What We Knew in ’72

March 20, 2014

I made the video above, “What We Knew in 82”, after discovering video of a talk given at Sandia Labs in 1982, by Dr. Mike MacCracken, then a senior researcher at Livermore Lab, and involved in DOE research on climate. The point of the piece was how much was known that long ago about the expected changes in climate due to man-caused greenhouse forcing.

Most people probably don’t know that the physics behind global warming was nailed in the 1950s by military research undertaken to produce the first generation of heat-seeking missiles – described below in a clip from Richard Alley’s “Earth: An Operator’s Manual” –

Now,  Dana Nuccitelli describes a paper in a major journal from 1972 that contains remarkable predictions made with the still-very-young science.


Dana Nucittelli in the Guardian:

John Stanley (J.S.) Sawyer was a British meteorologist born in 1916. He was elected a Fellow of the Royal Society in 1962, and was also a Fellow of the Meteorological Society and the organization’s president from 1963 to 1965.

A paper authored by Sawyer and published in the journal Nature in 1972 reveals how much climate scientists knew about the fundamental workings of the global climate over 40 years ago. For example, Sawyer predicted how much average global surface temperatures would warm by the year 2000.

“The increase of 25% CO2 expected by the end of the century therefore corresponds to an increase of 0.6°C in the world temperature – an amount somewhat greater than the climatic variation of recent centuries.”


Remarkably, between the years 1850 and 2000, atmospheric carbon dioxide levels did increase by very close to 25 percent, and global average surface temperatures also increased by just about 0.6°C during that time.

Sawyer also discussed several other important aspects of the Earth’s climate in his paper. For example, he addressed the myth and misunderstanding that as a trace gas in the atmosphere, it may seem natural to assume that rising levels of carbon dioxide don’t have much impact on the climate. Sawyer wrote,

“Nevertheless, there are certain minor constituents of the atmosphere which have a particularly significant effect in determining the world climate. They do this by their influence on the transmission of heat through the atmosphere by radiation. Carbon dioxide, water vapour and ozone all play such a role, and the quantities of these substances are not so much greater than the products of human endeavour that the possibilities of man-made influences may be dismissed out of hand.”

Indeed, over the past four decades, human carbon dioxide emissions have continued to increase more or less exponentially, and about half has continued to remain in the atmosphere with the other halfaccumulating in natural reservoirs. The carbon dioxide being absorbed by the oceans has contributed to the problem of ocean acidification, sometimes referred to as “global warming’s evil twin.”

Climate scientists also had a good idea how quickly carbon dioxide levels in the atmosphere would continue to rise as a result of human activities.

“Bolin has estimated that the concentration of carbon dioxide will be about 400 ppm by the year 2000. A recent conference put the figure somewhat lower (375 ppm).”

The latter prediction at the referenced 1971 conference on “the Study of Man’s Impact on Climate” turned out to be quite accurate. In 2000, atmospheric carbon dioxide concentrations were measured at about 370 ppm.

In his paper Sawyer discussed the predicted impacts resulting from a continued rise in atmospheric carbon dioxide. He noted that directly “it might make some vegetation grow a little faster,” which is generally true, although the situation is complicated. Sawyer noted that rising carbon dioxide levels would cause an increased greenhouse effect, and the associated warming would lead to more evaporation and more water vapor in the atmosphere. As a greenhouse gas itself, that rise in water vapor would act to further amplify human-caused global warming.

“…if world temperatures rise due to an increase in carbon dioxide, it is almost certain that there will be more evaporation of water–the water vapour content of the atmosphere will also increase and will have its own effect on the radiation balance.”

Sawyer referenced a 1967 paper by Manabe and Wetherald, who had calculated that a doubling of atmospheric carbon dioxide would by itself cause approximately 1.3°C global surface warming, but that warming would be amplified by a further 1.1°C due to rising water vapor concentrations if the relative humidity were to remain constant. Observations have indeed unequivocally shown that water vapor strongly amplifies human-caused global warming, for example as found in a 2009 study by Andrew Dessler and Sun Wong from Texas A&M University.

