And yet while 70 percent of Americans believe global warming is a big problem, they still rank it near the very bottom of their list of top 25 concerns.
"We were with you in the San Jose Airport. And a man came over to you and he says 'Who are you supporting, Obama or Hillary? Who are you supporting? Who are you supporting?'" Stahl asked.
Gore's response to the man? "Uh ha."
"So, let me ask you. Who are you supporting?" Stahl asked.
"I'm tryin' to stay out of it," Gore replied.
Getting Al Gore to talk about politics these days is hard work. But as a party leader and uncommitted superdelegate, his staying "out of it" isn't easy.
"Are they calling you every minute?" Stahl asked.
"Not every minute," Gore said.
"No? Lotta pressure though, I'll bet," Stahl remarked.
"We unplugged the phones for this interview, so I can't say with authority. But no, everyone -- they both call. And I appreciate that fact," Gore replied.
"And what about the idea of the honest broker who goes to the two candidates and helps push one or the other of them off to the side?" Stahl asked.
"Yeah, kind of a modern Boss Tweed," Gore remarked.
"Except his name would be Al Gore," Stahl said.
"Well, I'm not applying for the job of broker," Gore replied, laughing.
He's not ruling it out, but he says he already has a job, as he puts it, "P.R." agent for the planet.
"You have said, and I'm going to quote you, 'If I do my job right, all the candidates will be talking about the climate crisis,'" Stahl said. "I can't think of a time I've heard the candidates talk about it."
"Right. Well, I'm not finished yet," Gore said.
The Gore campaign on global warming went into high gear when his documentary "An Inconvenient Truth" was an unexpected hit. What he's been doing is holding seminars, where he trains other people to give his famous slideshow about the effects of greenhouse gases.
So far in all, he's coached about 2,000 people, teaching one little workshop at a time.
His slideshows are tailored to his audiences. For example, when he talks to evangelical Christians, he includes passages from the Bible.
Gore is trying to redefine this as a moral and spiritual issue. "We all share the exact same interest in doing the right thing on this. Who are we as human beings? Are we destined to destroy this place that we call home, planet earth? I can't believe that that's our destiny. It is not our destiny. But we have to awaken to the moral duty that we have to do the right thing and get out of this silly political game-playing about it. This is about survival," he said.