Today, the U.S. Court of Appeals for the District of Columbia unanimously upheld the Environmental Protection Agency’s (EPA) finding that carbon dioxide and other greenhouse gas emissions are a threat to public health and the environment. Although not a surprising decision, the ruling is a disappointing one. Unless Congress prohibits the EPA’s regulatory assault on fossil fuels, Americans will suffer from dramatically higher energy costs and a slower economy—all for no noticeable change in the Earth’s temperature.
In 1999, several groups of environmental activists sued the EPA to force the agency to regulate carbon dioxide from motor vehicles. Eventually the case made it to the Supreme Court; in April 2007, the Court ruled that carbon dioxide and five other greenhouse gas emissions (GHGs) are pollutants and can be regulated under the Clean Air Act. The Court ordered the EPA Administrator to determine whether these CO2 emissions were dangerous to human health and the environment and whether the scientific consensus on the effects of GHGs was settled.
In 2009, the EPA issued its decision, known as an endangerment finding, determining that carbon dioxide (a colorless, odorless, non-toxic gas) is a pollutant—not because it has any direct human health impact, but because—according to some—it can lead to sea level rises, stressed water resources, increased size and quantity of wildfires, and other effects linked to global warming.
Since the EPA has long ignored the disagreement among the scientific community regarding the EPA’s classification of CO2 as a pollutant as well as the magnitude of man-made warming, industry groups contested that the courts should reverse the EPA’s ruling on the grounds that it was arbitrary and capricious. When it comes to why climate change is occurring and how fast, the real scientific consensus is that there is no consensus. Despite a lack of scientific consensus, the challenge faced an uphill battle, because the courts are very deferential to agency fact-finding. The Supreme Court is unlikely to take up the case.