Sawyer also discussed that melting ice and snow in a warming world would act to amplify global warming, but suggested that increasing cloud cover might dampen global warming and act to regulate the global climate. However, recent research has shown that clouds may actually weakly amplify global warming as well. Sawyer also understood that significant global warming would cause changes in weather and wind patterns around the world.

All in all, Sawyer’s 1972 paper demonstrated a solid understanding of the fundamental workings of the global climate, and included a remarkably accurate prediction of global warming over the next 30 years. Sawyer’s paper was followed by similarly accurate global warming predictions by Wallace Broecker in 1975 and James Hansen in 1981.

This research illustrates that climate scientists have understood the main climate control knobs for over four decades. Perhaps it’s about time that we start listening to them.

The “..in the 70s they predicted an Ice Age” canard is sacred to climate deniers, of course, and I made this video early on to take that one apart. As the piece above shows, it was even shakier than I described below.

33 Responses to “What We Knew in ’72”

  1. omnologos Says:

    Unsure why you keep flogging the same dead horse…as I find myself having to repeat, in 1972 the scientific community was consensual in the fact that the world was cooling, and was expected to cool further whilst at the same time was also expected to stop cooling at some point thanks to GHG emissions.

    There is evidence of similar lines of thought as far back as 1961 IIRC.

    The problem of course was that the combination of worried scientists like Schneider with overeager journalists put to the fore the most unlikely scenarios, including an Antarctic ice surge (due to excessive cold and snow) that would have cooled the ocean surface significantly (this idea was supported by a Shackleton).

    SInce the media business hasn’t improved in accuracy in the intervening 42 years, and it’s actually evermore hungry of p*rnified news, we’re now submerged by silly scare stories about warming exactly like people in the 1970s were by silly scare stories about cooling.

    If anybody were seriously worried about global warming, the same silly scare stories would be seen as polluting the discourse, as useless uninformative distractions.

    • dumboldguy Says:

      O-Log is b-a-a-a-c-k! And as usual, he is busily “polluting the discourse with useless uninformative distractions”. This comment says NOTHING of value (except for telepsychiatrists, who, if they have nothing better to do, will find much of interest in O-Log’s incoherent babblings).

      • All semantics, no science, no math, all a waste of time. Pearls before swine. DNFTT. Same comments on every blog site he’s on. WHAAAT? It’s hard to reason with stupidity. It gets you down to their level. Pretty soon it’s , Oh yea, sez who. Better luck teaching remedial arithmetic to drunken freshmen at a noisy bar. 🙂 just as useless.

    • Would you like to document this “consensual view” of the scientific community that the climate was cooling in the 1970s? You mean the poem by Robert Frost as to how the world would end “in fire or ice”? Or maybe a TV science fiction program the Twilight Zone about how the Earth was going to freeze over?

      • omnologos Says:

        No John I did not say ‘in the 1970s’ and you did not read it. I said ‘in 1972’. There is a nice paper by Mitchell and it is even mentioned in the famous Connolley APS paper. That paper, as already discussed here and elsewhere, contains it all, present cooling, future warming etc etc and it went unchallenged for three years (it finally succumbed when doubts arose about the extent of the cooling, obviosuly).

        The scientific community of 1975 had already moved on from ‘global cooling’ but unfortunately the media and the media-savvy scientists kept pushing the meme until the early 1980s. That’s what people recall.

    • ontspan Says:

      As with most claims by contrarians, their claims are often easilly checked by visiting the SkepticalScience website where the evidence is weighed.

      Was there a consensus on a cooling world in the 70s? Nope. Again we find more unsubstantiated claims by omno.

      • ontspan Says:

        Oh, and before Omno protests that he only talked about a single year 1972…

        Even in that single year more neutral and warming papers apeared in the scientific literature then papers predicting cooling. As shown by the link in my post above.

