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The global cooling mole

By John Fleck and William Connolley

To veterans of the Climate Wars, the old 1970s global cooling canard – “How can we believe climate scientists about global warming today when back in the 1970s they told us an ice age was imminent?” – must seem like a never-ending game of Whack-a-mole. One of us (WMC) has devoted years to whacking down the mole (see here, here and here, for example), while the other of us (JF) sees the mole pop up anew in his in box every time he quotes contemporary scientific views regarding climate change in his newspaper stories.

The problem is that the argument has played out in competing anecdotes, without any comprehensive and rigorous picture of what was really going on in the scientific literature at the time. But if the argument is to have any relevance beyond talking points aimed at winning a debate, such a comprehensive understanding is needed. If, indeed, climate scientists predicted a coming ice age, it is worthwhile to take the next step and understand why they thought this, and what relevance it might have to today’s science-politics-policy discussions about climate change. If, on the other hand, scientists were not really predicting a coming ice age, then the argument needs to be retired.

The two of us, along with Tom Peterson of the National Climatic Data Center, undertook a literature review to try to move beyond the anecdotes and understand what scientists were really saying at the time regarding the various forces shaping climate on time human time scales. The results are currently in press at the Bulletin of the American Meteorological Society, and Doyle Rice has written a nice summary in USA Today, and an extended version based on a presentation made by Tom at the AMS meeting in January is on line.

During the period we analyzed, climate science was very different from what you see today. There was far less integration among the various sub-disciplines that make up the enterprise. Remote sensing, integrated global data collection and modeling were all in their infancy. But our analysis nevertheless showed clear trends in the focus and conclusions the researchers were making. Between 1965 and 1979 we found (see table 1 for details):

  • 7 articles predicting cooling
  • 44 predicting warming
  • 20 that were neutral

In other words, during the 1970s, when some would have you believe scientists were predicting a coming ice age, they were doing no such thing. The dominant view, even then, was that increasing levels of greenhouse gases were likely to dominate any changes we might see in climate on human time scales.

We do not expect that this work will stop the mole from popping its head back up in the future. But we do hope that when it does, this analysis will provide a foundation for a more thoughtful discussion about what climate scientists were and were not saying back in the 1970s.

Update: Full paper available here.

243 Responses to “The global cooling mole”

  1. 151
    pete best says:

    Re #150, that probably explains why western oil companies have now turned to unconventional oil sources such as Canada’s Athabasca Tar sands. A gian deposit of carbon producing menace in the form of soil that requires enourmous quantities of water, natural gas and leaves behind pollution you would not believe. 1 Mb/d today climbing to 5 mb/d come 2015. This is a disgusting practise carbon emissions wise but these are not the only heavy oil sources either but the only ones of significant volume in friendly countries. If we are producing these oils then the peak is in sight and $200 a barrel is coming.

  2. 152
    Nick Gotts says:

    Re #140 [Ray Ladbury]

    I think you misunderstand my intent.”

    Yes, perhaps I did. If so, I apologise.

    “I am trying to explain why those of an economic/business bent seem more likely to challenge the science (which they do not know) or propose geo-engineering solutions, while those of us who understand the science are more likely to suggest changes that affect our current economy (despite the fact that we are not trained in economics or business).
    In my experience, there is a tendency for people to think that whatever they don’t understand is simple.”

    I agree, and I think to some extent it is something you do as well. Specifically, you appear to think that economics is much more like physics than it really is. For example, you refer to the “laws of economics”. If there are such laws, they are very different from the laws of physics (at least those of fundamental physics), having a much narrower domain of application and even within that domain, much wider possibilities for exceptions to arise. Even such a simple economic “law” as “If the demand for commodity x rises, so will the price” is only true in certain circumstances. Also, economics, and social sciences generally, still encompass multiple competing research programmes. You appear to accept uncritically the programme of neoclassical economics, which is in large part ideologically driven. In general, the social sciences are much more prone than the physical sciences to ideological “contamination”, because they have a much more direct relevance to political and moral issues.

    “I am proposing that much of the opposition of the business-minded folks is because their theoretical understanding of the economy is insufficient to map out unintended consequences of drastic reduction of fossil fuel consumption.”

    Possibly some is, but a lot is either simple self-interest (because the profits of many types of business would be adversely affected); or ideological conviction that markets should not be interfered with.

    “I also stand by my differentiation of homo scientificus from homo economicus, as the former seeks work, eschews wealth and does whatever possible to maximize time spent at the lab.”

    Yes, I like this! My previous post was prompted by irritation at the misuse of semi-technical terms (Homo economicus and social engineering). However, the very existence of “Homo scientificus” is a problem for neoclassical economics, which relies on the assumption that we are all “Homo economicus”, or at least, that any deviations from this picture of human motivation and reasoning can be ignored. Neoclassical economics (at least so far as its microeconomic foundations are concerned) has long been largely detached from empirical investigation of how people actually behave, devoting itself instead to the mathematical ramifications of its assumptions in ever-wider areas. Experimental economics, behavioural game theory and now neuroeconomics and agent-based simulation challenge this detachment.

  3. 153
    Ray Ladbury says:

    Nick, I am really not a devotee of neoclassical economics. It’s yet another of the -isms I don’t believe in. However, I do think that there is a tendency of some in this debate to think making the economic changes needed to combat climate change will be easy. As such, I think that the neoclassical approach has some value in terms of challenging such assumptions. I believe that mitigating climate change is too important to tie the issue up with questions of how we remake society, etc. Establishing consensus on that is simply not going to happen, and any attempt to turn mitigation of climate change into an opportunity for social engineering will doom both to failure.
    I do believe some social change will be necessary–for instance that climate mitigation cannot be decoupled from economic development of the third world, since poor people will burn anything to keep warm, cook their food, etc.
    I also emphasize that whatever strategies we come up with have to work for humanity at its lowest common denominator. Homo Scientificus is by defintion exceptional. I also think that while altruism exists in humans, it, too, is exceptional. So we really cannot rely on the good well or common sense of humankind, since the average human possess neither.

