When we think about global warming at all, the arguments tend to be ideological, theological and economic.

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.

At least I sure hope it will - and I see good signs all the time, especially in things like the rise of local agriculture.

We're clearly not going to stop global warming at this point. We've already raised the temperature of the planet one degree. We've got another degree in the pipeline from carbon we've already emitted. What we're talking about now is whether we're going to have a difficult, difficult century, or an impossible one.

I think fracking for gas will reduce the incentive to turn to renewables, and I think it will do a lot of other damage across the countryside.

To me, it's more important to take the 60-70% of people who really understand that there's a problem [of climate change] and get some percentage of them active than to try and stamp out the last embers of pre-scientific thought.

Profiting from companies that are overloading the atmosphere with carbon and changing the atmosphere is wrong.