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The “hockey stick” slaps back

by Donald Prothero, Apr 17 2013
The rapid disappearance of the Arctic sea ice, with an averaged curve (black line) fitted to the annual cyclic variation of seasonal ice (noisy blue curve).

The rapid disappearance of the Arctic sea ice, with an averaged curve (black line) fitted to the annual cyclic variation of seasonal ice (fluctuating blue curve).

The year 2012 and now early 2013 have been an unending litany of bad climate news. After a record-breaking year of heat and drought in North America, and with devastating Superstorm Sandy, and record heat and fires in Australia, the year 2012 ended up being the ninth hottest year on record despite a strong La Niña cycle that should have made it a lot cooler. Once the current La Niña cycle ends, you can expect the next few years to blast past the previous global temperature record of 2010. As it is, nine of the ten hottest years on record were in the last decade—only the record-breaking El Niño  year of 1998 didn’t occur in the window between 2002 and 2012.

Even more alarming were the weekly reports about the incredibly fast loss of our global ice volume, from mountain glaciers to the Greenland and Antarctic continental ice sheets. Most serious of all, however, is the record melting of the Arctic ice. Last summer, the Arctic ice cap shrank to the lowest level ever measured, and even the winter ice pack was the fifth smallest ever measured. And the news just came in that the melting rate of the Antarctic ice cap is the highest ever recorded. If anything will cause the rapid rise of sea level, it will be the melting of these ice sheets. Then we’ll see not only low-lying countries disappear, but more storms like Superstorm Sandy, whose storm surge will reach much further inland with a higher sea level base.

Deniers pointed to the heavy snowstorms that hit North America in late winter and even the spring of 2013, and foolishly made jokes about global warming as they stood in the snow. Once again, they are confusing weather (the rapidly fluctuating changes in temperature and precipitation on a daily or weekly time scale) with climate (the long-term average of weather over years to decades or longer). Ironically, the late-winter blizzards are actually a prediction of the climate models: late winter storms are due to the increasing moisture that builds up in the atmosphere in a warming planet, especially because the Arctic is warming up, adding moisture to the system, and affecting climate in new ways. As Greg Laden explains, the new air currents triggered by the ice-free Arctic Ocean are like a hole between the freezer on top and the refrigerator below. The cold leaks downward more often, forming late snowstorms in North America, while the freezer itself (the Arctic) doesn’t get as cold as it’s supposed to.

Over and over again, we hear the climate deniers making the claim that the warming is “just part of a natural cycle”, and can’t be blamed on humans or our huge output of greenhouse gases. The best way to debunk that argument is to look at past climate records to see if the present-day warming is within normal variability. The most important recent study to examine the problem was the famous “hockey stick” paper of Dr. Michael Mann and his colleagues. First published in 1998, and frequently revised, it has been the focus of climate deniers trying to discount its serious implications. They have attacked not only the paper itself, but grandstanding right-wing demagogues like Virginia’s Attorney General Cuccinelli have tried to prosecute Mann in a great witch hunt (since dismissed in court as frivolous—and Mann is now at Penn State, so Cuccinelli can’t reach him). Mann has received numerous death threats for being a Cassandra bearing bad news (as he describes in his scary and unsettling book The Hockey Stick and the Climate Wars).

The Mann et al. (1998) "hockey stick" graph, showing the relatively steady climate of the past 1000 years, and the anomalously fast rise of temperatures in the last 150 years.

The Mann et al. (1998) “hockey stick” graph, showing the relatively steady climate of the past 1000 years, and the anomalously fast rise of temperatures in the last 150 years.

The chief legitimate scientific criticism about the original “hockey stick” paper (so-called because it shows climate as nearly a straight trend through the past 1000 years, culminating in a sharp bend upward in the past 200 years,  like the blade of a hockey stick) was that Mann and colleagues generated a composite curve of actual observed global temperatures (the last 150 years or so), with older records from tree rings, ice cores, and a few other data sources. Since all these recorders measure global temperature differently, it is always a challenge to calibrate them properly so they yield a single consistent climate curve. However, NONE of these attacks on the data of Mann et al. (1998) contradict the fact that the sharp rise in temperatures in the past 200 years is real, or that it is much more rapid than any climate change we could detect from these data sources over the previous 1000 years.

The new Marcott et al. (2013) expands the record way past the original data (shown on right), and clearly demonstrates that the past 150 years are NOT within normal variability during the entire past 11,300 years.

The new Marcott et al. (2013) expands the record way past the original data (shown on right), and clearly demonstrates that the past 150 years are NOT within normal variability during the entire past 11,300 years.

But all those criticisms of Mann et al. (1998) are now moot. A new study by Shaun Marcott, Jeremy Shakun, Peter Clark and Alan Mix of Oregon State University and Harvard (Alan was a classmate of mine when I studied paleoclimate at Lamont-Doherty Geological Observatory) has circumvented most of the objections to the original “hockey stick”. This study goes back 11,300 years with +/- 300 year resolution (the highest ever), through the entire Holocene interglacial, expanding the record much earlier than the 1000- to 2000-year records of older studies. Most of this older record comes from the isotopes of plankton in deep-sea cores, one of the oldest and best established methods of paleoclimatic temperature estimates. Most importantly, it comes primarily from this data source, and so is not hampered by the criticisms of compiling widely different data sources, the problem that plagued the original “hockey stick” curves. What it clearly demonstrates is that the warming of the past 150 years is not only hotter than at any time in the past 11,000 years, but it is MUCH faster as well, and NOT proceeding at the typical rates of global cooling and warming in the past when humans were not filling the atmosphere with greenhouse gases. If ever there was a smoking gun that we are responsible for global warming, this is it (along with many other lines of evidence that I have outlined in previous posts).

The Shakun et al. (2013) "wheelchair" graph, showing the climate trends of the past 20,000 years

The Shakun et al. (2012) “wheelchair” graph, showing the climate trends of the past 20,000 years

Still not satisfied? Then let’s expand it back to 20,000 years through the past glacial! The curve of the present Holocene interglacial of Marcott et al. (2012) can be added to data going back to the peak of the last glacial at 20,000 years ago to give a curve that is being nicknamed “The Wheelchair” (Shakun et al., 2012). Now we have 20,000 years of record to examine, the anomalously rapid heating of the past 150 years (the vertical line that forms the “back” of the “wheelchair”) really stands out as extreme and unnatural.

The EPICA-1 ice cores from Antarctica showed that at no time in the past 680,000 years has carbon dioxide been above 300 ppm--yet it is almost 400 ppm today.

The EPICA-1 ice cores from Antarctica showed that at no time in the past 680,000 years has carbon dioxide been above 300 ppm–yet it is almost 400 ppm today.

STILL not convinced? Then we will go even further back in time, to the EPICA-1 ice cores in Antarctica (Siegenthaler et al., 2005), which drilled back over 680,000 years into the past. This core recovered air samples from trapped gas bubbles that gives us an isotopic and carbon dioxide record through the past 6 or 7 glacial-interglacial cycles (each lasting about 110,000 years, and due to the Milankovitch orbital eccentricity cycle that has been well known for decades). As these records show, at no time during any of the previous interglacial cycles did the atmospheric carbon dioxide level exceed 300 ppm, even at the warmest part—yet our planet is well above 350 ppm today, and shooting rapidly to 400 ppm in a few years and possibly to 600 ppm before the end of the century. THAT is not natural “climate variability” by any stretch of the imagination!

The voices of climate denialism, fueled by funding from the energy industries whose mission is to confuse us with smokescreens of doubt, will keep attacking these data and trying to obscure what these plots tell us. For the longest time, it seemed that their PR was winning over scientific truth. But the last few polls seem to show the balance of public opinion changing the other way. A poll taken just after the 2012 election showed that 68% of Americans now regard climate change as a “serious problem,” up from only 48% in 2011, and 46% in 2009. A few weeks later, another poll found that 80% of Americans accept that climate is changing (compared to 73% in 2009), and 57% say the U.S. government should do something about it. And the most recent poll found that even a majority of GOP voters accept that climate change is real and that the government should do something about it (even if their leaders are still climate deniers)!

The times, they are a changin’ ….

133 Responses to “The “hockey stick” slaps back”

  1. Martin Lack says:

    Why not go back even further by looking at sea floor sediments too?
    As in, for example, Zachos et al. (2001), ‘Trends, Rhythms, and Aberrations in Global Climate 65 Ma to Present’, Science 292: 686-93.

  2. The Marcott et al. (2013) data set IS largely from sea-floor sediments and microfossils, as is the Zachos et al. (2001) data set. But going back the last 65 Ma is beyond the scope of this brief blog. I DID discuss it at length in my 2008 book “Greenhouse of the Dinosaurs” and also in my 2006 book “After the DInosaurs: The Age of Mammals”

    • Martin Lack says:

      Thanks Donald. I am sorry that I have only just noticed that this was a reply to me!

  3. Somite says:

    I would call this the seminal climate change denier debunking post. I am aware of the excellent work by skepticalscience but this condenses so many issues so very well.

    Of all the “isms”, denialism is prominent in the skeptical community and posts like these are very needed. Specially when prominent skeptics like Penn and Teller have been explicit denialists.

    • Nyar says:

      Skeptics are skeptical. Film at 11.

      • Marcel Kincaid says:

        The so-called “skeptics” of global warming *aren’t* skeptical; they will swallow any swill at all that matches their libertarian ideology.

      • Nyar says:

        They are skeptics whether you like it or not. Calling them deniers is just goebbelspeak.

        Also, what makes you think that the global warming skeptics are all libertarians?

      • Paul says:

        So they aren’t denying global warming? What’s your definition of “deny”?

      • markx says:

        Paul says: April 28, 2013 at 7:56 pm

        “..So they aren’t denying global warming? What’s your definition of “deny”?..”

        Paul, you can play games with word definitions all you like, it does not change the meaning of the word “skeptic”

        skep·ti·cal /ˈskeptikəl/Adjective
        Not easily convinced; having doubts or reservations

        “Denier” is a far less useful word, except perhaps as a derogatory label.

