Perhaps no other individual has more personified the American environmentalist movement over the last three decades than Al Gore, the former vice president of the United States and the Democratic Party's 2000 presidential nominee. In a conversation on Tuesday with UC Berkeley economist Laura Tyson as part of COAL + ICE, a three-week climate change festival in San Francisco co-organized by the Center on U.S.-China Relations, Gore argued that decarbonization must become "the central organizing principle of human civilization" in order to stave off the worst effects of global warming.

"It is a global emergency," he said. "People hear a phrase like that and it sounds a little 'hair on fire' hype. But this is an existential threat to the future of human civilization."

Amid the despair wrought by rising temperatures — and President Donald Trump's decision to withdraw the United States from the 2015 Paris Climate Agreement — Gore noted that "a sustainability revolution" was nonetheless proceeding.

"Already, here in the United States, there are five times as many jobs in solar as in coal," he said. "The famous Coal Museum in Kentucky just installed solar panels on its roof."

Watch the entire conversation between Gore and Tyson in the video embedded above. For a complete list of events included in COAL + ICE, click here.