I think we ultimately ought to look to put all uranium enrichment and fuel reprocessing, if any is done, under multinational control. Those are the two technologies by which nuclear energy can be translated into nuclear weapons programmes.

When I need to see the president, I make a request directly to his scheduler. I don't have to ask anybody's permission to see the president except the president. Some weeks, I see him multiple times. Some weeks, I don't see him at all.

I don't like the term 'global warming,' because it's misleading. It implies something that's mainly about temperature, that's gradual, and that's uniform across the planet. And in fact, temperature is only one of the things that's changing.

My understanding is that Exxon, in particular, did fund a variety of small think tanks to generate what amounts to propaganda against understanding of what climate change was doing, the human role in causing it.

Through space-based climate studies, my colleagues and I have learned that a stable and comfortable climate is not something to take for granted.

Environmental justice, for those of you who may not be familiar with the term, goes something like this: no community should be saddled with more environmental burdens and less environmental benefits than any other.

The way I think of it, economics and ecology occupy two intellectual silos, isolated from each other. Even when they do take each other into consideration, it's not uncommon for ecologists to spout absolute nonsense about economics, and vice versa.

The climate has always changed - after all, we've had numerous ice ages without human influence - but human activity has undoubtedly exacerbated Earth's natural trends beyond its capacity to adjust.