        Because opposing a CAGW alarmist argument are a broad spectrum of viewpoints, ranging from those who may think the world is absolutely precisely stable and has not changed and is not changing in temperature, to those who think the world is currently in a warming phase but this is completely natural, others who see the world has been warming for the last 120 years but think the anthropogenic component is minor, those who acknowledge recent warming and think the anthropogenic component is significant, but will be countered by natural feedback mechanisms, to those who believe it is likely that anthropogenic emissions may be a significant threat but not as immediately as the more alarmed may claim and that readily applicable solutions already exist….. etc.

        When it is used as bluntly as “a denier of science” then it truly is, as Nyar aptly stated above, goebbelspeak. Because science is all about observations, questions, experiments, and more questions.

      • Martin Lack says:

        Skepticism is a fundamental tenet of scientific enquiry. However, sadly, those who still question the reality of anthropogenic climate disruption are not skeptical: Far from being like Galileo or Darwin (challenging a consensus based on theological dogma), they are like Flat-Earthers of Young Earth Creationists (insisting they know best and that anyone who says otherwise has been duped by a devilish conspiracy).

        Oh, and, yes, they are mostly libertarians because, although theological dogma has been replaced by economic dogma, willful ignorance and ideological blindness are still a prerequisite for picking a fight with history and science.

  4. Max says:

    What the skeptics want to see is the proxy data showing the same trend as the more reliable instrument data. That would validate the proxy data. In other words, does the blue proxy curve in that hockey stick graph match the red instrumentation curve up to the year 2000?

    • Max says:

      I think stretching the proxy data FORWARD in time and showing that it matches thermometer readings would be more convincing than going further and further back in time. But that’s hard to do when the resolution for proxy data is 300 years.

      • Somite says:

        I bet part of the problem is that some of the proxy data comes from material from hundreds of years to form, the conditions for their formation don’t exist anymore or are contaminated by human influence. Dr. Prothero might correct me on this.

        But consider that the actual temperature does not matter that much. What we would need to detect is any variation that is as fast and pronounced as the current one and it just isn’t there. You’d have to go back much further in geologic time to find anything similar and the cause of it is understood and unrelated to the current rise in temperature.

    • Marcel Kincaid says:

      No, the only thing the so-called “skeptics” want to see is confirmation of their libertarian biases.

      • markx says:

        Rubbish … I’m about as far from a libertarian as you can get, and my skeptical alarm really started jangling when we were told the science is settled and the main evidence put forward was computer models and a ‘consensus’ head count.

        I remember one of my early biggest turning points was when I explained to my incredulous father they could actually measure incoming and outgoing radiation so they knew exactly what was happening, but then I went searching to prove my point and read Loeb etal 2009. (CERES ain’t quite so precise!)

        And recent repeated efforts to co-opt every single bit of extreme weather of any sort anywhere in the world as ‘evidence’ have not helped my skepticism one bit.

        (Definition: When I say I’m skeptical, I mean I don’t believe ‘they’ can be as certain of the mechanisms and outcomes as they state they are.)

        skep·ti·cal /ˈskeptikəl/Adjective
        Not easily convinced; having doubts or reservations

        And sorry, you can’t simply redefine and co-opt words to suit yourself.

      • tmac57 says:

        I guess that you have a ready explanation for this as well:

      • markx says:

        No, but perhaps you have a ready explanation for these:

        The Holocene Warming a (11,600-8,500bp)
        The Egyptian Cooling (8,500-8,000bp)
        The Holocene Warming b (8,000-5,600bp)
        The Akkadian Cooling (5,600-3,500AD)
        The Minoan Warming (3,500-3,200bp)
        The Bronze Age Cooling (3,200-2,500bp)
        The Roman Warming (500BC-535AD)
        The Dark Ages (535-900AD)
        The Medieval Warming (900AD-1300 AD)
        The Little Ice Age (1300AD-1850AD).

      • tmac57 says:

        How many of those periods changed state as rapidly as the current trend? Nobody seriously asserts that the Earth’s climate has never varied,but climate scientists seem to have a pretty good understanding of those past dynamics,and they have failed to come up with any scenario for the current trend that does not include human caused greenhouse gases as being the primary driver,and still,the range of likely climate sensitivity estimates centers around 3C degrees,despite what Nic Lewis thinks.

      • markx says:

        Tmac, I think you may find even the IPCC is reining in its sensitivity estimates, especially so with the deliberate leaking of the IPCC 5 draft by Alec Rawls, one of the ‘expert review panel’.

        See Figure 1.4 here

        and 11.1a here from Chapter 11 of the IPCC ar5 draft. Note the forecasts were done in 2007, the earlier simulations are retrofitted.

      • markx says:

        tmac57 says:
        April 24, 2013 at 2:52 pm

        How many of those periods changed state as rapidly as the current trend?

        Certainly this is a major point of debate prompted by the Marcott et al publication, and it would be nice to know.

        Tamino claims he has demonstrated that the methodology would detect a 200 year 0.9 C spike above the base proxy data…

        But … we are currently looking at 0.7 C of warming over 120 years, and the proxy data with its 300 year (average) resolution has been smoothed both statistically and naturally (laying down and mixing of layers).

        Let’s look at a 0.7 C rise peaking at 100 years, spread over 200 years, and presume 80% of it would be captured by the proxies – so therefore a physically recorded ‘spike’ of 0.56 C. And note such a ‘spike’ if present, should be centered on the average, not added above it.

        So, would a 100 year peak protruding 0.28 C above and below the proxy average be detectable?

        Clive best tests it here, but still as spikes above the average. Comments are worth a read.

      • Martin Lack says:

        Markx – If I will accept that you are not a libertarian, will you accept that I am not a communist? I only ask because, even though you may not be a libertarian, just about everyone of the very few experts (and many non experts) who validate your beliefs are libertarians and/or think all environmentalists are “Watermelons”.

        Furthermore, even though you may not rely upon conspiracy theory explanations to dismiss the opinions of the vast majority of genuine experts, that is exactly what those whom you choose to believe have done (and do).

        A great many have therefore been duped by the fallacy of the marketplace of ideas – and by an awful lot of money spent by the fossil fuel industry to copy the tactics of the tobacco industry before it – which has turned made people believe the science is not settled and that they are in a fight to preserve their liberty. You may well insist that you have not been so duped, but that does not change the facts of history.

      • markx says:

        Hi Martin…

        We have perhaps almost exhausted the possibilities of this discussion, and I’ll bid you adieu here, but this deserves a reply;

        You have simply resorted to a few basic ‘countering tools’ here:
        1. Categorization
        2. Blame Conspiracy beliefs
        3. Blame’Big oil’ Money

        Now I don’t mind which category you are in or consider yourself to be in, or what your political beliefs are. I’m more interested in what you believe in regard to the scientific intricacies of climate, and how an apparently intelligent man can have not one iota of doubt about the matter, especially when leaked emails showed key CAGW scientists expressed their own doubts and uncertainties.

        I believe labeling, categorization and denigration of those who don’t fully accept your viewpoint reeks of a tactical political play.

        Other than Lewindowsky’s cynical discredited and now suspended abomination there are few indications that conspiracy theories are the main driver behind these discussions.

        I have never yet seen any evidence put forward that “big oil” or “big anything” is systematically funding doubts, whilst on the other hand there are massive amounts (tens and hundreds of billions) being spent by US and EU governments on the issue.

        I feel I have in no way been duped: I do my own reading of published research on the matter, and see the many uncertainties and elaborate statistical computer constructions required to provide the ‘answers’.

        And in the end my position is simply that they don’t understand this as well as they say they do and their certainty is overstated.

        Regards, Mark.

      • Martin Lack says:

        I’m sorry, markx, your belief that Lewandowsky has been discredited is ridiculous: Even though the publisher of his ‘Recursive Fury’ paper may have been spooked by threats of legal action, the research presented in it (and the ‘Motivated Rejection’ paper) is not invalidated by any of the conspiracy theories put forward to discredit the finding that climate change skeptics tend to believe in conspiracy theories (surely even you can see the irony in this?).

        Even so, leaving aside all the conspiracy theory stuff, the research also confirmed that libertarian ideology predicts dismissal of climate science. I know this because I have read both papers. Therefore, your “skepticism” is at best unwarranted; and at worst an artefact of ideological prejudice.

      • Martin Lack says:

        Climategate 1.0 proved nothing other than that UEA staff became very frustrated by FOI requests for data that was already in the public domain.

        Climategate 2.0 proved that those doing the hacking were motivated by a desire to prevent progress at UNFCCC meetings.

      • Martin Lack says:

        As to your failure to see that the fossil fuel industry is behind the campaign to discredit climate science and scientists, I have already given you the link to Merchants of Doubt. If you are as open-minded as you claim, I challenge you to read the book for yourself (rather than listen to those who have told you not to).

        Yes, the environment has become a political football, but that does not mean that you have to platy with it! Let the science speak for itself. Contrary to what you have been told, concern over anthropogenic climate disruption is not based on computer modelling, it is based on atmospheric physics and palaeoclimatology.

      • markx says:

        Hmmm … never say never, or bid adieu too soon….

        Martin Lack says: May 6, 2013 at 1:52 pm

        “…. Contrary to what you have been told, concern over anthropogenic climate disruption is not based on computer modelling, it is based on atmospheric physics and palaeoclimatology.”

        So, given the frequent revisions and the incremental reductions we have seen of ‘climate sensitivity’ (the effect of a doubling of atmospheric CO2) are you telling me the physics has frequently changed?

        Or was it the knowledge of the complex interactions of the known physical effects, and the modelling thereof?

        And re the main topic of the article we comment upon here: comparing Marcott etal to Mann etal (ref hockey sticks) and Mann’s data telling us it has never been so hot before during the Holocene, to Marcott’s (spurious uptick and all) telling us we are now almost as warm as the early Holocene was;

        Is paleoclimatology a splendorous and many faceted beast which gives a wide range of results which must be carefully interpreted, or is it a simple physical measure?

  5. Max says:

    “What it clearly demonstrates is that the warming of the past 150 years is not only hotter than at any time in the past 11,000 years, but it is MUCH faster as well, and NOT proceeding at the typical rates of global cooling and warming in the past when humans were not filling the atmosphere with greenhouse gases.”

