Obama makes a moral case for action on climate change But in his remarks Monday after taking the oath of office, Obama chose to make a moral case - rather than an economic or national security one - for taking action. "We will respond to the threat of climate change, knowing that the failure to do so would betray our children and future generations," he said. The decision to frame a response to global warming as a defining aspect of his legacy has encouraged his environmental allies and reignited concerns among congressional Republicans and industry opponents. And it signaled that the issue continues to weigh on Obama, even as he and his aides have placed budget negotiations, immigration and gun control higher on their agenda. "It was about climate change for climate change's sake, and for his legacy," said Margie Alt, Environment America's executive director. This was more powerful than anything I remember him saying. It was a moral mandate that he laid out. Obama made a point of highlighting how much emphasis he gave the issue after Rep. Henry A. Waxman (D-Calif.) thanked him afterward for mentioning climate change. "I didn't just mention it, I talked about it," Obama parried, according to Waxman. In interviews this week, administration officials and those who lobby on both sides of the issue said Obama and his aides are examining the same regulatory options they had been considering before the election. Those include a possible cap on greenhouse gas emissions from existing power plants, policies to promote energy efficiency in the public and private sectors, ways to promote combined heat and power generation at industrial facilities, and an expansion of biofuel use and other forms of renewable energy at the Pentagon. "I think he has a lot of tools, and they're evaluating how to use them," said Carol Browner, who served as assistant to the president on energy and climate change during Obama's first two years and is now a distinguished senior fellow at the Center for American Progress. The White House is likely to build a public effort to rally support for these initiatives through the group Organizing for Action, the offshoot of Obama's reelection campaign. Its executive director, Jon Carson, served as the White House's liaison to environmental groups during the president's first term. "Having Jon over there gives me confidence," Alt said. They will need to do a lot of work to set themselves - and the administration and the country - up to do this. It's not going to be easy. Still, several experts questioned whether the Environmental Protection Agency - which oversees the effort to impose carbon limits on existing coal- and gas-fired utilities - would be able to assemble the rules before the end of the year.