COPENHAGEN (Reuters) - As President Barack Obama labored behind closed doors to break a deadlock over efforts to curb greenhouse gas emissions, Republicans from the U.S. Congress were outside those meetings urging him not to bother.

U.S. President Barack Obama attends the morning plenery session of the United Nations Climate Change Conference (COP15) at the Bella Center in Copenhagen December 18, 2009. REUTERS/Larry Downing

“We’re not going to let jobs be destroyed in America for some esoteric environmental benefit 100 years from now,” U.S. House of Representatives member Joe Barton told Reuters on the sidelines of the U.N. conference on climate change.

Barton, who would take over a powerful House committee that oversees environmental policy if Republicans were to regain majority control of the House, said he does not believe industrial emissions of carbon dioxide contribute to global warming and fears capping them would hobble the economy.

“If I am chairman two years from now, I’m going to repeal” measures such as U.S. funding to help developing countries battle climate change, outlined by Secretary of State Hillary Clinton on Thursday, the conservative Texas congressman boasted.

In a speech in Copenhagen on Wednesday, Democratic Senator John Kerry, a leading supporter of climate change legislation, called opponents “nihilists and naysayers.”

Instead of imposing new pollution controls, which Republicans characterize as a tax, many of them instead call for an energy and environment policy that expands domestic nuclear power and oil production and research into clean-burning coal.

Barton and five of his House colleagues traveled to Copenhagen to publicize their belief that carbon pollution should not be blamed for melting ice, rising sea levels and increasing chances of devastating flooding and drought.

“We don’t have an icecap in Texas,” Barton quipped to reporters.

The Republicans’ message was a reminder to Obama and his negotiators that anything they agree to in Copenhagen will have to be reviewed by Congress and that a Democratic majority in the House and Senate does not guarantee Obama can have his way.

Representative Fred Upton, whose home state of Michigan is suffering severe unemployment, said that a narrowly-passed House climate change bill would “lose by 50 votes” if it were debated now. A Senate version of that bill has been stalled for months.

U.S. politicians of various stripes are nervous about debating, amid high joblessness, a climate bill that could cause energy prices to rise, even if marginally.

Republicans in the House and Senate launched another offensive during the Copenhagen conference with moves to block Obama’s Environmental Protection Agency from regulating carbon emissions if legislation fails.

Barton, who told reporters “there has really never been an independent assessment of the methodology or of the data” that underpin U.N. efforts to counter global warming, said he would welcome one and mentioned the U.S. National Academy of Sciences as one possibility.

In June, the academy joined science academies of several other large countries calling on leaders to “seize all opportunities” to address global climate change that they said “is happening even faster than previously estimated.”