    If there had been 100-year temperature spikes in the past like there is now, would they be seen in data with 300-year resolution?

    • Somite says:

      The point is a spike iike that has not been detected anywhere the scientists have looked. And they keep looking. If this was a common event some data points would be a spike like the one detected in modern times.

    • itzac says:

      If we were talking about classical discrete sampling theory, you could miss any thing that didn’t last at least as long as your sample interval. But I don’t think that’s the case here. I’d need to know more about how the data are collected, but I don’t think it’s the case they represent perfectly discrete and contiguous 300-year intervals.

      You also have to allow enough time for the trend to reverse and return mostly to normal before the end of the sample interval. The current trends show now sigh of slowing down.

    • Marcel Kincaid says:

      Aside from the temperature graphs, there’s the physics and a great deal of other evidence. The so-called “skeptics” are always looking for something to confirm their libertarian biases while ignoring the overwhelming convergent evidence.

    • markx says:


      If you give Lewandowsky’s stuff one second of credibility, you undermine your own credibility – (talk about confirmation bias, I’m not sure any genuine person could regard that as science!)

      I did my own analysis of his data, he simply ignored things which did not suit him, but here is his moon landing conspiracy data: (sorry perhaps Excel tables don’t paste too well here:)

      Blv Moon Landing True + Blv AGW Climate change 1012
      Disblv Moon Landing + Blv AGW Climate change 6
      Blv Moon Landing True + Disblv AGW Climate change 123
      Disblv Moon Landing + Disblv AGW Climate change 4*
      Total 1145

      Notes. All surveys were posted on PRO CAGW sites. No possible indication of how genuine were the responses. *Two of the ‘skeptics’ were either insane or trolling jokers – they believed in every single possible conspiracy…..

      Then perhaps go here and see comments from skeptics regarding the Apollo 11 flight and see what people really think:

  6. WeatherDem says:

    Be careful: Marcott et al.’s paper does not make any conclusions regarding 20th century temperature reconstructions. From <a href=""Marcott's FAQ, reposted at RealClimate:

    Q: What do paleotemperature reconstructions show about the temperature of the last 100 years?

    A: Our global paleotemperature reconstruction includes a so-called “uptick” in temperatures during the 20th-century. However, in the paper we make the point that this particular feature is of shorter duration than the inherent smoothing in our statistical averaging procedure, and that it is based on only a few available paleo-reconstructions of the type we used. Thus, the 20th century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions.

    Q: Is the rate of global temperature rise over the last 100 years faster than at any time during the past 11,300 years?

    A: Our study did not directly address this question because the paleotemperature records used in our study have a temporal resolution of ~120 years on average, which precludes us from examining variations in rates of change occurring within a century.

    The region in the plot with a blue envelope surrounding the purple line is statistically robust (error bars). The recent uptick, while measured via other methodologies, is not robust in Marcott’s paper and thus cannot be used to make conclusions. Marcott’s paper demonstrates that most of the past 10,000 years was warmer than it was in the past 2,000 years.

    This doesn’t alter the fact that the globe has warmed rapidly in the very recent past and that humans are very likely the proximate cause. But we should discuss researchers’ conclusions accurately.

  7. Inigo de Ona says:

    “with +/- 300 year resolution (the highest ever)”

    With a resolution of this magnitude in the data, could there be unseen spike similar to that of the present that occurred in the past?

  8. lehnne says:

    Somehow the earth has managed to existd for billions of years with various life forms coming and going, my guess is that it will continue to do so

    • Wscott says:

      Well sure. The question has never been “Will the earth survive?” It’s (probably) not even “Will humanity survive?” But that doesn’t mean the impacts to our civilization and way of life won’t be severe.

    • tmac57 says:

      I guess that it is easy to be sanguine about a potentially catastrophic path of our biosphere,as long as you are not the one to have to endure the hardships,hunger,misery and early death that likely will be the fate of those whom you ignore,because they have not been born yet,or are too young to know or care about their future well being.

    • Marcel Kincaid says:

      Is that strawman the best you can do, lehne?

    • Martin Lack says:

      lehnne – Most scientists now agree we are unlikely to keep post-Industrial warming to 2 Celsius. By the time we halt the recent exponential rise in atmospheric CO2 concentrations (which will only happen if the rate of removal exceeds emissions), the equilibrium temperature difference is likely to be 4 to 6 Celsius… There is also the possibility that equilibrium may never be reached (i.e. the so-called runaway greenhouse effect) but let’s not go there (please)… The last time the Earth was 4C warmer than the pre-Industrial era, Antarctica was free of ice and sea levels were therefore 75 metres higher than they are today.

      All life on Earth is adapted to the way things have been for the last 12 thousand years; conditions which facilitated agriculture, urbanisation and civilisation. Therefore, I have no desire to wind the clock back 35 million years and I do not think you should want this to happen either.

  9. markx says:

    A note:
    Marcott’s uptick is from 1890 to 1950 (where his chart ends).

    Skeptical Science notes:

    While their reconstruction does identify an approximately 0.6°C warming between 1890 and 1950, the authors note in the paper that this result is probably not “robust.”

    Tamino notes that this uptick appears to largely be a result of proxies dropping out (although a smaller uptick seems to be a real feature), as many individual proxies do not extend all the way to the year 1950. If proxies with colder temperatures drop out, the remaining reconstruction can show an artificial warming toward the end.

    • Marcel Kincaid says:

      Your note does not negate the massive convergent evidence for AGW.

      • markx says:

        My note relates directly to the content of the article, and perhaps to some of the following comments promoting this article as as ‘a seminal post on the issue’.

        Like the article, the mass of the ‘convergent evidence’ is something worth looking at and debating one piece at a time.
        But let’s not do that here.

  10. Somite says:

    Another point is that there is no doubt there is current global warming as detected by modern instruments. The question of natural variability may be irrelevant because even if there has been warming in the past it could have been unrelated to changes in greenhouse gases and it was certainly not anthropogenic.

    The present warming is very likely anthropogenic and will have negative effects for humans regardless of whatever reason it may have warmed in the past.

  11. xbacksideslider says:

    Maybe its off topic but how do we resolve the conflict between energy poor and energy rich countries? Empower the state? Redistribution of energy access, rich to poor? Tell China to power down just because we are? White Western Northern Europeans insisting on universal asceticism?

    • Rob says:

      I’m basically a skeptic by any measure, but I’ve thought the only conceivably effective answer in a catastrophic scenario would be cross border. Rather than squeezing output in developed countries they would do things like paying the difference for gas and/or nuclear over coal in growing countries. It would be far better and rather than increasing friction it could be a good thing internationally regardless of climate. Maybe the developing countries would stipulate we drop ethanol too and it would really be a win win over the current ideas.

  12. BillG says:

    The reality is that once we convert the “climate deniers” solves almost nothing. Sure, perhaps this is where the discourse begins – but we are still far from energy alternatives to abandon fossil fuels. Denialism or not, we have been chasing to tame fusion power for 60+ yrs, millions spent and have basically buckus to show for it.

    Certainly we are and should continue fund R&D for energy replacements and efficiencies, but any magic bullet assurance is fantasy if we claim our concerns are only to lavish more currency and cure the deniers.

    • R.T. Weillich says:

      Solar energy is cheap. Lead acid batteries are cheap. Running the world isn’t an economic problem. The LOCE of a 2013 polycrystaline solar panel and car battery is 0.26 $/kWh over 20 years (Half the period of amortization for much of the existing energy infrastructure) including battery and inverter replacement. These costs are low, compared to 1.5 billion “developed” people, and they are comparable or even exceed what “developing” people are currently paying. Nor are cheap energy prices typically correlated with a tremendous economic advantage.

      The technical barriers to a solar economy were crushed in the 1990s. The economic barriers were crushed in the past decade. I understand that not everyone is up to date with economics of solar energy due to the pace of progress, especially in the past 7 years, but quibbling about technical issues is 20 years out of date.

      • Canman says:

        Lead acid batteries are not cheap! A simple car battery costs the better part of a c note. Do you have any citation for your 26 cents number and what the heck is LOCE?

  13. William Holder says:

    A great proponent of the AGW hypothesis for 15 years through 2003, I have been a serious skeptic since 2004. For me it was all about the environment. There has been little or no environmental consequence and little to no warming for the last 17 years – even though the bulk of our CO2 emissions have come in the last 35 years. At this point CAGW is just a sorry diversion from very real and ongoing environmental, social and economic problems. Just a lazy way for people to feel like they are making a difference. What’s easier than going to Home Depot for a cfl bulb or buying a new vehicle. Let’s just cover our landscape and shorelines with unsightly windmills – then everything will be alright.
    All of the development you have ever seen has taken place in just the last 150 years as we added 4 to 5 billion people. No one denies the destruction this has wrought on the environment. No one denies we will add another 4 to 5 billion people. Let’s just pretend whatever warming we may or may not get is more consequential than adding another 300 million people to our country – that’s just plain retarded. We’ve soiled our rivers, soiled our oceans, leveled countless acres of forest and jungle, over-fished our waters, introduced invasive species, built all over our hillsides and beaches and are directly responsible for countless extinctions to include many larger species. Much of what forest and jungle is left, many large species that remain are under extreme duress. NONE of this damage is attributable to .8C of warming much less the warming we are presumed to be responsible for since 1950 – this is habitat destruction, encroachment and hunting.
    How do we protect the environment as we add another 4 to 5 billion people – forget another .8C of warming – this is just a sorry diversion. You can explain to your grand children how you chose to ignore the obvious problems all around you because of a belief in models that to date haven’t been particularly accurate. We’ve wasted the goodwill of a generation and a lot of money and talent.
    You guys better hope we see some real warming soon and not just alarmist headlines based on models – the public doesn’t realize that there has been a pause or slowdown of almost 17 years – I don’t think they are going to be assuaged by claims that the heat is hiding in the ocean.
    As far as the hockey sticks – you guys know there are problems with these. To suggest as you have that Marcott confirms Mann is pretty out there.

