Guardian: Republican candidates for president are straddling the fence on global warming, to rather clumsy effect. The only reason their awkward manoeuvres haven’t brought them more grief is that nobody seems to be watching. The media shows no interest in pushing them on the issue, and they don’t get asked about it in forums or debates – except for that debate in Iowa where Fred Thompson so courageously refused to raise his hand. (You gotta respect a guy who can make laziness a virtue.) Most of …