Christian Science Monitor: Travelers troubled by rising airfares, canceled flights, and overcrowded tarmacs are hearing yet another reason to reconsider air travel. Some say it’s unethical to fly. Earlier this month, neighborhood and environmental activists staged events across Britain to dramatize concerns about commercial aviation. Donning masks of Prime Minister Gordon Brown and waving cardboard airplanes, they called on government to keep track of carbon emissions from planes and raise fees to …