Al Gore in San Francisco addressing climate change

This is the Week of California's Global Climate Summit in San Francisco. Attendees have come from the four corners of the planet. On Tuesday, Al Gore sounded as much a a candidate as an climate advocate.

Former Vice-President Al Gore, now an investor in green technologies and an avid environmentalist, appeared at the Coal and Ice exhibition, part of this week's Climate Summit in San Francisco a forum hosted by UC Berkeley Economist Laura Tyson, the former Chair of the U.S. President's Council of Economic Advisers under President Clinton. "Any of us who get involved occasionally have a struggle between hope and despair. I will admit that openly but I always do come down on the side of hope," said Mr. Gore.

In the early 2000's, initial projections about how quickly wind and solar would become  mainstream, have been realized almost 100 times faster. That's largely because the costs of wind and solar have plummeted.  "Already, here in the United States, there are 5 times as many jobs in solar as in coal.

"The famous Coal Museum on Kentucky just installed solar panels on it's roof," said Gore. But, Gore warns that environmentalists should not cry wolf. "We have to make the de-carbonization of the global economy, the central organizing principle of human civilization in order to stave off the climate crisis in time to avoid the truly catastrophic consequences. It is a global emergency. 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," said Gore. 

The former Vice President says the U.S. is not out the the Paris Climate Agreement just yet. "Under the law, the first day the United States of America could actually leave the Paris Agreement the next day after the next Presidential election."

Upon 30 days notice by a new President, the U.S. would be right back in it.

When Gore ended, to huge applause, he sounded like the Presidential candidate he once was, "We did not close our eyes. We did not turn away. We are awake. We are alive. We're paying attention.  We're gonna do the right thing."

No doubt, he is a man preaching to the choir, but a choir that appears to be growing.