I apologise for the brief intrusion of something vaguely related to climate science on this rowing-n-wiki blog; we'll return you to your usual programming shortly.
Maurizio Morabito attempts to establish that there was a consensus for global cooling in the 1960's (this is all part of a rather dull campaign to discredit the mighty number one climate paper "The Myth of the 1970s Global Cooling Scientific Consensus"; generally he appears to have failed to understand what we said, so I won't bore you by attacking it further). Evidence is apparently found in a 1961 UNESCO / WMO conference Symposium on Changes of Climate with Special Reference to Arid Zones which UNESCO have had the good manners to put online. Well, fascinating stuff, let's read on...
Since MM (prodded by good ol' boy Nigel Calder) found the thing, it is only fair to quote his best (or at least the first; I didn't bother read the whole thing) attempt at cherry picking:
Admittedly, it is easy to miss something in a document so big, but I am fairly confident the following are the most relevant findings for the present discussion (note that "some 115 scientists from 36 countries took part in the symposium"): (page numbers in the following refer to the PDF's, not the original) (1) At page 182, an intervention by E. Kraus of the Woods Hole Oceanographic Institution, Woods Hole, Mass., U.S.A., commenting a presentation by J. Murray Mitchell Jr. United States Weather Bureau, Washington, D.C. Perhaps the most interesting part of the evidence presented by Dr. Murray Mitchell, Dr. Rodewald and some of the other speakers is the way in which it falls into a pattern. Not only air temperature, but also subtropical rainfall, the tendency of hurricanes to move along certain tracks or seasurface temperatures, show a reversal of the preceding [warming] climatic trend during the last one or two decades. The true physical signiñcance of Dr. Murray Mitchell's result lies perhaps in the combined evidence, based on so many different variables.
I'm afraid I haven't read the report as far as page 182. But it seems reasonable to begin at the beginning, with the introductory review paper by Veryard (Met Office, Air Ministry, London) who proposes a "review of studies on climate fluctuations during the period of the meteorological record". This pretty well confirms what I already knew: that during this period, the global records that we take for granted today were only just being collated and were not widely available. Anyone publishing such a paper today would inevitably include a graph of the various temperature records: there is nothing like that (before you say: tech limitations prevented graphs: it isn't so: there are others elsewhere in the volume). Table 1 presents two studies that indicate the world has warmed between 1890-1920 and 1920-1950. There are various tentative patches of text such as In a more recent global study on secular change to be given in a paper by Mitchell at this symposium there is some confirmation that the "world-wide" warming trend of earlier decades was apparently reversed in the 19480s although temperatures have continued to rise in some places. Or: In trying to fit all the many bits of evidence together, one can hardly avoid the conclusion that during the period of the instrumental record there has in fact been a fairly general if not an overall warming-at least up to the 1940s. It would appear that this was slow and irregular at first but became more rapid later reaching a peak somewhere in the 1930s-4'0s. There can be no doubt that the rise has not been uniform or symmetrical in respect to the Pole ; it has been least or nil in middle latitudes of the Southern Hemisphere and greatest in high latitudes of the Northern Hemisphere, especially in areas bordering the Atlantic Ocean. It also appears that the rise of temperature in some areas has lagged behind the rise in others ; in fact, for a time at any rate, the fluctuations in some places have been opposed to those in others. Moreover, the warming has embraced
short-period variations, and might only be part of a much larger period fluctuation covering perhaps some hundred years.
I don't see any great endorsement of a clear cooling trend there. I see what I expected (don't you always?): uncertainty.
That refers to Mitchell (not the Mitchell) so we may as well skip ahead to P 161 to see what he has to say "ON THE WORLD-WIDE PATTERN OF SECULAR TEMPERATURE CHANGE" (don't shout, Murray, I can hear you). Oh look, there is his figure 1 on the right. Apart from the bizarre choice of units on the y-axis it is about what you would expect to see. And he says The fluctuations have consisted primarily of the well-known warming of the earlier decades of the century, and a tendency for cooling since about 1940 which appears to have not only halted but reversed the warming in most latitudes. You might complain that the cooling was fairly short-lived at that point an possibly a blip, a point that Mitchell was quite aware of, and tested for: It will be seen in Table 2 that the observed warming trends between 1890 and 19-49, with the exception of those in the Southern Hemisphere, remain highly significant (2-5 standard errors). According to Table 3, however, the cooling since 1940 loses much of its significance when viewed in this manner.
