The obvious issue is providing clean drinking water and sanitation to every single human being on earth at the cost of little more than one year of the Kyoto treaty.

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.

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

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.

To prepare adequately for the challenge of global warming, we must acknowledge both the good and the bad that it will bring. If our starting point is to prove that Armageddon is on its way, we will not consider all of the evidence, and will not identify the smartest policy choices.

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.

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.