  4. 154
    Nick Gotts says:

    Re #153: “Nick, I am really not a devotee of neoclassical economics…I also emphasize that whatever strategies we come up with have to work for humanity at its lowest common denominator. Homo Scientificus is by defintion exceptional. I also think that while altruism exists in humans, it, too, is exceptional. So we really cannot rely on the good well or common sense of humankind, since the average human possess neither.”

    So if not neoclassical economics, what are your grounds for your pessimism about most people? And no, “just look at the news”, as you’ve said before, won’t do it – that assumes the people making the news are a fair cross-section, and to justify that claim, you would need a model of how social institutions work. It’s as naive as saying “Look – you can see the Sun goes round the Earth!”.

    And please, I beg you, stop using “social engineering” as a scare-word. It really is as silly as the things gusbob has been saying over on “A galactic glitch”. I suspect that what you mean is what Karl Popper, in Vol. I of “The Open Society and Its Enemies” (I have the 5th edition), calls “Utopian social engineering”, of which Pol Pot’s “Year Zero” would be a good example, and which he contrasts with “piecemeal social engineering” – setting up or altering specific social institutions with a view to bringing about particular ends, while recognising that we can’t change everything at once, that there is no place outside society from which we can operate, and that all our actions are liable to have unintended consequences. A carbon tax or market in carbon permits would be social engineering. An international agreement to transfer low-carbon technology would be social engineering. Changing the law to make it easier to build nuclear power stations would be social engineering. Setting up NASA was social engineering.

    I do believe that there are fundamental problems with capitalism that make it very unlikely we can solve AGW, let alone that plus all the other serious environmental problems we face, without changing it so much that by the end of this century, it would be doubtful that it should be called by the same name. I could be wrong, indeed in some ways I hope I am, because the capitalist world-system is very well entrenched. Fortunately, I don’t need to know whether I’m right or wrong about the necessary extent of social change to have a good idea of some directions we need to move in – such as reducing the power of particular interest groups, like the fossil fuel lobby, to pollute at everyone else’s expense; and investing more resources in energy efficiency and renewable energy.

  5. 155
    Ray Ladbury says:

    Nick, Perhaps my pessimism has something to do with watching the evisceration of American democracy, or with watching the woefully inadequate response to the AIDS epidemic, or the backlash against the environmental movement or not just the utter failure, but the exacerbation of the racial divide in the US by well meaning attempts to remediate it. All of this has happened during my adult life.
    There are also the lessons of history. Ever read about the history of the British East India Company? It is a wonderful story of human folly–from the initial traders who tried to sell British woolens to Indian peasants to the final division of India and Pakistan. The thing is that the failure of the British Empire was not due to a lack of good intentions, but rather to the inability to carry them out in the face of incompetence, corruption and favoritism.
    You can also look at the history of the Belgian Congo…though there it really was the heart of darkness that cast it into hell.
    There is also the fact that what we are up against can’t be decided by a minority–really not even a majority. Since 10% of the human population could easily screw up any solution we come up with to climate change, a 90% score is not passing–especially if the 10% dissenters are influential.

  6. 156
    Nick Gotts says:

    Re #155 [Ray Ladbury]

    As with your earlier references to the news, your historical examples are merely anecdotal – they tell us little or nothing about how most people have behaved most of the time, let alone about what might be possible under different institutional arrangements. I have indeed read about the British East India Company, and your belief that the British Empire was founded or run with “good intentions” is laughable: it was founded and run by, and for the benefit of, a small ruling elite. I also doubt whether most black Americans would agree with you that the racial divide in the USA is now worse than it was around 1960, let alone 1860. Leaving aside these specifics, for every instance of wickedness or folly you raise – and there is certainly no shortage – I could come up with instances of human solidarity, compassion, courage and rationality. Until we have much better models of how innate human characteristics interact with the physical, social and informational environment, it is unjustifiable, intellectually, and I consider also morally, to dismiss the possibilities for very considerable improvements in how people treat each other, other sentient creatures, and the world. We do know from historical and social science research that human behaviour has considerable plasticity, alongside some features that are much less modifiable. To give an example that shows both aspects, in every society studied (so far as I know), most serious violence is carried out by adolescent and young adult males. However, the frequency of such violence varies by orders of magnitude between (for example) the Baka and the Yanomami. Similarly, in practically all societies (there are some claims of exceptions, in my view dubious), men have had some degree of social dominance over women – yet the differences in this respect between, say, contemporary Sweden and Saudi Arabia are considerable. All societies involve both cooperation and competition – but again, the balance between the two varies enormously. You have, in my view, utterly failed to show any scientific or rational grounds for your pessimism. Do you only accept the relevance of such grounds within physical science? If not, how about following your own advice to gusbob, and learning rather more before about the systematic study and research that has been done in history and social science before being so dogmatic? You will not, of course, find nearly so much consensus as in the natural sciences, but that does not mean it is justifiable to take your personal observations for general, immutable truths. In the course of one of our earlier discussions on this issue, I asked whether you had read any of the references I had provided. Your reply (I paraphrase, I hope accurately), was that you had read some, would like to read more but hadn’t time, and anyway, for every article saying people were cooperative there was another saying the opposite. Can you really not see the resemblance to gusbob’s attitude? I do apologise for the comparison, as I have considerable respect for your intellect and (in the physical sciences) knowledge and rigor; I make it in the hope of shocking you into a reassessment.

