Last week, the U.S. Court of Appeals for the D.C. Circuit heard oral arguments in West Virginia vs. EPA, the legal challenge to the Environmental Protection Agency’s (EPA) Clean Power Plan (CPP). West Virginia is leading a coalition of 27 states challenging the rule.

Why the uproar? Easy: CPP would hurt the U.S. economy without effectively combating climate change.

With its new regulations, the EPA hopes for a more than 30 percent reduction in power-plant carbon emissions by 2030. But even the agency admits that its proposed carbon restrictions would only cool the Earth by 1/20th of a degree over the next two decades.

Worse yet, that fraction of a degree would cost billions of dollars and hundreds of thousands of jobs. The American Action Forum (AAF) found that CPP would cost roughly $8.5 billion, making it nearly 10 times more costly than the most burdensome mandates of 2015. Most states subjected to the EPA’s mandate would see double-digit electricity price increases, leaving Americans in these states with less money to save and spend. CPP is also projected to shutter nearly 70 power plants, eliminating 125,800 jobs in the coal industry. The AAF report concluded that CPP could cost the U.S. economy $2.5 trillion by 2030.

This is more bad news for the coal industry, which has suffered huge job losses in recent years. Since 2008, more than 19,000 coal mining jobs have disappeared nationwide. West Virginia has lost over 5,000 jobs alone, while employment in Kentucky’s coal industry has shrunk by 37 percent.

Environmental regulations wreak havoc on employees—all for 1/20th of a degree.