    • Martin Lack says:

      Dear William: You are quite right to point out that over-population and resource depletion are problems that most people seem to obstinately refuse to acknowledge. These things are Limits to Growth phenomena, the approach of which we were warned about over 40 years ago. The mathematics of exponential growth (and consequential resource depletion) are incontravertible.

      You seem to accept this. Therefore, why is it that you do not accept the fact that, as with every other global resource that is not owned by anybody, the atmosphere has a limited capacity to deal with our pollution? Furthermore, how much longer are you going to continue to ignore the fact that, even if there were no inertia in the climate system, 0.8 C for 40% CO2 increase implies 2.5 C for a doubling of CO2? I would also suggest that, given the reality of a global radiative energy imbalance, it is time you stopped ignoring:
      1. all the positive feedback mechanisms that are now becoming obvious; and
      2. all the negative feedback mechanisms (that have caused a hiatus in land surface warming) that are now disappearing.

      Concern about anthropogenic climate disruption is not based on computer modelling; it is based on atmospheric physics we have understood very well for over 50 years. It is only the fossil fuel industry that does not want to accept this; and they have done a brilliant job (as did the tobacco industry before it) of perpetuating doubt and uncertainty and convincing many they are in a fight to preserve their civil liberties. Sadly, they are going to lose; because no-one can win a fight with the Second Law of Thermodynamics.

    • markx says:

      Well said William…

      … and I have a feeling that the availability (or not) of abundant cheap energy sources may prove pivotal in feeding and sustaining an extra 5 billion people on this planet.

      Anyone who forgets why energy facilitates development, advancement and education should watch again this brilliant Hans Rosling video (Hans Rosling and the magic Washing Machine)

      And governments would do well to heed his words there:

      Of the top level consumers (the rich) ..”… until they have the same energy consumption per person they should not give advice to others what to do and what not to do…!!! …”

      And, more importantly, “….Thank you industrialization, thank you steel mills, thank you power stations, thank you chemical processing industries that gave us time to read books!!…”

      • tmac57 says:

        Both of those statements have nothing what so ever to do with whether or not AGW is a real threat to our long term survival.
        Just because an energy source has been enormously useful in the past for humanity,does not undo the negative consequences that are building minute by minute as we continue down that road.
        We now understand that we are on the wrong path,and we need to face up to that error,and stop digging,so we can escape the hole that we have found ourselves in.

      • markx says:

        Of course, how we go about stopping digging, and the degree of urgency (panic?) with which we do so is relevant:

        German taxpayers have poured $130 billion into subsidizing solar panels, but ultimately by the end of the century, this will postpone global warming by a trivial 37 hours.

        The electric car is even less efficient. Its production consumes a vast amount of fossil fuels, and mostly it utilizes fossil fuel electricity to be recharged.

        Even if the U.S. did reach the lofty goal of 1 million electric cars by 2015 — costing taxpayers more than $7.5 billion —
        … warming would be postponed by only 60 minutes.

      • tmac57 says:

        Where in that article did it suggest that we should not be trying to move away from fossil fuels?
        The fossil fuel industry has been around for 150 years or longer ( do you think that they had any missteps along the way?).
        I think a few fits and starts can be expected while trying to change an entire worlds economy from a well entrenched network of energy sources to a completely new one.
        It is an illusion to think that all the problems with a new technology can be worked out on paper completely,before they are deployed. Just ask NASA about some of their accidents and oversights ( and you probably will never find a more risk adverse bunch than NASA).
        We will continue to learn by doing,and we will solve the problems as they arise,but doing nothing is worse than trying and failing,because doing nothing teaches you exactly nothing.

      • markx says:

        Fits and starts indeed…

        I guess that is the whole point of not panicking and instead proceeding carefully.

        Sure there are mistakes made and wrong directions taken, but luckily the world is largely ignoring the “we are already doomed, we must do something, yesterday!” approach. Less precipitous haste, likely equals less mistakes.

        An exception would be Australia; nobly bringing in a carbon tax (well, not so nobly, it was deal to gain a majority in parliament to allow the Labor party to govern) and blinkering themselves to the fact the renewing Australia’s largely 1970’s coal power generation technology would provide efficiency gains of up to 18% (hey, 18% less CO2 as well!) ….now coal plants are completely off the table, but nothing changes because it is exported instead.

  14. William Holder says:

    Taking an OTC medication for your constantly runny nose will only cover symptoms – you have to treat the infection. If our CO2 emissions are of serious consequence – and I see a world where technologies and efficiencies have been effective in controlling symptoms – it still comes down to an ever increasing population.
    Although the most dire warnings about population haven’t come to pass, the impact is obvious. CAGW assumes an ever increasing population – without this increase, our CO2 emissions should decline. But I maintain that is the least of our worries.
    Controlling the population is a bitter pill that makes the unimaginably large task of controlling our CO2 emissions look like eating a tasty cupcake. Unlike AGW there isn’t any financial incentive for anyone to stabilize or (how radical is this) reduce our population. We don’t know how to create a prosperous society without this growth. It’s time we start thinking about it. If we are to punish ourselves (and much of the world suffers already and relies on inexpensive and abundant fossil fuels), let us do it for the right reasons and in a way that will benefit our whole environment and in a way that will present a truly livable world 1000 years into the future rather than what feels like a more chaotic and more unhappy world and a less balanced world.
    Our are CO2 emissions a problem, yes and no, maybe – it seems difficult to prove. They certainly are a problem for China and India. Everything we do is of consequence. Nature controls populations – because of our warmer climate and advances in food production and medicine – there’s no controlling ours – it’s been disastrous – it’s been great – we have to get off this ride.
    For all the climate the earth has seen – we live in a paradise. If there is an ideal state of climate, we’re probably close. The pause of the last 17 years makes clear that nature has a way of working even when we try our best to screw it up. It’s not the occasional oil spill we have to worry about but rather the spill of human population. We are the most amazing thing nature ever produced – too capable for our own good. I remember clearly a world with half as many people – it was spectacular. I’m so crazy happy I won’t live to see a world with 11 to 12 billion people. I wish my great grand children could see the beautiful world I grew up in. A more relaxed, happier and thoughtful world. A world that seemed to offer great promise. It would be wise to put a big picture view in peoples minds – Gore was able to do this with a problem that may not even exist. Let us not create another generation of people believing the greatest threat to our planet are our CO2 emissions. We’re pretty efficient here and in many places around the world but all the efficiency in the world isn’t going to make up for another 4 or 5 billion people. We add 90 million people every year, that’s the equivalent of a country like Mexico. We add 3 million here – that’s like Dade and Broward counties in Florida.

    I’m just rambling sorry, I realize my posts don’t exclusively address the issues above. There’s just so much the world could focus on – there are alarmist headlines to be written. We’re so desensitized – too much ipad and twitter – we can’t read or write but we can tweet and message. Ask your average AGW advocate how many people don’t have ready access to clean water and they wouldn’t have a clue. Ask the average young person about global warming than ask him how many people died of malnutrition and related causes today – no clue. Ask him how many acres of jungle we lost last year and how many species scientists estimate we lost last year – no clue. Ask him how many people slept on a dirt floor last night – no clue.

    We’re keeping up – a bigger part of the world improves – population doesn’t seem to be an issue – but it is because in terms of absolute numbers – many more people are hungry today than there were even people on the planet 500 years ago. We can’t ignore a billion people or several billion people potentially a couple hundred years from now. We shouldn’t ignore the impact on the rest of the environment.

    • Max says:

      When countries industrialize, their population growth slows down, but their CO2 emissions increase, so as far as trends go, that’ll be the bigger problem.

    • markx says:

      It is not all doom and gloom.

      Needs economic development and cheap energy.

      No-one ever starved to death because there was a lack of food in the world, only because no-one could make a profit out of moving some there and selling it – usually a combination of paucity of purchasing power and a high cost of transportation.

      And we ain’t so many, really :

      World population approx 7 billion:

      Call them all to a meeting, standing in a crowd, each with a square meter of space:
      7 billion square meters.

      They would take up an area of about 84 km x 84 km ( 52 x 52 miles)
      ie, Were it flat, everyone in the world could meet on the main island of Hawaii.

      If we built a frame, and allowed a cubic meter of volume for every man woman and child, they could fit in a cube of 1.9 km x 1.9 km x 1.9 km (1.2 x 1.2 x 1.2 miles).

      • Martin Lack says:

        To save yourself further embarrassment, I suggest you watch the ‘Arithmetic, Population and Energy’ presentation by Alfred Bartlett (or at least read my summary of it). Perpetual exponential growth in population requires perpetual exponential growth in resource consumption (unless the rich become a lot less greedy). Furthermore, since you presumably agree that those who are poor have the right to aspire to be better-off, then consumption will increase even if population stabilises… Therefore, since we are already consuming more resources than the planet can deliver on a sustainable basis (using fossil fuel to produce food, etc), there is no room for optimism.

      • markx says:

        “Perpetual exponential growth in population requires perpetual exponential growth in resource consumption”

        That is logical enough, Martin.

        But are we still experiencing exponential population growth now? And what do we expect to happen in the future?

        Have we also reached “peak farmland”?

        Drawing on a host of data sets, the authors conclude that a combination of slowing population growth, moderated demand for land-intensive food (meat, for instance) and more efficient farming methods have resulted in a substantial “decoupling” of acreage and human appetites.

      • Martin Lack says:

        Try reading what I wrote again:

        “…since you presumably agree that those who are poor have the right to aspire to be better-off, then consumption will increase even if population stabilises.”

      • markx says:

        “…those who are poor have the right to aspire to be better-off…”

        At the most basic level I’m guessing by better off you may include avoidance of starvation. And the key to that is ready and widespread availability of cheap, abundant energy.

        No matter how you raise the scale, some will always be at the bottom end of it. They will need increased wealth to raise themselves from their current state.

        The poor should perhaps be grateful that someone is putting the brakes on the panic to some extent, but it is not the poor little average citizen skeptic who is so blamed and accused, it is big business and big government…

        …At least until they have maneuvered enough to ensure they will reap their rewards, then there will be no stopping the tax and trading juggernaut.

        I predict the economic effects will be immediate and painful, the effects on CO2 will lag far far behind, and I’m not sure we will see much effect on temperature at all; very likely that will be swamped by other influences.

