Obama climate plan may hinge on error in 1990 law

WASHINGTON — The pitched battle over President Barack Obama’s signature climate change policy, which is moving to the courts this week, carries considerable political, economic and historical stakes. Yet its legal fate, widely expected to be ultimately decided by the Supreme Court, could rest on a clerical error in an obscure provision of a 26-year-old law.

That error, which left conflicting amendments on power plant regulation in the Clean Air Act, will be a major focus of oral arguments by opponents of Obama’s initiative when the case is heard Tuesday in the U.S. Court of Appeals for the District of Columbia Circuit.

The initiative, known as the Clean Power Plan, which Obama sees as at the heart of his climate change legacy, gave the U.S. critical leverage to broker the landmark 2015 Paris climate change accord.

If the plan is struck down, the U.S ., the world’s largest carbon polluter over the centuries, will lose its main tool to cut greenhouse gas emissions. If it is upheld, it will transform the nation’s electricity system, closing hundreds of coal- fired power plants and setting in motion a wholesale shift to wind, solar and nuclear power, as well as to improved electric transmission systems.

Twenty- eight states and more than 100 companies and labor and industry groups are fighting to overturn the plan. Defending it are 18 states and dozens of environmental and public health groups that have joined forces with the Obama administration.

Nearly 20 lawyers will take turns arguing the case before 10 judges — much larger than the typical three-member panel. The judges have allocated four hours to hear the arguments, rather than the usual one or two.

The long- forgotten clerical error at issue in the case involves an update to the Clean Air Act passed by Congress in 1990.

The act, originally approved in 1970, is the legal foundation of the Clean Power Plan. An obscure provision in the law — Section 111(d) — gave the EPA broad authority to regulate unknown future pollutants. At the time, carbon dioxide was not considered a pollutant.

In 1990, when Congress passed the update to the Clean Air Act, it amended Section 111(d). A version of the amendment passed by the House said that if the EPA already was regulating power plant pollution under a separate section of the law, it could not use Section 111(d) to create new regulations on the same plants. A version of the amendment passed by the Senate, however, did allow such overlapping regulation.

When the two bills were merged, lawmakers forgot to strike out one of the conflicting amendments. So it was signed into law by President George H.W. Bush with both amendments.