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BBC contrarian top 10

Filed under: — gavin @ 13 November 2007

There is an interesting, if predictable, piece up on the BBC website devoted to investigating whether there is any ‘consensus’ among the various contrarians on why climate change isn’t happening (or if it is, it isn’t caused by human activity or if it is why it won’t be important, or if it is important, why nothing can be done etc.). Bottom line? The only thing they appear to agree about is that nothing should be done, but they have a multitude of conflicting reasons why. Hmm…

The journalist, Richard Black, put together a top 10 list of sceptic arguments he gathered from emailing the 61 signers of a Canadian letter. While these aren’t any different in substance to the ones routinely debunked here (and here and here), this list comes with the imprimatur of Fred Singer – the godfather to the sceptic movement, and recent convert from the view that it’s been cooling since 1940 to the idea that global warming is now unstoppable. Thus these are the arguments (supposedly) that are the best that the contrarians have to put forward.

Alongside each of these talking points, is a counter-point from the mainstream (full disclosure, I helped Richard edit some of those). In truth though, I was a little disappointed at how lame their ‘top 10’ arguments were. In order, they are: false, a cherry pick, a red herring, false, false, false, a red herring, a red herring, false and a strawman. They even used the ‘grapes grew in medieval England’ meme that you’d think they’d have abandoned already given that more grapes are grown in England now than ever before (see here). Another commonplace untruth is the claim that water vapour is ‘98% of the greenhouse effect’ – it’s just not.

So why do the contrarians still use arguments that are blatantly false? I think the most obvious reason is that they are simply not interested (as a whole) in providing a coherent counter story. If science has one overriding principle, it is that you should adjust your thinking in the light of new information and discoveries – the contrarians continued use of old, tired and discredited arguments demonstrates their divorce from the scientific process more clearly than any densely argued rebuttal.

397 Responses to “BBC contrarian top 10”

  1. 1
    CC says:

    I would like to comment on your claim that the argument about the reliability of climate models is false. In fact your statement is just as much an opinion as the statement of the sceptics. Predicting a warmer climate is very easy for a model, as CO2 just alters the radiative balance of the planet, but as an expert in boundary layer meteorology and land-atmosphere interactions, I have to admit that I am totally not convinced about the details that are given in the IPCC report.

    For instance, the knowledge about processes in stable conditions (at night, polar regions) is very poor, and many papers show the failure of the common surface parameterizations in these conditions. Also the success of parametrizations of convection and microphysics on a global model scale is still limited. These limitations have a large effect on the forecasts of precipitation and therefore on soil moisture.

    I agree on the prediction of the warming trend, but as it comes to the water cycle, I agree with the skeptics. The statement is thus not false, but I would classify it as disputable.

    I am slightly disappointed that the tone of the articles on realclimate is getting more and more arrogant, something that is not appropriate for good scientists as (most of) you are.

    [Response: There is a world of difference between acknowledging that models are imperfect (which they are) and claiming that they are fundamentally unreliable without mentioning what is being talked about. Do models reliably match the cooling during subsequent to the Pinatubo eruption? Yes. Do they reliably predict a northward shift in tropical rain bands during the mid-Holocene? Yes. Do they predict last glacial climates as cold as observed based on their included physics? Yes. etc. etc. Do they reliably project rainfall changes in the New York in 20 years time – probably not. Thus statements that are absent of nuance as in the ‘sceptic’ point put forward by Singer are indeed false, and not just a matter of opinion. What is being implicitly asserted is that modelling is a dangerous waste of time, rather than the fundamental way in which our theories of climate and climate change can be quantified and evaluated. Apologies for the anti tone of late – we will have more of substance soon. – gavin]

  2. 2

    “So why do the contrarians still use arguments that are blatantly false?” Because politics, not science, is what’s at issue here. George Soros recently analysed some of the methods: One influential technique – which Republican pollster Frank Luntz says that he learned from 1984 – simply reverses meanings and turns reality on its head. Thus, Fox News calls itself “fair and balanced,” and Karl Rove and his acolytes turn their opponents’ strongest traits into their achilles’ heels, using insinuations and lies to portray opponents’ achievements as phoney.

  3. 3
    gharman says:

    As a journalist that frequently writes about Global Warming issues in Texas, I have never fallen into the trap of providing “equal time” in a scientific debate when one position is obviously manufactured and/or manipulated. If there are published alternative viewpoints about aspects of current science, that is another matter. However, the out-and-out deniers that really make no effort to understand basic climate science to begin with — only their high-volume misinformed positions — simply don’t find room in my stories.
    I recently broke a personal practice of mine to engage in an online conversation with a homegrown denier in San Antonio. Most reporters I know learned their lesson a long time ago about this, that is is a hopeless endeavor. (Click on “What Lies Ahead” at to read the discussion in full.)
    I was struck by the fact that even on the fundamentals there was zero elasticity in this fellow’s debate. No movement.
    I’ve come to the conclusion that two elements seem to keep deniers in their fringe camps: a general lack of understanding of the scientific method and peer-review process (that’s across the U.S. population, I’m afraid), and the power of attachment, ie. the cultural/social identity, which seems to keep people from straying too far from familiar territory.
    That is: it takes more than access to good science to win over a denier. It takes a more fundamental shift on their part first.

  4. 4
    Erik Hammerstad says:

    And today the BBC brings a story by John Christy talking about the problems of mortals and the inadequacy of modelling and the IPCC process at But the BBC balances by bringing a contrarian view by Martin Parry at

  5. 5
  6. 6
    bjc says:

    Given the level of precision that is used in model-based predictions of temperatures, precipitation and sea level, aren’t the limitations in the models problematic. That is not the same thing as saying not to use models: it simply says that the full range of uncertainties needs to be acknowledged.

  7. 7
    Stephen Berg says:

    Excellent work, Gavin! Keep it up!

  8. 8
    Jim Galasyn says:

    Christy says

    …our own research indicates that alarming changes in the key observations are not occurring.

    What does he think about the recent acceleration in the Greenland ice sheet and polar ice melts?

  9. 9
    Timo says:

    The reason why I am a “sceptic” is because my gut feeling says that humans aren’t able to change course of Nature. The Earth has its own systems to cope with anamolies and will correct them at the appropriate time and place. And people will adapt to these “hick ups” of Mother Nature. History has proven that over and over again.

