By themselves, they are not enough; we also need to engage in political action.

It's much to the credit of the rest of the world that they have gone ahead and tried to do the Kyoto accords on their own. It makes it unbelievably difficult to do that, for a variety of economic and regulatory reasons, without the participation of the biggest energy user in the world.

Unfortunately, The End of Nature turns out to be correct, although I wish it were not so. The only places that I was incorrect was, as with environmental science at the time, the estimation of the speed at which we see the effects of global warming.

The consumer culture in general has washed over our civilization. For the last 50 years, if you've had a credit card and some access to money, you don't really need neighbors around you. And as a result, they dwindled. The average American has half as many close friends as they did in 1950. Three quarters of Americans don't know their next-door neighbor. They may know their name, but they have no real relationship with them. That's an utterly new place for human beings to find themselves in - I mean, we're a socially evolved primate.

Where people aren't as deeply reliant on fossil fuel as in the United States, it's far easier for them to imagine change on this scale. When you go to Europe, they're much more ready. They use half the amount of energy per capita that we use. They can imagine using less than that. They see the benefits. They're ready to go.

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.

The fight around climate change, which I've spent my life on, is somewhat more difficult than gay marriages because no one makes trillions of dollars a year being a bigot, and that's how much the fossil-fuel industry pulls in pumping carbon into the air. But the principle is the same, I think.