What were climate scientists predicting in the 1970s?
What the science says...
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The vast majority of climate papers in the 1970s predicted warming. |
Climate Myth...
Ice age predicted in the 70s
"If you go back to Time Magazine, they actually were proclaiming the next ice age is coming, now it's become global warming… How do you believe the same people that were predicting just a couple decades ago that the new ice age is coming?" (Sean Hannity)
At a glance
If you are aged 60 or over, you may remember this particular myth first-hand. For a brief time in the early to mid-1970s, certain sections of the popular media ran articles describing how we were heading for a renewed ice-age. Such silliness endures to the present day, just with a different gloss: as an example, for the UK tabloid the Daily Express, October just wouldn't be October without it publishing at least one made-up account of the impending 100-day snow-apocalypse.
There were even books written on the subject, such as Nigel Calder's mischievously-entitled The Weather Machine, published in 1974 by the BBC and accompanying a “documentary” of the same name, which was nothing of the sort. A shame, because the same author's previous effort, The Restless Earth, about plate tectonics, was very good indeed.
Thomas Peterson and colleagues did a very neat job of obliterating all of this nonsense. In a 2008 paper titled The myth of the 1970s global cooling scientific consensus, they dared do what the popular press dared not to. They had a look at what was actually going on. Obtaining copies of the peer-reviewed papers on climate, archived in the collections of Nature, JSTOR and the American Meteorological Society and published between 1965 and 1979, they examined and rated them. Would there be a consensus on global cooling? Alas! - no.
Results showed that despite the media claims, just ten per cent of papers predicted a cooling trend. On the other hand, 62% predicted global warming and 28% made no comment either way. The take-home from this one? It's the old media adage, “Never let the truth get in the way of a good story”
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Further details
In the thirty years leading up to the 1970s, available temperature recordings, with a poor global coverage compared to today, implied at times there might be an ongoing cooling trend. At the same time, research was continuing into the building levels of carbon dioxide and their effects on future climate, but the science world of that time was somewhat disconnected, compared to the modern age of instant communication, Zoom and so on.
There were also some notably cold winters scattered through that time, such as the UK one of 1962-63. As a result of these various goings-on, some scientists suggested that the current interglacial period could rapidly draw to a close, which might result in the Earth plunging into a new ice age over the next few centuries.
We now know that the smog that climatologists call ‘aerosols’ – emitted by human activities into the atmosphere – caused localised cooling closest to the areas where most of it originated. Smogs constitute a deadly health hazard and governments acted quickly to clean up that type of pollution: highly visible (unlike CO2), it was hard to ignore. Once largely removed, its effects no longer influenced Northern Hemisphere temperatures, that have steadily climbed since around 1970.
In fact, as temperature recording has improved in coverage, it’s become clear that the cooling trend was indeed localised – it was most pronounced in northern land areas. Other places around the world revealed a different story. Furthermore, at the same time as some scientists were suggesting we might be facing another ice age, a significantly greater number - approximately six times more - published papers indicating the opposite - that we were warming. Their papers showed that the growing amount of greenhouse gases that humans were putting into the atmosphere would cause much greater warming – warming that would exert a much stronger influence on global temperature than any possible natural or human-caused cooling effects.
By 1980, with northern hemisphere smogs a distant memory, the predictions about ice ages had ceased, at least among those working on the science, due to the overwhelming evidence for warming presented in the scientific literature (Peterson et al. 2008). Unfortunately though, the small number of predictions of an ice age were far more 'sticky' than those of global warming, so it was those sensational 'Ice Age' stories in the 1970s popular press that so many people tend to remember. Sticky themes sell papers. Today of course, with 40+years more data, far better coverage and a far bigger research community, we've reached a clear scientific consensus: 97% of working climate scientists agree with the view that human beings are causing global warming.
Last updated on 8 March 2024 by John Mason. View Archives
[DB] Read this post: Milankovitch Cycles
[DB] I'm not sure if you can access this link, but your posting history can be found here.
Bad news John/Dana/whoever is responsible for this page--the link to the video is dead. Maybe replace it with potholer54's video here
Please correct the caption to figure 1
Figure 1: Number of papers classified as predicting global cooling (blue) or warming (red). In no year were there more cooling papers than warming papers (Peterson 2008).
Of these 15 years, 14 had more warming than cooling papers
Looking at the data on the bar graph it appears that there is one year (1971) in which there were 2 cooling papers to the single warming paper.
It may be insignificant, but it is an error. A suggested correction.
Peter Gwynne, the author of the referenced Newsweek article from 1975, recently published the article "My 1975 'Cooling World' Story Doesn't Make Today's Climate Scientists Wrong" which is well worth a read.