  7. 157
    Ray Ladbury says:

    Nick, You say, “Until we have much better models of how innate human characteristics interact with the physical, social and informational environment, it is unjustifiable, intellectually, and I consider also morally, to dismiss the possibilities for very considerable improvements in how people treat each other, other sentient creatures, and the world.” Would it not also be fair to say that until we have better models of human nature, it is irresponsible to insist on using climate change as an occasion for remaking society–for social engineering on a grand scale?
    You claim that I have failed to justify my pessimism. Perhaps, but I would contend that you have equally failed to present any grounds for optimism. And certainly, history gives us plenty of evidence that if the human learning curve has a positive slope at all, it is pretty damned shallow. As Mark Twain said, “The past does not repeat itself, but it rhymes.”
    As to the East India Company, I apologize for being unclear. I include also the British Raj, and there, we had no shortage of good intentions–in Parliament and even among local functionaries. The point is that the British Raj was no more effective in giving good governance to India than was the Company, despite the government’s good intentions.
    And as to the experience of African Americans, I in no way denied progress. I merely said that there had been a considerable backlash (both wrt civil rights and to environmentalism) that has slowed progress to a crawl. And now we have more young, black men incarcerated than at any time in the past. No, there is progress and society changes dramatically. But damned if people don’t stay the same. You act as if the drive for human improvement were something new. Hell, Nick, with all due respect to your research, can you produce something as insightful as the Dhammapada or the Mahabharata, or even something as unquestionably true as the Golden Rule of Jesus (also Rabbi Hillel and many others). We have 5000 years of religion, Utopian dreams, Millenarianism, workers’ paradises, new German/Russian/Chinese…men–at least. I find it hard to believe that there is anyone out there who can claim not to know right from wrong. Yet we insist on feeling good if we choose wrong and eschew “wronger”. Even science has freed only a handful of humans from our own irrationality. More people believe in angels than in evolution.
    Don’t get me wrong. I believe in progress. I think it’s wonderful that we’ve given up human sacrifice (mostly) and that slavery is in the past (well, mostly) and women have rights (in some places) and that we don’t burn witches (though I’ve seen the aftermath of 2 being killed myself).
    In the end, Nick, you’ll have the same problem of everyone else who has believed in the perfectability of human nature: How do you shift the distribution so that the bottom 10% of humans (choose your criterion–intelligence, altruism, judgement…) don’t invalidate what the top 10% achieve? You’re in great company–Buddha, Jesus, Gandhi, Marx,…. It’s just a pity you don’t have better starting material.
    In the mean time, if we are to have any chance of developing better models of human nature, we’ll have to build enough consensus to survive climate change, and for that, we’ll have to work with humans as they are now in their current environment.

  8. 158
    Tommykey says:

    I apologize if someone already addressed above, as I did not read all of the comments. When I was 8 years old during the winter of 77/78, we had the worst winter that I remember here on Long Island. The trees and wires were encased in ice. We were without power for several days and had to heat our food with sterno cans. I think in that context, the media seized on predictions by a few scientists about a new ice age being upon us. I even have recollections of my mom saying “They say we are going into a new Ice Age.” If people believed such predictions back then, it was probably because the awful winter we had then made the idea seem plausible.

  9. 159
    Nick Gotts says:

    Re #157 [Ray Ladbury] Ray, I’d like to continue our discussion, but perhaps we should take it offline. Is it OK to reply to your NASA email address? I’ll just note here a couple of points where I think you misunderstand my position, quite possibly because I haven’t expressed it clearly.

    1) I haven’t attempted, in this exchange, to give grounds for optimism, although some of the references I’ve given in earlier ones show, for example, how altruism can be selected for; and empirically, that the neoclassical picture of Homo economicus is too pessimistic where motivation is concerned. However, my main point is that we have a great deal to learn about human potential, of human individuals but above all of human societies; and in certain branches of social and cognitive science, we have made real progress, and developed some useful investigative tools for making more. These results and tools were not available (or in Gandhi’s case, those available were not of interest) to the religious figures you mention; nor in great part to Marx, whose thinking was also badly distorted by the heritage of Hegelian idealism.
    2) I don’t “insist on using climate change as an occasion for remaking society–for social engineering on a grand scale?”. I think large-scale social change will turn out to be essential, but given the great difficulty of the task, I’d be happy to be proved wrong; and it would in any case have to be incremental.
    3) I don’t believe in “the perfectability of human nature”. I don’t even know what that would mean.

  10. 160
    Ray Ladbury says:

    Send email to my NASA address, and I’ll send you a more appropriate address to use–be sure to use the most current address (all NASA emails now must be of the form (That makes it )

    For what it’s worth, I don’t dispute that cogtnitive and even social sciences have made progress. And while it is not my day job, I do try (in vain, mostly) to keep up with what is going on. I have a few friends who are psychologists who help. The thing is that often the results of these studies tell us what was already evident in the lives of the shrewder among our leaders–people such as George Washington, Napoleon, Gandhi, Martin Luther King, etc. And yes, I’ve looked into some of the studies on selection for altruism. However, most of those studies I know of either take a very limited definition of altruism–reciprocal benefit, perhaps–or find that there is no benefit to the group (and may even be a detriment) of having more than a small percentage of true altruists. And indeed, this is consistent with my own expereince–I find the concept of true altruism (e.g. benefiting those outside the family or group) is quite alien to most people. And that is the point I am trying to make. It is certainly possible for many individuals to realize greater potential–in intelligence, benevolence, choose your potentiality. However, you are ultimately left with the fact that societies cannot ignore the left half of the bell curve–and I have difficulty understanding how you appeal to the average watcher of professional wrestling at a level loftier than bread and circuses. If this group insists on Hummers to compensate for their perceived, um, shortcomings, GM will make Hummers unless we regulate what they can drive or GM can make. If we insist on regulation, there will be a backlash, and that will have consequences in our ability to do what is needed in a democratic society.
    The problem with climate change is that is precisely the sort of problem where people underestimate risks–as with cigarette smoking. They will be susceptible to messages that reinforce what they want to believe and what their intuition tells them. And we already know that there will be no shortage of folks whose solution to coastal flooding will be simply to buy up all the high ground.

  11. 161
    Ron Taylor says:

    Ray said: “The problem with climate change is that [it] is precisely the sort of problem where people underestimate risks–as with cigarette smoking. They will be susceptible to messages that reinforce what they want to believe and what their intuition tells them.”

    Well said. Add to that the reality that any meaningful assignment of cost to carbon emissions will IMO impact the standard of living of Americans (which has been enabled by cheap energy and growing debt), and you have a perfect recipe for political paralysis. Where is the political will to come from? Americans have to be convinced to voluntarily agree to a lowering of their standard of living, that is, permit their government to take effective action. Maybe it will take something like the abrupt collapse of a section of the Greenland ice sheet to jolt people out of their self deception. Otherwise, we better hope for the election of a truly remarkable leader.

