Arguments
What 1970s science said about global cooling
Posted on 26 February 2008 by John Cook
A persistent argument designed to discredit the field of climate science is that scientists predicted an ice age in the 1970s. So popular in fact that it ranks an impressive #7 in the most cited skeptic arguments. The logic goes that climate scientists got it completely wrong predicting global cooling in the 1970s (it started warming instead). Hence climate science can't be trusted about current global warming predictions. Setting aside the logical flaws of such an ad hominem argument, was there any consensus among 70s climate scientists predicting global cooling?
The evidence for global cooling consensus
Most cited is a 1975 Newsweek article The Cooling World that suggested cooling "may portend a drastic decline for food production":
"Meteorologists disagree about the cause and extent of the cooling trend… But they are almost unanimous in the view that the trend will reduce agricultural productivity for the rest of the century."
A 1974 Times Magazine article Another Ice Age? painted a similarly bleak picture:
"When meteorologists take an average of temperatures around the globe, they find that the atmosphere has been growing gradually cooler for the past three decades. The trend shows no indication of reversing. Climatological Cassandras are becoming increasingly apprehensive, for the weather aberrations they are studying may be the harbinger of another ice age."
However, these are media articles, not peer reviewed scientific papers. Does a consensus on global cooling emerge from the scientific literature?
Skeptical quote mining of 1970s scientific literature
Most mentioned is Rasool 1971 which projected that if aerosol levels increased 6 to 8 fold, it may trigger an ice age. While Rasool underestimated climate sensitivity to CO2, its basic assertion that the climate would cool with a dramatic increase of aerosols was correct. However, aerosol levels dropped rather than increased. More on Rasool...
A 2003 Washington Post op-ed by James Schlesinger, Climate Change: The Science Isn't Settled, quoted a 1972 National Science Board report as follows:
"Judging from the record of the past interglacial ages, the present time of high temperatures should be drawing to an end . . . leading into the next glacial age."
The full quote from the report is as follows:
"Judging from the record of the past interglacial ages, the present time of high temperatures should be drawing to an end, to be followed by a long period of considerably colder temperatures leading to the next glacial age some 20,000 years from now. However, it is possible, or even likely, that human interference has already altered the environment so much that the climatic pattern of the near future will follow a different path.
For instance, widespread deforestation in recent centuries, especially in Europe and North America, together with increased atmospheric opacity due to man-made dust storms and industrial wastes, should have increased the Earth’s reflectivity. At the same time increasing concentration of industrial carbon dioxide in the atmosphere should lead to a temperature increase by absorption of infrared radiation from the Earth’s surface.
When these human factors are added to such other natural factors as volcanic eruptions, changes in solar activity, and resonances within the hydro-atmosphere, their effect can only be estimated in terms of direction, not of amount"
Schlesinger's op-ed has been quoted widely including James Inhofe's Senate testimony. Skeptic citing of the scientific literature have taken conclusions out of context, overlooking qualifications and stated uncertainties. What does a broader look at the scientific literature reveal?
A new paper exposing the myth of 70s global cooling
Over time, William Connelly has been steadily documenting 70s research predicting global cooling. It's a rich resource but as he admits, could be more accessible. Now he has collaborated with Thomas Peterson and John Fleck to publish The Myth of the 1970's Global Cooling Scientific Consensus, due to be published in the Bulletin of the American Meteorological Society.
The paper surveys climate studies from 1965 to 1979 (and in a refreshing change to other similar surveys, lists all the papers). They find very few papers (7 in total) predict global cooling. This isn't surprising. What surprises is that even in the 1970s, on the back of 3 decades of cooling, more papers (42 in total) predict global warming due to CO2 than cooling.
Figure 1: Number of papers classified as predicting future global cooling (blue) or warming (red). In no year were there more global cooling papers than global warming papers.
So in fact, the large majority of climate research in the 1970s predicted the Earth would warm as a consequence of CO2. Rather than climate science predicting cooling, the opposite is the case. Most interesting about Peterson's paper is not the debunking of an already well debunked skeptic argument but a succinct history of climate science over the 20th century, describing how scientists from different fields gradually pieced together their diverse findings into a more unified picture of how climate operates. A must read paper.
I've read quite a bit from this website. I'm not coinvinced of the veracity of the site; this could be remedied if a bibliography were published for each reference and a passage from these reports or abstract. In similar fashion to the way you provided the context in this article "The Science Isn't Settled, quoted a 1972 National Science Board report as follows"; Overall it's sketchy with the emphasis supporting AGW.
If, as you say, you found very few papers (7 in total) that predict global cooling but found more papers (42 in total) that predict global warming in the 1970's, then you obviously have already done some homework; so it shouldn't be too exhausting or a strecth to back up your claims by posting the necessary links, bibliography etc., for EACH of these papers instead of cherry picking select data. This is common on your site. To say there were 42 papers on AGW published in 1970's sounds impressive, but...
Kevinb3...the bibliography you seek is in the paper that the OP describes and to which it links, twice. All you need to do is follow the link.
You state cherry picking is common on the site, but provide no concerete examples, so that critcism is empty innuendo. If you want a proper discussion, talk about a specific examples and make a case.
