And what the Earth is facing, he said, is extreme weather events -- from massive flooding in Pakistan, to extreme drought and wildfires in Texas.
Gore appeared in Midtown Manhattan -- greeted with a standing ovation -- and addressed a number of common arguments from skeptics, even calling out House Speaker John Boehner (R-OH). Gore played a clip of Boehner essentially saying volcanoes could contribute more to global warming than humans.
"I don't believe speaker Boehner intends to deceive," Gore said. "I do believe that somebody told him that in a particularly persuasive way. I think he probably wondered when he made that statement."
Some of that persuasion Gore said, surely, comes from well-funded political contributions.
"(Carbon polluters) are the biggest source of campaign contributions," Gore said.
The Carbon Reality Project comes at a time when leading Republican presidential candidates openly express doubt about climate change. Texas Gov. Rick Perry -- who earlier this month skipped a campaign event with Sen. Jim DeMint to address his state's wildfires -- has said climate scientists "manipulate" data to keep their projects funded. Mitt Romney believes the world is getting warmer, but he "doesn't know if it's mostly caused by humans." And recently, a Gallup poll showed that only 53 percent of people believe global warming is a threat.
But Gore's message was that hope is not lost. "We are at a fork in the road," he said. "Accepting the reality is the key to making the right choice."