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.

If every country committed to spending 0.05 per cent of GDP on researching non-carbon-emitting energy technologies, that would cost $25 billion a year, and it would do a lot more than massive carbon cuts to fight warming and save lives.

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?'

The fact that we're catching more fish per person than we've ever done before doesn't mean that there are not particular places where we've managed fisheries badly.

Surely the biggest problem we have in the world is that we all die. But we don't have a technology to solve that, right? So the point is not to prioritize problems; the point is to prioritize solutions to problems.

We worry about the seemingly ever-increasing number of natural catastrophes. Yet this is mainly a consequence of CNN - we see many more, but the number is roughly constant, and we manage to deal much better with them over time. Globally, the death rate from catastrophes has dropped about fifty-fold over the past century.