  12. 162
    Matt says:

    Lotta comments on this subject!

    My issue is that the Arctic is working at over capacity to perform seasonal cooling, and the ice is growing and shrinking over a wider range than would be moral a hundred years ago.

    If we stop Greenhouse gases right now, this extreme oscillation would have a finite chance of catching in the icy condition with albedo effects causing solar reflection and the start of an ice age? Am I right here?

    If we include biosphere effects, then the main biospheric agents, us, would slow down economic activity and provide feed back, further pushing us into a glacial age.

  13. 163
    Nick Gotts says:

    Re #162 [Matt] “If we stop Greenhouse gases right now, this extreme oscillation would have a finite chance of catching in the icy condition with albedo effects causing solar reflection and the start of an ice age? Am I right here?”

    I’m no expert, but I’m fairly confident in saying no, you’re not. In any case, I wouldn’t worry about it. Short of a nuclear war or an unprecedented pandemic, the chances of us stopping greenhouse gases “right now” are, to a very close approximation, 0.

  14. 164
    David B. Benson says:

    Matt (162) — The swings between massive ice conditions (stades) and very little ice (interglacials) is controlled by the amount of sunlight recieved in the far north. This varies with changes in the earth’s orbit around the sun. These orbital forcings can be accurately computed for millions of years into the past and into the future.

    The next attempt at a stade is not for 20,000 years. This forcing is rather weak, so not much ice might form. The next, 50,000 years from now, seems likely to result in a stade, baring massive release of carbon into the active carbon cycle by burning fossil fuels, etc.

  15. 165
    Jim Eager says:

    Re Matt @ 162: “the ice is growing and shrinking over a wider range than would be moral a hundred years ago.”

    Moral???? Did you mean normal?

    “If we stop Greenhouse gases right now, this extreme oscillation would have a finite chance of catching in the icy condition with albedo effects causing solar reflection and the start of an ice age? Am I right here?”


  16. 166
    erikG says:

    Ray says:

    It is also clear that the current understanding of climate is not sufficient to map out all the unintended consequences of proposed geo-engineering schemes (other than reducing ghgs).

    Ray, I agree with your first point. But why do you feel so confident that we can map out all the consequences of reducing ghgs?

  17. 167
    Ray Ladbury says:

    ErikG, re: 166, First, greenhouse gasses are among the forcings for which we have the most certainty. Second, while there is some limited evidence that positie feedbacks are starting to kick in, we are still close enough to the state of climate that has persisted over ~10000 years that there’s hope we could again approach it. In reality, I hold out little hope that we’ll actually stop or even significantly decrease ghg emissions in the foreseeable future. What I am hoping (perhaps vainly) for is that we will slow things down enough that technological, agricultural, social and economic progress can keep up with the changes. The realistic goal is not stability, but keeping positive feedbacks low enough that adaptation is possible, if just barely.

  18. 168
    David B. Benson says:

    erikG (166) asks But why do you feel so confident that we can map out all the consequences of reducing ghgs? We have a good understanding of the major factors in the paleoclimate for the last 800,000 years and an excellant understanding of the role of global warming (so-called greenhouse) gases. So while we cannot predict all the consequences of reducing global warming gases, we can confidently predict the major ones.

    I am more optimistic than Ray Ladbury about eliminating net anthropogenic additions to the active carbon cycle, indeed going net carbon-negative, putting some back into the ground for the long term.

  19. 169
    Nigel Williams says:

    Can someone whack this mole for me? I see lots of ‘events’ that suggest GW is coming along very nicely, but what is the consensus on the meaning of the main global temperature data sources over the last couple of decades?

    Temperature Anomaly Compared to Hansen A, B, C: GISS Seems to Overpredict Warming.
    Jan 13 2008

    Main Observation:
    When comparing Scenario projections A, B & C, to land-ocean type data, it appear Hansen et al. 1988 over-predicted the real world warming that occurred in years following publication of his paper.

    Personally I don’t think the graphs matter much – the planet doesn’t give a toss about the historic records and is happily melting glacier ice at 1.5m per year,

    and is spending the northern winter merrily disposing of the perennial ice in the artic well in advance of the summer melt season

    and hey the droughts are still drying

    and the reservoirs are still lowering,

    so there is enough going on for those with eyes to see, but I keep getting charts flapped in my face and its good to have some sensible rebuttal to hand.


  20. 170
    Jon Sumby says:

    I don’t know if anyone from realclimate reads the comments but just in case, here are some quotes from an Aussie conference held in 1975 that may be of interest or use. They came from a conference proceedings book that I found in a secondhand shop. J

    Excerpts from a panel discussion at a climate change conference sponsored by the Australian Academy of Science and held at Monash University, December 1975. The opening comments were by Prof. H. Flohn (Meteorological Institute, Bonn University). Note the comments about rapid ice loss in the Arctic, on the order of ten years (this was in 1975!), and the need to make ‘critical choices’ about energy (carbon) use and warming for 2025 and later.

    Prof Flohn: ‘It is a question of how much man contributes to the state of the climate we have. If one deals from the matter from the viewpoint of energetics one comes to the result that the sum of man-made interference with this system is of the order of 10% of the energy which is converted in the climatic fluctuations we have experienced in the last 100 or 200 years. The strange fact is that the sum of these man-made effects (perhaps this is a controversial matter) should tend, generally speaking, to warming the atmosphere, while natural effects result in both warming and cooling, giving rise to non-periodic fluctuations.

    Now if we allow man’s interference with climate to increase exponentially as it has done in recent years, we sooner or later come to a state where this 10% rises to 100%, resulting in continuous warming made by man superimposed on these natural fluctuations of cooling and warming. This would be a really dangerous situation in that the Northern Hemisphere we have this extremely sensitive area of the Arctic sea-ice. The few people who have dealt with these models of the sea-ice have the feeling that this is in fact an extremely sensitive system, which will reflect very early and very substantially any sizeable warming of the Northern Hemisphere. The lifetime of individual ice floes is five or ten years, certainly not more than ten years, and once the ice is removed the present situation would not allow the reforming of permanent ice cover as we have it today.

