* Delegates describe meetings as encouraging
* Talks aim to pave way for U.N. agreement in December
(Adds quotes, updates throughout)
By Jeff Mason and Deborah Zabarenko
WASHINGTON, April 28 (Reuters) - U.S.-hosted climate talks with the world’s biggest greenhouse gas polluters concluded on Tuesday with signs of progress but sizable differences as nations work toward a deal this year to fight global warming.
President Barack Obama called the Major Economies Forum to relaunch a process that began under his predecessor, George W. Bush, whose initiative drew skepticism from countries who feared it would circumvent wider United Nations negotiations.
The two-day meeting was meant to pave the way for international talks in Copenhagen in December to forge a follow-up agreement to the Kyoto Protocol, which limits climate-warming greenhouse emissions and expires in 2012.
Results were mixed. Delegates praised the constructive atmosphere and Washington’s shift on climate policy, while activists and some European officials said more needed to be done.
"I come out of this meeting if anything a bit more optimistic," said Todd Stern, the U.S. special envoy for climate change, referring to the potential for a global deal.
"That does not change the fact that the issues are extremely difficult, that it’s not going to be easy to reach an agreement."
German Environment Minister Sigmar Gabriel said a lot had changed since the Bush process but that greater commitments from industrialized nations, including the United States, would be necessary to succeed in Copenhagen.
"It was very clear that the Americans are moving a lot," he told reporters. "Measured by what Europeans believe needs to be done to fight climate change, we’re still very far apart from each other."
Obama’s goal is to cut U.S. emissions of carbon dioxide and other greenhouse gases by roughly 15 percent by 2020, back to 1990 levels. The European Union has pledged to cut emissions 20 percent below 1990 levels by 2020 and says it would pursue a 30 percent cut if other industrialized nations follow suit.
Obama wants the United States to lead in the climate change fight, but U.S. officials have indicated they do not see a lot of room for maneuver on the 2020 goal. Obama aims to cut U.S. emissions more than 80 percent by 2050.
RESULTS, MORE MEETINGS
Environmental groups criticized the Washington meeting for not moving toward a more aggressive midterm target.
"Unfortunately, while the last two days brought soaring and inspiring rhetoric, reflecting the profound sea change in U.S. climate policy, it brought little in the way of real progress," said Carroll Muffett of environmental group Greenpeace.
At the meeting there were discussions on technology, including carbon capture and storage. Delegates ran out of time to talk about financing issues, one official said.
Bush opposed the Kyoto Protocol, saying it would hurt the U.S. economy and unfairly exempted fast-growing economies such as China and India.
The U.S. position in international talks is strongly linked to the fate of a climate change bill now moving through Congress, and Stern noted that any pact in Copenhagen would have to be palatable to U.S. lawmakers.
EU officials, who emphasized Europe’s leadership on the issue, expressed hope that American negotiators would have a clear mandate at the December talks.
U.N. climate chief Yvo de Boer, who described the United States as having been "largely absent" from the climate debate during the Bush years, praised the new forum under Obama.
"I saw none of the acrimony that I’ve seen in previous meetings of this kind," he told reporters. "I saw a good understanding and sympathy for each other’s positions but also the recognition that there is a huge challenge ahead of us."
The major economies represented at the meeting include Australia, Brazil, Britain, Canada, China, the European Union, France, Germany, India, Indonesia, Italy, Japan, Korea, Mexico, Russia, South Africa and the United States.
Another meeting is set for the end of May in Paris and a third is planned for June at an undecided location.
The process will culminate with a meeting of heads of state and government on the sidelines of the July G8 summit in Italy. Participants said the process could continue after that. (Editing by Chris Wilson)