In 2007, his tireless efforts to educate the world about global warming were celebrated on an international scale. He was awarded the Nobel Peace Prize alongside the United Nation's Intergovernmental Panel on Climate Change.
"It felt great," he says. "Not least because some people who weren't willing to listen before, some of the people in that group really began to open up and listen a little bit more."
Though leaders are starting to listen to Gore's urgent warnings, he says the world is still at risk. "We're still dumping 70 million tons of global warming pollution into the earth's atmosphere every day," he says. "Vindication would be when we really stop doing that and turn the corner, but the exciting, positive news is that there are a lot of good changes under way now."