DOHA - A row over who will pay for dealing with the accelerating impact of climate change soured UN debate in Doha, where a final day of haggling was expected to do nothing to curb greenhouse gas pollution.

The two-week talks are meant to end on Friday, under the leadership of the Middle Eastern oil-and-gas power Qatar, which has the world's highest per-capita emissions.

UN climate conferences, bringing together nearly 200 nations, are notorious for missing deadlines - a lack of urgency in stark contrast to mounting scientific evidence that global warming is worsening.

Many attending the Doha talks said 4 degrees Celsius of global warming looked almost inevitable and the opportunity to limit the temperature rise to the 2 degrees scientists say would prevent the worst consequences is all but lost.

"The question of climate management is extremely serious," Laurent Fabius, France's foreign minister, told reporters.