    Humans do influence the Earth (including its climate), no question about that. However, the question is; how much, in what sense, good or bad and does is it really harmful? Mother Nature is indifferent and will take its own course, irrespectively what humans will do trying to change that. Mother Nature is too big to fight against. Therefore, people will have to adapt to climate change, whatever direction it will take. It is like Judo; it is the principle of using one’s opponent’s strength against him and adapting well to changing circumstances

    The other reason for being a “realist” is the passionate way climate change (i.e. AGW) proponents claim to be right and the so-called deniers to be wrong. If a topic is becoming to passionate, mistakes can be made quite easily. And this applies for both sides.

    The most disturbing thing is the secretiveness regarding data, methods, codes and other information. If scientists are reluctant or completely unwilling to share this information which others, I am becoming suspious. If I (or others) am not allowed to analyse data and methods, how should I be convinced that you are right and I am wrong. Especially, given the fact that I have learned that climate is a natural phenomenon.

    For the time being I will remain to be a “climate realist”, adapt to a “warmer” world and further rely on Mother Nature and common sense. By the way: I am living in the Netherlands, close to the coast and a couple of meters below sea level. And I am not really concerned about disastrous sea level rise

    Thank you.

  10. 10
    Helen says:

    At the end of John Christy’s article ( he states,
    ‘Atmospheric carbon dioxide continues to increase due to the undisputed benefits that carbon-based energy brings to humanity. This increase will have some climate impact through CO2’s radiation properties.
    However, fundamental knowledge is meagre here, and our own research indicates that alarming changes in the key observations are not occurring.’

    What ‘alarming changes in the key observations’ could he be referring to?

    We are seeing a global temperature rise at what we think is an unprecedented rate, rapid melting of glaciers and ice sheets, it seems we don’t know enough about variability in ocean circulation to say either way.. So what are these ‘key observations’ he’s talking about?

  11. 11
    Keith says:

    OK. I’ve held this in for long enough. Let me start by saying that I’m a
    organic chemist working in the drug industry and work at the interface
    between biology and chemistry. So I have perhaps an interesting view on all this.

    Let’s start with the consensus thing since that’s easy to dismiss. Having a consensus view is not a scientific
    proof. A consensus opinion in science is a herd mentality. It’s poor science. This seems to be the mentality prevelant
    in the world of climate change. Now of course you could all be correct
    on AGW but consensus doesn’t make it so. Even data driven consensus. Do
    I have any evidence of this? Why yes as it happens.

    Not so long ago the scientific consensus was that peptidic ulcers were
    caused by excessive acid production in the stomach. This was backed by
    acres of scientifc work done in academia and industry. Indeed, Glaxo
    made huge amounts of money with a treatment that worked. All was well.
    The consensus seemed a pretty safe bet. Of course then these two crazy
    Aussies published a paper suggesting it was cause by a bacteria, H.
    Pylori. Oh how the scientific community laughed. That wasn’t the consensus. But then, 10 years
    later it was finally proved that they were indeed correct and then
    another 11 years before they were rewarded with their well deserved
    Nobel Prize for medicine. Scientific consensus. And we all know, as
    scientists, that this type of thing is pretty common, just not so well
    publicised. Sorry, but as a rule of thumb I’d say the scientific consensus is more
    often wrong than right. So I think we should very much put to bed the
    idea that scientific consensus has any scientific merit.

    My final point comes back to the old fav of models. The drug industry
    has spent a considerable amount of money, time and effort trying to
    design drug molecules in computers as well as modelling a massive amount of multifactorial data. And whilst some PR departments might
    show pretty pictures of the latest cancer cure being designed in a
    computer the reality is somewhat different. Even the very simplest
    molecular design experiments involving ligand and enzyme fail the vast
    majority of the time. Utterly. Even if we have a working example,
    efforts to apply it to a new system fail for unaccountable reasons. At
    molecular level we are, frankly, nowhere. This state of affairs though is better than where we
    were 20 years ago but still quite a long way from the dream. These models too always do very well when the are asked to explain historical data. We too also split out large datasets, use half to train the model and test it on the other set to check that it works. Man, a massive number of the learning (genetic algorithms etc) algorithism that you are using were first used in the drug industry. Guys, we’ve spent a fortune and we’ll continue to since it’s always cheaper and quicker than the real experiment. But that’s the rub. You have to do the experiment. The physical one. Recreate the whole system for real. Models are sold by modellers as the answer to a problem when in general they function as a means of generating new hypotheses to test in a real experiment. They serve very little real use going forward other than the reduce the actual number of experiments I will go out and do. And that, it seems, is the problem we have here. The only real experiment is one going forward which you clearly can’t do very easily. So I sympathise with the problem here. But that’s the key. The physical experiment. And, I really strongly feel that as somebody who uses models all time you have to be really for nature to really throw a curve ball at you. Frequently. This story isn’t done yet by a long way.

    I came to this site a quite skeptical on AGW. I still have some doubts
    about the quality of the data and I think the use of modelling should be
    taken with several large grains of salt. However, you have done much to
    correct many of the untruths which I’d previously thought correct. And I
    do believe that the environment is worth something and shouldn’t be
    abused. I simply do not share the consensus view that we can model what
    is going to happen in 50 years time with any level of certainty. Nature isn’t that easy.

  12. 12
    Glen Raphael says:

    The counter on #6 (“It’s the sun”) includes a claim that puzzles me. The text says:

    As there has been no positive trend in any solar index since the 1960s (and possibly a small negative trend), solar forcing cannot be responsible for the recent temperature trends.

    I don’t see how the conclusion follows from the premise. Let us suppose that (according to some measurement) solar activity was on an increasing trend until the 1960s and then leveled off at a threshhold level that was unusually high by historical standards. Couldn’t that put the temperature situation out of balance such that the planetary temperature keeps increasing subsequently?

    One could imagine that there’s some range of solar output our system can adapt to with cloud feedbacks, increased storms and such but when we get outside that range the planet can’t adapt in quite the same way and as long as solar output remains at its new level the planet keeps getting warmer (or cooler) until some new feedback mechanism kicks in and we reach some new equilibrium state. In that case, the solar increase until 1960 could still be causing an increase today.

    Why is this not a possibility?

    [Response: Because you would expect a rapid warming at the beginning of the period and gradually slower cooling as you get closer to equilibrium – the exact opposite to the behaviour seen. Plus there are other signatures of solar forcing that are not seen – the stratosphere should be warming, not cooling if the solar idea was correct. The cooling however is exactly what is predicted by GHGs. – gavin]

  13. 13
    Frank says:

    I have to agree completely with the first comment and disagree with the reply given by the author of the post. Models are not reliable, that means, when they are used to forecast global warming the forecast is subject to inadequate parameterization of physical processes, therefore the results of the model can only be trusted to the extent that we understand these inadequacies.

