The Working Group on Climate Change and Development says the poorest countries will be most affected by the problem, as they are least prepared for it.

A report, called Up In Smoke, says global warming threatens international plans to halve world poverty by 2015.

It called for richer countries to cut down their pollution levels and offer help to the poor countries.

If they don't, the group claims warming could even reverse achievements that have already helped the poor.

They added we couldn't choose between helping the poor or stopping pollution.