    My feeling is that if man’s interference with the climatic system is uncontrolled for some decades, together with the uncontrolled growth of energy use, sooner or later during the next century the warming will overwhelm the natural factors which usually produce cooling. Then the Arctic sea-ice would disappear rather rapidly, some models say in a period of ten years or less. This would cause the meridional temperature gradients between pole and equator to diminish greatly, to be necessarily followed by a shift of the climatic zones of the whole Northern Hemisphere and perhaps extending a bit beyond the equator.

    This is not an immediate danger, since certainly in the next few decades we cannot reach this level and man’s interference is more or less on a local or regional scale, rather than a global scale. But what will happen in 50 or 80 years [2025-2055] is uncertain and depends on the intensity of economic development, and on the options of energy production and energy use. In the future we will have to make critical choices.’

    The panel discussion ended with a comment from Prof. R. A. Bryson (Institute of Environmental Studies, University of Wisconsin).

    Prof. R. A. Bryson: ‘We have heard forecasts in this meeting of what carbon dioxide will do, very confident forecasts that it will go up, and so I have used that kind of forecast in my model. We have no reason to believe that the population of the Earth in the next few years is going to change its ways, or that the population of the Earth will change its course … On this basis I can predict that the general climate for the next five years will be similar to the last five years. That is a very gloomy forecast, because at the beginning of the last five years, there were 400 million less people than now. At the end of the next five years there will be 400 million more. If we have the next five years like the last five, another 1972, another 1974, and assume nothing about going up or down, but just staying put, that’s a gloomy forecast.’

  21. 171
    David B. Benson says:

    Nigel Williams (169) — When I was in high school, I read a little book entitled How to Lie with Statistics. I think it is still in print 50 years later.

    Your first main link appears to be a non-professional regarding statistics. Go read what Tamino does on his Open Mind blog, linked under the Other Opinions section of the sidebar.

  22. 172
    David B. Benson says:

    Nigel Williams (169) — Or just follow this link:

  23. 173
    Nigel Williams says:

    Thanks for the mole-whacker David!
    Following on with Jon’s post, its interesting to see what the world’s population has done since then. Jolly hockey sticks!

    As Bryson said we do seem to be ticking along at plus 400 million every 5 years. But then we knew that. What has eventuated, of course, is that many of that 400M are now aspiring to enter the fossil-fuelled red-meat-eating economy with their rocketing standard of living while we in the ‘west’ stagnate – satiated; exhausted and virtually unable to consume any more if we tried. So we stand by like a Mr Creosote and watch the children-countries run lemming-like to their doom, dragging us with them! Somebody out there has to be laughing, eh!

  24. 174
    Alexander Harvey says:

    Regarding the Miskolczi paper:

    I have had a little look on the web and I cannot find much in the way of a rebuttle for this paper.

    I find this a little surprising. At best it is a work of genius that is poorly explained. There do appear to be some “unexplained” gaps in the reasoning. That does not mean that they are specifically untrue but somehow I doubt that the reasoning is generally true.

    Firstly the appeal to Kirchhoff Eq(4): As far as I am aware the explicable result is that the return flux would lie between half and all of the absorbed flux in general. The result that they are equal may be specifically true but I could not see this being justified.

    More significantly the appeal to Hydrostatic equilibrium Eq (7): actually this it seems is largely an appeal to the conservation of energy. Eq (7) is, I feel not adequately justified as I cannot find any justification in the text.

    Without some adequate justification of this equation a good deal of what follows is unsupported.

    Finally the Virial Theorem: I have no problem with the theorem but the identification of the surface flux with either the surface atmospheric pressure or the gravitational potential of the atmosphere is not obvious. To begin with a flux is not easily identified with a reserve of energy without stating a relevant time constant and also the atmosphere was not the last time I looked supported by radiation pressure.

    Similarly the identification of Eu, the proportion of OLR, sourced in the atmosphere with the kinetic energy of the atmosphere may be specifically true but it is hard to see that it could be generally true. Such things may be the case but the identification of a surface or at least an effective surface effect, (radiation flux), with a mass property, (total kinetic energy) would require a lot of explanation in the general case. Once again it might be specifically true on this earth at this time but that surely is not good enough.

    Best Wishes

    Alexander Harvey

  25. 175

    A 2006 JPL paper reported unexpected ocean cooling 2003-2005, now put down to instrument error. That took a while to get all over the blogosphere and has found its way into the letters page of The Australian. Minus the correction, of course.

    I submitted a correction but wasn’t published.

    I do sincerely hope the ocean is warming; if not, the observed sea level rise would have to be almost entirely from glacier and ice cap reduction going much faster than predicted.

    The “skeptic” case would be stronger if it wasn’t based on disinformation; this is why I prefer to call it “denial”.

  26. 176
    gzuckier says:

    Time magazine had an article on global cooling in 1974 which had some impact; still available at,9171,944914,00.html
    Note that the two authorities cited are Reid A. Bryson and Donald Oilman, both of whom are currently opponents of AGW theory. (Also quoted is Kenneth Hare, saying that if the current drought continues people will go hungry, with no reference to cooling.
    In fact, at the time Hare said re cooling: “The slow cooling trend in parts of the northern hemisphere during the last few decades is similar to others of natural origin in the past, and thus whether it will continue or not is unknown”.)

  27. 177
    Adam says:

    Recently it appears that more ARGO data has been tossed about. If I’m correct the data suggests that there might be a trend of “slight cooling”. Any thoughts? This from NPR:

    “There has been a very slight cooling, but not anything really significant,” Willis says. So the buildup of heat on Earth may be on a brief hiatus. “Global warming doesn’t mean every year will be warmer than the last. And it may be that we are in a period of less rapid warming.”

