One of the problems with environmental issues is that the major news media cover them so poorly. With only a few exceptions (such as the stable of informed reporters at the New York Times such as Andy Revkin and Felicity Barringer), most major media outlets have a part-time reporter on the beat, covering typically just what comes out in press releases from environmental organizations or government agencies. There is very little digging around for contrarian trends, information, or analysis as you would find in the business or economics section. (I’ll note in passing that one of the major improvements in journalism over the past 30 years was the upgrade of business and economics coverage.)
So there was a major environmental new story last week that deserved to have made wider waves: Nature magazine’s study on species extinction, “Species–area relationships always overestimate extinction rates from habitat loss.” We’ve heard for a long time predictions that as many as 25 percent of the world’s species could go extinct by the year 2050. This is actually down a bit from the 1970s, when Oxford biologist Norman Myers went as far as to speculate that perhaps 50 percent of all species could go extinct by the year 2000, but that was back in the day when extravagant doomsday predictions (the most famous being Paul Ehrlich on population) were very much in vogue.
But not very much was known then, or today, about actual species extinction rates, a point the late Julian Simon made in a debate with Myers some years ago. The most commonly used analytical technique for generating extinction estimates is something called the “species-area accumulation curve,” which is based on field research about the natural land cover necessary to support a critical mass of a species. While the species-area curve has much to recommend it, it has a number of defects. The Nature magazine study published last week, based on an extensive re-analysis of the data, concludes that current species-area models overestimate species extinction by as much as 160 percent. The authors conclude that the estimates of species loss for the year 2050 “should be regarded as a high-end possibility rather than as supported by hard scientific evidence.”
The authors are careful not to dismiss species extinction as a pre-eminent environmental concern: “There is no doubt whatsoever that the Millennium Ecosystem Assessment has correctly identified habitat loss as the primary threat to conserving the Earth’s biodiversity, and the sixth mass extinction might already be upon us or imminent. Our results do indicate, however, that the backward SAR [Species-Area Relationship] is not the correct way to estimate the magnitude of the current extinction event.”
In contrast to studies appearing in Nature and other science journals with alarmist news that always get big play in the media this study received much more modest notice. Agence France Presse covered it, as did the BBC, and a small item online in the New York Times. By contrast, the Times covered the last Nature magazine article, published just six weeks ago, that carried the alarmist message of a growing extinction problem in its print pages, as did the Washington Post. But nothing in the Post at all about this new Nature article.
The asymmetry between coverage of alarmist and non-alarmist environmental news is that as the serial exaggerations of environmentalism fail to come to pass, public interest and attention for environmental problems slowly drains. As Times columnist Nicholas Kristof put it well in a column a few years ago, “environmental alarms have been screeching for so long that, like car alarms, they are now just an irritating background noise.” There’s a lot of new opinion poll data backing up this perception. When we get to the year 2050 and find that, say, only 7 percent of species have gone extinct (which is another better-founded estimate), will we regard this as a sign of success, or that we didn’t actually do much at all to change the underlying conditions driving the loss of biodiversity? Worth pondering.