The climate change is real today, but also the solutions that we have available to us that are cost-effective and beneficial to everyone are at our disposal now.

I cannot shy away from controversy. I don't know if it's my Irish blood, but I love it.

The climate change is real today, but also the solutions that we have available to us that are cost-effective and beneficial to everyone are at our disposal now.

We need an international solution to the challenge of climate change, there's no question about it. But the real key is, can you actually get that - or get that solution - without the US' involvement? Can you not lead domestically, and expect the rest of the world will take action... the US needs to lead, we need to be out there.

I don't think any administration, when they come in, thinks that their job is to tell the scientists what the science looks like or to be quiet about the science. Scientists need to remain true and not allow science to be politicized. Scientists are not politicians, and no politician should consider themselves to be a scientist.

I think climate change is probably the most extreme, and it's been going on for years because it's very difficult to talk about a planetary issue like climate change and to get people who live within four-year electoral cycles to actually pay attention to something that you predict is happening way in the future.

I definitely challenge people. But hopefully, I am working harder than anybody else, and so people won't resent the fact that I want them to work hard, as well.