We simply don't know yet what's going to happen to the carbon in the atmosphere.

The essential fact which emerges ... is that the three smallest and most active reservoirs ( of carbon in the global carbon cycle), the atmosphere, the plants and the soil, are all of roughly the same size. This means that large human disturbance of any one of these reservoirs will have large effects on all three. We cannot hope either to understand or to manage the carbon in the atmosphere unless we understand and manage the trees and the soil too.

If we want to go to space with humans, that's for fun not for science. Human adventures in space are just sporting events.

It's better to get mugged than to live a life of fear.

You have this world of mathematics, which is very real and which contains all kinds of wonderful stuff. And then we also have the world of nature, which is real, too.

We do not know how much of the environmental change is due to human activities and how much [is due] to long-term natural processes over which we have no control.

I think we're doing pretty well. It's clear the media, of course, always gives you the bad news.