    In recent years, heat has actually been flowing out of the ocean and into the air. This is a feature of the weather phenomenon known as El Nino. So it is indeed possible the air has warmed but the ocean has not. But it’s also possible that something more mysterious is going on.”

  28. 178
    Jim Bullis says:

    I have a question for those knowledgeable on the climate models. It relates more to the capacity of the ocean to moderate changes using its deep reservoir of cold water. Maybe it is a longer term effect that would be hard to see in ARGO data??

    It is well known that temperature in the ocean is about 4 to 6 degrees C at depths below about 500 meters. It typically cools rapidly as depth goes from about 70 meters to 500 meters.

    As storms increase, as for example Katrina, we know that significant deep currents occur (we known that oil and gas pipelines were wrecked in some places). Such storms must have a significant mixing effect in general. Since something like 70% of the worlds oceans are greater than 3000 meters deep, it seems that the predicted increase in storm activity with global warming might make this a significant counter action to global surface heating. I do not see anything about this kind of process in the IPCC4 report. Is this in the climate models?

    The process does not hinge on catastrophic events such as Katrina. We know from underwater sound studies that the “mixed layer” is quite variable for much less intensive storm effects, so this process would be active on a very general basis.

    Could this be a process where temperature and storm activity eventually reach an equilibrium state? In the process I am trying to describe, global warming would cause an increase in ocean surface temperature which would cause an increase in storm activity. This storm activity would mix ocean waters whereby cooler deep water would be brought upward to cool the ocean surface. The cooler ocean surface would then cause reduced storm activity. In this way, the deep ocean would take the brunt of global warming effects. Does it not have quite a lot of capacity to do that?

    To take this one step further, the deep ocean temperatures would gradually increase so that it would take more storm activity to get cool water up in each successive year. One would have to study this to see this on a quantitative basis, but intuitively, it seems this would end up as a moderating effect.

    Has this been already included in the models?

  29. 179
  30. 180
    Bill says:

    Science magazine (Dec. 10, 1976) warned of “extensive Northern Hemisphere glaciation.” Science Digest (February 1973) reported that “the world’s climatologists are agreed” that we must “prepare for the next ice age.” The Christian Science Monitor (“Warning: Earth’s Climate is Changing Faster Than Even Experts Expect,” Aug. 27, 1974) reported that glaciers “have begun to advance,” “growing seasons in England and Scandinavia are getting shorter” and “the North Atlantic is cooling down about as fast as an ocean can cool.” Newsweek agreed (“The Cooling World,” April 28, 1975) that meteorologists “are almost unanimous” that catastrophic famines might result from the global cooling that the New York Times (Sept. 14, 1975) said “may mark the return to another ice age.” The Times (May 21, 1975) also said “a major cooling of the climate is widely considered inevitable” now that it is “well established” that the Northern Hemisphere’s climate “has been getting cooler since about 1950.”

  31. 181
    Nick Gotts says:

    Re #180 [Bill]
    Bill, if that was an attempt at an April Fool, the joke’s on you (a) because you’re supposed to play such tricks before noon and (b) because denialists pump out this sort of bilge every day of the year. Assuming it wasn’t, the joke’s still on you for being a nincompoop – that is, assuming you’re not just an ordinary, common-or-garden liar. Of the articles you site, exactly one, the first, is in a peer-reviewed journal. The rest are in popular magazines or newspapers. In assessing the state of scientific opinion at a particular time, THESE DO NOT COUNT – they are written by journalists looking to sell the next issue, not by scientists. For the Science article, the correct citation is: Hays, Imbrie and Shackleton (1974) “Variations in the Earth’s Orbit: Pacemaker of the Ice Ages”. Science 174 (4270):1121-1132. If you look carefully, there’s a hint in the title as to what the paper is about: the influence of variations in the Earth’s orbit on the occurrence of ice ages. The final words of the paper are:
    “A model of future climate based on the observed orbital-climate relationships, but ignoring anthropogenic effects, predicts that the long-term trend over the next several thousand years is toward extensive Northern Hemisphere glaciation.”
    Take it slowly Bill, a few words at a time. What does “ignoring anthropogenic effects” mean? It means they are taking no account of anything people might do – like releasing greenhouse gases into the atmosphere for example. What does “long-term trend over the next several thousand years mean”? It means this is not about what will happen in our lifetimes, or our great-great-grandchildrens’.

    If you are capable of reading (I insert this since you clearly have not read the Science paper), follow the link to Tom Peterson’s paper online. If you have well-founded criticisms of that, do please post them.

  32. 182
    Ray Ladbury says:

    Bill, Hmm, how many of your sources are peer-reviewed science journals? One, and I notice you provide no timescale. At the time, the question was whether aerosols might cause significant cooling. There was no consensus AMONG SCIENTISTS on that.

  33. 183
    spilgard says:

    Re #180:

    Thanks for reinforcing the first sentence of Section 7 in the study cited in the main body:

    7. Media Coverage

    When the myth of the 1970s global cooling scare arises in contemporary discussion over climate change, it is most often in the form of citations, not to the scientific literature, but to news media coverage.

  34. 184
    Jim Bullis says:

    re 179 and my question 178

    Thanks for your response.

    The exerpts and the cite seem to relate to a different mechanism than I was attempting to describe. The cited article indicates a reason why ice is melting in Antarctica, yet the whole effect is to cool the ocean surface. This is said to have been brought about by stronger winds over the last 40 years. This process is consistent with global warming statements that winds will be stronger due to a hotter atmosphere. But since the ocean surface is made cooler, will not that actually act to cool the atmosphere.

    The process I describe is only slightly similar to this, but not as complex. I refer to an old book, Physics of Sound in the Sea, Summary Technical Report, National Defense Research Council, 1946 p88, where is shown a typical temperature-depth curve. From this I can quickly estimate that if the mixed layer, which now goes down 70 meters, were further mixed down to 140 meters, the entire new mixed layer would be cooled by 1 degree C. We know from experience in underwater sound studies that wind has a strong effect on mixing to such depths. Using a Wikipedia supplied calculation, the top 25 meters of the new cooler layer would take on enough energy by warming 1 degree C, to the previous equilibrium temperature, to cool the entire atmosphere by 10 degree C. And then, the wind would be no longer so strong. Thus it seems that there is a control system type mechanism of sufficient strength to have a meaningful part in regulating the atmospheric temperature. On a general world basis, the warmer water in the deeper ocean could eventually impact ice formation.

