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 only thing that will really change global warming in the long run is if we radically increase the speed with which we get alternative technologies to deal with climate change.

Obviously any group that has to have funding also needs to get attention to their issues.

For the longest time in Denmark I didn't want to say what I was politically. I thought it was irrelevant.

I found university a little dispiriting. I thought I would enter the great halls of Plato, but instead I entered the halls of an intellectual sausage factory. I wanted to do something not on the main course, and chose the environment.

Listen, global warming is a real problem, but it's not the end of the world. A 30-centimetre sea level rise is just not going to bring the world to a standstill, just like it didn't over the last 150 years.