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?

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.

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.

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?

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.

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.

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.