Al Gore is back — and he's angry.

The former U.S. vice president recently went on a profanity-laced rant during a speech at the Aspen Institute, calling "bulls**t" on climate skeptics who he says have "polluted" public debate over global warming. The problem, according to Gore, is that a small number of vocal skeptics have spread misinformation about climate science — a tactic he compared to tobacco companies' efforts to downplay the dangers of smoking.

"Some of the exact same people — by name I can go down a list of their names — are involved in this," Gore said Thursday. "And so what do they do? They pay pseudo-scientists to pretend to be scientists to put out the message: 'This climate thing, it's nonsense. Man-made CO2 doesn't trap heat. It may be volcanoes.' Bulls**t! 'It may be sun spots.' Bulls**t! 'It's not getting warmer.' Bulls**t!"

These skeptics have been so successful, Gore said, that public and political discussions about climate change have devolved into a cycle of partisan bickering. "It's no longer acceptable in mixed company, meaning bipartisan company, to use the godd**n word climate," he said. "It is not acceptable. They have polluted it to the point where we cannot possibly come to an agreement on it."

The speech marks the latest step in a forceful return to the spotlight for Gore, who had kept a low profile following a string of bad publicity in 2010. Gore and his wife announced last June they would separate after 40 years of marriage, and Gore then endured a month-long scandal in which he was accused of sexually assaulting a masseuse (he was later cleared of those charges). Aside from low-key statements and appearances, Gore made himself scarce for much of late 2010 and early 2011 — echoing his self-imposed exile after the 2000 presidential election — but the Nobel Peace Prize and Academy Award winner apparently couldn't stay quiet any longer.

In June, Gore penned a scathing, 7,000-word essay for Rolling Stone, in which he called out President Obama for failing to lead the nation and the world in a battle against climate change. The piece garnered international attention for Gore, and helped galvanize growing angst among environmentalists that American politicians have pushed global warming to the back burner. And now, as his tirade against climate skeptics makes headlines worldwide — it already "lit up the conservative blogosphere this weekend," ClimateWire reports — Gore is once again positioning himself as the leading voice in climate activism, which has struggled to gain traction in his absence.

Gore's speech was first reported by Real Aspen, which also provided the following audio recording (warning: the clip contains language that some readers may find offensive).