CRS Report – U.S. Climate Change Regulation and Litigation: Selected Legal Issues, Linda Tsang, Legislative Attorney. April 3, 2017 [via FAS] : “On March 28, 2017, President Trump signed an executive order to encourage and promote energy development by modifying climate change policies. As the Trump Administration implements its environmental policies, various legal challenges to Obama Administration climate change regulations remain pending before courts. During the last term of the Obama Administration, the Environmental Protection Agency (EPA)and the National Highway and Traffic Safety Administration finalized a series of regulations to address emissions from cars, trucks, and their engines that may contribute to climate change. In addition, EPA finalized regulations pursuant to its authority under the Clean Air Act (CAA) to reduce GHG emissions from stationary sources such as power plants, GHG-emitting oil and gas sources, and landfills. Various stakeholders have challenged amajority of these rules generally contesting the scope of EPA’s authority and its methods for regulating GHG emissions. In addition to the CAA, other environmental statutes such as the Endangered Species Act and the National Environmental Policy Act require federal agencies to consider climate change in their actions and decisions. The extent to which agencies may consider climate change effects and rely on predictive models, studies, and assumptions, however, has been challenged in court. Federal agencies are also required to consider the cost of GHG emissions in their rulemakings and environmental reviews. As the Trump Administration implements its policies on climate change, stakeholders may sue to ensure compliance with laws and judicial precedent that require consideration of climate change effects or costs.Climate change litigation may potentially increase as some stakeholders seek to reduce GHG emissions and address climate change effects. In the past, plaintiffs have had little success in using federal common law nuisance claims to force private entities to reduce their GHG emissions or pay damages for alleged injuries caused by their emissions. In 2011, the Supreme Court determined that these claims were displaced when Congress granted EPA authority to regulate GHG emissions under the CAA. If Congress amends the CAA to remove EPA’s authority, plaintiffs may seek to reintroduce these common law nuisance claims.However, they will likely face jurisdictional barriers that may be difficult to overcome.”