(USFWS proposal to amend regulations at 50 C.F.R. part 17, which implement the Endangered Species Act (ESA), to create special rule providing for the conservation of the polar bear; interestingly, while initial reason polar bears added to list of threatened and endangered species was loss of habitat due to "global warming", none of four alternative means examined for protecting polar bears included control of "greenhouse gas" emissions; rather focus is on regulating impact of direct human contact with polar bears).