The Food Gap predicts 2.4 degrees by 2020? I don’t think so.


The Food Gap study by an Argentinian NGO contains an embarrassing mistake: As its first key finding, it sais:

Following the current business-as-usual path, by 2020: The temperature of the planet would be, at least, 2.4ºC warmer.

This is of course patently wrong, and it only takes a quick look at the IPCC projections to figure that out. Which makes it doubly embarrassing, since as the first guiding principle they state: 

The analysis is based on the scientific evidence and conclusions from the IPCC Fourth Assessment Report (AR4).

The Guardian has the story; Realclimate has the scientific context.

Now of course this is being spun as if it’s alarmist propaganda gone wrong. Even the otherwise sensible Keith seems to frame it that way. No organization that wants to be taken seriously though would knowingly put in a glaring error like that, as it clearly blows away any credibility they may have had. The most likely explanation is that they honestly believed their own calculation. 

What can be learnt from this:

– Make sure you have the required expertise to write your story, and if you don’t, get people with such expertise to advise you. Base yourself on a proper reading of the relevant literature and/or on people who do.

– If people alert you to an error, check it (or let it be checked), and then fix it, even if that means postponing a deadline or changing something for the gazzilionth time.

Their refusal to correct their mistake after it was pointed out to them is flabbergasting. How stubborn, how stupid. I hope they learnt their lesson.


Tags: , , , , ,

97 Responses to “The Food Gap predicts 2.4 degrees by 2020? I don’t think so.”

  1. Dana Says:

    In a recent media article, Lindzen made basically the same mistake. He said:

    “the greenhouse forcing from man made greenhouse gases is already about 86% of what one expects from a doubling of CO2 (with about half coming from methane, nitrous oxide, freons and ozone), and alarming predictions depend on models for which the sensitivity to a doubling for CO2 is greater than 2C which implies that we should already have seen much more warming than we have seen thus far, even if all the warming we have seen so far were due to man.”

    He makes the exact same two errors as the NGO – ignoring the negative forcings and the ‘warming in the pipeline’. Of course, as a climate scientist, Lindzen really should know better. And I’m sure he does.

  2. Dana Says:

    The NGO will take heat for making this error – and rightly so. But I haven’t seen any criticism of Lindzen for doing the same thing (until I write about it on Skeptical Science). That’s a rather nasty double-standard. If anything Lindzen should take more heat, because he’s supposed to be the climate science expert.

  3. Bart Verheggen Says:

    Dana, very true.

  4. Stephen Says:

    Bart since I told the NGO their science was wrong last Sunday and a parade of experts did as well before the report was released I’m not sure you can draw your conclusion. My impression, based on several conversations, was they’d put over a year of effort into the study, had booked or done 25-30 interviews with media that they couldn’t back down. Even knowing they were probably wrong…and I think they did.

    The main thing they got wrong was the 2020 date. When we do get to +2.4C we will have many of the food problems they project

  5. Brandon Shollenberger Says:

    I was asked to address the comment made by Dana upthread by the blog host (on Keith Kloor’s blog). I don’t see the reason for his request, but since he asked, I figured I’d make a quick comment here.

    Dana, you say Lindzen ignores negative forcings. This seems to be contradicted by the fact Lindzen says, “Modelers defend this situation, as we have already noted, by arguing that aerosols have cancelled much of the warming.” You can certainly question whether or not Lindzen appropriately handled negative forcings, but it seems disingenuous to say he ignored them.

    You also say he ignores “warming in the pipeline.” I can’t justify this comment. As far as I can tell, Lindzen didn’t say anything about it, but he also didn’t give the numbers to show he was ignoring lag in temperature response. The lack of detail makes it possible, but not certain.

    Quite frankly, I don’t think Lindzen did anything rigorous enough for either of your criticisms to be applicable. Mind you, this lack of numerical analysis makes his claims hard to accept.

    He may be wrong, and his “essay” certainly doesn’t prove him right, but I don’t think you can fairly apply the criticisms you raise.

  6. Paul Kelly Says:

    The most likely explanation is that they honestly believed their own calculation. Where would they get such erroneous beliefs? Don’t they read climate blogs?

  7. Stephen Says:

    Paul just read my take on all this since I was ‘involved’

  8. Dana Says:

    Brandon, I think we’re arguing semantics here. Perhaps “ignored” is not the appropriate term, since technically Lindzen mentioned aerosols in the article. But his numerical calculation (based on ‘x’ radiative forcing we should have seen ‘y’ warming), he completely neglected negative forcings like aerosols. Perhaps that would be a more appropriate term to use.

