Prospects rise for a 2015 UN climate deal, but likely to be weak

A global deal to combat climate change in 2015 looks more likely after promises for action by China, the United States and the European Union, but any agreement will probably be too weak to halt rising temperatures.

Delegates from almost 200 nations will meet in Lima, Peru, from Dec. 1-12 to work on the accord due in Paris in a year's time, also spurred by new scientific warnings about risks of floods, heatwaves, ocean acidification and rising seas.

After failure to agree a sweeping U.N. treaty at a summit in Copenhagen in 2009, the easier but less ambitious aim now is a deal made up of "nationally determined" plans to help reverse a 45 percent rise in greenhouse gas emissions since 1990.

"We are in much better shape," a year before Paris than in the run-up to Copenhagen, said Yvo de Boer, who was the U.N.'s climate chief in 2009 and now leads the Global Green Growth Institute in South Korea, which helps poor nations.

The hope is that in Paris, delegates will also work out ways to ratchet up national plans in coming years to limit average temperatures rises to an agreed ceiling of 2 degrees Celsius above levels before the Industrial Revolution.

Temperatures have already climbed 0.85 C (1.5 F). "Not in my wildest dreams do I expect the Paris agreement to close the gap to 2 degrees," de Boer told Reuters.

China, the United States and the European Union, which together account for more than half of world greenhouse gas emissions, have indicated they want some sort of global accord in Paris, sharply raising the chances of success for the summit.

"The prognosis is vastly better than going into Copenhagen," said Robert Stavins, director of Harvard University's Environmental Economics Program. "The...