The global cooling myth dies again

Climate science 1956: A Plass from the past

Yes, I know everybody used to think we were headed toward an ice age. Well, except Dr. Frank Baxter (and Frank Capra) in 1958. And except for James Hansen for three decades, of course. And the National Research Council along with the vast majority of climate scientists from the 1970s on.

I have previously written about the work of physicist Gilbert Plass (see 1953 Popular Mechanics: Growing Blanket of Carbon Dioxide Raises Earth’s Temperature).

Our favorite climate de-crocker, Peter Sinclair has a new video with a “General Electric: Excursions in Science” recording from 1956 on Plass’s work:

The myth never dies that “In the 1970’s all the climate scientists believed an ice age was coming” (as Crichton has one of his fictional ‘environmentalists’ say in the novel State of Fear). Any climate hawk 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.


I still recommend an excellent review article in the Bulletin of the American Meteorological Society (BAMS) by Thomas Peterson, William Connolley, and John Fleck, which concluded:

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.

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.

And, to complete the circle, nearly a quarter century before then, Popular Mechanics warned us:

Actually, Time magazine reported on Plass’s work in May 1953, in an article titled “Invisible Blanket,” which ends “for centuries to come, if man’s industrial growth continues, the earth’s climate will continue to grow warmer.”

The New York Times reported on Plass’s work in 1956 with this strong headline:

As an interesting aside, the NYT warned a “rise in the average temperature of only 4 degrees C. would convert the polar regions into tropical deserts and jungles, with tigers roaming about and gaudy parrots squawking in the trees,” which is hardly the most noticeable consequence of turning polar regions into the tropics “” 80 to 280 foot sea level rise anyone?

Who is this remarkable climate scientist, Gilbert Plass? The Encyclopedia of Earth has the answer:

Gilbert N. Plass (1921–2004) was a Canadian-born physicist who made important early contributions to the carbon dioxide theory of climate change. He graduated from Harvard University in 1941, received a Ph.D in physics from Princeton University in 1947, and eventually became a professor at Texas A&M University. Between 1953 and 1959, Plass developed an early computer model of infrared radiative transfer and published a number of articles on carbon dioxide and climate. Plass used new detailed measurements of the infrared absorption bands and newly available digital computers to replace the older graphical methods.

Plass developed his approach with a thorough set of one-dimensional computations, taking into account the structure of the absorption bands at all layers of the atmosphere. His final figures showed convincingly that adding or subtracting CO2 could seriously affect the radiation balance layer by layer through the atmosphere, altering the temperature by a degree or more down to ground level. In a seminal article in 1956, Plass calculated a 3.6 °C surface temperature increase for a doubling of atmospheric CO2. Contrary to the conventional wisdom at the time, Plass argued that the effect of water vapor absorption did not mask the carbon dioxide effect. Plass also postulated that the oceans would be able to sequester only a small amount of the anthropogenic carbon, resulting in an increase in atmospheric CO2. He calculated that consumption of all of the Earth’s fossil fuel resources over the next millenium would increase surface temperature by 7 °C. Plass’ work was pivotal in the establishment of the central role of carbon dioxide in climate change, and in the danger that anthropogenic carbon emissions posed to the Earth’s climate system.

Pretty darn accurate for 50-year-old analysis on the most primitive computers (see Hadley Center: “Catastrophic” 5–7°C warming by 2100 on current emissions path and “The Copenhagen Diagnosis” warns “Without significant mitigation, the report says global mean warming could reach as high as 7 degrees Celsius by 2100”).