There was no scientific consensus in the 1970s that the Earth was headed into an imminent ice age. Indeed, the possibility of anthropogenic warming dominated the peer-reviewed literature even then.
So begins an excellent review article [PDF] in the Bulletin of the American Meteorological Society by Thomas Peterson, William Connolley, and John Fleck. I had blogged on this when USA Today reported it but just realized I hadn’t blogged on the article itself.
The BAMS piece is easily the most thorough explanation and debunking of the issue I’ve seen in a scientific publication. Any progressive who is engaged in the climate change arena must be able to quickly and assuredly respond to this myth because it continues to live on, thanks to the deniers’ and delayers’ clever strategy of ignoring the facts.
Heck, even commenters keep defending the absurd line in Crichton’s novel State of Fear, when he has one of his fictional environmentalists say, “In the 1970s, all the climate scientists believed an ice age was coming.”
The BAMS piece examines the scientific origins of the myth, the popular media of the 1970s who got the story slightly wrong, the deniers/delayers who perpetuate the myth today, and, most importantly, what real scientists actually said in real peer-reviewed journals at the time. Their literature survey, the most comprehensive ever done on the subject, found:
The survey identified only 7 articles indicating cooling compared to 44 indicating warming. Those seven cooling articles garnered just 12 percent of the citations.
The authors put together this figure on “the number of papers classified as predicting, implying, or providing supporting evidence for future global cooling, warming, and neutral categories”:
The article ends with a powerful discussion of what the National Research Council concluded in its 1979 review of the science:
In July 1979 in Woods Hole, Massachusetts, Jule Charney, one of the pioneers of climate modeling, brought together a panel of experts under the U.S. National Research Council to sort out the state of the science. The panel’s work has become iconic as a foundation for the enterprise of climate change study that followed (Somerville et al. 2007). Such reports are a traditional approach within the United States for eliciting expert views on scientific questions of political and public policy importance (Weart 2003).
In this case, the panel concluded that the potential damage from greenhouse gases was real and should not be ignored. The potential for cooling, the threat of aerosols, or the possibility of an ice age shows up nowhere in the report. Warming from doubled CO2 of 1.5-4.5 degrees C was possible, the panel reported. While there were huge uncertainties, Verner Suomi, chairman of the National Research Council’s Climate Research Board, wrote in the report’s foreword that he believed there was enough evidence to support action: “A wait-and-see policy may mean waiting until it is too late” (Charney et al. 1979). Clearly, if a national report in the 1970s advocates urgent action to address global warming, then the scientific consensus of the 1970s was not global cooling.
Oh, and one more thing, deniers — it ain’t cooling now either.