Another denier talking point — ‘global cooling’ — bites the dust

USA Today reports on an important review article:

The supposed “global cooling” consensus among scientists in the 1970s — frequently offered by global-warming skeptics as proof that climatologists can’t make up their minds — is a myth, according to a survey of the scientific literature of the era….

But Thomas Peterson of the National Climatic Data Center surveyed dozens of peer-reviewed scientific articles from 1965 to 1979 and found that only seven supported global cooling, while 44 predicted warming. Peterson says 20 others were neutral in their assessments of climate trends.

The study reports, “There was no scientific consensus in the 1970s that the Earth was headed into an imminent ice age.

“A review of the literature suggests that, to the contrary, greenhouse warming even then dominated scientists’ thinking about the most important forces shaping Earth’s climate on human time scales.”

Now this isn’t really news to readers of Climate Progress or Real Climate (here and here) or William Connolley, but the global cooling nonsense is still the most common way people dismiss global warming to me. Michael Crichton repeats this attack in his 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.


This clever and popular attack tries to make present global-warming fears seem faddish, saying current climate science is nothing more than finger-in-the-wind guessing. This attack appeals especially to conservatives who want to link their attack on climate scientists to their favorite attack against progressive presidential candidates — that they are flip-floppers. But it just isn’t true, and it’s good to see this analysis is going to be published in the Bulletin of the American Meteorological Society (BAMS). [I’ll link to the study when it is up.]

Interestingly, USA Today gives famed denier Pat Michaels a chance to respond, but he makes a bizarrely lame argument, which, for anyone who understands the subject (or has read my book), should make one more worried about catastrophic global warming, not less:

Some have doubts about the new survey. “The paper does not place the late ’70s in its climatic context,” says Pat Michaels, a senior fellow in environmental studies at the Cato Institute in Washington, D.C.

“The temperature records we had at the time showed a very sharp cooling from the mid-’40s to the mid-’70s,” Michaels says. “And scientists attempted to explain that as a consequence of the pollution that was preventing solar radiation from reaching the surface.

“At the time, scientists thought the cooling effect of pollution was greater than the warming effect of carbon dioxide,” Michaels adds. “They were attempting to explain the dramatic cooling of the ‘70s.”

Well, it wasn’t “very sharp” or “dramatic” cooling. But yes, scientists were trying to come to grips with why global warming trends stalled for a couple of decades. I explain what this really means in my book:

Global warming leveled off between 1940 and 1975. As explained in Chapter Two, this was largely a result of dust and aerosols sent by humans (and volcanoes) into the atmosphere, which temporarily overwhelmed the already well-understood warming effect from greenhouse gases. In the 1970s, a few scientists wondered whether the cooling effect from aerosols would be greater than the heating produced from greenhouse gases, and some popular publications ran articles about a new Ice Age. Most climate scientists were far more worried about the long-term greenhouse gas trends, even in the midst of short-term cooling-and they proved to be right.

[That is precisely what the new BAMS study demonstrates.]

The aerosol effect was fully explained in the 1980s, and became part of scientific modeling “that is in remarkable agreement with the observations,” as Tom Wigley, a leading climatologist with the National Center for Atmospheric Research, wrote in a 2003 letter to the U.S. Senate. Ignoring the science, the Deniers keep repeating the fiction as if it were the latest argument, sounding a bit like Flat-Earthers, but much more dangerous. Senator Inhofe used this smear in his 2005 Senate hearing [on climate change]….

A spring 2003 workshop of top atmospheric scientists in Berlin concluded that the shielding effect of aerosols may be far greater than previously estimated. Nobel laureate Paul Crutzen said, “It looks like the warming today may be only about a quarter of what we would have got without aerosols. This conclusion would suggest the planet may be far more susceptible to warming than previously thought. Crutzen noted that aerosols “are giving us a false sense of security right now.” A 2005 study led by researchers at the National Oceanic and Atmospheric Administration [subs. req’d] concluded, “Natural and anthropogenic aerosols have substantially delayed and lessened the total amount of global ocean warming — and therefore of sea level rise — that would have arisen purely in response to increasing greenhouse gases.”

And this brings us to the true irony of Pat Michaels bringing up this issue:

The real irony here is that the aerosol shielding issue, fully explained, gives the public greater reason to act preemptively on climate, not less. The entire record of climate science, rather than being a narrative based on fickle fads, is one of relentless, hard-nosed, continual progression of knowledge, which is characteristic of science, as opposed to politics or propaganda.

Kudos to USA Today for this story and to the climate scientists of the 1970s who continued to warn about the dangers of global warming even as global temperatures temporarily stopped rising.


One final point — if you want to see just how impervious the doubters and deniers are to the facts, read the comments on the USA Today article.