U.S. insists it supports U.N. on climate

By Deborah Zabarenko and Jeff Mason

WASHINGTON (Reuters) - The United States insisted on Thursday it was serious about global warming and tried to reassure skeptics that President George W. Bush's gathering of major polluting nations would not undermine U.N. efforts.

But some participants and environmentalists were unconvinced, voicing concern that Washington was trying to rally support for voluntary emissions cuts rather than the mandatory reductions called for in the 1997 Kyoto Protocol.

"I want to stress that the United States takes climate change very seriously, for we are both a major economy and a major emitter," U.S. Secretary of State Condoleezza Rice said at the start of the two-day conference.

"Climate change is a global problem and we are contributing to it," Rice said. "Therefore, we are prepared to expand our leadership to address the challenge."

Outside the State Department where the sessions were held, dozens of protesters held up anti-Bush placards, "Bush is a criminal" and "Stop Global Warming Now." Diplomatic security formed a line to stop protesters from entering the building. Nearly 50 demonstrators were arrested.

By most counts, the United States is the world's top emitter of greenhouse gases. But Bush, who rejected the Kyoto Protocol, continues to resist binding targets, calling instead for voluntary approaches and "aspirational" long-term goals.

Rice said individual nations should set their own goals to curb climate-warming emissions, especially carbon dioxide from coal-fired power plants and petroleum-fueled vehicles.

Critics questioned whether such voluntary targets would work.