    One can argue whether asking for reliability is unnecessary from a political point of view (and maybe impossible to attain in a model), but that is certainly not the same thing as asking for everybody to agree that models are reliable (when they are simply not). Science people tend to think that no credit should be given to the right answer for the wrong reasons. We know models are deficient to the extent that our knowledge of key physical processes is deficient. Why then force people to think that global warming is going to occur based on model “evidence”? Is not the main reason for using models that we want to learn how the climate system works?

    The author mentions that models are able to match the cooling due to the Pinatubo eruption (among other successes). I am interested in the nuances of this affirmation. Do we know reasonably well what was the aerosol composition after the eruption? Do we know good parameterizations of the aerosol radiative effects? Or is the model match of the cooling more an exercise in fitting the aerosol properties so that we obtain the observed cooling. Do models reproduce reliably the vertical temperature change and spatial distribution after the Pinatubo eruption or only the mean surface cooling?

    [Response: You fall into the same false dichotomy as Singer. The idea that there are simply two classes of model “reliable” or “unreliable” is just not correct. It depends entirely on what it is you want to know about. The climate models are pretty reliable at global mean changes, variations as a function of latitude and for large scale phenomena – they are not reliable for short term, local projections. If you want to have a heuristic test for what you should rely on and what you shouldn’t, ask two questions – do the different (somewhat independent) models give the same response? and are there good observational and theoretical understandings for this response? If the answer is yes, then that’s a pretty good guess. If not, then the question is not yet resolved. This isn’t perfect and all the models could agree and still be wrong (due to some key piece of physics that everyone is missing) – there was an example of this in the Antarctic ozone hole which came as a surprise to everyone.

    You make one other mistake – we don’t think that global warming is going to continue simply because models say so. That result is purely a function of our ever increasing burden of greenhouse gases – specifically CO2, our knowledge of radiative transfer (which is pretty good) and our assessment from past history for how sensitive the climate is (see here). No models required (though they do help).

    With respect to Pinatubo, I recommend a section in our recent paper which discusses just that. Pinatubo was pretty well observed and so we know what the aerosol load was, what the relevant aerosol size distribution was, what the impact on the short wave and long wave was, how much cooling there was, how much reduction in water vapour and how the wind patterns reacted (a more positive winter NAO). All of these features emerge from model simulations and the match to observations is very strong. – gavin]

  14. 14
    Michael says:

    Gavin, what is your response to the idea that climate science is in its infancy? You come across as very sure of yourself. Your hesitance to look at your own work with a grain of salt is practically forcing your audience to look at you with a grain of salt. I am not referring to the AGW vs deniers scuffle, but to your positions on climate sensitivity, the MWP, and your trust in climate simulations.

    [Response: Possibly adolescence rather than infancy, but my apparent confidence in debunking obvious rubbish is not very relevant to dealing with real issues. In my own work, I am daily made aware of the shortcomings of our understanding – in proxy records, aerosol physics, turbulence to name but a few areas. And I like to think that my papers are extremely up-front about potential problems – so much so they are frequently quoted back to me as if I didn’t write them. On climate sensitivity, I think a lot of evidence points to something around 3 deg C being the most likely and hoping for a small number or panicking due to to the potential for a larger number are not sensible positions. The MWP is pretty much irrelevant for understanding either forcing or responses or internal variability since the error bars on everything mean that nothing is usefully constrained. Climate simulations are simply quantitative workings out of our basic assumptions – they work pretty well (which comes as a surprise if you are involved in building them), and they get better as you improve the basic physics. I trust them as far as they match up to observations – and in the paleo climate they do surprisingly well. – gavin]

  15. 15

    This is a lot of the same old same old on the part of the contrarians. Either The data isn’t good,the use of 1998 instead of the trend before and since, or computer models are imperfect (hello! what isn’t). Water vapor as a forcing rather than a feedback, and,of course, the Sun.

    These arguments have been debunked and refuted many times over. Gavin asks “So why do the contrarians still use arguments that are blatantly false?” Maybe the now famous statement by Jack Nicholson’s character in ‘A Few Good Men’ applies- “They can’t handle the truth!”

    Further enhanced greenhouse warming isn’t unstoppable,yet, but another 4 years of mostly voluntary measures by the World’s largest emitter of GHG’s will take us pretty close to that catastrophe waiting to happen.

  16. 16
    Dave Rado says:

    Re. #12, and Gavin’s reply, I wish Richard Black’s counter had made the point about the stratosphere cooling, and also about nights warming more relative to days and winters warming more relative to summers, and so on, as I think it is the multiplicity of different strands of indisputable evidence such as this is what will convince laymen.

  17. 17
    Dave Rado says:

    Re. Keith, #11, please read Spencer Weart’s histories of Simple Models of Climate, and of General Circulation Models of Climate, as they will open your eyes, if you are as open-minded as you appear to be. Of course there are lots of uncertainties, the biggest one being what human emissions will be in the future; but the uncertainty ranges are clearly stated in the IPCC reports.

  18. 18

    Of course the models match Pinatubo. The scientists have had over ten years to get the parameters right. But they still have not solved the tropical lapse rate problem, nor did they get the speed of melting of the Arctic ice correct. Moreover they still cannot reproduce the rapid climate changes at the start and end of the Younger Dryas or any of the other Dansgaard-Oeschger events.

    Just as the sceptics will not admit they are wrong, the same is true of the scientists. It is pointless telling a sceptic that AGW (anthropogenic greenhouse warming) is a danger, and it is pointless telling a modeller like Gavin that his model is wrong. No one ever admits they are wrong because it means losing face. See “How to Win Friends and Influence People” by Dale Carnegie.

    What is happening is that the scientists are defending their models against the sceptics instead of looking to see why they are wrong. Meanwhile the world is racing towards another rapid climate change and catastrophe!

    [Response: Nice one alistair… How might you explain that the predictions of cooling from Pinatubo were done prior to them being recorded? ( ) – gavin]

  19. 19
    Dennis says:

    Your Statement:

    So why do the contrarians still use arguments that are blatantly false? I think the most obvious reason is that they are simply not interested (as a whole) in providing a coherent counter story.

    My response:

    They are speaking to their audience. Those people don’t read science blogs. The audience believes anything that sounds like a rebuttal right or wrong, truth or fiction. I spoke to a flight crew member perhaps a pilot or co-pilot, not stupid individual. But he said “sir the planet has been changing for millions of years”. I told him ” I know, I am a geophysicist, every dramatic shift in climate has had dire circumstances for extant life!”. He gave me a blank stare, and walked away (no new data accepted period). What to do?