    As I mentioned before, the kind of mixing caused by a storm like Katrina, would be very strong. In relation to the gulf stream, this would have a far reaching impact all over the North Atlantic. And it might explain why a very active hurricane season would be followed by a fairly quiet season.

    I gather from your response that the effects I describe are not in the major climate models. Is that right?

  35. 185
    Jim Bullis says:

    RE 184

    I have looked at the CCSM POP (Parallel Ocean Model) in very superficial detail, but it seems that there is not provision for computing vertical mixing in the ocean on a regional level that would relate to real storm activity. There are variable fields provided in the program that enable calculations regarding mixed layer depth, and vertical temperature.

    I tend to conclude that broad and general winds are included from the statement, ” Wind stress (ws) and atmospheric pressure (ap) forcing don’t depend explicitly on the ocean state so the forcing terms in the equations are updated depending on the value of {ws,ap}_interp_freq. For example, with ws_data_type = ‘monthly-calendar’, ws_interp_type = ‘linear’, and ws_interp_freq = 24., the code will linearly interpolate monthly wind stress values at the beginning of each day and will use this interpolated value for one model day. ” This is from .

    However, the fact that only long term average winds would be here accounted for seems to preclude effects of transient winds, though huge as in hurricanes. They seem to address the type of processes referred to by Hank Roberts, comment 179 above.

    I would appreciate any possible guidance in looking at this question. I also note that it must be quite a burden to keep up with questions, and am truly impressed with the efforts made by this community.

  36. 186
    Jim Eager says:

    I just noticed today that Hadley Center has posted this disclaimer at the top of their HadCRUT3 and other temperature data pages:

    “We have recently corrected an error in the way that the smoothed time series of data were calculated. Data for 2008 were being used in the smoothing process as if they represented an accurate esimate of the year as a whole. This is not the case and owing to the unusually cool global average temperature in January 2008, the error made it look as though smoothed global average temperatures had dropped markedly in recent years, which is misleading.”

    Of course we here already knew this, but the all to obvious error didn’t stop the skeptic and denial crowd from seizing upon the bogus marked drop and proclaiming their ignorance to the world.

  37. 187
    Rando says:

    My recollection of the state of ‘climatology’ in the 70′s was that the science itself was fairly immature to the point where there was still debate on whether climatology should even be described as an ‘applied’ science. In those days the field was really just evolving. Therefore, I’m not surprised at the lack of peer reviewed scientific literature on climate issues from that period – especially publications on climate-change mechanisms. The so-called experts at that time were few and scattered through-out various diciplines, and the subject still largely shrouded in speculation, rudimentary hypotheses, and tentative correlations. It’s no surprise that most references to 70′s cooling and impending ice-ages are found mostly in media publications of the time – this was good human interest stuff which sold magazines and newspapers. We believed at the time (and still do) that significant climate change had occurred in past, and that there were a number of potential ‘natural’ causes that could be identified as forcing agents, although these were poorly understood. Our knowledge gap has now narrowed to the point where the legitimate scientific community can now determine that human influences are affecting significant changes to global climate which are unprecedented in terms of intensity and time-of-onset. And we can do this with ~90% certainty.

    We’ve come a long way, baby!

  38. 188
    Ray Ladbury says:

    Rando, I dispute your characterization of climate science in the ’70s as “immature”. Indeed, all the forcers we now find in climate models were known, albeit their relative magnitudes were still in dispute. And people even got the cause of the cooling pretty much right–sulfate aerosols. The science itself is over 150 years old. The fact that there are still uncertainties in no way detracts from the maturity of the science, nor from the certainty of what we in fact do know.

  39. 189
    Jim Bullis says:

    Where can I ask a question without getting buried in a bunch of references on what was said in the 1970′s and assertions of authority or arguments about when stuff was known?

    Beginning with reference 178, there was a question followed by a partial answer 179 and an attempt at further clarification 184,185. This might have been an interesting technical topic, at least I think so, but this seems to have been lost in the useless acrimony.

    These discussions are not idle chatter for me. I am trying to understand enough of climate science that I can make sense of it in business planning.

    Notwithstanding the above, I want to be clear that I appreciate the public service provided on this information site. I also am sensitive to the frustration that must come from offering a public service in the face of irrational objections to your information. I hope that I am not on the irrational side, by your perception or in fact.

  40. 190
    Ray Ladbury says:

    Jim Bullis,
    Although hurricanes are large and impressive, they and other impulsive events probably have less effect than the more steady forcers. One can treat them as Poisson events, and in general the effect of such events can be replaced with its average. It is like volcanos. We don’t know when they’ll happen or how big they’ll be, but we do know on average what their contribution is over the long haul.
    It is quite possible that you might see a significant effect over a short period, but that is the distinction between climate and weather. I don’t know if this helps you or not, but it is one way of dealing with such discrete, large events.

  41. 191
    Jim Bullis says:

    190 Ray Ladbury,


    I am reacting to statements saying that a result of global warming would be an increase in general storm activity. I used hurricanes as a particularly strong illustration where vertical mixing would be very significant. But we know from underwater sound research that a degree of vertical mixing occurs for much more moderate storm activity. Thus there would seem to be a feedback mechanism where such vertical mixing would serve to tap into the deep ocean reservoir of cold water. I am thinking of this as a more or less local process where wind causes waves that are directly capable of causing mixing.

    I think I understand in general how this could be handled on a probabilistic basis to allow for varying winds. However, I can not tell for certain from the description of the “Parallel Ocean Program” (POP) that goes with the CCSM program that this is currently part of this climate model.

    I asked my questions hoping someone would point me to the right place to look in the model description. Or perhaps it is done by some other modeling group.