Does anyone want to read more?
- Log in to post comments
More like this
As a native Mississippian, I must protest:
Nobody named Nigel could ever qualify as a good ol' boy.
Thank you for your comment William. Perhaps we can all avoid boredom by looking at a rather obvious point: your "mighty number one climate paper" :):):) is devoid of historical perspective.
Because all you have done is judge the past by comparing to the present. Rather like dismissing Plato and Aristotle as naive charlatans because they did not know about particle physics and misunderstood gravity: a truly dull exercise indeed. Shall we bin Newton's work for being so wrong about Mercury?
[You certainly need to be aware of the errors in it, if you want to know the details of mercury's orbit, or more philosophically how the world actually works. P+A have nothing useful to say about gravity. The people to blame are those who blindly believed them -W]
And so...was there an IPCC in the 1960's or 1970's talking about upcoming global cooling? Of course there wasn't. Was there a consensus that the globe was cooling at the time? Of course there was. In fact, but please correct me if I am wrong, to this day all evidence points that the world had been cooling, in the 1940s-1970s period at least.
[You are wrong, on many levels. Lets use http://en.wikipedia.org/wiki/File:Instrumental_Temperature_Record.png as our temperature record (you can propose another representation if you prefer). If you put a best-fit line from 1940 to 1970, I think you would see a cooling (significant, though? Don't know). But it can also be read as a hump around 1940 followed by a flat period from 50 to 70. Whatever: over interpretation of minor wiggles isn't a good idea.
But that, of course, is what we know *now*. The issue we addresses in our paper was what people knew then, and what they made of it. The issue in this post is what was known in 1961. Was there a consensus that the globe was cooling then? No. Read the introductory paper, it is clear that there was unclarity -W]
All one has to do to prove or disprove evidence for a "global cooling consensus" is a slight modification of the definition of the expression.
I just wish you had recognized this point in the "mighty number one" paper, thereby calling the bluff on both sides of the debate. But you haven't. And so I can just as reasonably claim that there was a global cooling consensus up to around 1977-1979. One all.
[I think you've missed the point. There are at least 3 possible questions:
1. do we (now) think it was cooling then; and how would we judge it
2. did they (then) think it was cooling
3. did they (then) think it was cooling, and what did they think they should do about it.
Our paper accepts that the answer to 2 is Yes (for the mid-70's, though with hints of reversal that had become more obvious by the late 70's) and examines 3. We find that the majority of scientists (that were interested in the question) then expected future warming, and pointed their policy in that direction -W]
Ideally, next step could be an analysis of how a majority of scientists, like generals, seem to battle according to the rules of the previous war, and so when the world has cooled they all agree it _is_ cooling, and the most vocals among them talk to the media and politicians about it; and when the world has warmed up suddenly in the majority they agree that it _is_ warming. And once again, the most vocals among them talk to the media and politicians about it.
What has changed between the 1960-1970 "global cooling" and 1990-2000 "global warming" consensus (yes, it's the fourth declension!) is called globalization, the oil shocks, the Montreal Protocol, the green movements, the end of Communism, etc etc.
That's why we have now a panel called the IPCC, and an officialized, engrained consensus, that would have had little chance to exist 30 or 40 years ago.
'Was there a consensus that the globe was cooling at the time? Of course there was. In fact, but please correct me if I am wrong, to this day all evidence points that the world had been cooling, in the 1940s-1970s period at least.
All one has to do to prove or disprove evidence for a "global cooling consensus" is a slight modification of the definition of the expression. '
So if you change the key term to mean something different to what it generally designates you can create a factually accurate statement whose purpose appears to be to deceive people unaware that you have changed the meaning of global cooling.
Just as the term global warming in contemporary culture refers to anthropogenic influence on global climate increasing temperature with severely detrimental effects for humans and many other species, global cooling in common parlance refers to far more than a cooling trend over a handful of years with no further consequences.
It is hard to believe that you are as naive as you claim. In any case ignorance is not an excuse for idiocy.
Dear "Eh?"
I rather wished one could have had a more intelligent conversation.
The "mighty number one" paper fails to define "consensus", and whatever "global cooling in common parlance" is supposed to mean, it is not defined in that paper either.
