Two days before Christmas, the Federal Appeals Court for the District of Columbia reinstated (PDF) the Clean Air Interstate Rule (CAIR) while the Environmental Protection Agency (EPA) makes changes to it. Judge Judith W. Rogers said, "The parties’ persuasive demonstration, extending beyond short-term health benefits to impacts on planning by states and industry with respect to interference with the states’ ability to meet deadlines for attaining national ambient air quality standards for PM2.5 and 8-hour ozone, shows that the rule has become so intertwined with the regulatory scheme that its vacatur would sacrifice clear benefits to public health and the environment while EPA fixes the rule."

The AP reported that "The Environmental Protection Agency had predicted that the Clean Air Interstate Rule would prevent about 17,000 premature deaths a year by dramatically reducing sulfur dioxide and nitrogen oxide emissions. In addition, the EPA said the rule would save up to $100 billion in health benefits, eliminate millions of lost work and school days and prevent tens of thousands of nonfatal heart attacks."

Though the decision is being seen as a Christmas gift to environmental groups, it will also provide greater regulatory certainty for emitters in the 28 affected states, including power generators.