While reiterating that he is a "firm believer" that climate change is real and affected by human behavior, President Obama made clear today that he won't be proposing major new efforts to control U.S. carbon emissions anytime soon.

In his first news conference since winning re-election, Obama acknowledged that "we haven't done as much as we need to" to fight global warming, but he also offered few details on how he intended to proceed on the issue beyond what he was able to do in his first term.

Instead, Obama acknowledged the difficulty of moving major climate legislation, even for a newly re-elected president.

"I don't know what either Democrats or Republicans are prepared to do at this point because this is one of those issues that is not just a partisan issue. There are regional differences," he said. "There's no doubt that for us to take on climate change in a serious way would involve making some tough political choices."

Obama's comments are sure to disappoint environmentalists who had been hoping that in the wake of Superstorm Sandy, the president would push for swift action to control heat-trapping emissions, perhaps in the form of a carbon tax as part of the year-end "fiscal cliff" negotiations.

"We can wait no longer to take action on the climate crisis. … As the president will see when he visits New York this week, the dangers of climate disruption are all too real for the millions of families affected by Superstorm Sandy,” said Michael Brune, the Sierra Club's executive director.

“President Obama rightly acknowledges that climate change is happening -– now he should do something about it by finishing the job of cleaning up dirty power plants, building on energy efficiency innovations, saying no to dirty fuels like tar sands and scaling up clean energy."

The president today said actions he took in his first term -- including doubling fuel-efficiency standards on motor vehicles -- have had an impact on greenhouse gas emissions.

He promised that "over the next several months" he would conduct "wide-ranging conversations" with scientists, engineers and elected officials to find out what more can be done in the short term to reduce carbon emissions. A continued education process, he said, is needed to develop long-term solutions and "make sure this is not something we're passing on to future generations."

But he also said he has more pressing items on his agenda as he begins his second term.

"Understandably, I think, the American people right now have been so focused and will continue to be focused on our economy and jobs and growth, and if the message somehow is we're going to ignore jobs and growth simply to address climate change, I don't think anybody is going to go for it," he said. "I wouldn't go for it."

Earlier in the news conference, Obama also seemed to indicate immigration reform would be an issue that would be addressed sooner rather than later.

Paul Bledsoe, an independent policy consultant who has worked on energy issues on Capitol Hill and in the Clinton administration, said Obama was correct in saying any climate strategy must help increase economic growth to be politically viable.

"The good news is that a carbon tax would increase growth more than the mix of taxes on labor and capital that a carbon tax could displace, according to most studies, including by conservative economists," Bledsoe said. "Congress and the administration have to start thinking of climate in these broader economic terms."

One issue that didn't arise in this afternoon's news conference is Obama's pending decision on the Keystone XL oil pipeline. The fate of the Alberta-to-Texas crude conduit is being closely watched by industry and environmentalists looking for signals on how Obama's second term will play out.

May Boeve, executive director of 350.org, a foe of the pipeline, released a statement saying Obama could show he's serious about fighting climate change by rejecting the pipeline.

"The pipeline would unlock so much carbon that climate scientists say, if it were built, it would be 'game over' for the climate," Boeve said. "The president can stop this dangerous pipeline with his pen, and if he does, the American people will support him."