Think on a 50-year scale, which is a much more natural time-scale for global warming. The US is right now spending about 200 million dollars annually on research into renewable energy.

I think it's great that we have organisations like Greenpeace. In a pluralistic society, we want to have people who point out all the problems that the Earth could encounter. But we need to understand that they are not presenting a full and rounded view.

I'm an old member of Greenpeace. I worried intensely, as I think most of my friends did, that the world was coming apart.

The second thing is, if you want to do something about global warming, you have to think much more long-term. There is something wrong with saying we should start using renewables now, while they are still incredibly expensive.

I think Al Gore has done a great service in making global warming cool. He's basically taken it from a nerdy, almost ignored issue to making it what it is - namely, a problem.

Wishful thinking is not sound public policy.