  20. 20
    Doug says:

    Keith complains of a “herd mentality” among those who perceive anthropogenic global warming. I think I know what he’s talking about, but I don’t think it applies to the climate science community. I work in forest conservation in the northwest U.S. and I regularly confront herd mentality among those who profit from logging. They see chainsaws as the solution to every problem in the forest. These herd thinkers tend to really latch onto an idea and block contrary ideas from their thinking. Example: excess fuel in the forest must be removed by logging rather than by reintroducing fire. Whereas the climate science community actually seem to exhaustively explore possible alternative explanations for their observations. This is healthy science.

  21. 21
    Frank R says:


    I agree with you that models cannot be classified as reliable and unreliable without a proper context. That said, reliability of models can only be called for when one expects to take action using model results. This is the political use of the model. The scientific use of the model is attempting to shed light into the workings of nature. For this particular use, reliability is not really important, as long as one is keeping track of “the potential problems”.

    I am reading the Pinatubo section of the paper, and I have to say that I like better your moderate scientific prose when it comes to the uncertainty in the aerosol content and properties, than the tone of certainty that is implied on your blog comments ;)

  22. 22
    Dave Rado says:

    Gavin wrote in response to post #13:

    You make one other mistake – we don’t think that global warming is going to continue simply because models say so.

    Part of the problem here is that I have frequently heard climate scientists on TV and radio programmes, when asked how we know for sure that current warming is “man-made”, reply: “because the models do not match the observed data unless human-emitted CO2 is taken into account.” I think taking that line is a big mistake, as you say there is plenty of evidence apart from the models, especially radiation physics; but this line is s used by a lot of climate scientists when talking to laymen.

  23. 23
    cce says:

    Off topic. Maybe this has been posted before, but has anyone seen this particular piece of lunacy?

  24. 24

    Nice one Gavin! You are right – the Pinatubo match was a good fit.

    However it was caused by changes in solar radiation due to a dust cloud, not changes in greenhouse gases. Therefore it was not a good test of modelling greenhouse gases See “The Dust Settles on Water Vapor Feedback” Anthony D. Del Genio Science 26 April 2002:
    Vol. 296. no. 5568, pp. 665 – 666 DOI: 10.1126/science.1071400

    Yet it was claimed as a success by the anti-sceptics, and you are still claiming it as a success. There is a spinning of the science to support your models, and dismissal as irrelevant any anomalies such as the tropical lapse rate which could point to errors. I have to agree with the point made by CC in #1 “that is not appropriate for good scientists as (most of) you are.”

  25. 25
    Joe Duck says:

    Gavin: The climate models are pretty reliable at global mean changes, variations as a function of latitude and for large scale phenomena – they are not reliable for short term, local projections. If you want to have a heuristic test for what you should rely on and what you shouldn’t, ask two questions – do the different (somewhat independent) models give the same response? and are there good observational and theoretical understandings for this response? If the answer is yes, then that’s a pretty good guess. If not, then the question is not yet resolved. This isn’t perfect and all the models could agree and still be wrong (due to some key piece of physics that everyone is missing)

    Gavin thanks – this statement was *extremely* helpful to my understanding of how modellers view the climate models and why the model data can have problems but still strongly suggest AGW.

  26. 26
    Richard Ordway says:

    “I simply do not share the conscensus view that we can model what is going to happen in 50 years time with any level of certainty. Nature isn’t that easy.”

    You are gravely mistaken, misinformed and do not know what you are talking about. Why don’t you read here first before making broad pronouncements on something you obviously know nothing about.

    Future climate model results have ranges- not specifics because there is no consensus on specifics.

    Where in the world did you ever get an idea that “with any level of certainty” the scientific community predicts what exactly is going to happen?

    If you mean a conscensus that the Earth’s average surface temperature is going to increase over the next century, then you are right.

    Literally, with the increasing forces involved, you or anyone else has to dream up a counterbalancing force of equal or greater magnitude…maybe an asteroid or Yellowstone…but even then they would have to be extremely large…the added Co2 and Methane would probably still remain doing their work after the “incident” was over.

    As they say, barring an extrordinary “biblical event”(sorry), there are simply no forces strong enough to accomplish this…and no one on Earth in their wildest imaginations can think up or even come close to proving that any large enough “reasonable” forces exist to counterbalance GW no matter how hard they have tried.

    Jeees, do you have any idea at all the magnitude of the forces involved that are powerful enough to have changed the Earth’s average surface temp by 1 degree F in 100 years???

  27. 27
    caerbannog says:

    he consensus seemed a pretty safe bet. Of course then these two crazy
    Aussies published a paper suggesting it was cause by a bacteria, H.
    Pylori. Oh how the scientific community laughed. That wasn’t the consensus. But then, 10 years
    later it was finally proved that they were indeed correct and then
    another 11 years before they were rewarded with their well deserved
    Nobel Prize for medicine. Scientific consensus. And we all know, as
    scientists, that this type of thing is pretty common, just not so well

    And how did those Aussies ultimately prevail? Did they write op/ed puff-pieces for right-wing political rags? Did they go on conservative talk-radio shows to complain about how they were being repressed? Or did they succeed in convincing their peers by producing outstanding research that was published in peer-reviewed journals?

    To make a credible case, you are going to have to show us some outstanding research challenging AGW that the deniers have published in peer-reviewed journals. Nobel Laureates don’t earn their laurels by publishing puff-pieces in the Wall-Street Journal or the American Spectator.

  28. 28
    Mary C says:

    Re 9. Timo – First I think you have to get rid of the idea of something called “Mother Nature”. There is no such being, just physical laws within which or through which our universe is bound to operate and which scientists are constantly striving to understand. Human beings are simply one aspect of that universe, also constrained by those same physical laws.

    There seems to be a belief that it is arrogant to say that something so insignificant within the greater scheme of things as man can have an impact on the operation of that universe. And that, I daresay, is indisputably true. But, nevertheless, man has the capacity to impact a tiny speck of that universe through his actions. If you doubt that something insignificant can change the earth, then you are unaware of history of the earth as it is understood by scientists today. The earth is not a static place, unchanged and unchanging since the birth of the universe 13.5 billion years ago or even since its own birth 4.5 billion years ago. All those physical laws keep it in a constant state of change. And one of the changes was brought about by bacteria:

    “It is widely believed that 2000 million years ago the cyanobacteria—oxygen eliminating photosynthetic prokaryotes that used to be called blue-green algae…effected one of the greatest changes this planet has ever known: the increase in concentration of atmospheric oxygen from far less than 1% to about 20%. Without this concentration of oxygen, people and other animals would have never evolved”
    Margulis, Lynn and Karlene V. Schwartz. Five Kingdoms, 2nd edition. W. H. Freeman and Company 1988. p28.

