There is no threshold level of fine particle pollution below which health risk reductions are not achieved by reduced exposure.

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.

The EPA's greenhouse gas regulations, along with a host of other onerous regulations, are unnecessarily driving out conventional fuels as part of America's energy mix. The consequences are higher energy prices for families and a contraction of our nation's economic growth.

We are very confident that the data is showing that carbon capture and sequestration is technologically feasible and it's available. It has been successfully demonstrated and there are full-scale both conventional and unconventional coal projects with CCS that are moving forward. So there is no question that there's continued investment in this technology.

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.

People are not running to build coal facilities because of the price of natural gas, but we do see them being constructed, and there is an interest in fuel diversity, so we took the exercise pretty seriously.

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.