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.

The total efforts of the last 20 years of climate policy has likely reduced global emissions by less than 1 percent, or about 250 million metric tons of carbon dioxide per year.

In the rich world, the environmental situation has improved dramatically. In the United States, the most important environmental indicator, particulate air pollution, has been cut by more than half since 1955, rivers and coastal waters have dramatically improved, and forests are increasing.

Money spent on carbon cuts is money we can't use for effective investments in food aid, micronutrients, HIV/AIDS prevention, health and education infrastructure, and clean water and sanitation.

Even if I was a bad right wing guy, to the extent of whether my arguments are right or wrong, they're right or wrong independently if I'm right or left.

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.