INTRODUCTION

On May 15, 2008, the U.S. Fish and Wildlife Service, an executive branch agency within the Department of Interior, issued a regulation listing the polar bear under the Endangered Species Act (ESA), a federal statute designed to prevent the extinction of imperiled plants and animals, due to global warming and the melting of the bear's sea-ice habitat. This highly publicized milestone firmly cemented the polar bear as the iconic example of the devastating impacts of global warming on the planet's biodiversity. While the polar bear is the most well-known species imperiled by global warming, and the first to be listed under the ESA solely due to this factor, it was not the first species protected under the statute in which global warming played a significant role. Two years earlier, on May 9, 2006, the National Marine Fisheries Service, declared two species of Caribbean coral Threatened under the ESA.

The ESA has been declared by the U.S. Supreme Court to be “the most comprehensive legislation for the preservation of endangered species ever enacted by any nation.” The statute is widely considered to be one of the strongest environmental laws in the United States, and hence one of the most controversial. The listing under the ESA of species threatened by global warming raises the possibility of applying this law, which “admits of no exception,” and which affords endangered species “the highest of priorities,” to the seemingly intractable issue of reducing U.S. greenhouse gas emissions.