Three debates down and one to go, and climate change has still not been addressed by the presidential candidates and their running mates in face-to-face confrontations.

The punchy debate last night between President Obama and Mitt Romney opened with testy exchanges on energy in which the president accused his opponent of ignoring renewable power. Romney, in turn, attacked Obama for presiding over rising gasoline prices and faking support for fossil fuels.

But with the election inside of three weeks away, the town hall-style debate at Hofstra University on New York's Long Island firmly established climate change as an outcast issue in the race. Advocates have attempted all manner of attention-getting to highlight the subject, from delivering reams of petitions to praying.

Bill McKibben, whose climate protests this year have been a thorn in the administration's side, said satirically before the debate that it would be nice if the candidates "happened in passing to note" the visible impacts of warming, like record melting of Arctic ice and the drought consuming 60 percent of the United States.

In what turned into a very feisty debate on other subjects, neither candidate mentioned those events.

"Look, climate change is the biggest thing that's ever happened," McKibben said. "And hence the silence about it is both odd and paralyzing. It keeps us from really talking about the scale of change that we need."

Looking for guidance from above
Others hoped for divine intervention. A group of about 20 religious activists associated with Young Evangelicals for Climate Action traveled to the debate to hold prayer sessions asking that both candidates embrace the "moral" challenge of climate change.

"We hope that Governor Romney sees the light," the Rev. Jim Ball of the Evangelical Environmental Network said as he drove toward the site. "We're going to be there providing the governor support for doing the right thing. And he can point to young evangelicals and say, 'They get it. It's their future.'"

Ben Lowe, a 28-year-old organizer of the young evangelical group, went to the debate to "bear witness to the lack of climate science" in the race.

"One of my biggest disappointments of the election so far is that neither candidate has shown the leadership that we're hoping for on the climate crisis," Lowe said. "For us, it's not just an energy issue, it's not an economic issue; it's a moral issue and it's a spiritual issue. And honestly, it's a pro-life issue."

Obama showed early in the confrontation that he had jettisoned his passive strategy of the first debate 12 days ago. He repeatedly jabbed back at Romney's assertions by saying, "That's not true." He also sought to cast Romney as old-fashioned on energy, describing the Republican's plan as one that fails to see 10 years into the future.

"So he's got the oil and gas part, but he doesn't have the clean energy part," Obama said.

Romney accused the president of being responsible for rising gasoline prices and reduced access to public lands for oil production, and being disingenuous about supporting fossil fuels. He also spoke to conservative voters by describing Obama as environmentally extreme, claiming that the administration tried to stop an oil well in North Dakota because "20 or 25 birds were killed."

Sparring over the coal vote
"This has not been Mr. Oil or Mr. Gas or Mr. Coal," Romney said of Obama. "I don't think anyone really believes that you're a person who's going to be pushing for oil and gas and coal."

At another point, Obama leveled a similar criticism at Romney, who sought to close down a coal-fired power plant based on pollution when he was governor of Massachusetts.

"Now suddenly you're a big champion of coal?" Obama said.

The sparring on energy was one of the most heated exchanges in the debate with both candidates trying to attract economically minded voters along coal seams, in oil patches and in industrial towns.

When Obama emphasized his "all of the above" energy plan, it sparked a combative back-and-forth duel with a subtext about who would create more jobs by permitting the private sector to develop fossil fuels on public land and on the outer continental shelf.

Romney: "That's the problem. In the last four years, you cut permits and licenses on federal land and federal waters in half."

Obama: "Not true, Governor Romney."

Romney: "So how much did you cut it by --"

Obama: "Not true."

Romney: "By how much did you cut them by then?"

Obama: "Governor, we have actually produced more oil --"

Romney: "No, no, how much did you cut licenses and permits on federal land and federal waters?"

Obama: "Governor Romney, here's what we did: There were a whole bunch of oil companies --"

Romney: "No, I had a question, and the question was how much did you cut them by? How much did you cut them by?"

Obama: "You want me to answer a question? I'm happy to answer the question."

Both candidates bow to renewable energy
There were also sharp exchanges on renewable energy, with Romney making his boldest statements on that issue since the campaign began. The statements followed months of attacks on Romney by Obama for opposing the production tax credit, which benefits generators of wind energy in Iowa, Colorado and other swing states.

"I believe very much in our renewable capabilities -- ethanol, wind, solar -- would be an important part of our energy mix," Romney said. "But what we don't need is to have the president keeping us from taking advantage of oil, coal and gas."

The president, meanwhile, made a strong argument for more efficient use of gasoline through alternative vehicles and strengthened fuel economy standards. It was perhaps a peek into his energy priorities if he's re-elected; Obama has been vague about the policies he would pursue in his second term.

"But we've also got to continue to figure out how we have efficient energy, because ultimately, that's how we're going to reduce demand, and that's what's going to keep gas prices lower," he said.

But advocates are increasingly saying that Obama needs to provide the nation with a reason for converting its energy systems into ones that use cleaner power. Without describing the impacts of climate change, there's less motivation to undertake an expensive overhaul, they say.

"Both candidates vied to restate their commitment to more dirty oil, gas and coal production while ignoring the contradiction between an 'all of the above' energy program and reducing emissions of climate disrupting gases," Erich Pica, president of Friends of the Earth Action, said in a statement after the debate. "'All of the above' is not an acceptable energy policy or a responsible climate policy. It's a highway to hell -- a road to deeper droughts, fiercer fires and storms, messier spills and dirtier air."

Still, some Democratic strategists believe Obama has little to gain by addressing climate change three weeks before an election that might pivot on the electoral votes of hard-to-win states like Ohio, Virginia and Colorado.

"The lion's share of folks of who care about climate change know that he's a much better alternative than Romney, and he doesn't have to do a whole lot of education there," said Joe Trippi, who advised past presidential candidates. "The question is, how useful is highlighting the [climate] issue to pull some of these swing voters over with him?"

Not very, he said.

Reporter Robert Eshelman contributed. Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC., 202-628-6500