    When Lindzen says “alarming predictions depend on models for which the sensitivity to a doubling for CO2 is greater than 2C which implies that we should already have seen much more warming than we have seen thus far”, that’s where he’s ignoring the thermal lag from the oceans. He’s using the IPCC equilibrium climate sensitivity value, but the planet is not currently in equilibrium. In this case, the term “ignored” is appropriate (“neglected” would also work).

  9. kkloor Says:

    Let me clarify something (which I should do as well in my comments at RC): I don’t have an issue with an NGO making an honest error. Based on what I’m reading from Stephen Leahy, it sure seems hard to imagine how they could make that error in the first place.

    But whatever. What gets my goat about this is that he went out of his way to try and get it corrected days before the report’s public release. And it seems that he got a number of climate scientists involved. Still, they refused to do anything about it. That’s just unbelievable to me.

  10. Gavin Says:

    Dana, A better way of stating it is that Lindzen makes a great deal about the uncertainty in aerosol forcing (which undoubtedly exists), but then does his calculation assuming that they have zero effect with zero uncertainty. Not at all a consistent position.

  11. Brandon Shollenberger Says:

    Dana, without seeing actual calculations from Lindzen, or at least the numerical results from those calculations, I don’t see a way to know what he did and did not ignore. I don’t find his comments compelling, but without more detail, I’m not willing to guess at what he got wrong.

  12. Dana Says:

    Gavin, I agree, that’s a good way of putting it. Then again, isn’t assuming they have zero effect with zero uncertainty the same as neglecting their effect?

    Brandon, Lindzen gives the 86% figure (see the quote in my first comment). If you look at the IPCC report and add up the anthropogenic greenhouse gas components he discusses, it comes out to right around that figure (I got 80%, but close enough). He’s very clear that he’s including all of the positive anthropogenic forcings and neglecting the negative forcings.

    He’s also quite clearly ignoring the thermal inertia of the oceans, as I showed in the quote in my last comment.

  13. dhogaza Says:

    Paul Kelley:

    The most likely explanation is that they honestly believed their own calculation. Where would they get such erroneous beliefs? Don’t they read climate blogs?

    Well, they are in Argentina, and unlike our host’s country (where almost everyone knows English better than most Americans), “English as a second language” is a reality in Latin America. Lots of people speak Spanish and even in Spain, the rush to learn English is very recent. They’re not culturally opposed as has been true in France (which a year or so ago lost an appeal in the EU to continue publishing all official docs in French as well as English), but it’s been a poorer, more isolated country and very seriously, in Latin America it’s similar. Tech people learn English but aren’t necessarily fluent in it.

    I’ve helped run what was once a large open-source software community, and in the beginning, the Spanish speakers had a very difficult time reading/writing/contributing due to our using (like so many international efforts) English.

    The Dutch didn’t. The French … not part of the deal.

    It’s really easy to assign malice – as Keith Kloor does – when isolation (Argentina!!!!) and language issues might well play a role.

    Of course, folks like Kloor would reject that.

  14. Paul Kelly Says:


    The report is footnoted with many references to IPCC and WMO reports, so it is doubtful a lack of language skills caused the error. I haven’t followed this much as it winds around the blogosphere, but it seems everyone could just agree that this is a very flawed report that should be ignored until it is redone using the correct science.

  15. Rattus Norvegicus Says:


    The IPCC reports are available in translation.

  16. Paul Kelly Says:

    Rattus Norvegicus

    Of course they are, which is why dho’s explanation doesn’t make much sense.

  17. Bart Says:


    Though Lindzen obviously knows about aerosols and inertia in the climate system, he choses to ignore their very significant influence in his calculation as cited by Dana in his first comment.

    Whereas about the NGO one could say “don’t assume malintent when incompetence does fine as an explanation” (though Stephen’s account shines a different light on it), for Lindzen that wouldn’t apply.

  18. Brandon Shollenberger Says:

    Dana, since you mentioned it, I looked at the figure in the IPCC report, and it seems to me Lindzen’s representation is accurate. The figure shows about 3W/m^2 of forcing from the things he listed (I’m not sure where freon falls). Albedo is shown as having a negative forcing of about half that. This is perfectly in line with what Lindzen said.

    Your complaint doesn’t make sense to me. So what if Lindzen didn’t include negative forcings in his calculation of that 86%? There is nothing inherently wrong with that. He did a calculation without negative forcings then discussed what people claim about negative forcings. It is perfectly accurate, and it is in no way what the NGO did.

