It was a lot of hot air about a lot of hot air.

Democrats took to the Senate floor Monday night to talk about global warming and did not let up until morning.

"Climate change is real, it is caused by humans, and it is solvable," said Sen. Brian Schatz, D-Hawaii.

In Schatz's view, the debate, such as it was, showed that a growing number of senators are committed to working together on climate change, even if no Republicans were among them. "This is where intractable, longstanding issues get solved," he said of the Senate.

Despite that bravado, Democratic leaders made it clear they have no plans to bring a climate bill to the Senate floor this year. Indeed, the issue is so politically charged that a host of Democrats who face tough re-election fights in the fall opted to skip the session. Sens. Mary Landrieu of Louisiana, Mark Pryor of Arkansas, Mark Begich of Alaska and Kay Hagan of North Carolina were among Democrats who stayed away.

Sen. James Inhofe, R-Okla., said Democrats who showed up were not convincing anyone with their stunt.

"They'll have an audience of themselves, so I hope they enjoy it," Inhofe said about an hour into the marathon, planned to last for nearly 15 hours. Inhofe's speech marked the only time Republicans engaged in the debate. Two other GOP senators, Alabama's Jeff Sessions and Senate Minority Leader Mitch McConnell of Kentucky, took to the Senate floor earlier Monday to denounce Democrats before the overnight session began.

Leading off, Senate Majority Leader Harry Reid, D-Nev., called climate change "a question of our own survival" and said the United States and other countries have a responsibility to act "before it is too late."

House Democrats pushed through a bill to limit greenhouse gas emissions blamed for global warming in 2009, then lost their majority the following election. A climate bill led by then-Massachusetts Sen. John Kerry collapsed in 2010 without a vote in the Democratic-controlled Senate.

Sen. Barbara Boxer, D-Calif., said the climate debate, which had its own Twitter hashtag, #Up4Climate, had drawn interest from around the nation and the world. Democrats received two separate petitions urging them to act, with a total of about 100,000 signatures, Boxer said.

"The American people are listening," Boxer said. "They care." She added that the event should "wake up Congress to the dangers of climate change."

Boxer and Sen. Sheldon Whitehouse, D-R.I., lead the recently launched Senate Climate Action Task Force, which organized the session.

Whitehouse said the session was needed to highlight obstacles to climate legislation, including ads financed by Charles and David Koch, conservative activists who have spent $15 million on Senate races, mostly criticizing Democrats over Obamacare. The Koch brothers, whose interests include oil, chemicals, textiles and paper, have also spent millions on ads critical of action against climate change.

Whitehouse conceded that lawmakers do not have the 60 votes needed to act on the matter, even in the Democratic-controlled Senate, but said the speeches could help change the dynamic.

"Tonight is not about a specific legislative proposal," he said. "It's about showing the environmental community, young people and anyone paying attention to climate change that the Senate is starting to stir and we want to get some actions going."

The episode followed overnight speeches last year by Republicans Sens. Rand Paul of Kentucky and Ted Cruz of Texas. Paul criticized U.S. drone policy, while Cruz pushed to take money away from the new health care law.

White House spokesman Jay Carney praised the participants for bringing attention to "a very important subject that the president is concerned about." He cited a climate action plan announced by Obama last year. The plan would impose the first-ever limits on carbon pollution from new and existing power plants, as well as boost renewable energy production on federal lands and increase energy efficiency standards.

McConnell said the talkathon amounted to "30 hours of excuses" from senators who think it's OK that "families are losing work because of government attacks on the coal industry."

"It's cruel to tell struggling coal families that they can't have a job because some billionaire from San Francisco disagrees with their line of work," McConnell said. He was referring to Tom Steyer, a former hedge-fund manager and environmentalist who says he will spend $100 million — $50 million of his own money and $50 million from other donors — to make climate change a top-tier issue in the 2014 elections.