Conventional wisdom has it that if the leaders of the world can't agree on a round of negotiations to liberalise world trade then there's no chance they will agree on measures to tackle climate change.

After all, a pact to cut greenhouse gas emissions will involve re-tooling vast swathes of industry and impact the way companies do business from Boston to Beijing.

But is that view right? British economist Nicholas Stern - author of a seminal report in 2006 on the economic fallout of global warming - thinks not.

"Actually, agreement on climate change, I think, will be easier than agreement on trade," he told reporters in Davos. "People understand climate change much better than trade."

The crunch will come in December, when world leaders meet in Copenhagen to hammer out a replacement for the current Kyoto protocol which expires in 2012.