30

it is projected that man's potential to pollute will increase 6 to 8-fold in the next 50 years. If this increased rate of injection... should raise the present background opacity by a factor of 4, our calculations suggest a decrease in global temperature by as much as 3.5 °C. Such a large decrease in the average temperature of Earth, sustained over a period of few years, is believed to be sufficient to trigger an ice age.

Interestingly enough, that's not some journalist's imagination running wild, not a "myth started by Newsweek and irresponsible journalism", but a scientific paper published in Science in 1971 ( "Atmospheric Carbon Dioxide and Aerosols: Effects of Large Increases on Global Climate" [Science 173, 138–141]) by Prof. Stephen H. Schneider. To make it even more interesting, three decades later

[...The author...] was a Coordinating Lead Author in Working Group II IPCC TAR and was engaged as a co-anchor of the Key Vulnerabilities Cross-Cutting Theme for the Fourth Assessment Report (AR4)

Was there as much "scientific consensus" on "anthropogenic global cooling" in 1970s, as there was on "anthropogenic global warming" in 2000s?

Update:

In one of research papers used in linked question, one can find following sentence:

By the early 1970s, when Mitchell updated his work (Mitchell 1972), the notion of a global cooling trend was widely accepted

vartec
  • 26,581
  • 5
  • 97
  • 155
  • 4
    possible duplicate of [Did we have a "global cooling" 40 years ago?](http://skeptics.stackexchange.com/questions/2667/did-we-have-a-global-cooling-40-years-ago) – Suma Jul 05 '11 at 13:51
  • 4
    @Suma - having read that question, it is not a duplicate, IMO: that question asks whether there was cooling, whereas this asks whether there was 'scientific consensus'. – ChrisW Jul 05 '11 at 14:52
  • 7
    @ChrisW, I am quite sure that the answers given clearly demonstarate that there was no concensus at that time, or ever. – JasonR Jul 05 '11 at 15:08
  • @Suma: there are two things wrong with the alleged duplicate. It answers question if there was cooling or not, which I'm not asking. And answers use IPCC as source, which is not reliable, as uses materials that are not peer reviewed, or outright not even scientific (advertisements, BSc thesis etc.) – vartec Jul 05 '11 at 15:20
  • If you think that question was handled badly, what reason do you have to think this one will do any better? If you think the answer is bad, this does not make this not a duplicate of that one. – Suma Jul 05 '11 at 19:01
  • 1
    However, on second reading I agree it is not a duplicate. The linked questions asked about the climate around 1970, while this one asks about prevailing climate theories around 1970. – Suma Jul 05 '11 at 19:04
  • I think you're misinterpreting your last quote, the global cooling trend refers to the observed cooling, not the extrapolation towards a new ice age. The trend refers to the observed data, not the prediction of future global cooling. – Mad Scientist Jul 06 '11 at 08:30
  • 2
    @vartec “use IPCC as source, which is not reliable” – sorry, but this is getting ridiculous. In fact, the IPCC reports are some of the most rigorously drafted, scientifically accurate statements in all of history, perhaps *the* most rigorous ones. Every single claim made therein is supported by numerous studies and a broad consensus. Every dubitable claim is marked as such, and every reliable potential counter-evidence is *also* listed. So even though the document has a clear agenda (policy-making), it carefully investigates the opposite side. If the IPCC is unreliable, then so is everything. – Konrad Rudolph Jul 06 '11 at 10:11
  • 2
    @Konrad: first of IPCC reports are these papers, where they for example can't tell year 2350 from 2035. Second of all, IPCC reports are **not scientific papers**, and are based on **not peer-reviewed sources**. In fact IPCC is an institution, which by definition is **political, not scientific**. – vartec Jul 06 '11 at 10:30
  • @vartec Let’s take this to the chat. But I’d please like references for the claim that the IPCC reports are substantially based on non-peer-reviewed sources. Your other claims are true, but irrelevant. – Konrad Rudolph Jul 06 '11 at 10:34
  • 2
    Examples "reliable" IPCC: http://news.bbc.co.uk/2/hi/south_asia/8387737.stm http://www.telegraph.co.uk/earth/environment/climatechange/7177230/New-errors-in-IPCC-climate-change-report.html and quote from last one " senior scientists are now expressing concern at the way the IPCC compiles its reports and have hit out at the panel’s use of so-called “grey literature” — evidence from sources that have not been subjected to scientific ­scrutiny." – vartec Jul 06 '11 at 10:34
  • 2
    @vartec I never claimed that the IPCC reports were free of mistakes. In fact, that would be an outrageous claim. But (once again!) if that makes the whole report unreliable, then there are no reliable documents anywhere. – Konrad Rudolph Jul 06 '11 at 10:37
  • 1
    @Konrad: **scientific** value of IPCC report is null, zero, nada. – vartec Jul 06 '11 at 10:46
  • 6
    @vartec And with that you have concluded the “monoscussion”. Welcome to skeptics. – Konrad Rudolph Jul 06 '11 at 11:49
  • 4
    @jwenting If you actually have an answer then post it as an answer, answering in a comment without backing it up with evidence is completely useless. – Mad Scientist Jul 07 '11 at 08:15
  • 3
    @jwenting: If you are going to disregard the carefully considered consensus of scientists in a field, and not give any supporting evidence, you really may not be comfortable on this site. – David Thornley Jul 08 '11 at 01:26
  • 1
    "or outright not even scientific (advertisements, BSc thesis etc.)" A bachelor of science thesis is scientific. It gets peer review by the professor who supervises it. – Christian Jul 08 '11 at 15:20
  • @Chris: B.Sc. thesis is not scientific - it's not required to (and usually doesn't) contain any original research, review by teacher is not a peer review. – vartec Jul 08 '11 at 15:40
  • @DT "concensus" isn't science, it's politics. Therefore it has no value. The lone wolf is very often right where the "concensus" says the opposite. – jwenting Jul 11 '11 at 06:49

2 Answers2

20

In a word, no.

