(Bloomberg News) President Barack Obama must fight to defend rules cutting global-warming emissions that some lawmakers have vowed to block, said Frances Beinecke, head of the Natural Resources Defense Council.

The Environmental Protection Agency rules covering major polluters such as power plants and similar actions that don't require congressional approval are Obama's best chance to curb greenhouse-gas emissions in the near future, Beinecke said today. Obama failed this year to push climate-change legislation though a Congress controlled by fellow Democrats. Republicans, who will control the House next year, opposed the measure.

"It's absolutely critical that EPA move forward with the rule-makings that it has on climate," Beinecke, president of the nonprofit environmental group, said in an interview at Bloomberg headquarters in New York. "That will be a very tough fight."

The EPA's carbon regulations are set to begin January 2 and will apply to new or modified industrial sources of pollution. Lawmakers such as Senator Jay Rockefeller, a West Virginia Democrat, and states such as Texas have sought to delay or cancel the rules, saying they would hurt the economy.

The EPA issued guidance last week letting states determine on a case-by-case basis the "best available control technology" that companies should use to limit the carbon- dioxide pollution that contributes to climate change. Energy efficiency probably will emerge as the most cost-effective approach, the agency said in an e-mailed statement.

American Electric, DuPont

The rules fall short of legislation sought by a coalition of environmental groups and companies such as American Electric Power Co., the biggest U.S. producer of power from coal, and DuPont Co., the third-biggest U.S. chemical maker. A "cap-and- trade" bill limiting carbon pollution and establishing a market in pollution allowances stalled this year in the Senate after a version passed the House in June 2009.

"The big packages with pretty bows are not on the radar right now," said Beinecke, 61 who has been president of the New York-based environmental group since 2006. "The big fix is very challenging, but the incremental steps still are very much ahead of us, and that's where we're going to focus."

Most Americans want government to move forward with measures to improve air and water quality, Beinecke said. This month's elections that handed control of the House to Republicans and produced victories by several candidates who deny that humans are contributing to climate change shouldn't be seen as a vote against the environment, she said. Democrats will still hold a majority in the Senate.

'Holding Firm'

"The American public continues to be deeply committed to the environment," Beinecke said. "People do not expect to go back to polluted air." For Obama, "holding firm, moving forward in the areas that he has authority to do so will be very important."

Politics and the recession were to blame for the Senate's failure to pass a cap-and-trade law, Beinecke said.

Rockefeller, who wrote legislation to delay the EPA's carbon regulations for two years, has said the agency's case-by- case approach will make it harder for companies to build or expand their operations.

The administration is facing lawsuits over the pending rules, which were crafted after EPA Administrator Lisa Jackson declared greenhouse gases a public threat last year. The "endangerment finding" followed a 2007 Supreme Court ruling stating that EPA had the power to regulate carbon emissions as a pollutant under the 1970 Clean Air Act.

Texas has challenged the EPA's rules and told the agency in August that it doesn't plan to comply with them.