Experts say that to make a serious dent in American carbon emissions, Mr. Obama’s administration would have to enact policies that would force the two most polluting sectors of the nation’s economy — cars and coal plants — to slash their emissions. Mr. Obama has already signed a United Nations accord pledging that the United States will cut its greenhouse gas emissions 17 percent from 2005 levels by 2020 and 83 percent by 2050; there is simply no way to hit those targets, experts say, other than by going after cars and coal. And he then would have to make the case to other nations that the United States had taken action — and that they must, too.
He is making some headway on those fronts.
In his first term, Mr. Obama’s E.P.A. used the authority of the Clean Air Act to issue tough new vehicle fuel-economy standards of 54.5 miles a gallon by 2025. The regulations forced automakers to build fleets of fuel-sippers, and according to the E.P.A. they will lead to a cut of about 180 million tons of carbon a year by 2020, rising to 580 million tons by 2030 and 1.1 billion tons annually by 2050.
The agency is now drafting a regulation, expected in June, to slash pollution from existing coal-fired power plants. Details aren’t yet available, but experts estimate that it will cut an average of 200 million to 500 million tons of carbon emissions annually within a decade. And the E.P.A. estimated that regulations on building and appliance efficiency have cut or prevented the annual emission of 350 million tons of carbon. That means the combined impact of the current and forthcoming E.P.A. regulations could lead to cuts of over one billion tons of emissions annually.
So, if the anti-Keystone people really want to make a dent in carbon emissions, they should support and help the president to reach his goal. I'm very tired of liberals who say the president has done nothing for the environment. His actions speak for themselves.