When discussing overall impacts on employment, it is important not to overlook the new technologies and industries that can be driven by pollution control standards.

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.

When discussing overall impacts on employment, it is important not to overlook the new technologies and industries that can be driven by pollution control standards.

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.

Climate change is the greatest threat of our time.

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.

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.