I could cite sources, but William Connolley has already exhaustively researched this (summary here), including Rasool and Schneider. Nothing in your question implies that he has incorrectly characterized the prevailing scientific views at the time.

Connolley cites a 1975 NAS report as more representative of the scientific (not media) consensus of the time. You can read the forward here. This report notes that scientists were not confident in their ability to predict climate trends back then:

Unfortunately, we do not have a good quantitative understanding of our climate machine and what determines it's course. Without this fundamental understanding, it does not seem possible to predict climate-neither in short-term variations nor in any in its larger long-term changes.

The paper you cite is one assertion that "global cooling" is possible. It is not a consensus. One or two assertions don't make a consensus, especially a paper like Rasool and Schneider, which is riddled with flaws. There appear to have been other scientists with similar concerns, and perhaps fewer analytic errors in their work, as well, but again, a handful of people don't make a "consensus."

Cherry picking one or two examples which happen to run against the prevailing scientific views at the time -- which were, in short, that climatologists in 1975 were not confident in their ability to predict climate changes at all -- in no way suggests any kind of consensus. There is no credible claim of a consensus for global cooling in your question, only a dodgy paper and an unsupported assertion.

Connolley's own conclusion, from reading the papers cited, is as follows:

Finally, its clear that there were concerns, perhaps quite strong, in the minds of a number of scientists of the time. And yet, the papers of the time present a clear consensus that future climate change could not be predicted with the knowledge then available. Apparently, the peer review and editing process involved in scientific publication was sufficient to provide a sober view. This episode shows the scientific press in a very good light; and a clear contrast to the lack of any such process in the popular press, then and now.

Regarding your partial-sentence quote from Peterson, Connolley, and Fleck, let's look at the whole sentence, in context:

Indeed, the Earth appeared to have been cooling for more than 2 decades when scientists first took note of the change in trend in the 1960s. The seminal work was done by J. Murray Mitchell [in 1963, showing that] global temperatures had increased fairly steadily from the 1880s, the start of his record, until about 1940, before the start of a steady multidecade cooling (Mitchell 1963). By the early 1970s, when Mitchell updated his work (Mitchell 1972), the notion of a global cooling trend was widely accepted, albeit poorly understood.

It is quite clear, in context, that this refers to the post-1940s cooling rather than to supposed predictions of a new ice age. Today it is understood that this (ultimately temporary) drop was due to aerosols and industrial pollution and was mainly a Northern Hemisphere, rather than a global trend. But yes, it's correct to say that scientists in the seventies agreed that there was cooling from the 40s through the early 70s, and, with the caveats noted above, they still do.

Mike Samuel
  • 405
  • 3
  • 13
Craig Stuntz
  • 500
  • 3
  • 8
  • I wouldn't call commenting on **two** papers "exhaustively researching" – vartec Jul 07 '11 at 13:09
  • 7
    @vartec: Calling Connolley's work "commenting on **two** papers" is a *blatant* mischaracterization. He examines *dozens* of papers, with specific comments on at least twenty (I'm too lazy to count, but you're wrong by at least an order of magnitude). Please note that there are links in the first page. You can click them to read further. Did you read what he wrote at all? – Craig Stuntz Jul 07 '11 at 13:18
  • @Craig: summary only talks of two, in the other page, you have things like for example http://www.wmconnolley.org.uk/sci/iceage/kukla-matthews-science-1972.html BTW. how is for example Isaac Asimov a scientist? – vartec Jul 07 '11 at 13:34
  • 7
    @vartec, did you actually *read* his comments on Asimov? If you did, you would have seen *"Note: this is not a scientific reference. Its here as an example of the mistake that a well-read non-expert can (and did) make."* – Craig Stuntz Jul 07 '11 at 13:57
  • @Craig: ok, so let's assume that's one part of the answer, another one would be to show that there is actually more consensus on anthropogenic global warming now. – vartec Jul 07 '11 at 14:51
  • 3
    @vartec Consensus has been shown: http://skeptics.stackexchange.com/questions/41/is-there-any-solid-causal-evidence-for-human-activities-contributing-to-climate-c/486#486 – Konrad Rudolph Jul 07 '11 at 17:09
  • @vartec would 14,000 papers be enough? http://www.slate.com/blogs/bad_astronomy/2012/12/11/climate_change_denial_why_don_t_they_publish_scientific_papers.html – JasonR Dec 11 '12 at 13:37
5

The short answer... No!

From Peterson (2008):

enter image description here

Another good summary of this topic can be found on the Skeptical Science site: http://www.skepticalscience.com/ice-age-predictions-in-1970s-intermediate.htm

  • 6
    Please expand your answer and summerize the main points of your sources. – SIMEL Jun 19 '14 at 18:55
  • Or at the bare minimum enter an image description so that those using screen readers can have some sort of answer at all. – Rick Aug 20 '18 at 12:46