The Myth of the 1970s Global Cooling Consensus
“A pervasive myth has taken hold in the public consciousness: That there was a consensus among climate scientists of the 1970s that global cooling or a full-fledged ice age was imminent.”
At least that is according to Thomas Peterson, William Connolley and John Fleck writing in the proceedings of the 20th Conference on Climate Variability and Change, held in New Orleans in January this year. Their paper goes a long way to dispel that myth while at the same time providing a good overview of the development of current global warming theory including key milestones.
It did perhaps all begin with the Swedish scientist, Svante Arrhenius, who in 1896 suggested that by doubling atmospheric carbon dioxide global temperature may rise 5-6C.
The establishment of the station atop Mauna Loa in the Pacific in 1957 was another key event. According to Peterson et al by 1965 this data was sufficient to show an unambiguous trend of increasing carbon dioxide and showed an increase that exceeded Arrthenius’s 70-year old estimate.
By 1967 the first seminal modelling results from the Geophysical Fluid Dynamics Laboratory Team were published concluding that a doubling of carbon dioxide would raise the temperature by 2C. By 1975 based on new modelling results Wallace Broecker asked “Are we on the brink of pronounced global warming?” in a paper published in the journal Science (Vol 189, pgs 460-463).
So, how did the myth of a consensus on global cooling take hold?
According to Peterson et al, when the myth of the 1970s global cooling scare arise in contemporary discussion, it is not to citations in the scientific literature but to news and media coverage at that time. Furthermore they indicate that contemporary quoting of the media articles is often selective and out of context.
In their survey of the scientific literature from 1965 to 1983 Peterson et al found only seven articles indicating cooling compared to 42 indicating warming.
It is a fascinating little paper, have a read:
[link from Luke Walker]