problem due to burning fossil fuels for power and transport while it was the world's poorest people who were bearing most of the brunt.

"Climate change was first seen as a scientific problem, then an economic one. Now it is becoming a matter of international justice," report author Kate Raworth said.

"Human rights principles give an alternative to the view that everything -- from carbon to malnutrition -- can be priced, compared and traded," she said. "These principles must be put at the heart of a global deal to tackle global climate change."

Far from the tentative goal of cutting global carbon emissions in half by 2050 a new climate deal to replace the Kyoto Protocol which expires in 2012 has to set a target of 80 percent, Oxfam said.

It said rich countries had to take the lead and foot the bill for curbing carbon emissions and for helping the poorer nations adapt to the climate change that was already inevitable.

Yet it said those same countries were dragging their feet in negotiations on a new deal which is supposed to be agreed in Copenhagen at the end of next year, giving countries three years to ratify it in order to avoid hiatus after Kyoto ends.

"They are using spurious economic arguments to do as little as possible when in fact morality, science and human rights demand much more from them," Raworth said.

Scientists predict that global average temperatures will rise by between 1.8 and 4.0 degrees Celsius this century due to carbon emissions, bringing floods, famines and more violent storms and putting millions of lives at risk.

There is a broad agreement that efforts must be made to limit the temperature rise to 2 degrees. But some scientists now believe that a 4 degree rise is much more likely, bringing with it catastrophic change and species wipe-out.

On Wednesday Britain and Bangladesh, one of the poorest countries which is already facing major climate change problems like flooding, will sign an accord opening the way for direct transfer of money to help with adaptation costs.