Does anyone have a link to the Scientific American article from the 1950s (or 60s?) called "Carbon Dioxide and Climate". So far I have seen only the attached rather blurred scan. I would like to read it (and find out the date!)
[PS] Fixed image size
This looks to be the G Plaas paper. You can find references and links to these early papers here including this one. See also the wonderful Weart book "The discovery of global warming".
For the sciam reference, see here. A republish of july 1959 article.
Note that this is offtopic. Please do not continue discussion in this thread.
LizR @58, Scientific American republished that article in 2008 "to offer an historical perspective on some of the issues being discussed at the United Nations Framework Climate Change Conference". The full original version including charts and illustrations has also been reproduced as a PDF here.
The "most cited" 1970's article heading this SkS post does contain a grown-up bit of referencing that I don't see discussed in the comment thread here. The 1975 Newsweek article "The Cooling World" quotes from "a recent report by the National Acadamy of Sciences" which is the 1975 report by the Panel on Climatic Variation "Understanding Climatic Change: A Program for Action". This long report (a transcript of sorts here) is certainly not about global cooling but about the threat from any form of climate change.
Beyond that basic conclusion, the report does strangely pull its punches when it comes to CO2 emissions, even though CO2 is the first man-made impact to be listed and its impacts are then enumerated.
Yet the message that CO2 presents a threat is somehow lost, with the 'Program for Action' calling for research into climate rather than a reduction of CO2 emissions. Somehow the stark message of the Charney Report just four years later is absent, such conclusions overwhelmed by talk of other human impacts. The report gets bogged down with the likes of the theoretical potential of aerosol cooling (that "cannot be reliably determined from present information") becoming more important in future:-
And the impact of waste heat (which logically could be a big problem if fossil fuels were replaced by thermally inefficient nuclear power) is considered along with other various albedo effects, all competing with the CO2 message.
Yet, there are certainly no predictions of a "cooling world", no ice age being predicted here. Rather, the message is that climate change is dangerous.
What happens when we take this article's opening statement, "1970s ice age predictions were predominantly media based", and apply it to today's climate debate? Let's see:
"Climate change fears (ice age predictions) of the early 21st century (1970s) were predominantly media based."
Is that not an accurate statement? The public's perception of climate change in the modern era has been shaped by the media, not science. Of the millions of people who think they're saving the planet by driving a Prius, only a tiny fraction, far less than 1%, have actually taken the time to review actual scientific data on the topic. They don't know what the term 'greenhouse gas' actually means, nor do they care to. (They also don't know that the Nickel in their beloved Prius's batteries was extracted though mining operations that are more polluting than almost any other human activity).
The media shaped public opinion on climate in the 1970s just like it does today.
No, Kabothpa, it is not an accurate statement. You seem to have neglected "science" in your comment: the '70s predictions were almost entirely media, with little science, while today there is a very strong science foundation reagarding future warming.
You have played "bait and switch" (perhaps not intentionally) by first discussing a general statement about the 1970s ice age predictions, and finishing with a statement about media shaping public opinion. How public opion is shaped is not a discussion about the scientific position, and the 1970s scientific position on cooling (extremely limited support) is not at all like the current scientific position on CO2-caused warming (very strongly supported).
Recommended supplemental reading:
My 1975 'Cooling World' Story Doesn't Make Today's Climate Scientists Wrong
It's time for deniers of human-caused global warming to stop using an old magazine story against climate scientists.
by Peter Gwynne, Inside Science, May 21, 2014
Bruce:
From the first reference at your link (Hanson et al 1981)
"Summary. The global temperature rose by 0.20C between the middle 1960's and 1980, yielding a warming of 0.4°C in the past century. This temperature increase is consistent with the calculated greenhouse effect due to measured increases of atmospheric carbon dioxide. Variations of volcanic aerosols and possibly solar luminosity appear to be primary causes of observed fluctuations about the mean trend of increasing temperature. It is shown that the anthropogenic carbon dioxide warming should emerge from the noise level of natural climate variability by the end of the century, and there is a high probability of warming in the 1980's. Potential effects on climate in the 21st century include the creation of drought-prone regions in North America and central Asia as part of a shifting of climatic zones, erosion of the West Antarctic ice sheet with a consequent worldwide rise in sea level, and opening of the fabled Northwest Passage." (my emphasis)
Hardly in support of global cooling. The second reference: Benton 1970 also predicts global warming with increasing carbon dioxide. After the first two I stopped checking.
