Climate change is the single biggest thing that humans have ever done on this planet. The one thing that needs to be bigger is our movement to stop it.

Remember...this year has already seen more billion-dollar weather-related disasters than any year in US history. Last year was the warmest ever recorded on planet Earth. Arctic sea ice is near all-time record lows. Record floods from Pakistan to Queensland to the Mississippi basin; record drought from the steppes of Russia to the plains of Texas...This is what climate change looks like in its early stages.

We've abnegated the Kyoto treaty, we've instituted a voluntary program that's obviously not been working, we've taken every effort to excise references to global warming from official documents, to try to undermine international conferences that work on environmental issues, and on and on and on.

The fact that Washington has been a complete logjam for anything for the last six years has got to change because we need to have federal policy that really allows us to move quickly and nimbly.

There is no real scientific debate over what is happening; of course there is debate over exactly how it is going to play out in the decades ahead, because this is a large experiment that we haven't done before, and no one knows precisely how one can ever precisely predict what effects this heat will have. But all the science in the last few years, or almost all of it, really serves to show that the effects are larger and more rapid than we had thought even a decade ago.

Winning slowly is another way of losing. Americans are screwing up our health care system again right now. That's going to cause grave trouble for people over the next five, 10 years. There are going to be lots of people who die, lots of people who are sick. It's going to be horrible. But 10 years from now it will not be harder to solve the problem because you ignored it for those 10 years. With climate change, that's not true. As each year passes, we move past certain physical tipping points that make it impossible to recover large parts of the world that we have known.

There is basically no one not on the payroll of Exxon Mobil or coal companies who any longer contend that this is not something to worry about.