Slate: James Hansen, NASAs top climate scientist, is one of the most impassioned and trusted voices on global warming. People listen closely to what he says about how drastically the climate is changing. But when Hansen suggests what to do about it, many of those same people tune him out. Some even roll their eyes. What message is he peddling that few seemingly want to hear? Its twofold: No. 1, solar and wind power cannot meet the worlds voracious demand for energy, especially given the projected needs...