A group of 17 climate and health related organizations have filed a challenge in the U.S. Court of Appeals for the D.C. Circuit to the Environmental Protection Agency’s rescission of its 2009 finding that greenhouse gases pose a danger to public health and welfare. The petition for review does not indicate any legal arguments to support the challenge; those will be asserted in the opening brief filed by the petitioners.

The new case does provide a mechanism for the Supreme Court to revisit its decision in Massachusetts v. EPA, which allowed EPA to issue its 2009 endangerment finding. In that ruling, the Supreme Court decided that greenhouse gas emissions met the Clean Air Act’s definition of an “air pollutant.” As a result, the EPA is required to determine if emissions endanger public health and the welfare of the public, or if the science is too uncertain to make such a determination.

In its recent final rule, EPA argues that the Clean Air Act doesn’t authorize the agency to set emission standards in response to global climate change concerns, and the endangerment finding and resulting emissions regulations applicable to commercial trucks therefore have no legal basis.