    Human release of additional carbon dioxide into the atmosphere is unlikely to bring about the kind of profound change that the advent of significant quantities of free oxygen into the atmosphere had. Life will not disappear, and even human life will most likley continue, until, as you indicate, still greater changes may wipe it out completely. But the changes that could be brought about because CO2 will act within the atmosphere as the physical laws say it must may very well have consequences that will be painful for humanity and that could destroy the world as we know it today. Given that fact and given the fact that we have some good ideas on how we could reduce the extra CO2 we are currently putting out, why should we not make an effort to eliminate or at least minimize a threat?

  29. 29
    Richard Ordway says:

    # 11. Ok, Keith. re. “peptidic ulcers proves that scientific consensus is bogus.”

    Gavin puts his time and reputation on the line with this blog and cites multiple, exact world-wide publicly-available references as all *real* scientists do.

    So you now do the same, Keith. Give us verifiable references (internet links that we can click on) to verify what you are talking about.

    I couldn’t even find a definition of the phrase “peptidic ulcers” when I checked internet sources for “peptidic ulcers” for five minutes (maybe it exists, but I could not find the defintion.)

    At best, this is an extremely rare subject, at worst a strawman.

    So, give your clickable references and then we can talk…

  30. 30
    Svet says:

    The response to “2. IF THE AVERAGE TEMPERATURE WAS RISING, IT HAS NOW STOPPED” is “cherry-picking”. What troubles me is that the HadCRUT3 Global surface temperatures graph does show a distinct leveling off over the last six years. I know that you shouldn’t just look at a few years in isolation but six years does seems a long time when you consider that the dramatic warming took place in the ten years of the nineties. My question is hypothetical. If six years is not enough to be significant then what length of time will be significant? Put another way, if the leveling off continues for another four years will it then be significant?

    (I know that the GISS graph doesn’t show this leveling off and I suppose looking at the Hadley Centre figures is a kind off cherry picking. However, you have to choose one or the other and the Hadley Centre is a respected organization isn’t it?)

  31. 31
    Majorajam says:

    Good post. The embarrassing lack of internal consistency in ‘skeptic’ community arguments is the most reliable way a lay person such as myself can begin to know what to believe. For example, early on in my education, I came to one former Harvard professor’s blog and read a post that cited three studies that contradicted the theory of AGW, (or should that be in scare quotes?)- entitled something to the effect of, ‘so much for a consensus on peer reviewed literature’. All well and good except in one problem: each study patently contradicted the other, (in one it was the sun, another the oceans, and the third, well, it was all a figment of our imagination). Neither this former professor nor his minions of educated sounding (and rather rabid) commenters so much as noted the peculiarity in the thread. So it is certainly useful to the lay person to highlight this overwhelming red flag, as it gives them evidence they can relate to and does not resort to beating them over the head with arguments from authority (consensus, consensus, consensus!), necessary though these can sometimes be.

    If I may though, though I understand their demise has heretofore been greatly exaggerated, (mimicking their claims), the power of denialist arguments over the public and policy seems to be waning, (witness a full week of major network programming in the United States, American Football included). What isn’t waning are the, IMO, badly flawed economic arguments against mitigation, and, frankly, more effort needs to be expended here to justify anything resembling a policy with teeth (e.g. mandated/operative targets). The Stern Review was a notable failure in establishing the necessary economic analytical framework: any CBA that can be shown to depend largely on the relative merits of esoteric discounting parameters is dead on arrival. The most promising route for getting somewhere in that regard is an approach that better describes the real world issues, (issues that Stern highlighted but didn’t directly model), a la what Weitzman has done, (though we don’t know for sure what types of answers we would get, his approach would likely auger for more aggressive policy than a standard CBA). However, James Annan has raised questions about the modeling of the climate in this work.

    Pursuant to the objections he has raised, I have two questions for the blog moderator(s) (read your response to my question in the other thread Gavin- thanks), and/or anyone else who can give me a good answer: if you are modeling average temperatures as a scalar of emissions over the maximum timescale that could be considered relevant for current emissions policy- say two centuries- is it best to describe that scalar as an uncertain single point estimate or an uncertain distribution of scalars? I wasn’t able to determine this from what I read of the certainty of uncertainty thread.

    Secondly, is it at all possible, given the current state of the science, to come up with any estimates of the magnitude and timing of long-term feedbacks- what Annan and Hargreaves have treated as forcings in their work that places very tight limits around climate sensitivity? One that could be employed in economic modeling. The question applies both to estimates and error bars around timing of these effects kicking in, timing around how long they will take to come to full fruition if relevant, (such as with ice sheet melt), and the magnitude of their effect on climate if they did. I’m not expecting a long answer actually, just a sense of how limited is the knowledge.

  32. 32
    Ray Ladbury says:

    I have never understood the seeming comfort that denialists take in trying to discredit the models, as if they were somehow discrediting the hypothesis of anthropogenic causation thereby. In reality, the case for anthropogenic causation does not depend in any way on the models. There is simply no doubt that climate change is occurring, and there is no other credibel driver that could provide the energy driving that change. Indeed the models are the only thing that limits the risks posed by climate change? How else would we know to expect 3 K per doubling and not 10 K per doubling? How else do we allocate mitigation resources effectively? Lack of certainty is not an excuse for inaction–let alone for complacency.

  33. 33
    PJB says:

    Re 11: I don’t understand how people can continue to pull the “scientific consensus is not scientific proof” card. Don’t people who make this statement understand that scientific consensus is the closest thing we will ever get to proof? Taking that road might as well be an argument against the whole of science and the means by which we come to accept anything as fact. The question “is there scientific consensus?” is asked by laymen, like myself, to feel confident that conclusions like AGCC, are made with an acceptable degree of certainty. Oreskes’ paper was designed to be a reasonable response of Science to this question. The IPCC exists specifically to this purpose (assuming policy makers are people). Unless I’m mistaken, scientific consensus is not a consensus of opinion (as you seem to imply with your herd mentality comment), but one of the actual science. The results of one paper help verify those of another, climate models help verify the basic assumptions of the science. This synergy that results when results do not contradict one another reduces the uncertainty. Throw in the peer review process, and the fact that many scientific papers go out of their way to challenge the conclusions of others, and you’ve got a pretty solid system. So while there may be many questions within climatology that remain to be answered, didn’t Oreskes’ paper do a reasonable job of letting us laymen know how well we can gauge the (un)certainty of the response to our question, “does the Science agree that AGCC is real?” A slightly less objective answer would come from the question “is the Science really sufficient to support this conclusion?” What’s the IPCC for again?

