Various: Greenhouse gas emissions must be cut more quickly and deeply than thought only two years ago to avoid dire consequences, and a straight-up carbon tax is the only realistic way to do it, top climate scientist James Hansen said in an interview. New research paints an even gloomier picture of global warming than the already grim report put out in early 2007 by the UN’s Nobel-winning scientific panel, he told AFP at the margins of a major climate conference. Director since 1981 of …