As we previously reported, in December of last year, EPA determined that climate change caused by emissions from greenhouse gases endangered the public welfare and the environment. These so-called “endangerment findings,” while not directly imposing requirements on industry or other entities, paved the way for future EPA action to address climate change. In response to EPA’s endangerment findings, 10 petitions were filed urging EPA to reconsider its findings under the Clean Air Act. The parties argued, among other things, that the climate science could not be trusted, questioning the findings of the Intergovernmental Panel on Climate Change (IPCC), the U.S. National Academy of Sciences, and the U.S. Global Change Research Program. After months of consideration, in an over 200-page response, EPA denied the petitions, finding that the science to support EPA’s endangerment findings is “robust, voluminous and compelling.” Further legal challenge is most certainly to follow.