SANTA FE— Greenland has become global warming's poster child: rising temperatures melt glaciers, threatening a devastating rise in sea levels that could inundate coastal cities around the world. Greenhouse gases from factories and cars are to blame, according to the conventional story, which features prominently in Al Gore's documentary, "An Inconvenient Truth." And yet there was Los Alamos National Laboratory climate scientist Petr Chylek last week, standing before a gathering of his colleagues to explain that Greenland isn't actually warming. What gives? Chylek is a dissenter from the scientific mainstream. While most scientists think greenhouse gases are responsible for changes...