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The Myth of the Global Cooling Consensus

By definition, fact and myth are worlds apart. One is a persistent truth; the other is a persistent untruth. Yet we still confuse myth with fact all the time. A myth's pervasiveness serves as its disguise. Repetition and blind acceptance ground it into reality.

One myth that's been hibernating, but has recently resurfaced back into popular discussion, is the idea that back in the 1970s, climate scientists were united in predicting global cooling. Not only does that notion fit in with America's recent cold snap, as well as the so-called "pause" in global warming (which isn't really a pause), it also acts as a convincing rebuttal to the genuine scientific consensus on climate change. Armed with the myth of a global cooling consensus, pundits can argue that those who study the Earth's climate are little more than unscientific, money-grubbing scaremongers.

"Back in the 1970s, all the climate scientists believed an ice age was coming. They thought the world was getting colder. But once the notion of global warming was raised, they immediately recognized the advantages. Global warming creates a crisis, a call to action. A crisis needs to be studied, it needs to be funded..." author Michael Crichton wrote in his controversial anti-climate change novel State of Fear.

"This cycle of science... if we go back to 1970, the fear then was global cooling," Lou Dobbs recently stated on Fox News.

Contrary to what Crichton, Dobbs, and others might assert, climate scientists never agreed that the Earth was destined for long-term cooling back in the 1970s. Yes, the Earth cooled between 1940 and 1970, but it was exceedingly slight. Scientists now agree that the cooling resulted from excessive use of sulfur-based aerosols. Aerosols only remain in the atmosphere for a short period of time compared to other greenhouse gases, so the aerosol cooling effect faded away as atmospheric carbon dioxide concentrations rose. Knowing this, the majority of climate scientists at the time still anticipated warming. A review of climate change literature between 1965 and 1979, undertaken in 2008, found that 44 papers "predicted, implied, or provided supporting evidence" for global warming, while only seven did so for global cooling.

"Global cooling was never more than a minor aspect of the scientific climate change literature of the era, let alone the scientific consensus..." the reviewers remarked.

Today, the myth of the 1970s global cooling consensus lives on through blanket statements, often cited back to cherry-picked news media coverage from the time. A popular choice is a 1975 Newsweek article ominously titled "The Cooling World." The article claimed "The evidence in support of these predictions [of global cooling] has now begun to accumulate so massively that meteorologists are hard-pressed to keep up with it." It also portended a "drastic decline for food production." The passing of time revealed both statements to be spectacularly incorrect. TIME magazine also ran a story in 1974 about another possible ice age.

"Globally averaged temperatures were cooling, but this was largely due to changes in the Northern Hemisphere," writes Thomas Peterson of the National Climatic Data Center. "A closer examination of Southern Hemisphere data revealed thermometers heading in the opposite direction." They have continued to do so.

There was never scientific consensus that the Earth was cooling. That is a myth. That's not to say that there weren't alarmists forecasting doom. Some did; they just weren't scientists. Those people also weren't helping anything. Climate change deserves honest discourse from both sides of the political spectrum. The Left's alarmism may be as equally counterproductive as the Right's denialism. Climate change is real and something needs to be done about it. To find a solution we need to strip away biases, do away with petty point-scoring, and recognize what we agree upon: a less polluted planet benefits everyone.

Source: Peterson, Thomas C., William M. Connolley, John Fleck, 2008: The Myth of the 1970s Global Cooling Scientific Consensus. Bull. Amer. Meteor. Soc., 89, 1325–1337.

(Images: Associated Press, IPCC)