    As for your second point, your quote doesn’t show what you claim it shows. What it shows is Lindzen claims we should have seen much more warming than we have (under certain assumptions). It doesn’t show how much warming we have seen. It doesn’t show how much warming he thinks we should have seen. Without these numbers, how can you know he ignores thermal inertia?

    For example, suppose we have seen .8 degrees of warming. Now suppose 86% of the warming we would expect from doubling CO2 would be 1.8 degrees. Now, let’s suppose with thermal inertia accounted for, we wouldn’t see 1.8 degrees yet. Instead, we would only see 1.2 degrees so far.

    That is still much more warming than the .8 degrees we have seen. It also doesn’t require ignoring thermal inertia. Given that, how can you know Lindzen didn’t think about thermal inertia? Maybe he did think about it, but he decided it wouldn’t change the (non-numerical) conclusions, so talking about it wouldn’t accomplish anything.

  19. Brandon Shollenberger Says:

    Bart, the more time I spend on this, the more what you guys are saying about Lindzen makes no sense. Allow me to paraphrase him, “We have 86% of the forcing one would get from doubling CO2 levels. There are negative forcings people claim would cancel out a significant portion of the 86%.”

    He clearly did a calculation without negative forcings then discussed the claimed impact negative forcings would have on his calculation. This is perfectly valid. There is nothing inherently wrong with doing a calculation which ignores certain inputs. In fact, testing hypotheses often relies on doing just that. Considering that, how in the world do you claim he ignored negative forcings?

    As for thermal inertia, what you guys are saying doesn’t make sense to me at all. Lindzen says we should have seen much more warming if we were at 86% of the forcing (discounting aerosols). You claim this means he is ignoring thermal inertia. I don’t get it. Are you guys actually saying we wouldn’t have seen much more warming than we have if we were at 86% instead of about 50%? If not, you can’t say Lindzen ignored thermal inertia.

    As far as I can tell, Lindzen was right on both counts. If we were at 86%, we should have expected to see much more warming (if sensitivity was >2C). Thermal inertia would change the exact amount of extra warming we should have seen, but it wouldn’t have stopped all the warming. And yes, there are aerosols people claim would cancel out much of the warming we would have otherwise expected.

  20. Bart Says:


    Lindzen remained sufficiently vague so that the implication to the echo chamber is clear, but so that he can defend himself (or you him) from outright falsehood. But looking at the substance, he’s making very much the same mistake as the NGO did.

    If you claim that there’s nothing “inherently wrong” with ignoring negative aerosol forcing and thermal inertia, than that should count for the NGO as well as for Lindzen. Since that’s the basis where both make a wrong argument, either both are wrong or both are right. Or there’s a double standard or misunderstanding somewhere.

    Lindzen implied (though left it somewhat vague) that since CO2 equivalent was already at 86% of a doubling, the warming according to the consensus estimate of climate sensitivity should have been much higher than waht is observed, and that therefore this sensitivy is overestimated. His argument goes wrong because 1) it ignores the negative aerosol forcing and 2) it ignores thermal inertia.

    1) and 2) are the same issues as where the NGO went wrong.

  21. Dana Says:

    Good summary, Bart.

    Brandon, Lindzen’s entire point in this quote is that we should have seen more warming by now from the GHGs we’ve emitted if the IPCC’s climate sensitivity is correct. This is simply wrong. He supports this incorrect conclusion by saying that we’re 86% of the way to the doubled CO2 forcing. This is wrong, because it neglects the negative forcings, which, if taken into account, bring the net forcing down to 1.6 W/m2, which is 43% of the way to the doubled forcing (3.7 W/m2). Lindzen is wrong by a factor of two.

    Now, he’s very sly about this, because he does mention aerosols, even though he’s neglecting them in his calculations. And he does mention that he’s only looking at the positive anthropogenic forcings. These statements are correct, but they do not support his conclusion. His conclusion is what’s wrong.

    It’s also clear that he’s ignoring thermal inertia, because without it, the warming would be 75% larger by now. The only way to say we should have seen “much more warming than we have seen thus far” is to neglect these two factors.

    The FEU made the exact same two omissions in their overestimate of the warming by 2020.

    Anyway, I’ve written an article about this, although it’s aimed at a general audience, so it’s very un-technical. It will be published on Skeptical Science later today.

  22. Brandon Shollenberger Says:

    Bart and Dana, you two are being ridiculous. Bart, you say:

    If you claim that there’s nothing “inherently wrong” with ignoring negative aerosol forcing and thermal inertia, than that should count for the NGO as well as for Lindzen. Since that’s the basis where both make a wrong argument, either both are wrong or both are right. Or there’s a double standard or misunderstanding somewhere.

