But I will tell you that I didn't go to Washington to sit around and wait for Congressional action. Never done that before, and don't plan to in the future.

Greenhouse gas pollution, through its contribution to global climate change, presents a significant threat to Americans health and to the environment upon which our economy and security depends.

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.

Any first-generation technology will. But we are looking at carbon the same way we look at every pollutant under the Clean Air Act; we look for the new technologies that are available. We recognize that these power plants are going to be around for decades.

EPA gets to set a standard for new. For the existing, EPA sets guidelines for what we think is appropriate, but then states develop plans that work for them, taking into consideration their specific energy mix.

I think that one of our most difficult international challenges is clearly climate change and making sure that the Paris agreement goes forward. While I think the international community understands that President Trump is not taking the same position as President Obama.

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.