Killing the myth of the 1970s global cooling scientific consensus

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 in the Bulletin of the American Meteorological Society (BAMS) 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 on this blog keep defending the absurd line in Crichton’s novel State of Fear, when he has one of his fictional environmentalists say, “In the 1970’s 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% 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°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:


14 Responses to Killing the myth of the 1970s global cooling scientific consensus

  1. Mike N says:

    12% of the citations seems about right given 7 articles out of 51 published… Not sure I understand that point.

  2. llewelly says:

    Mike N, it shows that an article on cooling, on average, would be expected to be no more cited (and no less cited) than an article on warming. If articles indicating cooling had been disproportionately more likely to be cited, the claim that there was no scientific consensus in the 1970s that the earth was headed into an ice age would be weaker.

  3. Sean J says:

    October 2008 is the hottest October on record:

  4. paulm says:

    Scary temperatures!

  5. paulm says:

    Hey Joe you got a citation…

    Hell and high water: Chaos reigns as floods and 70mph winds batter Britain

  6. Uosdwis says:

    Education by popular media. They just refuse to let go of that 1979 Newsweek cover.

  7. cce says:

    The October GISS numbers have a processing/data error. They will almost certainly be revised downward in the coming days.

    On another note, I have a short “Layman’s” guide to the 1970’s cooling “consensus.”

  8. Jim Eaton says:

    Hey, even the books and movies of the time were looking at global warming. For example, Soylent Green (1973) based on the book, Make Room, Make Room (1966), and Blade Runner (1982) based on Do Androids Dream of Electric Sheep? (1968). Both of the movies and books looked at a bleak future due to global warming and overpopulation.

  9. Dano says:

    Just because the myth has been “killed” doesn’t mean residents of Winguttia or Simpletonia will stop using it.



  10. David B. Benson says:

    Sean J — A discussion of this error can be found in a new thread on RealClimate, “Mountains and molehills”.

  11. PurpleOzone says:

    Popular media had vivid articles about global cooling. I remember one — Washington Post — included the phrase “possibly the best 15 years the world has (or will) ever know” referring to 1955-1970 “mild” temperatures, i.e., warmer than normal.
    A book I read ~1974-78 postulated an ice coming coming as inevitable, and talked about the wonder of Paris, children on carousels, etc., topped with layers of ice and finished sadly with “goodbye, Paris”.
    Why did the media choose to emphasize the minority research? Are ice ages more dramatic? Or do they sound more plausible than roasting given that much of the U.S. was under ice 12,000 years ago?
    Although I had had a detailed explanation of greenhouse gasses, and their potential effect on earth, after Venus was determined to be astonishingly hot, in 1963, by a senior scientist, and I was horrified by it, I don’t remember seeing any popular accounts of it in the media.
    Thanks for calling attention to this research.

  12. T B says:

    Problem is that the review ignores some pretty glaring Global Cooling prognosticators. The leading one being that it was addressed in Hansen’s seminal paper on warming where he treats his warming theory as contrarian to the leading cooling theories. Hansen wouldn’t have specifically called it out as contrarian if it didn’t have widespread scientific support. Secondly, contemporary scientific programs called out global cooling as a valid scientific theory. The show ‘Cosmos’ highlighted the scientific theory about deforestation increasing the earths albedo and accelerating the cooling effect.

  13. Nick says:

    “# Sean J Says: November 10th, 2008 at 10:11 pm October 2008 is the hottest October on record:

    How’s that ‘hottest October on record’ working out for you Sean…

  14. J4zonian says:


    Your post is unclear: do you mean Hansen wouldn’t have called WARMING contrarian if COOLING didn’t have support? The use of language is not always perfectly logical or clear, as evidenced by your use of it. Perhaps H was also being less than perfectly explicit. Contrarian can mean “opposed to”, which warming certainly is in relation to cooling.

    Whether something is called a valid scientific theory on a TV show is indicative of nothing: in fact one of the glaring weaknesses of the 1000ppm people is that they (you?) continue to use Newsweek and George Will and TV as references.

    (And just an aside, why not pick a new moniker? Naming yourself after a disease that has been a scourge of humanity for millennia and is one of the signs of the coming apocalypse might not be the most politic choice, although it IS revealing.)

    Nick: Your link goes nowhere. So I guess that hottest October thing is working out pretty well so far. Being wrong and smarmy at the same time is not the best combination. Wanna try again?