The sooner we switch away from carbon-based fuel and start relying on renewable energy sources available in the United States, the sooner we will grow our economy by creating the millions of new jobs that will come from retrofitting homes and businesses, building smart grids, renewable energy systems and planting trees and all the rest. We need to create a lot of jobs that can't be outsourced.

Today we're dumping 70 million tons of global-warming pollution into the environment, and tomorrow we will dump more, and there is no effective worldwide response. Until we start sharply reducing global-warming pollution, I will feel that I have failed.

I've been dreaming of this moment since I was a kid growing up in Tennessee: that one day, I'd have the chance to come here to Madison Square Garden and be the warm-up act for Elvis.

The mountain glaciers in every region of the world are melting, many of them at an accelerated rate, threatening drinking supplies - drinking water supplies and agricultural water supplies. We have these record storms, drought, floods, fires, three deaths (ph) in the American West, climate refugees beginning now, expected to rise to the hundreds of millions unless we take action.

We are in an unusual predicament as a global civilization. The maximum that is politically feasible, even the maximum that is politically imaginable right now, still falls short of the minimum that is scientifically and ecologically necessary.

We are running out of time, we must have a planetary solution to a planetary crisis.

I do genuinely believe that the political system is not linear. When it reaches a tipping point fashioned by a critical mass of opinion, the slow pace of change we're used to will no longer be the norm. I see a lot of signs every day that we're moving closer and closer to that tipping point.