Skeptic Zombie Killed...Again David Roberts
Sun Feb 24, 7:31 PM ET
The Nation -- Long-time greens are painfully aware that the arguments of global warming skeptics are like zombies in a '70s B movie. They get shot, stabbed, and crushed, over and over again, but they just keep lurching to their feet and staggering forward. That's because -- news flash! -- climate skepticism is an ideological, not a scientific, position, and as such it bears only a tenuous relationship to scientific rules of evidence and inference.
One of the most resilient skeptic tropes is the notion that back in the '60s and '70s the scientific community predicted that the globe would cool in the coming century. "Those scientists ... first it's one trendy theory, then it's the opposite. You just can't trust 'em!"
(Incidentally, this is one of the many skeptic arguments debunked by Coby Beck in our definitive How to Talk to a Climate Skeptic guide. If you're looking for ammo when talking to your local skeptic, bookmark it.)
Now comes a new study showing, once and for all, that:
there was no such consensus in the scientific community -- quite the opposite, and
there was no such consensus in the popular press.
Forthcoming in the Bulletin of the American Meteorological Society, the study "surveyed dozens of peer-reviewed scientific articles from 1965 to 1979 and found that only seven supported global cooling, while 44 predicted warming. [Study co-author Thomas] Peterson says 20 others were neutral in their assessments of climate trends." Added Peterson, "I was surprised that global warming was so dominant in the peer-reviewed literature of the time."
As for the popular press, says Peterson, "even cursory review of the news media coverage of the issue reveals that, just as there was no consensus at the time among scientists, so was there also no consensus among journalists."
So, that's that. The zombie's dead, right? [Ominous bumping, shuffling sound in background.]
(In addition to Peterson, who works at the National Climatic Data Center, the survey was co-authored by William Connolley, who blogs at Stoat and occasionally at RealClimate, and John Fleck, a science journalist who blogs at InkStain.)
If you care about the scientific issues involved, read on:
Insofar as there were scattered predictions of cooling in the '70s, they had to do with what's called "global dimming" -- the tendency of particulate pollution (soot) to block solar radiation a cool the earth's surface temperature. Since human beings have been pumping more and more pollution up into the atmosphere for centuries now, global dimming has become a significant and measurable phenomenon. It is, for example, largely responsible for the leveling off and even dropping of global temperatures in the '40s, '50s, and '60s. For a while, some scientists thought that the dimming effect would outweigh the greenhouse effect in the long run, leading to aggregate global cooling.
It didn't work out that way. A couple of papers in Science in 2005 showed that dimming had halted and reversed by 1990, mainly due to the reduction in particulate pollution in developed countries. (Ironically, that victory over pollution may now accelerate the effects of greenhouse warming. D'oh!)
For a while, a few (not most) scientists thought that one set of factors would outweigh another. We now know that they were badly wrong. This isn't some sort of embarrassing gotcha. It's progress. It's how human beings figure stuff out. It's how science works. |
