CO2 may, in fact, be the cause--but to claim the science is settled to the same degree as, say, evolution or plate tectonics is ridiculous. Easterbrook thinks that solar output and natural decadal oscillations are largely to blame. I wouldn't be surprised if diminished albedo due to (anthropogenic)soot is a factor in glacial recession as well. There is a NASA study underway right now investigating this--which, of course, begs the question: Is this really settled?