The media have trapped us in a feedback loop of doom and gloom preventing us from thinking rationally about risk. That, at least, is one conclusion from John Tierney’s column in today’s New York Times.
“When judging risks, we often go wrong by using what’s called the availability heuristic: we gauge a danger according to how many examples of it are readily available in our minds. Thus we overestimate the odds of dying in a terrorist attack or a plane crash because we’ve seen such dramatic deaths so often on television; we underestimate the risks of dying from a stroke because we don’t have so many vivid images readily available.
Slow warming doesn’t make for memorable images on television or in people’s minds, so activists, journalists and scientists have looked to hurricanes, wild fires and starving polar bears instead. They have used these images to start an “availability cascade,” a term coined by Timur Kuran, a professor of economics and law at the University of Southern California, and Cass R. Sunstein, a law professor at the University of Chicago.”
Tierney argues that the more worried people become, the more the media ministers to those worries, with the result that the availability cascade leads to a false consensus (the false consciousness of today):
“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.”
Note that neither Tierney nor the availability critics are denying that global warming exists: What they are talking about is how risk calculation becomes irrational. An availability cascade makes adversarial reasoning extremely difficult – so when a two papers examining the link between global warming were published last year, the more authoritative won, which said the effect was marginal, was marginalized in news coverage by the less robust paper claiming a link.
Because the media are biased towards sensationalism to begin with – if it bleeds, it leads – and biased against analyzing numbers (look at how they are replaced by adjectives in many stories on risk), it’s easy for activist groups to start an availability cascade of bad news (as has happened with phthalates and the risk of environmental exposure to trace amounts of chemicals). But getting out of this mess doesn’t mean creating an alternative cascade of good news, or practicing what counts as objectivity for reporters – listening to the other side. It means doing something deeply unfashionable, which is taking scientific authority seriously. It means finding out what kind of consensus has been created within a field by dint of rigorous critical reflection and evaluating challenges to that consensus honestly.
Ironically, journalism was once thought to be a science; Columbia’s Graduate School of Journalism offers a masters in science degree in journalism. We would be spared a great deal of doom-mongering if journalists recovered a sense of scientific method by testing each proposition against the best arguments for and against it. What counts as authoritative knowledge in each field and where are the weaknesses in that knowledge. The result wouldn’t just restore authority to science, they would restore authority to journalism too.