  34. 34
    Kevin says:

    Keith (#11):

    In your example 2 scientists published an alternative view going against the consensus. and they convinced enough people that enough evidence was built to support their view. Now there is a different consensus and the two scientists have a nobel prize.

    Are you saying that climate scientists are all so scared of going against consensus that there aren’t a few in the world willing to try for a Nobel prize by proving everyone wrong? If not, then why aren’t there scientists publishing contrarian papers for everyone to laugh at, but be unable to prove wrong?

    Additionally, a new consensus has now arisen in your example. Does this mean if someone publishes a paper against the new consensus they should be immediately given the Nobel prize, or perhaps more research be done? If that further research proves to be wrong, what does this mean for the consensus?

    You may be a scientist, but do you understand the scientific method? All theories in science are theories of consensus – the theory with the most supporting evidence is the theory of the consensus. If you want to knock it down you don’t just throw out more theories, you need facts that contradict or are unexplained by the current theory. And the new theory has to explain the old facts and the new facts.

    So far climate sceptics have been unable to find contrary facts or really even explain all of the current facts.

  35. 35
    petefontana says:

    What is an “entrainment coefficient”? Can anyone explain why it matters so much to the climate and climate models?

    Thanks in advance.

    [Response: In the tropics, the surface heating by the sun makes the atmosphere unstable. Convection results. Because of the large amounts of water vapour, clouds will form during that process and release more heat leading to further convection. The end result is a cumulus tower that can reach the tropopause (and a lot of rain). These moist convective plumes are highly turbulent and so they ‘entrain’ dryer air from outside the plume as they rise. To entrain means to gather air up from the environment and mix it with the plume. The entrainment coefficient in the Hadley Centre model controls how much air from outside the plume mixes in. If it is small, the plumes are smaller and rise higher, if it is large, the plumes are fatter but do not rise as high. This effects the cloud amount, upper tropospheric water vapour, temperature values and the Hadley circulation and so the climate can be quite sensitive to it’s value. In the real world, things are not this simple and different plumes will have different entrainment rates – more sophisticated parameterisations use a spectrum of plumes to do a better job of this – however, I think it’s fair to say that there isn’t a really good theory that predicts what the entrainment should be in any particular circumstance in the models. – gavin]

  36. 36
    Chris C says:

    RE 24

    No one said Pinatubo was a demosntration of GHG forcing, but a demonstration of model adequacy. The problem is that ‘skeptics’ won’t be happy unless they can have another planet Earth which we can use for experiment and have time-travel capability. Until then, bashing models, and using worn-out arguments will keep happening.


  37. 37
    cat black says:

    I find it generally shocking that the scientific community is not allowed to have a “consensus” when confronting a set of observations. How else are we to proceed with the work except to agree that the data is 1) real and 2) reflective of nature? And if it is real and represents natural realities then why can we not all, as intelligent people, agree (pending new observations) on a rational explanation for the observations? Science is a process, not a product as such, and it loops around endlessly taking new input and creating new ideas on the fly. This is a feature, not a bug, and it allows us to make provisional assessments and MOVE ON. The only reason someone would have trouble with that is if they think of the world in terms of unchanging absolutes, as if there can only be One Truth and not, instead, a working set of theories and a cloud of old and new observations that both support theory and yet point in additional fruitful directions.

    Likewise, when I hear someone say “well how can people possibly change climate? It makes no sense to me” as if that, in itself, is both the question and the answer, and to miss the obvious relevant fact that there are 6 billion of us, and all our unsleeping machines, and our cities and factories, working unceasingly in the effort, and then my head wants to explode with their narrow and self serving, relentless stupidity.

    I understand that there are dense scientific theories involved, and a crushing quantity of data and observations, and that this is overwhelming to anyone without the time and education to wade through it. But given that, and not saying that every single living human must understand entirely the total of the work, cannot people who are not able to wrap their heads around it simple — oh say — accept the current theory, and it’s inherent implications for policy, and otherwise STFU?

    Seriously. John Coleman (The Weather Channel) claims to have (I paraphrase) read dozens of scientific papers, spoken to many scientists, and thought about the question “a lot” and he is now convinced that AGW is a scam. My god, what an ego. Free speech issues thrown aside, what gives him the privilege to trash talk the life’s work of thousands of dedicated men and women who have probably already *forgotten* more about climate theory than John Coleman will ever know in his entire life?

    It’s really just anti-science rearing its head. So long as science, medicine and technology generate more stuff to buy people are happy. But once it turns up something troubling the ad homs start, it’s strawmen at every corner, and “who really trusts all that voodoo science anyway” all over the farm. Look people, you screwed up, OK? We all screwed up. Data is in, evidence all over the place. Things are falling apart around our ears. Time to face the music. It was a nice ride while it lasted, nothing lasts forever, thems the breaks. Get over it. Think about that whole “what is a solar economy anyway” question and really apply yourself to the answer, because like it or not, kick and scream all you like, doesn’t matter, the party is over.

  38. 38

    Bravo BBC! Great idea to find any insights behind all that contrarian bluster. I suspect that the low level of response to the reporters survey shows a certain degree of hesitation, perhaps healthy scepticism about a stance melting like Arctic Ocean ice in July.

    The question about models being flawed is not fair, because they pointed current warming in the right direction for decades, they have not changed projecting this warming trend despite a contrarian inspired certainty , inescapable variation, which requires a profound cooling trend to come any day, month or century, a perfect non argument presented to sway lethargic politicians in not changing their present pollution embracing course. Models represent all we know about the atmosphere, they forecast next few days temperatures with astounding precision, anti model chaps may have forgotten that they also project cyclone/hurricane tracks with unheard of precision compared to a few decades ago. All we know is perhaps not all there is, exploration through observation is not enough mingled with academic theory (models), there are many integrations left to do, I suggest doing more work in horizontal observations rather than always with data from vertical profiles. The two have to match, and I have found proof that vertical data extrapolations are not reconciled with horizontal observations.