    • Whoops! Consensual? Oh thats rich. 🙂 I want to see the reference on that for sure!
      relating to or involving consent, esp. mutual consent.
      “he admitted to having consensual sex with two women”

      Ah, yes. I should have looked in my omnothesaurus, I guess. It is a VERY difficult read, and it’s too early in the AM for a useless headache.

      Maybe its like Humpty Dumpty. :/
      “When I use a word,” Humpty Dumpty said, in rather a scornful tone, “it means just what I choose it to mean—neither more nor less.”
      “The question is,” said Alice, “whether you can make words mean so many different things.”
      “The question is,” said Humpty Dumpty, “which is to be master—that’s all.”

  2. “… suggested that increasing cloud cover might dampen global warming and act to regulate the global climate. However, recent research has shown that clouds may actually weakly amplify global warming as well.”

    If we look at the past …

    then you may want to supplement these statements of cloud cover (and reference links that it contains) with the following citations eg from this presentation (Observed Cloud Cover Trends and Global Climate Change, Joel Norris Scripps Institution of Oceanography – http://scrippsscholars.ucsd.edu/jnorris/files/caltechweb.pdf) :
    “- cloud changes since 1952 have had a net cooling effect on the Earth …”
    “ -multidecadal reliable observations of the upper atmosphere over the ocean are not available …”
    “- anthropogenic or natural external forcing is unlikely to directly produce the observed cloud trends …”
    “ – there is not yet enough information to attribute the cloud trends to anthropogenic global warming …”

    “Sherwood and colleagues’ study represents a big advance, but questions persist.” For one thing, better estimates of ocean cloud cover explain only about half of the variation in climate sensitivity estimates. Uncertainty over the cooling effects of ice cover and clouds over the continents remain.”

  3. The world viewed through a straw. The idiots are back. Pick a year. Pick any year. Sheer stupidity. Lizard brain strikes.

    On a different note, this article shows just how accurate predictions were. It contradicts a whole host of denier canards. The scientific predictions are correct. Even before computers, the equations showed how much warming. They accurately predicted that water vapor was a feedback that amplified warming from human CO2 emissions. The amount of warming was predicted correctly. Atmospheric science goes back much further than the 70s. Further, papers on global cooling refer to slow changes over thousands of years. That is the slow interglacial cooling trajectory we were on before the rapid AGW temperature rise due to human CO2 activity.

  4. rayduray Says:


    I have a cause I’d like you to join me in. Many of you will be familiar with statistics super-star Nate Silver and his FiveThityEight blog. He’s just moved from the NY Times to Disney’s ESPN.

    He’s usually terrific on sports and politics, but he’s taken a header on climate science. Here’s a guest article on a topic we’ve covered here. The cost of climate related disasters. Astonishingly, Nate Silver has been induced (probably by an ESPN hack-executive) to feature an article by the bete noir, Roger Pielke, Jr.

    We are doing a pretty good job bashing Pielke and offering alternative real and credible sources. Perhaps you could join the fray?


    Here is what I wrote as a comment a few moments ago at the 538 site:

    Ray Duray · N/A
    Attn.: Nate Silver

    I’m astonished. I follow the news of climate science closely and one of the last people on the planet I’d trust on this topic is Dr. Pielke. His record has been to distort the science for the sake of ideology. Isn’t this precisely what you railed against in your “Manifesto” castigating op-ed writers? You’ve fallen into the same trap as you accuse to NY Time, WaPo and other conventional media sources of.

    I’m disappointed. Perhaps you can give equal time to a real climate specialist such as Dr. Jeff Masters of Weather Underground, Richard Alley and/or Michael Mann of PSU, Joe Romm of Climate Progress (as a non-scientist advocate) or I can recommend a dozen others worthy of mention who do real science and not ideologically motivated propaganda.