      • Max says:

        The UN’s population projections were too low in 2011, and I don’t see any explanation why all of a sudden they’re too high.

        “Throughout the 2000s, there were two reports where they predicted a peaking in the low 9 billions, then a decline. The big news here is that there’s no peaking and no decline, and continued increases over the entire century to 10 billion…
        One reason is that African governments have neglected to invest in family planning programs.”

        Here’s their graph.

    • Martin Lack says:

      You are correct, William. You did not address the very specific evidence I put forward to show that your ‘scepticism’ regarding climate change is misguided.

  15. Dorkyman says:

    I hear where you’re coming from. However:

    (a) It appears obvious that the collective will to make the kinds of enormous civilization-altering changes that you and your peers would propose is simply not there and in my view will never be there. So we must learn to adapt to whatever temperature changes come our way.

    (b) It may very well turn out that we really don’t know all the factors very well, and that gaia will take care of herself, thank you very much. I recall as a young engineering student reading a very old back issue of Scientific American, and the big concern expressed by a very learned author in that issue was that, at current rates of growth, the island of Manhattan would be under eight feet of horse manure by 1950. Sorry to say I interpret the current “sky is falling” doomsayers in a similar light.

    • tmac57 says:

      Did ‘Gaia’ take care of all that predicted horse manure? No, it was the switch from horse transport to the automobile.
      Now if we can just manage to switch from fossil fuels (another crappy output) to less polluting sources then maybe we won’t find ourselves in deep doo-doo in the future.But it won’t be because of any actions on Gaia’s part,it will be because we finally collectively woke up and took action.
      Naysayers are part of the problem,not part of the solution.

      • markx says:

        Nope… the problem is everyone is out there marketing their own “solutions”, hoping to be on the crest of the wave making a dollar at the expense of everyone else.

        The world moved seamlessly from wood to coal to oil and now to gas….

        If there is really a great panicked urgency about ‘solving this problem’, (and I think we should move very carefully and deliberately) then the solutions (to reducing CO2 output) are right there – gas, more efficient use of coal (efficiency gains of 15 to 18% readily available for coal generation but are stymied by a push for wind and solar) and of course nuclear power – small, modular and available, and bolt in to our current grids …..

        …but no – everyone lobbies for their own version of heaven and we just get bogged down in politics and rhetoric and must hear condemnation and doom but no practical solutions from the religiously righteous ‘saviours’.

      • tmac57 says:


  16. Canman says:

    A lot of you in the skeptical community need to take a critical look at wind and solar. A ridiculously anti-capitalist, anti-consumptionist author named Ozzie Zehner has one of the most devastating takedowns of solar power I have ever seen:–OqCMP5nPI

    His book, ‘Green Illusions’, has an equally devastating chapter on wind.

    At the dreaded blog, WattsUpWithThat, according to guest writer Paul Homewood, Germany opened two coal plants in 2012 and has six scheduled to open in 2013:

    • Martin Lack says:

      They are only doing this because they have shut-down their nuclear programme in an irrational knee-jerk reaction to what happened at Fukushima. Last time I checked, Germany was not prone to being hit by Tsunamis. However, none of this changes the fact that they are well on the way to producing 30% of their electricity from renewable sources. They are therefore way ahead of the UK in the process of insulating themselves from the forthcoming effects of an irreconcilable conflict between exponential growth in demand and an asymptotic decline in production. In this regard, it should be noted that, even if it were wise to extract it, all the oil beneath the Arctic would be consumed by the USA in less than one year.

  17. markx says:

    Here ya go:

    It may not be as bad as we thought …

    …(ain’t that so much better than always having to hear “It’s worse than we thought!”?)

    re climate sensitivity (to a doubling of CO2):

    In 2011 Schmittner posited 2.3°C, as we reported here. The previous year NASA studies suggested 1.64°C for a doubling. Terje Berntsen at the University of Oslo has suggested only 1.2°C-2.9°C with 1.9°C as a mean. Another Bayesian analysis by Magne Aldrin [source - discussion] posited 1.2°C to 3.5°C at 90 per cent confidence.

    The differences may not sound like a lot. But the global mean temperature has risen by around a degree since 1850, and the current CO2 concentration is rising by a mere 2 ppm (parts per million) annually – it’s around 390ppm at present. Any changes will be slow, giving policy makers and technologists a long time to prepare, and develop economical low-carbon alternatives.

    • Martin Lack says:

      So The Register is, in your view, a more reliable source of information regarding climate science than the aggregate opinion of active climate researchers? I think we can therefore safely assume that you are suffering from the Dunning-Kruger effect and/or that you are a conspiracy theorist.

      • markx says:

        Oh Martin, Martin ,Martin …. surely you note that The Register article is simply citing studies by numerous climate scientists …. sure we could go in and quote from each one individually, but in the interests of brevity I thought those most interested would seek the details themselves.


        In 2011 Schmittner posited 2.3°C …..
        The previous year NASA studies suggested 1.64°C for a doubling. Terje Berntsen at the University of Oslo has suggested only 1.2°C-2.9°C with 1.9°C as a mean.
        Another Bayesian analysis by Magne Aldrin … posited 1.2°C to 3.5°C at 90 per cent confidence.

        And the study the article focused on:

        Publishing in the American Meterological Society’s Journal of Climate, a new paper … “An improved, objective Bayesian, approach for applying optimal fingerprint techniques to estimate climate sensitivity”, Nicholas Lewis applies objective Bayesian techniques and uses more up-to-date observational data to derive his conclusions.

      • markx says:

        Furthermore the leaked IPCC Ar5 Chapter 11 draft seems to agree with these figures above (and I believe it was leaked due to a concern the editors would change this…)

        The projection is for between 0.4 and 1.0 degrees of warming for the period 2016-2035 compared to the period 1986-2005.

        You would expect a “best guess” to be in the centre of the range.

        But oddly we find this phrase in Chapter 11:
        [...] it is more likely than not that actual warming will be closer to the lower bound of 0.4°C than the upper bound of 1.0°C

      • Martin Lack says:

        It was leaked because someone who was clearly already a conspiracy theorist decided to breach their contract as a reviewer.

      • markx says:

        …sigh, it aways goes the same way

        …”97% of climate scientists”….

        and then… “conspiracy theory”…

        Tell me, do you think its likely the doctors who rejected Marshal and Warren’s work on H pylori (gastric ulcer causative agent) conspired to do so?

      • Martin Lack says:

        You are clearly far more intelligent than me; and therefore refuse to be duped by such blatant ‘argumentum ad verecundiam’ as this. What a shallow blind and thoughtless ‘sheeple’ I am… Good luck with the Nobel Prize for Physics nomination (which you deserve for overturning 150 years of research into atmospheric physics).

      • markx says:


        There is little argument about the basic physics behind the theory (especially from me) … the questions centre on the feedback and buffering mechanisms and the role of many other factors governing our planet’s temperature.

        Currently we have before us a perfectly plausible theory, probably much simplified, and it may well turn out to be correct in the end …. but, we don’t know that yet.

        There are those more learned than I who question it, and the manner in which the explanations constantly change.

        Here is one I chanced upon last night:

        Dr David Evans worked for the Australian Greenhouse Office from 1999 to 2005, building the carbon accounting model that Australia uses to track carbon in its biosphere for the purposes of the Kyoto Protocol. He is a mathematician and engineer, with six university degrees including a PhD from Stanford University.

      • Martin Lack says:

        I suspect David Evans is just another academic who does not want to face reality. This is because it is impossible to explain all the data unless you accept that CO2 is the main driver. For example: “…cyclical solar activity (variation in total solar irradiance (TSI), sunspots or anything else) cannot explain ongoing warming of the last 150 years. However… [they do] explain why the warming that has occurred – and is occurring – has not been consistent…”

        I think you (or Dr Evans) also need to read this:

      • markx says:

        …nice – but oversimplified… things are not quite so well understood…

        Wiki tells it well in this case, (see under Problems)(Google Milankovitch_cycles)

        And so does Skeptical Science:

        …. while we know changes in the orbit pace ice ages, the precise way the three Milankovitch variations conspire to regulate the timing of glacial-interglacial cycles is not well known.

        For example, about 800,000 years ago a shift of the dominant periodicity from a 41,000 yr to 100,000 yr signal in glacial oscillations occurred ….. and while a lot of ideas exist for why this should be the case, there’s no bulletproof answer to this.

        Explaining the 100,000 yr recurrence period of ice ages is difficult because although the 100,000 yr cycle dominates the ice-volume record, it is small in the insolation spectrum.

        Therefore, there’s still a lot to be done here.

        I’m not worried about us going into another ice age, I think the 60,000 year story seems reasonable.

        You may like this paper which says our CO2 releases conceivably may prevent ice ages happening for hundreds of thousands of years.

        Note also re forcings above: “Models require some amplifying feedback, from sea ice … or the terrestrial biosphere ….to nucleate on the basis of insolation forcing, but insolation is always the primary driver.”


        An anthropogenic release of 300 Gton C (as we have already done) has a relatively small impact on future climate evolution, postponing the next glacial termination 140 kyr from now by one precession cycle.

        Release of 1000 Gton C … is enough to decisively prevent glaciation in the next few thousand years, and given the long atmospheric lifetime of CO2, to prevent glaciation until 130 kyr from now.

        If the anthropogenic carbon release is 5000 Gton or more….[...]… The model predicts the end of the glacial cycles, with stability of the interglacial for at least the next half million years

  18. markx says:

    Single study? See above.

    Ah, Skeptical Science ‘sloganeering’. (yeah, I learnt that word from them, before I was blocked there) :-(

    Rewriting History at Skeptical Science:

    The response in the comments section from Cook’s readers was simple: ‘Antarctic ice is increasing. You cannot take a paper that has three years worth of data and conclude that the continent was losing ice’. They cited references that Skepticalscience neglected – which showed an overall increase in Antarctic sea ice.

    The rewriting that John Cook undertook is now recounted at Bishop Hill.

    In the first step Cook changed the entire article, taking (lead)from the criticisms. Next, he deleted his original ‘responses’, and added new ones that made it appear as though these commenters did not know what they were talking about.

    After this was openly revealed, John Cook offered explanations for his actions. It went something like this: ‘I accidentally mistook my readers to have responded to my updated article. Thinking that was indeed the case, their comments sounded silly to me. So I ended up adding responses to guide new readers’

    It still goes on wholesale today, deleting and blocking. I have experienced their deleting debating style first hand. There is plenty more, but you have to go here to read it (and if you are going to quote them as a credible source you should for your own sake at least see how they operate):

    • markx says:

      Above (18) was a reply to:

      under (17) tmac57 says: April 24, 2013 at 2:35 pm
      Here ya go right back at ya:

      Single study syndrome

    • tmac57 says:

      I read contrarian comments at SKS all the time, so why aren’t they being deleted? It’s because they stay on topic,avoid ad hominem attacks and offensive language and generally follow the clearly laid out commenting policy. Maybe that’s not your style or cup of tea…fair enough,but that doesn’t make their information wrong,and I would put their integrity about providing truthful scientific information up against WUWT or Bishop Hill any day.
      People looking back on this argument 20 or 30 years from now will look upon Watt’s et al the same way we now view the sleazy pushers of tobacco products, after it was found out that they knew for decades that their product was causing harm,but denied it until they couldn’t fight the science any longer.

  19. markx says:

    By the way; A marvelous history of the progression of climate science here, well written and an easy read (and for the excitable, you will be pleased to know it fully supports a pivotal role for CO2!):

    I always find reading the historical progression of any area of science fascinating.

  20. Mal Adapted says:

    While I’m surprised to see markx recommending it (I think he’s not really a denier, he just likes to argue), I’ll add my own endorsement of Spencer Weart’s The Discovery of Global Warming, either as a printed book or in web form at that link. I saw the following comment on another blog:

    Weart’s interactive html history is divided into subtopics addressed in many bite-sized “essays” (his term) that can easily be read in a single sitting and don’t have to be read in any particular order, and the writing is excellent. I find the Weart essays (which I downloaded as PDF’s to my e-reader for reading on my daily commutes) to be page-turners, albeit speaking as someone who was already interested in this subject.


    • markx says:

      I’m surprised too Mal, but I think perhaps the deceptive headline was irresistible … Marcott slaps down nothing of course, and the uptick is a messily contrived construct which did not appear on Marcott’s earlier PhD thesis on the topic.

      Nevertheless, the construction (before the uptick)is a meaningful and useful contribution to our state of knowledge on the topic, and departs far from Mann’s blatant construct in that it reverts to the previously held position that a significant portion of the earlier Holocene was as warm or warmer than today.

      True, I am not a denier, and although I am not sure I like arguing, I feel it is very necessary in this case to counter the ‘science is settled’ call to precipitous action.

      I strongly feel that the science on the topic is very far from being understood, and that the false use of every dramatic weather event of any sort as ‘proof’ is an abomination, as is the certainty with which extremely complicated, finely and intricately reworked, adjusted and re-adjusted satellite and Argo float data are quoted in the MSM news releases, in spite of many uncertainties and provisos within the scientific papers.

      Weart is an extremely talented writer, and we need a lot more publications such as his on many other aspects of science (I see he has also written on the history of physics.

      These need to be studied in schools. Topics are far more interesting and more easily understood when we can see the development of knowledge instead of simply being handed a list of ‘facts’. And it brings home the fluidity and ongoing nature of scientific discovery.

      • Martin Lack says:

        Markx – No sensible climate scientist argues that every dramatic weather event is proof of anything. However, they do point out that an increasing frequency of extreme weather events of all kinds (hot, cold, wet and dry) can be deduced from the basics of atmospheric physics as being inevitable. Of course, this is why such people try so hard to dispute the reality of every Hockey Stick graph; and why they dispute historical/statistical analyses of the last few decades of weather such as Hansen et al last year (i.e. the “climate dice are now loaded” paper).

        However, what I would really like to know is how anyone could possibly think that, since the Industrial Revolution, the Earth’ climate would not be impacted by:
        — a sevenfold increase in the the human population;
        — a similar increase in the number of methane-producing livestock;
        — a super-exponential increase in the burning of fossil fuels.

        Therefore, those who still dispute the reality of anthropogenic climate disruption have not only picked a fight with history; they have picked a fight with science – the Laws of Conservation of Energy and Mass, and the concept of Entropy in particular. Defeat is therefore inevitable. The only question that remains is how bad do things have to get before they are willing to admit they are wrong?

      • markx says:

        Noted, Martin. To me its a question of degree and the time span involved..

        And a couple of good links here:

      • Martin Lack says:

        Richard Lindzen is either completely incompetent or deeply hypocritical. I can say this because I witnessed his presentation in the Palace of Westminster in February 2012. Sadly, he has never answered any of my questions (which flowed from witnessing his misleading talk). Most especially, he has never explained why he used the very same tricks (that he falsely claims almost every other climate scientist on the planet of having used) to support his spurious arguments.

      • markx says:

        EPA drought index USA 1895 to 2011.

        Average drought conditions across the nation have varied since records began in 1895. The 1930s and 1950s saw the most widespread droughts, while the last 50 years have generally been wetter than average (see Figure 1).

      • Mal Adapted says:


        I feel it is very necessary in this case to counter the ‘science is settled’ call to precipitous action.

        What kind of “precipitous action” are you afraid of? Bearing in mind that uncertainty isn’t your friend, and the current scientific consensus for AGW could actually be too optimistic, what do you think the consequences of that action will be, relative to the consequences of doing nothing?

      • tmac57 says:

        I have made the same point about uncertainty to Markx on several occasions, he seems hopelessly stuck on the idea that because there are statistical uncertainties,that therefore AGW will probably be less than modeled,without ever addressing the upper bounds of those same statistical models,which you rightly pointed out have actually underestimated some predictions,such as Arctic ice decline for example.

      • markx says:

        Thus far, if you ignore attempts to co-opt every drought flood, snowstorm and wildfire, disaster scenarios have not eventuated.

        There seems to be plenty of evidence we should quell the panic and proceed slowly and carefully. For instance, installing high efficiency coal generation to replace other more polluting types seems perfectly logical at this stage.

        And a tale for you … many years ago a certain city council where I resided for a time decided, for the sake of the environment, to declare a two km wide green belt around certain areas of the periphery of the city.

        This had three major effects.

        1. Elderly farmers and hopeful investors who had been expecting certain land to be developed were stymied, and in the case of the elderly , saw their retirement hopes dashed.
        2. Some extremely lucky, astute, insightful, and … um… well connected investors, saw their long term, more distant investments skyrocket in value. In effect the payouts for them were brought forward 15 years.
        3. Eventually, about 10 to 15 years later, the green belt had to be developed too due to population requirements, and the survivors eventually saw their money.

        Perhaps you can see the parallel with many of the those pushing to save the world. Now. With their help.

        And: as someone else said: “I’ll treat it like it’s a crisis when the people who keep telling me it’s a crisis start acting like it’s a crisis”.

      • Martin Lack says:

        “…if you ignore attempts to co-opt every drought flood, snowstorm and wildfire…”

        Given that, adjusted for inflation, Federal US spending on disasters in 2010-13 is already double that of 2000-09 and quadruple that of 1980-89, why would you want to ignore reality?

      • markx says:

        There is a very simple and logical answer to that, Martin.

        A helluva lot more people are building far more expensive structures everywhere, and more so in the path of harm.

        Disaster relief, inflation adjusted, will continue to increase as a population and its wealth increase.

        And note, re the 2011-12 doubling: Sandy accounted for US$60 billion of that US$136 billion disaster relief spending for 2011 2012.

        I’d guess that happens when a tidal storm surge hits a major city – as it undoubtedly did when one hit Hamburg Germany in 1962 , killing 300 people, or closer to home and still earlier; Galveston USA in 1906 when 6,000 died.

      • Martin Lack says:

        Are we agreed then, that exponential growth (in anything) is a massive problem most people do not appear to recognise (or want to look at)?

        Exhibit A:

        Exhibit B:

      • markx says:

        Martin Lack says:April 30, 2013 at 1:48 pm

        Are we agreed then, that exponential growth (in anything) is a massive problem most people do not appear to recognise …

        Agreed. But…

        1. That is not the point you were making immediately above. Your ‘then’ is incongruous. The discussion above was about whether recent weather events are being co-opted as ‘proof’ of CAGW, and you then proceeded to do just that yourself.

        2. Population growth is beginning to taper off, some predictions already put peak global population at about 2050 (somewhere around double the current number).

        3. Reduction in population growth in any society appears to be primarily be linked to increasing of wealth. Conceivably (no pun intended) we may delay that process if we significantly delay economic advancement of underdeveloped countries.

        4. If one wishes to counter population growth but also hinders economic development, it would appear a possible result may be a population boom followed by something equivalent to a ‘dying off’.

      • Martin Lack says:

        I am not the one who is perpetually trying to move the goalposts or shift the blame for our predicament onto someone else. I am just trying to get you to see that you cannot look at one problem in isolation – they are all connected: All our environmental problems are consequences of the scale of many human activities (including reproduction). Trying to suggest (as you appear to be doing) that tackling anthropogenic climate disruption (ACD) is likely to delay solving global inequality/poverty is simply an inversion of reality.

        Sure, ACD will stop population growth but, it will also render large parts of the planet even less capable of supporting humans than they are already; and it will cause massive migration problems. Because of ACD, we cannot solve global starvation by growing more and more food on less and less productive land; and people cannot aspire to a better standard of living if they are dead.

      • markx says:

        ACD? … we’ve had to rename it, yet again?

      • tmac57 says:

        ACD? … we’ve had to rename it, yet again?

        Says the purveyor of the term “CAGW” which is a denier’s strawman way of implying that serious scientists and other people who are concerned about what we are doing to change our climate,are all a bunch of panicky chicken littles running around in terror.

      • markx says:

        Speaking of moving goal posts:

        Our global temperature is often depicted as an ‘anomaly’ ie +0.7 C …. so much above or below the mean global temperature.

        But, the accepted ‘mean global temperature’ has apparently changed with time:

        1988: 15.4°C
        Der Spiegel, based on data from NASA.

        1990: 15.5°C
        James Hansen and 5 other leading scientists claimed the global mean surface temperature was 15.5°C. Also Prof. Christian Schönwiese claimed the same in his book “Klima im Wandel“, pages 73, 74 and 136. 15.5°C is also the figure given by a 1992 German government report, based on satellite data.

        1999 14.6°C
        Global and Hemispheric Temperature Anomalies – Land and Marine Instrumental Records Jones Parker Osborn and Briffa google Jones Briffa cdiac ornl jonescru

        2004: 14.5°C
        Professors Hans Schellnhuber and Stefan Rahmstorf in their book: “Der Klimawandel”, 1st edition, 2006, p 37, based on surface station data from the Hadley Center.

        2007: 14.5°C
        The IPCC WG1 AR4 (pg 6 of

        2010: 14.5°C
        Professors Schellnhuber and Rahmstorf in their book: Der Klimawandel, 7th edition, 2012, pg 37 based on surface station data.
        google cdiac temp jonescru

        2012 14.0 °C
        Press Release No. 943 World Meteorological Society Globally-averaged temperatures in 2011 were estimated to be 0.40° Centigrade above the 1961-1990 annual average of 14°C.

        2013 Wikipedia: 14.0°C
        Absolute temperatures for the Earth’s average surface temperature have been derived, with a best estimate of roughly 14 °C (57.2 °F).[11] However, the correct temperature could easily be anywhere between 13.3 and 14.4°C (56 and 58 °F) and uncertainty increases at smaller (non-global)

      • markx says:

        Sorry – references are available above but the spam filter does not allow many links (a pity on a site such as this) And I have not tested suggested Google searches….

      • markx says:

        tmac57 says: May 1, 2013 at 10:06 am

        “..Says the purveyor of the term “CAGW”..”

        So you think that is a misnomer? It’s not so catastrophic then?…

        Great news, and I kinda suspected that may be the case all along. Let’s deal with the current steady warming and fossil fuel depletion problems sensibly and methodically.

      • tmac57 says:

        No it only becomes catastrophic when policy makers are conned into believing that our current course should be to ignore action on CO2 mitigation because:
        1. It’s not happening
        2. If it is happening,it’s not a problem
        3. If it is causing problems,they are not so bad
        4. If they are becoming bad,it’s not us
        5. If it is us,it’s more costly to deal with it than to endure it
        6. If it’s more costly to endure the effects,there’s nothing we can do that is effective
        7. If there is something we can do,we’ve waited too long. Too bad so sad future generations…deal with it!

      • markx says:

        Tmac. Here you have simply trotted out another ‘standard reply’ from the SKS playbook.

        The real ‘state of play’ is that we have out there an array of opinions which span the whole spectrum from:

        Ranging from “Catastrophe! It is already too late!” (James Hansen) …

        …to “We must pull out all stops and act immediately because it is an absolutely certain, just look at Frankenstorm Sandy” (Tmac and co),

        …to “Yeah, it has perhaps been warming up for 120 years, we are undoubtedly contributing to an extent but how well do we really understand this?” (me … and others)

        …to “It ain’t happening”.

        This is a good thing, as politicians, inherently incapable of having opinions (weather-vanes that they are with no interest in the world other than the chair that is their seat) then end up responding to the middle ground.

        And so, with a few silly and notable exceptions…. (Germany shuts down its Nucs for a bit of public approval in hope of future votes? Australia saves the world with a carbon tax to guarantee an extra two seats in parliament?….. the USA mandates the use of corn ethanol as a way to subsidize its farm sector?)….

        … the world proceeds quite carefully and gingerly down the path to ‘renewable energy’.

      • tmac57 says:

        I think you have misrepresented James Hansen’s current view.Here is what he said after his retirement last month:

        We can’t burn all the fossil fuels without guaranteeing that young people and future generations are going to suffer the consequences of that

        I think that is an entirely defensible statement.

      • markx says:

        ….James Hansen’s current view….

        Ah yes ….. is that the sound of shifting goalposts?

      • tmac57 says:

        I used “Hansen’s current view” wording because that’s what I found from his most recent statement.
        I don’t know what your source for

        Ranging from “Catastrophe! It is already too late!” (James Hansen) …

        was since you didn’t cite one,so I used what I know for sure he is saying now. If in fact Hansen felt at some point that it was too late (again source?) then clearly he has changed his mind.
        Do you have a problem with people changing their views,as new evidence comes in? But leave it to you MarkX to try to make every little element in a statement try to conform to your preset notion of that the whole endeavor of climate science is up to no good,or hasn’t a clue what they are talking about, (except for the brilliant ones who have the WUWT imprimatur of coures!)

      • markx says:

        Tmac, I think it is good that people change their mind and rephrase their statements as new information comes in:

        As Hansen does here in his 15 April 2013 paper titled;

        “Making Things Clearer: Exaggeration, Jumping the Gun, and The Venus Syndrome”

        While his overall theme there is justifying his earlier statements (note the title) he very carefully steps back from a number of his earlier more alarming comments;

        (regarding statements in his book “Storms of my Grandchildren”)

        The concept of a runaway greenhouse effect was introduced by considering a highly idealized situation with specified troposphere – stratosphere atmospheric structure, a simple approximation for atmospheric radiation, and no inclusion of how clouds might change as climate changes, as is appropriate for introduction of a concept.

        More recent studies relax some of the idealizations and are sufficient to show that Earth is not now near a runaway situation, but the idealizations are still sufficient that the studies do not provide a picture of where Earth is headed if all fossil fuels are burned. …[...]…

        Climate system inertia means that it will take several centuries for the eventual extreme global warming mentioned above to occur, if we are so foolish as to burn all of the fossil fuel resources..

        And, on
        he makes this rather pleasing, more nuanced statement, seemingly accepting other possibilities do exist.

        “But whether climate change will be moderate — something humans and most species can adjust to — or whether climate change accelerates and spins out of control, with devastating consequences for future generations — that depends. …” (and yes, then goes back to alarm bells..)

        And… You mistate my position:

        My position is that I believe some scientists and politicians have overstated the certainties of their understanding of a possible threat, and have therefore quite possibly overstated the certainty, degree and imminence of that possible threat.

        In the process they have unfortunately managed to manufacture a ‘religious zealotry’ which I believe inhibits sensible discussion and scientific progress on the matter.

  21. Canman says:

    Here is a shorter more concise Ozzie Zehner takedown of solar cells:

    Here are some of the points he makes:

    > The price of polysilicon is less than a fifth of the cost of a system.

    > Rooftop systems require an inverter that will fail in five to ten years.

    > Solar cells degrade over time (about 1% a year).

    > Their manufacture releases GHG’s, such as hexafluoroethane, nitrogen trifluoride and sulfur hexafluoride that are ten to twentyfive thousand times as potent as CO2.

    > At the end of their useful life, they require special disposal to prevent toxic substances such as cadmium from leaching out.

    > They’ve become a visible symbol put on buildings in cloudy or foggy areas, sometimes not even facing the sun.

    > They are just a drop in the energy bucket. Spending huge amounts to double or triple solar cells, makes them two or three drops in the bucket.

    • Martin Lack says:

      One day, fossil fuels will run out (or their use will be prohibited on environmental grounds). Therefore, we need to find alternative (and substitute their use wherever that is physically possible). Therefore, if we somehow avoid an ecological catastrophe, we may well need to develop civil nuclear power. Therefore, what we definitely do not need is to continue to argue about whether burning fossil fuels is the primary cause of climate disruption that was predicted; and which is now accelerating faster than expected.

      • Canman says:

        As a cornucopian, I suspect hydrocarbons will be renewable with bio and nano technology long before they run out. I think nuclear will turn out to be the best long term energy solution.

      • tmac57 says:

        I think most people who accept AGW also would be in favor of bio fuels,IF,they are close to being carbon neutral (not corn ethanol for example).I think we’ll get there eventually.
        Nuclear is a whole other can of worms,which seems to have a lot of trouble with getting financing,and cannot seem to control cost overruns that end up being shifted to rate payers way beyond what they were expecting.
        And still the nuclear waste issue hangs over the industry’s head.Still,it does seem like a better option than coal.

      • Max says:

        Wind, solar, and nuclear won’t replace petroleum until all cars are electric. Until then, some have advocated for flex-fuel cars that can run on methanol, which can be made from natural gas and garbage. Just don’t breathe it, as it’s toxic.

      • Canman says:

        I suspect when cars finally convert to all electric drive trains, they will be powered by some sort of highly efficient hydrocarbon fueled engine driving a generator with a small battery or capacitor for ballast. Perhaps a sterling engine or this new two-cycle engine:

        Airplanes will almost certainly require carbon based fuels, unless of course some sort of really small scale nuclear technology is invented.

    • tmac57 says:

      Just to pick one item (for now) “> Rooftop systems require an inverter that will fail in five to ten years.”

      Isn’t that a bit like saying an argument against having a car is “that in 5 to 10 years it WILL fail”? Of course it will…then you repair it,and move on. And by the way,I worked for 39 years in the telecom industry,and have seen many inverters operate without failure for decades,so the whole premise is bogus anyway.If one ever did fail,we repaired it,not replace it at full cost,if that’s what Zehner was pushing as a drawback.

  22. tmac57 says:

    Two more items addressed:

    “> Their manufacture releases GHG’s, such as hexafluoroethane, nitrogen trifluoride and sulfur hexafluoride that are ten to twentyfive thousand times as potent as CO2.
    > At the end of their useful life, they require special disposal to prevent toxic substances such as cadmium from leaching out.”

    Under “Hazardous Materials” and “Life-Cycle Global Warming Emissions”

    • Canman says:

      I suspect that green regulators, who would love to nitpick the petroleum and nuclear industries to death, will do their best to sweep problems with their beloved solar and wind industries under the rug.

    • tmac57 says:

      Similar to the way the GOP deniers in congress nitpick renewable energy industries to death?

      • Canman says:

        I don’t think the GOP or climate skeptics are trying to nitpick solar to death. They are against subsidies for it, not against people freely choosing it. In fact two of the best known climate skeptics, Anthony Watts and Burt Rutan, both have solar power in their homes and were both original leesees of GM’s ill-fated EV1 electric car.

  23. markx says:

    Whether or not coal fired power stations are a good thing (environment wise) really depends on what they are replacing. And in most situations they are replacing millions of cooking fires, hundreds of thousands of ancient coal fired boilers, and removing the need for tens of thousands of dirty, wet outdoor coal storages.

    The energy demand is already there, and is being met. Just not efficiently.

    The precipitous push to ‘green, expensive power’ is plainly harmful to the environment, because those who cannot afford it still require energy and will source it where they can.

  24. markx says:

    Precipitous action folly: The move towards CFLs – compact fluorescent lights. Like me, you will have discovered that paying 10 to 15 times more for a CFL bulb does little for the environment, nothing for my pocket, and one helluva lot for Philip’s coffers.

    The extra cost was supposed to be offset by lower energy usage, and longer bulb lifetimes. But, fluorescents don’t like to be cycled, and if they are cycled frequently will have a life span little better than an incandescent bulb. In fact, with the older fluorescent tubes, shop owners have calculated it is cheaper to leave large signs constantly lit as the extra power used is markedly less than the cost of constant tube replacement.

    Considering all the effort, cost and raw materials going into CFLs, in balance they have done little for the environment, but were instrumental in making Philips the predominant lighting seller in the world.

    And now after a few years, its all about to be replaced by LEDs.. and it appears that IS good technology.

    • tmac57 says:

      Well,I agree that the life expectancy of CFLs was oversold because of the short cycle problem,but if you try to limit the minimum ‘on’ time to 15 or more minutes,then the problem pretty much goes away,and I would guess that most people tend to leave their lights on for at least that long in most situations.
      Your “10 to 15 times cost” is way off base from my experience, probably 3 time more is closer to the truth (depending on type ) for the most common bulb used.
      I also am more in favor of the LED lights,but Jeezuss Christ they are so expensive!!! Talk about not helping your pocket book! I do expect fully that they will become cost competitive fairly soon though,if they want to truly compete in the market.

  25. frank rizzo says:

    I bought Mann’s book and must say it was a tough read with all the deniers and political conflicts. I mean I’m sure this stuff happens much more than we are all aware of but this wasn’t my idea of a good book. Look up hockey stick in Wikipedia and you pretty much can see how the book reads.

    • Canman says:

      If Mann wants to be taken seriously, he should go defend himself against Steve McIntyre at Climate Audit or against Willis Eschenbach at Climate Ect. Willis Eschenbach claims that he submitted an article that was an improvement on a Michael Mann paper to Geophysical Research Letters only to have it rejected and then later published by … Michael Mann:

      • John Samuel says:

        Mann is taken seriously by the real world. The likes of McIntyre and Eschenbach are just desperate for the oxygen of publcity as their analyses falter.

      • markx says:

        Michael Mann is a talented, verbose writer who would appear to me to be a man with a belief and an agenda:

        In the context of this article on Holocene temperatures it is worth going back to assess Mann’s original contention that the MWP (Medieval Warm Period) was ‘cooler than the present’ (of course, he has to rename it the MCA, the Medieval Climate Anomoly, as otherwise the whole thing would fail the Orwellian test).

        Available here: (needs a log in – no cost) Global Signatures and Dynamical Origins of the Little Ice Age and Medieval Climate Anomaly. Michael E. Mann, Zhihua Zhang, Scott Rutherford, Raymond S. Bradley, Malcolm K. Hughes, Drew Shindell, Caspar Ammann, Greg Faluvegi, Fenbiao Ni

        See Fig. 2. Reconstructed surface temperature pattern for MCA (950 to 1250 C.E.) and LIA (1400 to 1700 C.E.). Shown are the mean surface temperature anomaly (left) and associated relative weightings of various proxy records used (indicated by size of symbols) for the low-frequency component of the reconstruction (right). Anomalies are defined relative to the 1961– 1990 reference period mean.

        In discussion: Note Figure 2 – the top figures showing the temperature anomaly map of the world for the MCA (compared to the 1961 to 1990 period)…..and the weighted proxies on the right……

        ….to me it is an incredible construct: Note all the blue (cooler than recent times) on that map.

        However, there is warming indicated in the immediate area of the vast majority of the proxies!!

        Starting in northern America we see a cluster of proxies – by the temperature anomaly map, all apparently warmer than now, except for one cooler site.

        Down to the Caribbean … neutral, but heavily weighted..

        Peru, Ecuador, looks like it was warm there…. back up to Greenland … a very warm spot…, across to Europe, only two proxies, one heavily weighted, but both warmer, across to northern Russia …one isolated proxy with an isolated warmer spot … to central China, there is a cooler spot… (disputed by recent Chinese publications ..

        Then head a bit east in China..another very hot spot…then all the way down to Tasmania and New Zealand – Tasmania is cooler, NZ is warmer than now…… Back to Africa, 3 proxies, one cooler (and heavily weighted) and one very lightly weighted and warmer, and one neutral…

        Then look at all the modeled cooling on the map … right across central Asia, based on 4 proxies (!!), all of which were warmer except one… ALL of the Southern Ocean, the southern Indian Ocean, and southern Atlantic oceans were supposedly much cooler, (based on Tasmania, and three proxies in Africa?!!)

        All of the eastern Pacific is shown as cooler, … based on a string of proxies in the western Americas, (which were mainly warmer), and perhaps those of eastern China ..which were warmer also!! (??!)

        I do appreciate the vast effort and detailed measurements and complicated science which have gone into this effort, but to me it is simply a theoretical, biased construct.

      • tony duncan says:


        I have read everyone of the comments on this post, and I hate to to say it because I want to believe you are an actual skeptic but you use way too many arguments that are in the denier “playlist”. I realize that I WANT you to be a real skeptic because you do not resort to adhominems even after numerous disagreements, and that is a feather in your cap regardless.

        Your dismissal of lewandowsky was an early giveaway, as well as your reliance on WUWT, and other beyond biased sources. Mostly it is your lack of willingness to actually engage in real dialogue. Now I consider myself a skeptic and i frequent denier blogs because i do believe the issue is so politicized that it would not be easy for the climate science community to acknowledge serious problems with ACC initially and that it is quite possible that some issue will be picked up in a denier blog for obvious reasons.
        I too am not convinced the science is well enough understood in numerous areas. I too think there are holes and out right mistakes in many of the arguments. I too can think of scenarios where CO2 does not lead to temp increase of more than another 1Ç* and find it conceivable that it could be much less than that from some sort of mitigating feedback that is not well understood. I ALSO have great faith in human ingenuity and the ability to ramp up technological solutions or solutions that require pretty large scale scail reactions if it is really understood to be necessary. I Do not see a reasonable scenario, where human civilization falls apart solely because of ACC.
        I also consider it absolutely necessary to consider realistic political and rational economics in making decisions for how to proceed.
        To me those are valid skeptical positions to take, yet you seem to me very much to fall into the denier camp because your response to the science is to find some source that appears to refute it. You do not appear able to acknowledge that it is conceivable that the uncertainties could lead to MUCH worse consequences than have been imagined.
        For instance I predicted the SIE for the arctic last year would be 4.9m km2. it was admittedly a conservative prediction considering the recent trend, and I was VERY skeptical of extreme alarmists would confidently predicted it would go below 4 km2. Only the most extreme predictions got it right. The arctic is a very strong predictor for ACC. As are numerous other empirical measures. Global surface temps not increasing significantly for 10-15 years is a possible indicator of uncertainty, but it is in no way a strong signal one way or another since natural variation at this point in the concentration of CO2 is still strong enough to mask the signal without there being anything wrong with climate models.
        Your critique of Mann seems clearly biased. there have been numerous reconstructions that come to very similar conclusions, and the most recent in fact points to there being no global MWP. Your analysis of his paper is clearly one sided, and it is celar that much of the source of your objections to ACC coem form sources that have an obvious political agenda to disprove ACC>. I see no interest in you in critiquing the sources that you use, only on critiquing sources that show ACC being a potentially serious problem.

        that brings me to Lewandowsky. I have read all sorts of back and forth about the paper from supporters and detractors and it is extremely hard to determine who is full of shit and who is being honest. In reading the paper itself there are certainly issues that I have with it. making a correlation to faked moon landing was in my view a ridiculous case to make. I can understand it form a metaphorical point of view,. but I know for certain that I have never seen that brought up in thousands of discussions with deniers. the effect of that comparison was to just infuriate them. That being said, there is no question in my mind that a huge number of deniers believe in conspiracy theories that are fairly untenable. Possibly a majority of those that comment on the denier blogs that I see.
        I just see lewandowsky, maybe with major methodological faults (maybe not) as confirming what is extremely obvious. I have had many discussions about Climate change devolve into Obama being a muslim born in Kenya, and a possible majority of deniers are right wing or libertarian who are convinced there is a vast socialist conspiracy, as well as large numbers who believe that literally thousands of scientists are fraudulently upholding ACC even though they know, somewhere in their hearts, that it is just propaganda>
        there are people like Pilke and Curry who i do not classify as deniers, but consider more political opportunists. I spent a lot of time trying to consider them neutral but there have been too many instances where they have ignored of forwarded nuanced stances that seemed carefully constructed to support an agenda of not shutting deniers out. But in both cases they do accept the basic premises of ACC and occasionally point out important mistakes of caveats that are not well expressed by supporters of ACC.
        Finally your allusion to a religious zealotry is something I have not found an ANY scientist that supports current ACC theory. Not from Hansen, mann or any other. that does not mean i don;t think they have agendas and that they are necessarily accurate in their conclusions or analysis, But I have YET to see anything written or seen anything from even the most vocal scientific advocates of ACC. ON the other hand I have seen religious like zealotry on almost every site that that contends ACC is not a significant problem.
        There are actually a number of other aspects of your comments that I find to be unskeptical, but I got little sleep last night so I have to stop here.

  26. RAO says:

    Can you go back one more 1000 years of temperature so I can see that too please.I would specifically like to see if 2000 years ago we came to he same temperature range without the same levels of CO2.