Actually, if it had been, I think I would have written a very positive blog about that paper.
That is exactly the ambiguity both sides of the debate (ab)use to demonstrate whatever they want to demonstrate.
I am afraid the "mighty number one" paper, by failing to recognize such an extremely basic point, has just added to the noise, and clarified pretty much nothing...apart from restating that there was no IPCC in the 1970s. As if anybody needed to be reminded about that...
http://epw.senate.gov/public/index.cfm?FuseAction=Minority.Blogs&Issue_…
Yawn.
So this is how the climate change 'debate' proceeds isn't it?
"Scientists in the 1970s thought the earth was cooling!"
"No. Scientists then thought the earth was warming, as shown by all the available documentary evidence."
"That might be true, but scientists in the 1960s thought the earth was cooling! What's more, if you define 'the 1970s' to mean 'the 1960s', then you can see that my original claim was correct. After all, when it comes to redefining terms, Clinton Did It Too."
"You, Sir, are an idiot."
The only real way to judge the significance of MM's post is by the following criteria: does it get a mention on the Rush Limbaugh show? If it does, he wins.
"I see what I expected: ... uncertainty. "
I see a remarkably similar geospatial pattern in the description of the 1890-1940 warming as has more recently been described in the 1970-present warming.
[Apologies for the delay, links trigger the spam filter -W]
re: #2
"What has changed between the 1960-1970 "global cooling" and 1990-2000 "global warming" consensus (yes, it's the fourth declension!) is called globalization, the oil shocks, the Montreal Protocol, the green movements, the end of Communism, etc etc."
Sure, but more relevant, we have rather more scientific knowledge than we used to. As far as I know, nobody in the 1960s had well-calibrated models for the dimming effects of sulfate aerosols, whose magnitudes seem perfectly capable of explaining at least some of the 1940-1975 temperature non-trend, amidst the usual noise.
Compare
0) GISS Temperature, especially Northern Hemisphere, which generates most sulfur dioxide.
and
1) Historical sulfur dioxide emissions 1850-2000. Figure 3 shows global *sulfur dioxide* emissions tripling between 1945 and 1975, and then falling back as Clean Air Acts started taking effect, especially visible in Europe and North America. By eyeball, thatâs from ~23,000 metric Kilotonnes to a peak of ~75,000, an increase of ~52Mt/year.
[Um, but there is a problem here, viz http://en.wikipedia.org/wiki/File:Climate_Change_Attribution.png which disagrees -W]
3) Mt Pinatubo, 1991 is believed to have emitted ~17Mt SO2.
Since Pinatuboâs 17MT caused a temporary ~.5-.6C dip in Northern Hemisphere, it seems plausible (by no means proved, but plausible by order-of-magnitude) that a 52Mt increase in yearly emissions could generate a ~ .4C NH dip from ~1945-1975, amidst the usual noise. Of course, not all SO2 is equal, as some is blasted into stratosphere (like Pinatubo) and sticks around longer, and has wider geographic effects, rather than being more localized and getting washed out faster.
I wish more people would put volcanoes and ENSOs in temperature charts, like GISS does, to remind people of this. It would be nice to see the background sulfates as well.
4) If one wants to get serious, thereâs: Hansen papers, see 1992-1993, especially POTENTIAL CLIMATE IMPACT OF MOUNT PINATUBO ERUPTION or IPCC AR4 WG I, Chapter 2, especially Section 2.95, Figure 2.23.
Even with all the uncertainties mentioned by IPCC, I think the scientific basis is rather stronger than it was in the 1960s.
Very quick reply as I do not have a proper internet connection at the moment
re: #10
I certainly hope that nowadays "the scientific basis is rather stronger than it was in the 1960s"...but that is a point against the "mighty number one paper".
If we only discuss in terms of absolutes (using, of all thing, the "common parlance" of the moment without bothering to define what it actually is), then we can throw the whole history of Science and much if not all epistemology into some kind of uninteresting ghetto.
re: reply to #2
The fact that there was a lot of (recognised and openly discussed) uncertainty in the 1960s and 1970s may indicate how scientists at the time felt more free to talk about what they did not know, instead of feeling obliged to stick to the party line, lest the world goes to the dogs.
For a counterexample, check the (absence of) reporting from the recent Copenhagen session on detection and attribution, the one thing that would close down the debate.
