State Coalition Vows to Fight Possible Vehicle Emission Rollback

A dozen U.S. state attorneys general and the District of Columbia say they will unite to legally challenge any effort by the Trump administration to roll back planned limits on greenhouse gas emissions from cars and light-duty trucks for 2022-2025.

The lower limits are directly linked to fuel economy targets because carbon exhaust from petroleum-burning engines varies with the amount of hydrocarbon fuel they burn.

Carmakers agreed in 2011 to double their average fuel efficiency to 54.5 mpg by 2025. But the pact included a midterm review of the feasibility of that goal. The Obama administration declared the original targets viable just before turning over the White House to incoming President Donald Trump in January. Trump has ordered a new review of the standard.

The state coalition contends that current standards would lower carb emission by the equivalent exhaust output of 422 million vehicles and generate $100 billion in long-term fuel savings for the states’ residents.

The alliance consists of Connecticut, Delaware, the District of Columbia, Iowa, Maine, Maryland, Massachusetts, New York, Oregon, Pennsylvania, Rhode Island, Vermont and Washington.

Carmakers claim the original emission and fuel economy targets have become unrealistic because cheap fuel has prompted a huge swing in car sales from coupes and sedans to larger and less efficient SUVs, crossover vehicles and pickup trucks. But they also hope to avoid being forced to meet two sets of regulations in the U.S.