  39. 39
    EricM says:

    RE: 23
    Disregarding the references to volcanoes and solar irradiation, what is your objection to the graph? Why is it lunacy? Is the simple cyclical plot of temperature versus time over the last 4500 years wrong? If not, then you should print it out and tape it to the wall as a daily reminder of why there are so many “skeptics” about AGW. Many scientists get so wrapped up in the technical discussion of radiative forcings, feedback mechanisms, the reliable of modelling, etc, etc, that they lose sight of the forest for the trees. This type of chart is way too basic to “explain” what is going on and is thus disregarded. The layman, however, looks at the simple temperature versus time chart and says, “by golly, looks like we’re warmin up – nothin near the peak though. Hey Bubba, grab me another beer will ya?”
    I think Timo in 9 has it right. Most people see a cycle that’s happened before, not a crisis. Mother Nature will adapt. So will we.

  40. 40
    Edward Greisch says:

    I could use some help with and other places on AlterNet. I direct the readers of to RealClimate once in a while. I try to convince them that AGW requires some really drastic changes and get resistance just like what RealClimate is always fighting. I think that there are several types of reasons for the resistance. Some of the reasons:

    The coal industry has a gross income of $100 BILLION per year. That $100 BILLION per year could be easily sunk by the nuclear industry unless people can be persuaded that nuclear power is dangerous. That $100 BILLION per year could also be decimated if people got serious about AGW. Do the coal companies have an incentive to lead people astray? Yes. Is $100 BILLION per year enough incentive? Yes. Can the coal industry afford to hire doctors, economists, environmentalists, web site designers, computer scientists, psychologists, advertising agencies, authors, publishers and lots of other people on $100 BILLION per year? Of course. Can the coal industry afford to set up hundreds of web pages on hundreds of computers in hundreds of locations and “game” the search engines on $100 BILLION per year? Yes. And they do.

    People try to use the web to find truth rather than doing it the hard way: getting an education. The search engines do not understand the web pages they find. They are just machines. They have no idea of whether or not the web pages they find tell the truth. In the US, we have “freedom of speech,” which means that nobody has to prove that anything is true before publishing it. The result is that lies get published far more than the truth. The average person is completely clueless and believes whoever seems to have the most authority. How hard is it to find the truth on the web? Very hard. Gavin, if you teach any courses, are they FREE on the web or do you charge tuition? If they were free, would they be easy and fun like cartoon shows, the level most people are willing to watch? Is your university library on the web as free downloads or do students have to pay outrageous prices for textbooks? Do you game the search engines like the coal companies do? If you look into how search engines sort out web pages, you will find out that they do mathematics on the number of links, etc. to figure out who the authority is. Search engines don’t ask human scientists for evaluations.

    Of course, the evolutionary design of the human brain is also a barrier to sanity.

  41. 41
    Edward Greisch says:

    There has been another confirmation of the idea that we will cause our own extinction in about 200 years if we don’t stop AGW. Extinction of Homo Sapiens is such a dire possibility that no such chance is tolerable. Severe action must be taken even on scant evidence. Here are the URLs again on how it happens:

  42. 42
    jacob l says:

    you might want to compare the bbc’s questionnaire to that of Steve Milloy
    bbc skeptic questionnaire
    I thought the bbc’s was much better.

  43. 43
    gator68 says:

    You story about the ulcers is a good one. However, before the evidence came out about the virus, why shouldn’t someone believe ulcers were caused by excess acid? Especially if someone made a drug based on this idea that worked? And what changed — was it bloggers complaining, or people doing experiments and publishing results?

    If the theory of AGW were untrue, all the deniers have to do is show where it is wrong. Do the science. Publish data. Instead, we see propaganda by non-experts promoting a mish-mash of conflicting arguments. This isn’t a case of “consensus” science vs. brave mavericks. This is a case of an evidence-based theory being confronted by evidence-less politics.

  44. 44
    pete best says:

    Hang on, the debate is over in some parts of the world. Europe for one as plans are afoot post kyoto etc to cut emissions significantly in principle and hopefully in reality. The UK is ratifying a climate change body and written into law on emissions cuts. USA and Asian governments recognise threat and have some current possibility of acting equally across all 52 states.

    Real climate has always been pragmatic and If I understand your position right it is that with significant emissions control started by no later than 2015 (400 ppmv first realistic 2C warming probability) and resulting in no more than 450 ppmv ultimately (as this is the guaranteed 2C minimum rise by this CO2 level) we can then stop rises from going above this temperature.

    All the major players now accept mainstream warming is occuring mainly because it is only 20 years since the human signal has arisen from natural variability.

    The contrarians are losing the battle but will we be in time is the issue for me.

  45. 45
    John says:

    #1 I must say I have to agree with your statement. I think a key ‘sceptics’ argument is that computer models are easy to get right in hindsight, but harder to get right looking forward. The trick, of course, is to make a model predicting the future which actually comes true. I think more people would believe the global warming theory if any of the IPCC models actually got it right. One only has to look at the 2001 IPCC forward looking forecast to see how wrong it was. Current global temperatures (2007) are below the ENTIRE RANGE predicted in that report.

    [Response: This is just not correct. 2007 is on track to be the 2nd warmest year on record and the long term trend of ~0.2 deg C/decade is exactly in line with projections. The specific projections from TAR are compared with obs in Rahmstorf et al (2007, Science) and show a very good match to trends. It should go without saying that individual years are subject to ‘weather’ noise variations, but I don’t think you even need to invoke that here. – gavin]

  46. 46
    Douglas Wise says:

    I agree with everything written by Keith in #11. I, too, started reading this website, sceptical for exactly the same reasons as Keith, and, like him, have become less so. Keith requires a real experiment to validate the models and points out the obvious difficulty of undertaking such. However, it occurs to me that there may be extant data that would allay most of my prevailing doubts. Having asked for it in a previous thread, I received no satisfactory response. If I may, I’ll try once more.

    I accept that CO2 is a greenhouse gas and that combustion of fossil fuels and deforestation have resulted in and will continue to result in atmospheric increases not seen in the previous 650000 years. In theory, this should lead to greenhouse warming which may be exacerbated by a positive water vapour feedback. The former will certainly happen but its extent may or may not have been exaggerated by the models. I lack the knowledge , experience and probably intelligence to make a useful judgement. I must therefore accept what I’m told by the model experts as an article of faith or look for corroboration from real data. The data that I think would convince me relate to changes in brightness temperatures as measured from space in various ranges of the infrared spectrum.

