An availability cascade is a self-reinforcing process of collective belief formation by which an expressed perception triggers a chain reaction that gives the perception increasing plausibility through its rising availability in public discourse. The driving mechanism involves a combination of informational and reputational motives: Individuals endorse the perception partly by learning from the apparent beliefs of others and partly by distorting their public responses in the interest of maintaining social acceptance. Availability entrepreneurs-activists who manipulate the content of public discourse-strive to trigger availability cascades likely to advance their agendas.
John Tierney notes that while 2008 may just be underway, we’re smack dab in the middle of a global warming cascade:
Once a cascade is under way, it becomes tough to sort out risks because experts become reluctant to dispute the popular wisdom, and are ignored if they do. Now that the melting Arctic has become the symbol of global warming, there’s not much interest in hearing other explanations of why the ice is melting — or why the globe’s other pole isn’t melting, too.
Global warming has an impact on both polar regions, but they’re also strongly influenced by regional weather patterns and ocean currents. Two studies by NASA and university scientists last year concluded that much of the recent melting of Arctic sea ice was related to a cyclical change in ocean currents and winds, but those studies got relatively little attention — and were certainly no match for the images of struggling polar bears so popular with availability entrepreneurs.
Roger A. Pielke Jr., a professor of environmental studies at the University of Colorado, recently noted the very different reception received last year by two conflicting papers on the link between hurricanes and global warming. He counted 79 news articles about a paper in the Philosophical Transactions of the Royal Society, and only 3 news articles about one in a far more prestigious journal, Nature.
Guess which paper jibed with the theory — and image of Katrina — presented by Al Gore’s “Inconvenient Truth”?
It was, of course, the paper in the more obscure journal, which suggested that global warming is creating more hurricanes. The paper in Nature concluded that global warming has a minimal effect on hurricanes. It was published in December — by coincidence, the same week that Mr. Gore received his Nobel Peace Prize.
Via Newsbusters, where surprise is expressed over the fact that such an article would appear in the New York Times. It’s really no surprise, though; Tierney is one of the few columnists who will occasionally pierce the veil of left-wing opinion that dominates the Times.