By Daniel Cohen, The Hill.

Power plant emissions of carbon dioxide have been falling for a decade, even without national regulations. However, further progress could cease in the absence of the Clean Power Plan, whose fate awaits hearings by the Supreme Court and U.S. Court of Appeals.

That's the conclusion of scenarios modeled by the Energy Information Administration (EIA) in the "early release" issued last week of its "Annual Energy Outlook 2016." The scenarios predict that power plant carbon dioxide emissions would be 20 percent lower with the Clean Power Plan than without it.

In an earlier piece in The Hill, I noted that U.S. power plant emissions are already declining at a faster pace than needed to attain the Clean Power Plan's 2030 target. Emissions dropped 21 percent from 2005 to 2015, more than half of the 32 percent cut needed by 2030. Coal use is down sharply again so far this year.