Scripps News: The realists in the global-warming debate have a new mantra: Too Little, Too Late and Too Much, Too Soon. According to Jim Hansen of the NASA Goddard Institute for Space Studies, to whom many political and environmental leaders turn on climate-change questions, we must reduce greenhouse gases by 80 percent within 12 years or it will be too late to prevent a climate catastrophe. Hansen thinks this won’t happen because it simply costs too much. He knows the citizens of the world won’t …