    • dumboldguy Says:

      Looked over the comments on that article, and it looks as if enough people have taken Silver to task without me adding another. If he doesn’t get the message that Pielke is a lying sack of horsepucky from what has already been said, anything I may add won’t help.

      • rayduray Says:

        Thanks for checking out the 538 article. 🙂

        • omnologos Says:

          Dunno what Peter thinks of the 538 controversy but Connolley isn’t impressed. Where are the published peer reviewed articles showing Pielke Jr wrong? And SREX and the IPCC.

          This story risks convincing Silver and other fence sitters that way too many alarmists are close to unhinged and impossible to reason with.

          • rayduray Says:

            Re: “too many…. are close to unhinged and impossible to reason with.”

            Narcissus, you staring in the mirror again? 🙂

        • dumboldguy Says:

          climate progress chipped in—-Pielke is whining and complaining that he’s being picked on


          • rayduray Says:

            Re: “Pielke is whining and complaining that he’s being picked on”

            I don’t think we should relent until the bastard is a screaming paranoid copy of Frank Wisner, a worthless criminal CIA agent driven by his demons to suicide.

            Oh, is that too real for some of you? 🙂

          • omnologos Says:

            Thank you ray for this unaugustus perfect example of unhinged thinking that’s impossible to argue with. 😎

          • dumboldguy Says:

            I seem to have misplaced my omnodictionary.
            WHAT does “unaugustus” mean?

          • omnologos Says:

            The opposite of majestic: “pitiful, pathetic”

          • dumboldguy Says:

            Ah, yes. I should have looked in my omnothesaurus, I guess. It is a VERY difficult read, and it’s too early in the AM for a useless headache.

    • andrewfez Says:

      Rob Honeycutt is already on the scene. He used to troll hunt on climate crocks youtube videos, and i’ve witnessed his patience and endurance when dealing with some of the more boisterous elements of the anonymous denial party such places on the internet attract.

  5. toby52 Says:

    Great post.

    Think there is a typo in the last paragraph … surely should be 1950 to 2000. Change from 1900 to 2000 is closer to 1C.


  6. redskylite Says:

    1970s Global Cooling Awareness (Wikipedia):

    Concern peaked in the early 1970s, though “the possibility of anthropogenic warming dominated the peer-reviewed literature even then”

    1972 – 1976 Maurice Strong was the head of the UNEP – Quote from Maurice Strong 1972 – “After we established the United Nations Environment Programme (UNEP), one of the first things we did was to organise expert group meetings on climate change. After I left, UNEP joined with the World Meteorological Organization (WMO) in creating the inter-governmental panel on climate change. ”

    So climate change was gathering international concern way back in 1972, for those, who are like me and want to learn more about the problem of man induced climate change there are several free on-line courses upcoming from established universities.

    I recommend Omnologus, has a rest from his SQL manuals and to learn something new. I hope he doesn’t think he knows it all now.

    Commencing March 31st University of Chicago

    Commencing April 8th University of California

    Commencing August 11th University of Melbourne


  7. rayduray Says:

    Hey Boobs,

    Check out this 1930s retro look for the Okie panhandle:


    Grapes of Wrath going on sale soon!

    Get ya some Dust Bowl Blues?

  8. Gingerbaker Says:


    “…in 1972 the scientific community was consensual in the fact that the world was cooling, and was expected to cool further …”

    Oh…. a consensus! Great – could you please share the link to the poll numbers on that?

    Or is ” a consensus” merely your assertion based on the fact that a paper came out in 1972 that might have said something about cooling?

    Just wondering, since the planet has been heating up way more than 100 years and most climate scientists in 1972 just possibly were aware of how strange that is, since we really are still in an ice age, and temperatures should have kept getting colder.

  9. redskylite Says:

    The Myth of the 1970’s cooling consensus by Thomas C. Peterson (research meteorologist at NOAA’s National Climatic Data Center in Asheville, NC. He is a lead author on the IPCC Fourth Assessment) et al


  10. Does anybody see any parallels here? Pielke, mono, Monckton….

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