If you want to fight carbon emissions, then join the Pigou Club and push for taxes on bad energy. If you want to fight carbon emissions at a personal level, then act as if there were a high tax on your use of energy from carbon-emitting sources, and reduce your use of that energy. If you are not really all that worried about carbon emissions, but you get pleasure from making empty, self-righteous gestures, then do what Al Gore does — buy carbon offsets.

Arnold King at TCS, Via “The Economist Blog”, Via Joshua Gans.