The US Supreme Court ruled Apr. 2 that the US Environmental Protection Agency has the authority, under the Clean Air Act, to enact limits on carbon dioxide emissions.
The lawsuit was filed by Massachusetts along with several other states, US cities, and environmental groups.
“Because greenhouse gases fit well within the act’s capacious definition of air pollutant, EPA has statutory authority to regulate emissions of such gases from new motor vehicles,” Justice John Paul Stevens wrote in the majority ruling. “The statutory question is whether sufficient information exists to make an endangerment finding. In short, EPA has offered no reasoned explanation for its refusal to decide whether greenhouse gases cause or contribute to climate change. Its action was therefore arbitrary, capricious,...or otherwise not in accordance with law.”
The justices ruled five to four in favor of the group led by Massachusetts in reversing a court of appeals ruling. Chief Justice John G. Roberts wrote a dissenting opinion.
“Global warming may be a ‘crisis,’ even ‘the most pressing environmental problem of our time,’” Roberts said. “It is not a problem, however, that has escaped the attention of policymakers in the executive and legislative branches of our government, who continue to consider regulatory, legislative, and treaty-based means of addressing global climate change.”
Patrick Michaels, Cato Institute senior fellow in environmental studies, said, “The implications may be quite staggering. The decision means that CO2 qualifies as a pollutant, something that causes net harm. This surely will open up a massive number of subsidiary cases.” The Cato Institute is a think-tank based in Washington, DC.
Michaels questions what levels of CO2, if any, are to be allowed without being considered to be pollutants.
“There is very little in our society that does not have some relationship to the production of CO2,” Michaels said. “We have now entered the era where the courts will enter into almost every aspect of our lives.”