On May 15, 2008, the deadline imposed by court order, the Fish and Wildlife Service (FWS) listed the polar bear as a threatened species under the Endangered Species Act (ESA). At the same time, it published an ESA "special rule" limiting the application of ESA prohibitions to activities affecting the bear. The listing and special rule sparked debate not only because of the polar bear's charismatic qualities. Thus, the consequences of the listing, many thought, could be vast. This argument has some flaws. A second point is that while the causal nexus between "specific sources" and adverse effects on polar bear habitat may be elusive, some federal actions—such as CAA regulations—may increase GHG emissions from enough sources that the linkage may be more clear. First, the 90-day finding .
On May 15, 2008, the Fish and Wildlife Service (FWS) listed the polar bear as a threatened species under the Endangered Species Act (ESA). At the same time, it published a "special rule" limiting the application of ESA prohibitions to activities affecting the bear. The listing and special rule attracted attention due to the likelihood that the listing will be used as a legal basis to attempt to force reductions of greenhouse gas emissions from sources nationwide. At least two arguments might be made. First, the ESA prohibition of "takes" could be argued to be violated by major greenhouse gas sources. The special rule seeks to bar this argument, but has been challenged in court. Second, the ESA might require consultation with the Fish and Wildlife Service before a federal agency can authorize a major source of greenhouse gases, though the Service argues that current science does not support an adequate causal nexus between specific sources of greenhouse gases and specific effects on polar bears.