Should the U.S. take action on climate change prior to a global treaty? Eric Posner and Cass Sunstein argued against unilteral action in a well-known paper. The argument received more extensive discussion in a book by Eric Posner and David Weisbach (with Sunstein dropping out because of government service). I’ve argued (see this paper) that this position is misguided. Now that he’s back at Harvard Law School, Sunstein is free to speak out, and he now endorses unilateralism in a Bloomberg op. ed:
No sensible person thinks that the U.S. should spend billions of dollars to achieve small greenhouse-gas reductions. Some imaginable initiatives should be rejected because they would cost too much and deliver too little. At the same time, the U.S. should not overlook opportunities to produce significant emissions reductions at justifiable expense. Recent regulations have easily passed that test. Future initiatives should be embraced when they do so as well.
He also observes that such actions signal to other nations that we are serious about seeking international agreement and stimulate technological advances in clean energy. Hopefully, his change of views represents an emerging consensus among policy analysts.