Sometime this summer, the Senate will have a debate over an energy bill. What kind of energy bill? That's still the unanswered question. But the timing, at least, is propitious: After all, 2010 is shaping up to be the hottest year on record, and the summer months should be particularly unpleasant. And studies have shown that people are, predictably, far more receptive to talking about global warming during the sweltering heat than during the winter months.