    Lindzen and the NGO didn’t do the same thing at all. Lindzen did one calculation which left out certain inputs. He then discussed other inputs which could impact the calculation. This is not what the NGO did. The NGO did the same sort of initial calculation, but it used the result to make predictions about what will happen in the future without ever acknowledging negative forcings. There is an enormous difference. Dana, you say:

    It’s also clear that he’s ignoring thermal inertia, because without it, the warming would be 75% larger by now. The only way to say we should have seen “much more warming than we have seen thus far” is to neglect these two factors.

    I gave a direct response to you on this issue. I even included a hypothetical situation fleshed out with numbers. You ignored it. You simply repeated your claim that it is “clear” Lindzen is ignoring thermal inertia. It isn’t clear at all. Saying it is clear while ignoring my response doesn’t help anything. If I am wrong, and so is my response, so be it. But you have to show I am wrong, not just say it over and over.

    For now, let’s try to focus on one issue and resolve it. You both claim Lindzen ignored thermal inertia. I’ve explained (with numbers!) why I don’t believe such. Neither of you has responded to explanation, so I’ll try again. Would you please give me a direct answer to the following two questions.

    If we were at 86% of the forcings one would expect from doubled CO2 levels, and the sensitivity to such was two degrees, how much warming would we expect while accounting for thermal inertia? Is this amount significantly higher than the amount of warming we have seen?

  23. Heiko Gerhauser Says:

    This discussion of Lindzen sounds all too familiar:

    He has been using this line of reasoning for years. Lindzen thinks aerosols are a fudge factor, and gives little credibility to high aerosol forcing estimates. A few years down the line from my earlier post I now also know a bit more about thermal inertia and the wars being fought over ocean heat uptake. Let me suggest that Lindzen is also rather skeptical of claims that the oceans are taking up much heat in W/m2.

    In principle, it sounds easy to measure (to a chemical engineer like me at least who looks at the Earth as if it was a reactor vessel filled with water), either temperature change of the ocean times mass times heat capacity, or Radiation in, Less Radiation out from the Earth system equals accumulation.

    But in fact it is not, and an estimate of zero W/m2 going into ocean heat accumulation over the last few years is well within the error bounds of either method.

    Lindzen does think that aerosol forcing is close to zero and heat accumulation also close to zero and that the forcing today is therefore close to 86% of doubled CO2 and the reason we are not at 3C is that climate sensitivity is more like 1C per 3.6 W/m2 forcing. As straightforward as that.

  24. dhogaza Says:

    The report is footnoted with many references to IPCC and WMO reports, so it is doubtful a lack of language skills caused the error.

    I wasn’t talking so much of the making of the error, which clearly wasn’t caught by the scientist who vetted the report (and who was in the hospital when the error was brought to the NGO’s attention, and is in his 80s as well, so quite possibly was not only in the hospital but incapacitated).

    I was speaking of the reaction to being notified of the error, and that the language barrier might have played a role there.

    I’ve worked on a regular basis with people from a wide variety of countries, and language barrier issues are very real.

  25. Dana Says:

    Brandon, the only difference between Lindzen and FEU is that Linzen mentioned the factors he was neglecting, which I assume FEU did not. Lindzen then proceeded as though the factors he was neglecting did not exist (or assumed that they have zero impact on the climate, if you prefer to look at it that way).

    Heiko – perhaps Lindzen does think the aerosol forcing is close to zero, but he provided no support of that belief. He just said black carbon is positive and aerosols are negative, and threw in a reference to Ramanathan, and assumed the positive and negative effects have equal magnitude. Ramanathan’s latest work concludes that the negative aerosol forcing significantly outweighs the positive forcing, by about 1.4 W/m2.

    Click to access ramanathan_carmichael_2008.pdf

    So if Lindzen wants to argue that the net black carbon forcing is zero, he shouldn’t be referencing Ramanathan, which contradicts that position. Granted there is a large uncertainty and the net forcing *could be* zero, but the most likely value is strongly negative.

    As for your thermal inertia question Brandon, I don’t know how to quantify the thermal lag of the oceans. As I noted, without any thermal inertia, we would have seen 75% more warming by now. Quantifying the lag wouldn’t be helpful anyway, since Lindzen is extremely vague with his “much more warming” statement. How much is “much more”? To me, a couple tenths of a degree is not “much more”, so the logical conclusion is that he’s also ignoring the 0.6°C warming in the pipeline. I can’t prove he’s ignoring it, because his comments are so vague, but it’s the logical conclusion. It’s Lindzen’s own fault for making a subjective statement rather than a precise scientific one.

