Agence France-Presse: President Barack Obama’s cabinet lieutenants pressed Wednesday for urgent action in Congress against global warming, but faced Republican barbs about crippling costs and faulty science. At an Earth Day hearing on climate change in the House of Representatives, Energy Secretary Steven Chu said the United States faced a “defining challenge” if it wanted to avert two looming dangers. “The first is that the world will fail to take action on climate change in time to prevent its …