When you cite papers that predict additional warming and say that they support claims of global cooling it is easy to get a lot of papers. Scientists read the citations and realize that the claims of predictions of global cooling rely on readers who do not check the citations.
Just like Michael Sweet says.
Bruce @65 . . . . what, if any, is the point you are wishing to make?
Have you read any of the alleged 93 papers? It would be wise of you to read at least a small sample of those papers to see if they were really "concerned". Be wise of you, because Notrickzone is a notorious Fake News outlet, which spouts an amazingly-large amount of BS on all sorts of topics and seems to enjoy winding-up gullible & ignorant readers. (Presumably that's how they make their money at the website.)
That's not to say that it ain't (just) possible that the Notrickszoners might actually have published something truthful this time [gotta be a first time for them, sometime, right?] . . . but judging by their track record, they usually only prefer to to tell a truth is it's a half-truth which misleads or misdirects the gullible readers. So be on your guard, Bruce !! And do a bit of cross-checking.
Now, back to the Notrickszone message.
And the first question is : So what? Bruce, read the brief article above [by John Russell] and view the 5-minute video by David Bedford. And look at the [1914] report mentioned in post #64 just above your own post #65.
Look again at the reality, Bruce : the globe is warming rapidly; sea level is rising ever faster; the world's ice is melting rapidly decade by decade. (Not many glaciers left in Glacier National Park now, Bruce. Sad. ) And the world has just had its 4 hottest years on record ( 2014 / 2015 / 2016 / and 2017 is in the bag ! )
And it's gonna get hotter still — as said by virtually all the scientists who know what's what. There's no reason left to believe any of the BS coming from the science-deniers (or from Notrickszoners, either). Look around, Bruce — unlike in the 1970's , there are nowadays no credible scientists remaining, who think Global Warming ain't happening.
And all the climate scientists have got the evidence backing their opinion !!
So, Bruce, what do you think? (Forget the Notrickszone rubbish/spin.)
Typo correction : that should read "... look at the [2014] report mentioned in post #64 ..."
Only clairvoyants in 1914, could perceive a 1975 'Cooling World' Story !
As this is your first post, Skeptical Science respectfully reminds you to please follow our comments policy. Thank You!
Is this 'a new one'?
" They told me when I was at school we were heading steadily for another ice-age and the cause was CFCs.
I’ve asked in here more than once what happened to the hole in the ozone layer that would inevitably grow and grow and let all the heat out. Nobody will tell me."
www.craigmurray.org.uk/forums/topic/climate-change-hysteria/#post-48853
[TD] Sort of, here.
James Charles,
The issue with the ozone hole is that harmful UV radiation is allowed in. I have never heard of significant heat being let out.
If "they told me at school" was that college, high school or elementary school? Was it in a Science class or an English class? It is unlikely that it was college. Grade school teachers are not really atmospheric experts. Do we rely on experts or grade school teachers?
Mr sweet,
This may enlighten you
Cooling of the Arctic and Antarctic Polar Stratospheres due to Ozone Depletion
William J. Randel and Fei Wu
National Center for Atmospheric Research, Boulder, Colorado
"The Antarctic data show strong cooling (of order 6–10 K) in the lower stratosphere (∼12–21 km) since approximately 1985. The cooling maximizes in spring (October–December), with small but significant changes extending throughout Southern Hemisphere summer. "
Barry, how do you understand stratographic cooling affecting surface climate? Note that one the big fingerprints for GHG warming is surface warming but stratispheric cooling. However, changes in ozone muddy the picture so detecting the GHG effect means separating this from O3 changes.
scaddamp,
It is often quoted that many gases such as carbon dioxide , methane and water heat up the eath by allowing visible light to enter and block the infrared radiation coming out.
Amongst these gases ozone is often included for it too is purportedly acting in a similar way.
Are you therefore suggesting that Ozone in the troposphere does not have such an effect? I think the Climate Kids would dissagree with you.
"Close to the ground, ozone acts as a greenhouse gas and can be formed by burning gas in cars and factories" Re The climate kids!
https://climatekids.nasa.gov/greenhouse-cards/
Ozone is a powerful greenhouse gas in the troposphere.
However, your paper was on stratospheric cooling and looking at the effect of stratospheric ozone. It did not seem pertinent in any way to Michael sweet point. ie the wierd idea that hole in ozone layer was going to cool the earth. I am asking what you think the relevance of your quoted paper on stratospheric cooling is to this question. The ozone in the stratosphere is generated by UV interactions in the stratosphere. It is not a pollutant coming up from the troposphere.
It might also help discussions if you explained why you think ozone depletion reduces stratospheric temperature (or perhaps more to point, why ozone warms the stratosphere).