As for your answer to question 2, if that is a yes, well, that's what I wrote and I can only be very happy about it. So we are all satisfied that there was global cooling at the time and people believed there was, aren't we 8)
re: #8
I sincerely hope Rush Limbaugh will NOT mention any of my blogs, ever. Otherwise I wonder what evidence I would be asked to present to demonstrate I am not in the payroll of some evil organisation bent on world domination. Don't you know, I published once an article in a publication that received some money at some point from Exxon...
Something I donât get about global warming denailism â why they never bother to support their arguments? By this I mean they (and their supporters) have pumped millions and millions of dollars into PR campaigns, fake grass roots organisations, scientists-in-your-pocket to lend credibility and loads of lobbyists â all used to back the same rough set of three arguments; itâs not really happening/the science is not clear so lets not nothing/it is happening but it is not all bad.
But what they have never done is fund some science. I donât mean a conference or opinion piece by a paid denial scientists, I man the think they all claim to be about; the truth â real objective science.
For example recently the Cato Institute ads; it must have cost in excess of $1 million as just the New York Times ad costs $150,000. So why not spend the PR cash on financing a expedition to the Arctic to uncover the truth â publish the results in a peer-reviewed journal â then the âconsensusâ would collapse under the one thing that canât be ignored; the truth?
I mean Exxon was estimated to have spent around £100 million over the past 10 years â imagine how much science they could have done? Why were they not sending teams to to measure glaciers or uncover the climate sink data of the oceans? I man we heard over-and-over that the climate science we do have is bias and part of some ill-defined conspiracy to fleece research funds; so why did the denialists not simply fund un-bias research?
Could it be because, like the creationists, they know deep down the people with the chequebooks who fund this stuff know they are wrong (as Exxon has admitted) and the PR battle is the only place they have a chance of winning?
anarchist 606,
You are correct. There is no evidence that global warming is not happening nor that it is not caused by Man. And the PR men know this, and that is why they only try to throw doubt on hte scientific claims. That technique worked well in maintaining tobacco sales long after it had been proved scientifically that tobacco led to lung cancer.
The problem is that the scientists were wrong about an imminent ice age in the 1970s so this is just the sort of fodder that is needed to cast doubt on the science.
I just don't think that denying that the scare ever happened is the right way to counter that argument. Denying the truth, known to people of my age, hardly helps inspires confidence in scientists, and is really playing into the hands of those who out of pecuniary motives, wich to blacken the name of science.
anarchist 606,
You are correct. There is no evidence that global warming is not happening nor that it is not caused by Man. And the PR men know this, and that is why they only try to throw doubt on hte scientific claims. That technique worked well in maintaining tobacco sales long after it had been proved scientifically that tobacco led to lung cancer.
The problem is that the scientists were wrong about an imminent ice age in the 1970s so this is just the sort of fodder that is needed to cast doubt on the science.
[You're wrong. As our paper demonstrates. If you have refs that say otherwise, you should suply them -W]
I just don't think that denying that the scare ever happened is the right way to counter that argument. Denying the truth, known to people of my age, hardly helps inspires confidence in scientists, and is really playing into the hands of those who out of pecuniary motives, wich to blacken the name of science.
It's surprising no one has mentioned that among 'what has changed between the 1960-1970 "global cooling" and 1990-2000 "global warming..."'
...is that a lot of CO2 has been put into the air. Half of the anthropogenic increase in CO2 concentration following the Industrial Revolution has taken place since 1975.
It's hardly surprising that the consensus is much more solid now given that the forcing is so much larger than it was 30-40 years ago.
Given that the CO2 forcing in the 60s was still not "out of the noise", and the sulphate -ve forcing was significant (not to mention possible solar and other long-term trends that I don't know about), it seems quite reasonable (even in hindsight) that "global cooling" would have been a reasonable hypothesis at that time. As Raymond puts it, things have changed since then and the forcing effects are now (significantly) in the black.
Of course, if there really was actual global cooling (ie onset of next ice age) then the geo-engineering solution is very simple - burn just enough C to balance the negative forcings...
Re #13 Sorry about the double post. Thirteen has always been my unlucky number :-(
Re #15 The consensus is now much larger but the urgency is much less. The 1970 scare was partly caused by the discovery of abrupt climate change. Now it is known that the climate has changed even more abruptly than suspected then, but we are only worrying about what will happen in our grandchildren's lifetime, ignoring the threats that we may have to face.
