The Kyoto treaty has an estimated cost of between US$150 and $350 billion a year, starting in 2010.

Of course, the world is full of problems. But on the other hand it's important to get the sense... are we generally moving in the right direction or the wrong direction?

I really try to say things as they basically are and it so happens that it is a good message that things are getting better, but there are still problems.

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.

We've had the U.N. for almost 60 years, yet we've never actually made a fundamental list of all the big things that we can do in the world, and said, 'Which of them should we do first?'

Listen, global warming is a real problem, but it's not the end of the world. A 30-centimetre sea level rise is just not going to bring the world to a standstill, just like it didn't over the last 150 years.

So it's mainly a question of helping the Third World overcome the effects of global warming.