My suggestion is that we should first work to ensure the Third World has clean drinking water and sanitation.

It seems incontrovertible to me that there is a global warming effect and that it is going to be serious, probably not in the amount of, say, six degrees warming, but it's likely that we'll get two to three degrees warming and that will be serious enough.

There is no question that global warming will have a significant impact on already existing problems such as malaria, malnutrition, and water shortages. But this doesn't mean the best way to solve them is to cut carbon emissions.

I'm a vegetarian, but I don't expect other people not to eat meat.

When thinking about the future, it is fashionable to be pessimistic. Yet the evidence unequivocally belies such pessimism. Over the past centuries, humanity's lot has improved dramatically - in the developed world, where it is rather obvious, but also in the developing world, where life expectancy has more than doubled in the past 100 years.

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?'

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?