The Department of the Interior is expected to announce soon that polar bears have been designated a threatened species under the Endangered Species Act. The justification for such a move will not be that polar bears are actually declining. Rather, the justification will be based on speculation that they may decline in the future as a result of global warming. Global warming, so the argument goes, is causing Arctic sea ice to melt, and, unless that process is arrested, polar bears will be unable to survive because they need Arctic …
