A U.S. News reader makes a good point:

Public debate over global warming, including the possibility that human activities are partly responsible, has been prominent in the news media for several years [“Madam Enforcer,”April 30]. Now we have people like Sen. Barbara Boxer and many others who are ready to rush headlong into doing something about it. But, before we attempt to do something, shouldn’t we have a debate about whether the proposed remedies could be expected to actually accomplish anything?