  42. 192
    Carolus Obscurus says:

    And guess what’s the breaking news in today’s Daily Mail?

    Over the past half-century, we have become used to planetary scares. In the late Sixties, we were told of a population explosion that would lead to global starvation. Then, a little later, we were warned the world was running out of natural resources. By the Seventies, when global temperatures began to dip, many eminent scientists warned us that we faced a new Ice Age.

    – from an essay entitled ‘The Real Inconvenient Truth’ by former UK Chancellor Nigel Lawson, author of the upcoming book ‘An Appeal To Reason: A Cool Look At Global Warming’

    The article is worth taking apart, sentence by sentence — does anybody feel like going to the trouble?

    See here:

  43. 193
    John Quiggin says:

    Way above here “Would they also use “Back in the 1950s, scientists didn’t believe in plate tectonics” as a criticism of modern geological science?”

    Absolutely they would and routinely do.

  44. 194
    Rando says:

    Re: Jim Bullis
    Not that the topic of SST impact on storm charactistics and resulting feedbacks isn’t interesting, I believe the original post was in response to observed (percieved?) cooling in the 1970′s that gets referenced by some as evidence of dominant non-anthropogenic (or at least poorly understood) climate influences.

  45. 195
    Thomas Siefferman says:

    Post 144 still has not received an adequate response. The onset of Solar Cycle 24 has arrived with a whimper, the solar ‘conveyor belt’ has slowed to a crawl, the continuing few spots have been from Solar Cycle 23 making it one of the longest solar cycles in recorded history. The resumption of ‘normal solar flare activity’ has twice failed to meet the ‘Consensus Panel’s forecast’ (I guess the sun just didn’t read the report) and the latest prediction has become the most open ended ‘CYA’ prediction in the history of Solar Cycle predictions (maybe July but it could be the first quarter of 2009).

    Us Global cooling ‘moles’ need two answers:
    [1] If we enter a Dalton Minimum at best (look up the years around 1815) or a Maunder minimum at worst (look up Little Ice-Age), how will the current ‘CO2′ levels help the USA and Canada feed the world as we currently do? Please show me the Climate model that is currently in existence that can retro-forecast the temps seen in those periods.

    [2] If we did every thing to shut down our current economies and stop all production of CO2 and it doesn’t help, and we enter a solar induced global cooling, where will you gather all your AGW theory papers so we can burn them for heat? ;-)

  46. 196
    alan packham says:

    Wow, so many ineresting and informative articles. As a non scientific mortal who is striving to understand what is going on with climate change, I am more and more drawn to the theory that global warming/cooling has occured and re-occured for millions of years. I am sure however that our activities are hastening the process substantially and that it is essential that we take any action that we can take to mitigate this. Surel this must be worthwhile.

  47. 197
    Ray Ladbury says:

    Thomas Siefferman [195]: Regarding your points–they have been dealt with previously
    [1] First, the current solar cycle is not yet outside of the normal range–the standard deviation on solar min is +/-1 years–we’re still within the 90% CL. Also, keep timescales in mind. Minima in solar activity (ala the Maunder Minimum) last of order decades. The effects of CO2 last on the order of centuries to millennia. That means that when solar activity again rises, greenhouse warming will kick in with a vengeance. As to whether CO2 will help during the minimum–keep in mind that the limiting factor is usually not “heat” but “light”.
    [2]I see no need to reply to your straw man. No one is talking abour “stopping economies”. Rather we are talking about devoting substantial effort to making economies more efficient and sustainable. Should you care to discuss reality rather than straw men, I’d be happy to comment.

  48. 198
    T Siefferman says:

    195 [2] Was meant as a joke not a ‘Straw Man’, notice the winking smiley. To Point. Where has solar minimum been discussed?
    Little Ice Age was on the Order of 200 years (1650 -1850) with minor warming in between; Medieval Warm Period [MWP] was 500 years (800-1300) showed a temperature anomaly of 0.2C and Greenland was pretty much ice free in the southern extremes.
    If the 2004 data is true with a 0.4C temperature anomaly, then why aren’t we more ice free than during the MWP?
    What was the causation of the MWP?
    Can ANY of the current models being promulgated today retro-forecast the past weather extremes?
    Before we shut done CO2 production, hobble our economy based on theories presented here, show us the proof of your models. Otherwise this is just a bunch of banter without substance.
    If you want to convince the world of AGW then prove it by showing that your models match with the past.
    Otherwise avoid looking like fools and reject the fallacy of ‘consensus’ science and re-evaluate your theories as the world will not believe you.
    Based on CO2 alone your theories fail. They are too narrow a focus, lack explanations for the past data, fail to account for feedback and effects of other aspects of climate such as Solar Cycle, Cosmic Radiation and cloud formation, increased sequestration of CO2 by oceans in warmer climes, volcanic variations, etc.
    Plus they are based on invalid temperature recordings, they fail to account for heat island effects on temperature recordings when compared to the past recordings where there was virtually no heat island effects. The only way to “get rid” of global cooling moles is to account for the past better than you currently are.

  49. 199
    Ron Taylor says:

    Re 198. T. Siefferman, you get the prize. That has to be about the most complete collection of utter nonsense I have read on these pages. If you made even a modest effort to understand the information available to you on this site, you would know that. As for the “fallacy of consensus science,” that just happens to be the way science is done.

  50. 200
    T Siefferman says:

    #199 If you disagree with #198 state your disagreements, not a global slap of ignorance.
    There is no place for consensus of ‘opinions’ of scientists, there is however a place for agreement that the theory presented has validity and adequately predicts the past and has a high probability thereby of predicting the future.
    All the dates of climate variations listed above are agreed upon. Temperature monitoring stations have become surrounded by buildings and recordings of temperatures become suspect.
    No theory presented to date can account for the climatic variations listed (Little Ice Age nor Medieval Warm Period).
    All theories to date fail to include agreed upon factors that we know even today that affects day to day weather.
    AGW demands that we reduce CO2 production and prefer we stop without a sound theory that will have on climate but there is a known effect on civilization.
    Rethink you response and please respond with more civility.

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