    I have read that the brightness temperature of infrared in the CO2-relevant band is 215K, that in the water vapour bands 275K and that passing to space unimpeded by greenhouse gases is 288K. I would expect the last figure to remain constant. With increasing CO2, I would expect the figure of 215K to be reducing. Given positive feedback from water vapour, I would also expect the figure of 275K to be falling. Are my assumptions valid? If they are, is there evidence for falling brightness temperatures? If not, why not?

    I would be extremely grateful for a response from Gavin or anybody else who is an authority on this subject.

  47. 47
    Rikard says:

    Gavin responded thus:
    [Response: Because you would expect a rapid warming at the beginning of the period and gradually slower cooling as you get closer to equilibrium – the exact opposite to the behaviour seen. … – gavin]

    As you have heard before, one of the sceptics arguments is the mismatch between warming (starting in the late 70:s) and the rapid increase of man-released CO2 (starting in 1945). Thus, they can refute your argument with the same argument you use for refuting them. Any comments?

    Also, the arguments from the “cosmic ray” theorists refers to a particular kind of solar activity, which peaked in the late 1990:s (particles of 10 GeV as derived from measurements of impacts in ion chambers, see eg Ahluwalia, 1997). While your argument refutes general solar activity as a sole climate driver, it doesn’t address this particular competing hypothesis. Can you further your argument in this respect?

    [Response: I’m not the one claiming that there is only a single driver for climate change. You need to take everything into account (including solar). When you do, the offset in the 1940s to 1970s is small. But if you take out GHGs and increase solar to anything you like, you still don’t get a match with the recent observations. You just can’t get an accelerating trend in the last couple of decades if your forcing stopped growing in 1960.

    The Ahluwalia curve (which is pushed very strongly and uniquely by Nir Shaviv) is made up of two separate cosmic ray curves (neither of which show a trend) but are offset. They are stitched together so that the ‘trend’ comes from starting at the lower curve and ending with the higher one. No continuous record shows any such increase. It is, to say the least, unconvincing. – gavin]

  48. 48
    Keith says:

    Wow. It’s good to see that I have provoked a debate. Firstly let me apologize, Richard, that my typing was not as good as it should be. It is Peptic ulcer rather than peptidic ulcer. That should clarify things as far as looking at the story online as to how this story developed.

    As for the two Nobel winners the story is summarised here

    The story goes that Barry Marshall and Robin Warren, in order to prove, to a skeptical scientific community, their theory, actually drank a suspension of H pylori so as to get an ulcer and then showed that treatment with antibiotics cleared the ulcer.

    So caerbannog and Ricahrd, there’s my clickable links. Oh and H pylori isn’t a virus. It’s a bacterium. Totally different.

    Thanks to Dave Rado for the links. Fabulous summary of some of the work and I recognised some of the methods that we use to attempt to computationally describe biological data. I wish I could respond with some decent links to similar issuse in my field but sadly most of the journals are subscriber only and expensive. J Med Chem tends to be the best and the cheapest if your particular institution has access. Oh and thanks for suggesting I was open minded. Much appreciated.

    I think though that a few people have misunderstood my point. I am agreeing that properly published data is the only way to go. On the other hand consensus is simply a majority view which can often turn out to be incorrect. There is no need to be so defensive. I also accept that the consensus could be correct but that is exactly why it should be tested. It’s a little sad though that my scientific integrity is being challenged when I am actually doing using the scientific method. Generate hypothesis. Test to generate data. Check hypothesis, revise and tests again. And keep going round that loop. But being part of or not of a consensus view is not in the scientific method. It is a view that is shared but has no actual scientific value in the end. As I think Our Nobel prize winner above demonstrate.

    I accept that the climate is changing, I just query whether this can be quantified with any certainty in a computer model without the experiment being done. Personally, as somebody who spends a considerable amount of time doing experiemnts in the lab I am uncomfortable with the level of experimentation that is being done (that is a personaly opinion that you are free to ignore). I find it tiring that this gets reduced to a slanging match and people get characterised as right wing oil lovers. This is a scientific debate and I am trying to give you an indication of my experience as an end-user of models.

    I actually sit right next to our molecular modeller at work. We’ve spent the last 4 years trying to understand exactly how our drugs are working on a molecular basis. This type of thing is supposed to be pretty well understood from a scientific point of view, but for 4 years we’ve got nowhere. The models gave a plausible and self consistent answer but when we subsequently tested it further they always failed. Eventually, what was happening was revealed to us in a crystal structure and all our ideas and models were wrong. It turns out that the protein rearranged itself to accomodate the drug; the so-called induced fit method. At which point we realised why 4 years of comupter modelling and testing ahd got us nowhere. My point is that sometimes nature does things which simply cannot be predicted by modelling. It’s not a freak event or the hand of God or any such nonsense. It’s that sublte interplay of biology, chemistry and physics that cannot be explained until after(!) you’ve had the eureka moment or that one piece of data. That is the nature of real wet dirty science. Models are great but they are no substitute for the real thing.

    So sorry folks, I think the models are still likely (in my experience) to be wrong and possibly by some margin. But keep going, please, becuase it’s quite clear that something is happening and so it’s important to keep testing the hypothesis. I am skeptical, yes, but I respect the difficulty of the work. I did not intend to suggest that the work was bogus. I just come at this from a different angle and with a different experience of models. I had just hoped that it might be valuable for one discipline to hear the experiences of another and maybe go away and reflect. For me I have found this site to be tremendously valuable and I’ve learned a lot. I’d hoped that might be a two way process.

    Over to you….

  49. 49
    guthrie says:

    #11, Keith- I’d love to have a second earth to experiment upon, but the ethical protocols preclude me sentencing 7 billion humans to be experimented upon. (Not to mention the lack of a second planet)

    So, since your gold standard is physically and ethically impossible, are you prepared to accept the physical experiments on infra-red absorption of CO2, and on other parts of the physics of the climate? Then, if you accept them, will you accept 20 years worth of modelling that is trying, and apprently succeeding in continual improvement?
    What would convince you that they can model 50 years ahead in climatology with worthwhile accuracy?

  50. 50
    David Thorpe says:

    I don’t know if you’ve come aross tis hoax perpetrated on scientifically illiterate contrarians in the last week?

    I was interviewed for BBC World Service’s Newshour last night about it – which you can listen to for a while on their website (the 20.00 hrs edition, about 20 minutes into the programme).

    Two points I made especially: I wish the sceptics would spend more time looking at the evidence for global warming and not waste their time with conspiracy theories: there aren’t any. And the writer of the hoax is anonymous because we may be thinking of another. Our message is – look carefully at the evidence.

    It is also talked about on today’s blog at

    In case you missed the hoax, it’s written up here: