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.

States with tremendous oil and natural gas reserves have the most to gain economically from proper regulation.

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.

Transparency is all about letting in and embracing new ideas, new technology and new approaches. No individual, entity or agency, no matter how smart, how old, or how experienced, can afford to stop learning.

Climate change is the greatest threat of our time.