Syracuse -- US "zeal" to reverse years of disengagement on environmental issues has spurred optimism for a landmark deal on global warming later this year, delegates to Group of Eight climate change talks said Thursday.

"The fact that (US) President (Barack) Obama has committed to work with zeal ... towards Copenhagen is very important," EU Environment Commissioner Dimas Stavros said at the gathering of G8 environment ministers and their counterparts in eight emerging economies.

The "G8-Plus" talks are among several forums on the way to a UN meeting in Copenhagen in December aimed at sealing an international pact for curbing greenhouse gases beyond 2012.

That is when the Kyoto Treaty -- rejected by Obama's predecessor George W. Bush -- is set to expire and is to be replaced by the Copenhagen deal.

The Bush administration maintained that Kyoto would be too costly for American businesses to implement and demanded that developing countries should do more.

Czech Republic Environment Minister Martin Bursik, who met the US leader in Prague earlier this month, said Thursday: "We are on the way to Copenhagen."

"President Obama told me that their chief negotiator Todd Stern will go to Copenhagen with the strongest possible mandate," said Bursik, whose country holds the rotating EU presidency.

"This should open the doors and get us out of the deadlock and get China and India on board," Bursik said.

The United States and China are the world's top two carbon polluters, but US per capita emissions are four to five times those of China and about double those of Europe.

Stavros said he was also encouraged by major policy changes within the United States.

"The US Congress appears to be committed in the battle against climate change," he said, pointing to an energy bill before Congress that includes a market-based cap and trade plan designed to help slash greenhouse emissions by 80 percent by 2050.

Under the system, companies can buy "emission credits" from companies that pollute less, leaving overall emissions at an agreed ceiling.

The EU commissioner also praised the US Environmental Protection Agency's move to deem carbon dioxide and other greenhouse gases a health risk, a significant shift from the Bush administration, which failed to heed EPA warnings on the possibly devastating consequences of inaction.

EPA Administrator Lisa Jackson is attending the talks here on her first international trip in the job.

The three-day meeting in Sicily brings together countries responsible for more than 40 percent of the world's carbon gas emissions.

Ministers from the G8 grouping of Britain, Canada, France, Germany, Italy, Japan, Russia and the United States have been joined here by their counterparts from China, India, Brazil, Mexico, Indonesia, South Africa, South Korea and Egypt.

Earlier Thursday, they pledged new commitments to stopping biodiversity loss even with resources hit hard by the global financial crisis.

They will agree a "Syracuse Charter" spelling out ways to reinforce and extend goals for 2010 that were set in 2002, EU Commissioner Stavros said. "Efforts must be redoubled and we must start thinking beyond 2010."

Climate change is a growing threat to biodiversity at a time when a quarter of all animal and plant species may be at risk of extinction, according to the International Union for Conservation of Nature.

"We must deliver together what science has told us," Swedish Environment Minister Andras Carlgren told the news conference, saying "carbon emissions must peak in 10 years."

Some 1,000 activists meanwhile staged a protest Thursday accusing the conference of being "part of the problem, not part of the solution."

The group Contro-G8 (Against G8) staged the protest far from the heavily secured G8 venue, the medieval Maniace Castle at the tip of a peninsula jutting off Syracuse.

AFP/Expatica