["The 1970 scare was partly caused by the discovery of abrupt climate change" sounds implausible - I think the timing is wrong. Refs? -W]
Re #16
But William don't you realise that is what we have done. We have prevented the next ice age, but we have gone too far now and are about to trigger a new hothouse world!
Alastair B. McDonald:
I must be around your age and at the time, as a physics student, was writing for a popular science magazine, which involved excerpting/summarizing articles from the professional literature.
Your memory must be playing tricks; I clearly recall already at the time the understanding being that (1) the cooling was caused by aerosols, and (2) that those aerosols would wash out in time, while (3) the build-up of greenhouse gases would go on unabated, and thus eventually take over.
Any "scare" did not involve the primary science sources I had access to at the time -- just as the Peterson et al. (2008) paper asserts.
Re #19
Well if you were in the know, what you say may have been the case. I was just an engineer who, like many of my contemporaries, only heard about the new ice age. I had been told earlier by a fellow student about the Callendar effect, but I personally was more worried about the effect of CFCs on the ozone layer.
My point is that there was a scare about a new ice age, and it makes scientists appear disingenuous to deny it, which is what William tried to do.
[You're singularly short of refs. You have a pile of unanswered questions stacked up in these comments -W]
And it is not just that scare that he denies. He also denies that abrupt climate change is a future possibility.
[Nope. Never have. Just to be explicit: abrupt climate change *is* a future possibility. Happy now? -W]
William,
There is a history of the discovery of Abrupt Climate Change here: http://www.aip.org/history/climate/rapid.htm
[So there is. The bit you want is A breakthrough came after the ice drillers went to a second location, a military radar station named "Dye 3" some 1,400 kilometers distant from Camp Century. By 1981, after a decade of tenacious labor and the invention of an ingenious new drill, they had extracted gleaming cylinders of ice ten centimeters in diameter and in total more than two kilometers long. Dansgaard's group cut out 67,000 samples, and in each sample analyzed the ratios of oxygen isotopes. The temperature record showed what they called "violent" changes â which corresponded closely to the jumps at Camp Century. Moreover, the most prominent of the changes in their record corresponded to the Younger Dryas oscillation seen in pollen shifts all over Europe. It showed up in the ice as a swift warming interrupted by "a dramatic cooling of rather short duration, perhaps only a few hundred years. -W]
and here you will find an excerpt from a meeting report that appeared in Science at about the same time as the scare: http://www.wmconnolley.org.uk/sci/iceage/kukla-matthews-science-1972.ht…
IMHO, the relevant sentence which shows the concern over "rapid changes" is this: "Global cooling and related rapid changes of environment, substantially exceeding the fluctuations experienced by man in historical times, must be expected within the next few millennia or even centuries." [my emphasis]
[You've just redefined rapid, so you lose -W]
Moreover, it is the same names: Kukla, Matthews, Broecker, etc. that appear on your web page and also feature on Stephen Weart's Rapid Warming Page.
Can I point out to you the in Weart' page he reports that 'The respected climate expert C.E.P. Brooks offered the worst scenario. He suggested that a slight change of conditions might set off a self-sustaining shift between climate states. Suppose, he said, some random decrease of snow cover in northern latitudes exposed dark ground. Then the ground would absorb more sunlight, which would warm the air, which would melt still more snow: a vicious feedback cycle. An abrupt and catastrophic rise of tens of degrees was conceivable, "perhaps in the course of a single season."(5)'
Now look at this http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png The ice over the Arctic Ocean is melting exposing dark water!
No that is the bit you want!
That is too late for the ice age scare.
The pollen shifts and fossil coeloptera had already shown that these changes occurred in less than fifty years. The latest ice cores show a switch out of the Younger Dryas in PERHAPS 3 YEARS OR LESS. [Alley, 2002]
No, "rapid climate change" and "abrupt climate change" are two terms for the same thing.
To make me happpy now, you would need to accept that rapid climate change is also a future possibility :-(
[No problem: rapid climate change is also a future possibility -W]
I get the impression that you think abrupt is a hundred years. The scientists knew even then in the 1970s that it was much less, but they were afraid to say so publicly because of the derision they would most likely have recieved, not unlike that meted out by you recently.
[I get the impression that you don't know what I think -W]