The state of Alaska and Safari Club International claimed the mammal should not be protected, calling the decision to do so "arbitrary and capricious and an abuse of agency discretion."

The heart of Sullivan's decision was whether the Fish and Wildlife Service had made a rational decision in its 2008 listing. Noting the wildlife agency took three years to evaluate a massive, complex, and rapid developing body of scientific evidence Sullivan concluded that the 2008 decisions was "... a reasoned exercise of the agency's discretion based upon the facts and the best available science as of 2008 when the agency made its listing determination."

The judge also struck down environmental arguments, including from the Center for Biological Diversity, that the U.S. government did not go far enough in protecting polar bears, and that polar bears should be listed as endangered rather than threatened.

This decision is an important affirmation that the science demonstrating that global warming is pushing the polar bear toward extinction simply cannot be denied," said Kassie Siegel, director of the Center for Biological Diversity's Climate Law Institute. "Maintaining Endangered Species Act listing for the polar bear is a critical part of giving this species back its future."