Late last year, a UN climate conference in South Africa agreed that countries would reach a new worldwide deal to cut greenhouse gas emissions by the end of 2015 so it could come into force by 2020.

Green economic growth rather than strict targets for cutting greenhouse gases needs higher priority if the world is to reach a deal, writes Reuters.

Despite growing scientific evidence of a warming world, greenhouse gas emissions continue to rise and United Nations talks aimed at doing something about it are moving at a glacial pace.

Years of talks have failed to deliver a deal to replace the Kyoto Protocol, which set emissions targets for industrial nations.

And despite agreement last year to set up a Green Climate Fund to raise aid for poor nations to help them cope with the effects of climate change, it took until last week just to decide who would sit on its governing panel.

"It's going to be very difficult to reach a deal by 2015," said Robert Stavins, director of the Harvard Environmental Economics Program. He said new approaches were needed to permit economic growth that does not damage the environment.

Yvo de Boer, head of the U.N. climate change secretariat in 2009 when a summit in Copenhagen tried and failed to reach a global deal, called for a re-think to allow greener economic growth, especially for poorer nations.

"The climate change negotiations have focused very heavily on targets, legally-binding regimes and consequences if you fail (to cut emissions)," he told Reuters.

"Not nearly enough focus has been on how we can create an architecture ... which allows countries to engage on climate change while at the same time growing their economies and lifting people out of poverty," he said.

De Boer, who is now an advisor to accountancy firm KPMG, said there should be more focus on measures such as cleaner standards for power plants, steel mills, paper production or vehicles.

Aid to Mali, for instance, could be directed to steel mills to make them as efficient as those in Germany.

Many of the most vulnerable states, like low-lying Pacific island nations that fear rising sea levels, want faster action.

"Unless there is immediate progress to dramatically reduce emissions we are moving rapidly to a point where we will have to begin a conversation about adaptation and the relocation of vulnerable populations at a previously unimaginable scale," said Marlene Moses, chair of the Alliance of Small Island States.