I am reading this book called The Undercover Economist. It is blah. But I quite like this chapter about externality charges. The author discourages the moral tone in environmentalism: "If they (made evident the environmental cost of our actions), environmentalists could argue their points from an economic standpoint; much of the moral tone would drain outof the environmental debate, but the environment itself would be much more effectively dealt with."
This closely parallels Eduardo and my debate on the ethics of eating. (Kind of funny, because I only read this chapter after posting my 2 posts and 3 comments.) But it is important to separate moral posturing from morality. The view I support is motivated by environmental-cost concerns, the "moral vegetarian" view is motivated by ethics of animal suffering; but they are both moral views insofar as they are making moral claims about what we ought to do. So similarly, environmentalism does not cease to be a moral issue even if you take the moral tone out of the debate and replace it with economic analyses.
So, the moral of the story (har har har!): Ethicists have much to learn from economists, but maybe economists can listen to the ethicists a bit too, before making the confusion between claims motivated by moral concerns and moral claims.