Kevinb3@21
This is underestimating the resources of this platform by a great margin.
For example within the left margin are some buttons to click - one of these is labeled "History of Climate Science". Anybody checking this part of SkS will have to have enourmous time to spend on reading. Advance the timeline to 1972 and click on the year dots and then look down to the section below the graph - you'll see links there (in abundance).
@ ajki
I think it's more of a question of overestimating the site.
It "might" be possible for the layperson to find the links by data mining the site that align to the "7 total" papers on cooling, or "42 total" that deal with warming. However if the research is already done by the author of this article then there should be no need for someone looking for sunstantiating this article to go on a wild goose chase. The articles the author is referencing almost surely don't have global cooling or warming in the headline which would mean the reader would have to dig deep in each paper to find the reference if it's not clearly outlined in the abstract. Most peer reviewed papers are not written for the consumption of the layperson, they're highly technical.
It's the authors responsibility to back up their claims by posting source. I have many times looked at source materials that were used a basis for extrapolating opinion on other topics and found that I don't agree with the conclusions the author has arrived at based on the data, but, I often do as well. It's relative. However, with the topic of AGW there's impetus for direcet proof over assertion because it's a highly charged topic politically.
@ Stephen
I looked at that biblio, it had over 100 papers, I don't see specific links to the 7 cooling papers or the 42 warming papers broken out. Like I said, the author has combed through that biblio and pulled out certain specific references. They need to be more specific and not rely on the readers patience to prove their veracity or not. I'd like to read the specific papers this author is using as their primary evidence.
Kevinb3 if you look at the appendix of the paper it gives a list of the papers predicting cooling and the papers predicting warming. What more do you want, that is the form in which references are usually made in scientific papers, and if you disagree with the findings then the onus is on you to look up the papers and analyse them for yourself. There is no other way of establishing the "veracity" of the survey than reading the papers for yourself, and the authors make that as easy for you to do as you caould reasonably expect.
Kevinb3, look at table 1 in Peterson, Connolley and Fleck (linked in the OP). The paper discusses the majority of the cooling papers more extensively in the text.
Dikran, What more do you want?
Either links, which aren't always readily available, or pdfs of said papers. Not explanations or interpretations as to what the papers say from third parties. Yes, I could go on a research binge and gather up said articles, but it goes back to my original point really. The site is expounding on what it states is truth, but IMO the source material should be offered up if it's going button up. Since the homework is supposedly done, then it should be easy.
@ Tom
BTW, thanks, looking below the long list of papers I did find the table, but I still reference my above point.
From John Cook's notes to the OP (visible only to SkS authors):
7 Cooling Papers:
Climate Modification by Atmospheric Aerosols (McCormick and John H. Ludwig 1967) - Theoretical considerations and empirical evidence indicate that atmospheric turbidity, a function of aerosol loading, is an important factor in the heat balance of the earth-atmosphere system. Turbidity increase over the past few decades may be primarily responsible for the decrease in worldwide air temperatures since the 1940's.
Barrett 1971 (???)
Rasool & Schneider 1971
Atmospheric Turbidity and Surface Temperature on the Polar Ice Sheets (Hamilton & Seliga 1972) - DATA relevant to the causation of climatic change, particularly changes in mean annual temperature at the surface over intervals of from 10 to 105 yr, have been accumulating gradually in various laboratories engaged in studying the two long ice cores from Camp Century, Greenland, and "New" Byrd Station, Antarctica. This note consolidates these and other data and interprets them in the framework of existing theory. It appears that millenial and longer variations in cloud-level temperature on the polar ice sheets have been caused by changing atmospheric turbidity over the past 10 5 yr.
Aerosols and climate (Chýlek, J Coakley - Science, 1974)
A nonequilibrium model of hemispheric mean surface temperature. (Bryson & Dittberner 1976)
The influence of pollution on the shortwave albedo of clouds. (Twomey 1977)
The remainder of John Cook's notes to the OP (visible only to SkS authors):
http://www.ametsoc.org/Chapters/asheville/mythAshevilleJanuary2008.ppt
http://ams.confex.com/ams/pdfpapers/131047.pdf
William Connelly blogs on his paper: (good comments)
Kevinb3 - The references (papers on cooling, warming, or neutral) are clearly listed in Peterson et al, Table 1. A quick search on Google Scholar (which is extremely useful for this) shows that many are articles in Science or Nature, which require subscription or purchase.
Several notes here:
Kevinb3, you are being unreasonable. The whole point of people conducting surveys is to give a summary of what has been published on some topic. If you don't accept the survey then the onus is on you to conduct a survey of your own and draw your own conclusions. The authors of the survey have identified the papers for you, requesting they give links rather than the normal form of citations used in journal papers is basically asking to be spoon-fed.
I am beginning to suspect that you don't actually have any objection to the concusion of the survey and are just using the "method of unreasonable expectations" to avoid accepting it.
Kevinb3 If a climate website wanted to publish an article on the TCP paper, that shows the 97% concensus on climate change, would they be required to give links to all 12,000 papers that were considered, or would it be O.K. just to give a link to the paper itself?
I get it KR. Thanks