The campaign to discredit predictions of man-made global warming—originally organized by readily identifiable vested interests—has by now recruited a large popular constituency of declared “skeptics” increasingly disposed to “take a stand”: some of them opposed to government regulation in general, some resistant to any claims to intellectual authority (perhaps especially scientific), and some mobilized by a version of the right to individual freedom of opinion. As a result, confidence in the expertise of scientists has reached an all time low: Internet (...) sites, radio talk shows, and television channels preferentially transmit “contrarian” attacks on the credibility of climate scientists. Even our most responsible newspapers and journals, in their very commitment to the traditional ethic of “balance,” sometimes contribute to the widespread misimpression that climate scientists are deeply divided about both the extent of the dangers we face and the relevance of human activity to global warming. Not knowing who or what to believe, the natural response for most people is to do nothing, and the consequence, as Thomas Homer-Dixon wrote last year for the New York Times: “Climate policy is gridlocked, and there’s virtually no chance of a breakthrough” (2010). Meanwhile, as evidence both of the role of human contributions to global warming and the dangers of that warming continues to mount, consensus among climate scientists grows ever stronger, and those of us who attend to that evidence are increasingly alarmed. (shrink)