Allison's practice focuses on environmental and administrative law, with an emphasis on air issues, including global climate change, emissions trading, and the establishment and implementation of national ambient air quality standards. She has extensive experience in appellate and district court litigation, agency rulemakings, compliance advice, and legislative representation. Her representative clients include companies and trade associations in the electric generation industry, petroleum industry, manufacturing industries, and transportation and land development industries. Allison is admitted to practice before the US Supreme Court; the US Courts of Appeals for the Second, Third, Fourth, Fifth, Ninth, Tenth, and DC Circuits; the US District Court for the District of Columbia; and the US District Court for the Eastern District of Virginia. Relevant Experience Represented electric power industry in the Supreme Court and the DC Circuit in landmark case Massachusetts v. EPA involving whether the EPA has authority under the Clean Air Act to regulate greenhouse gas emissions to address global climate change. Represent client before Supreme Court in Utility Air Regulatory Group v. EPA, which will address the limits of EPA's authority to regulate greenhouse gas emissions under the Clean Air Act’s Prevention of Significant Deterioration and Title V permitting programs. Defended companies before the Supreme Court, Courts of Appeal, and US District Courts from tort suits alleging that carbon dioxide emissions from the companies' normal business operations contribute to the "nuisance" of global climate change (American Electric Power Co. v. Connecticut; Comer v. Murphy Oil; Native Village of Kivalina v. Exxon Mobil). Represent clients in every major rulemaking before the EPA regarding regulation of greenhouse gas emissions under the Clean Air Act. Represent clients in litigation in every challenge in the Court of Appeals and Supreme Court to the EPA's Clean Air Act greenhouse gas regulatory program. Represent clients in EPA rulemakings and proceeding to establish new source performance standards for new power plants under section 111(b) of the Clean Air Act and standards of performance for existing power plants under section 111(d). Represented electric generation client in rulemaking proceedings involving New Mexico's greenhouse gas regulatory programs and in challenges to those programs in the New Mexico Court of Appeals and New Mexico Supreme Court. Represent numerous industrial clients in litigation before the DC Circuit involving challenges to EPA's revision of the national ambient air quality standards for particulate matter, ozone, and nitrogen dioxide. Advise clients on issues related to climate change and the Endangered Species Act and National Environmental Policy Act. Represent clients in litigation involving whether the public trust doctrine extends to the atmosphere and can be used to limit greenhouse gas emissions and address climate change.