"... personal credentials in the area of Global Climate research ..."  If that's a requirement to comment on the subject, no one on these boards is qualified to say anything (with the possible exception of WW).  Heh, *Dr. Krugman* wouldn't be qualified to comment.  ;-)  However, as a man once said, "The main reason to acquire an education is so that you can detect when someone is talking rubbish ..."  In this specific instance, when the Good Doctor implies that the U.S. is 100% responsible for the global climate 'crisis' (i.e., "the World may never recover!"), I think it's worth pointing out that the U.S. has produced only about 25% of the extra atmospheric CO2.   

Are we really to believe that every U.S. molecule of CO2 is somehow 3x as pernicious in its climate effects as CO2 produced elsewhere in the world?  That's what we have to believe, to take Dr. Krugman at face value here.  (Some do!  See EN's comments, below.)  How does that work, exactly?