Even as he prepares to argue for action at the international climate conference, President Barack Obama is getting some reminders of the domestic political divide _ and anxiety _ over climate change.
Twenty congressional Republicans, including the top House GOP leadership, sent a letter to the president Friday expressing their "grave concern" that the U.S. delegation might commit to mandatory greenhouse gas emissions reductions.
"Only a treaty ratified by the United States Senate or legislation agreed to by Congress may commit our nation to any mandatory emissions reduction program," wrote the Republican lawmakers.
"Congress has the sole responsibility to approve such a program," they added, asking for clarification "that the U.S. negotiators will not commit our government to an emissions reduction protocol at Copenhagen.'"
No such assurance came from the White House. Spokesman Benjamin LaBolt said Obama's emissions target for the conference is based on a bill passed by the House, and legislation with similar goals that "the Senate also intends to pursue."
The letter was signed by the two top ranking Republicans in the House, Rep. John Boehner of Ohio and Eric Cantor of Virginia, and 18 other GOP lawmakers including a number of committee chairmen. It reflected their strong opposition to legislation that would reduce U.S. greenhouse gas emissions from power plants and industry by 17 percent by 2020.
The House narrowly passed the bill last summer, but it has stalled in the Senate, which is expected to take up climate legislation in the spring.
Obama has said the United States is prepared to commit to reductions in the 17 percent range by 2020 in negotiations at Copenhagen.
"In addition to working together to pass the largest investment in renewable energy in U.S. history, the administration has been in a dialogue with Congress throughout the year regarding comprehensive energy legislation that sets a market-based cap on carbon emissions," LaBolt said.
How much of a commitment the Obama administration is prepared to make at Copenhagen has worried some congressional Democrats as well.
On Thursday, nine Democratic senators wrote to the president that while they remain committed to tackling climate change, they want assurances that any agreement reached at the conference "is environmentally sound, affordable and fair," and includes "significant commitments and actions by all major emitting countries."
"Poorly designed climate policies could jeopardize U.S. national interests by imposing burdens on U.S. consumers, companies and workers without solving the climate challenge," the Democrats cautioned.
The prospects for a tentative agreement at the two-week Copenhagen talks, which are scheduled to conclude Dec. 19, have increased since both China and India announced domestic targets for slowing emission increases as their economies continue to grow quickly.
Obama had planned to attend the conference Dec. 9, but on Friday the White House said he now will go on Dec. 18, at the end of the conference when many other state leaders will be there _ a sign of growing optimism that at least a tentative agreement might be reached.