The U.S. Supreme Court’s opinion in Weyerhaeuser Co. v. U.S. Fish & Wildlife Service raises important questions about the scope of the Endangered Species Act’s (ESA’s) protections for critical habitat. Foremost among them is a question one might think was long settled: what is “habitat”? In a short ruling, the Weyerhaeuser Court opined that “critical habitat” must first be “habitat,” but it did not attempt to define exactly what habitat is or how much deference the U.S. Fish and Wildlife Service should get on what is both a biological and policy question.

This Article, adapted from Chapter 16 of What Can Animal Law Learn From Environmental Law?, 2d Edition (ELI Press, forthcoming 2020), explores existing and potential wildlife conservation policies that could play a vital role in mitigating global climate change. It describes how climate change is impacting wildlife and biodiversity around the globe and reviews the history and current state of U.S. policy, including how the federal government currently manages climate change issues under the ESA.

The Endangered Species Act defines an endangered species as one at risk of extinction “throughout all or a significant portion of its range.” The U.S. Department of the Interior (DOI) has repeatedly defined “significant portion” to mean an area of the range essential to species persistence. This definition is redundant, and various iterations of the definition have been struck down in the past. At the same time, other proposals to list a species only in a portion of its range fail to satisfy the statutory requirements.

Two carbon pricing bills were introduced during the 115th Congress. Reps. Carlos Curbelo (R-Fla.) and Brian Fitzpatrick (R-Pa.) introduced the MARKET CHOICE Act during the summer of 2018. Reps. Ted Deutsch (D-Fla.) and Francis Rooney (R-Fla.) introduced the Energy Innovation and Carbon Dividend Act (Energy Innovation Act) in November 2018, and reintroduced it early in the 116th Congress, where it presently has more than 65 cosponsors. By different methods and with different comprehensiveness, both of these bills place a Pigouvian tax on greenhouse gas (GHG) emissions.

The U.S. Department of the Interior and National Oceanic and Atmospheric Administration recently finalized comprehensive changes in how the Endangered Species Act (ESA) is implemented. These changes address the species listing process, critical habitat designations, protections for threatened species, and the §7 consultation process.