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

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.

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.

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.

I love disagreements. I love the democratic process. If I'm in a room where everybody agrees, I start to nod off.

Critics play a dangerous game when they denounce the science and law EPA has used to defend clean air for more than 40 years. The American people know better.

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.