In their essay Breaking New Ground on Issues Other than Global Warming, Professors Kathryn A. Watts and Amy J. Wildermuth have presented a thoughtful preliminary analysis of the Supreme Court's handiwork in Massachusetts v. EPA. They are correct that the decision potentially paves new ground in administrative law, particularly with regard to state standing. The Court's approach to review of agency decisions to decline rulemaking petitions is also potentially significant, but perhaps less ground-breaking than they suggest. In the context of climate change policy their assessment of the Court's decision is too modest, however, for Massachusetts virtually ensures federal regulation of greenhouse gases from motor vehicles and other emission sources. While the Court did not order the EPA to regulate with respect to climate change, the majority opinion gives the Agency little option but to regulate, and not just for motor vehicles. Unless the relevant provisions of the Clean Air Act are revised by Congress in new climate change legislation, Massachusetts v. EPA will mean greenhouse gas emission limits on a wide variety of sources.


Massachusetts v. EPA, state standing, administrative law, environmental regulation, greenhouse gas emissions, environmental protection, vehicle emission standards, Clean Air Act, climate change

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Document Type


Place of Original Publication

Northwestern University Law Review Colloquy

Publication Information

102 Northwestern University Law Review Colloquy 32 (2007)


COinS Jonathan H. Adler Faculty Bio