Via Forbes:

Unlike prior regulatory efforts to improve air quality by reducing toxic emissions, the EPA’s Clean Power Plan (CPP) aims to cut non-toxic carbon dioxide emissions by about a third. The stated reason is to slow the increase of the Earth’s temperature by 0.018 degrees Celsius by 2100.

Back when one of the aims of the EPA was merely clean air and water, mitigating air pollution from industrial sources typically entailed installing emissions control equipment, often at great cost. But, the net result was cleaner air.

The challenge with reducing carbon dioxide emissions is that carbon dioxide and water are typically the two emissions products that experts strive to produce as they are the two non-toxic products of clean fossil fuel combustion. Short of entombing carbon dioxide deep underground, an experimental process known as sequestration, the only ways of reducing carbon dioxide emissions from power generation are to switch fuels and/or improve efficiency.

See the article here.