  26. Stephen Says:

    dhogaza. Hisas’ english was excellent, her understanding of climate science not as good. IPCC reports are extremely technical, very easy to mis-understand what you are reading.

  27. Brandon Shollenberger Says:

    Brandon, the only difference between Lindzen and FEU is that Linzen mentioned the factors he was neglecting, which I assume FEU did not. Lindzen then proceeded as though the factors he was neglecting did not exist (or assumed that they have zero impact on the climate, if you prefer to look at it that way).

    Dana, this is untrue. Lindzen did not proceed to do anything. He made the calculation. He discussed the negative forcings. He listed a counterpoint to the claims regarding negative forcings. He then never said anything about it again.

    He just said black carbon is positive and aerosols are negative, and threw in a reference to Ramanathan, and assumed the positive and negative effects have equal magnitude.

    This is also untrue. Lindzen never claimed the net forcing was zero. All he said was aerosols can cause warming. If you want to argue he implied the forcings were equal, you can (not that I’d agree), but it is ridiculous to say he assumed something when there is no evidence he did so.

    I can’t prove he’s ignoring it, because his comments are so vague,

    You said Lindzen ignored it. I said you couldn’t know this; you just repeated your claim. I disputed your certainty again; you said it was “clear” Lindzen ignored it. I pointed our there was no basis for your claim, giving a fairly lengthy explanation; you ignored what I said and again claimed it was clear Lindzen was ignoring thermal inertia.

    After all that, is it too much for me to ask for you to say, “I was wrong”? Or failing that, “You were right”?

  28. Dana Says:

    I’m not going to play silly games, Brandon. Lindzen’s conclusions were wrong. Period. End of story. He tried to justify those wrong conclusions by only looking at half the picture. That’s all there is to it. Lindzen did not provide any reason to support his assumption that the net aerosol/black carbon is zero. In fact, he referenced a source which says it’s not zero.

    And it’s still quite obvious that Lindzen ignored thermal inertia. The fact that I can’t prove it due to his vagueness does not mean he didn’t ignore it. The fact that he cited an *equilibrium climate sensitivity* value is very strong evidence that he did ignore it.

  29. Dana Says:

    By the way, my article on the subject:

  30. Paul Kelly Says:


    The 2.4C error here is not the story. The story is the NGO’s reported insistence, after the error was identified, that their science is solid. If they can’t admit the error underlying the report, what value can the report have.

    Hisas’ expertise is not climate and it might be something to know where she got her climate particulars. It was probably not from Dr. Canziana.

  31. Heiko Gerhauser Says:

    Hi Dana,

    I think you’ve got a pretty good grasp of the aerosol issue and you need to think a bit more about thermal inertia. As I said above, heat accumulation can be measured and the units are the same as for forcing, namely W/m2. There are two ways to measure it, take the mass of the water in the oceans in kg and multiply by temperature change in K and heat capacity in kJ/kgK and you get heat added to the ocean in J. Divide by the time in s and you get W, divide again by the surface area of the world and you get W/m2.

    Or look at the radiation hitting the Earth in W/m2 and the radiation leaving the Earth in W/m2 and subtract, again you get a value in W/m2. The two are roughly the same as heat accumulation in the atmosphere and in soil is negligible in comparison to heat accumulation in the oceans, and the standard chemical engineering wisdom applies: Accumulation equals Input – Output

    The radiation hitting Earth can be measured, so can the radiation leaving it, we know the cP of the oceans and their mass, and can, in principle at least, measure their temperature.

    Within the accuracy of these measurements, heat accumulation may very well be zero right now.

    This leaves circular logic for determining your “we would have seen 75% more warming” estimate. How do we get there, if we cannot measure it? Simple, with our estimate of climate sensitivity and forcings we need that much heat accumulation to make the equation balance, and as that much heat accumulation is about as consistent with our measurements as a value of 0, it glibly gets accepted as established fact.

  32. Dana Says:

    By the way, Lindzen has previously made this same argument, but actually quantified the amount of warming he claims we should have seen.

    “the observed warming is only about one-third to one-sixth of what models project.”

    Stefan Rahmstorf confirms that Lindzen’s main error is ignoring the thermal inertia.

    “[Lindzen’s] argument is incorrect because it ignores a critical factor: ocean heat uptake. Ocean heat uptake (“thermal inertia”) leads to a time lag of the actual warming behind equilibrium warming. Ocean heat uptake is not just a theoretical or modeled phenomenon, but a measured fact.”

    See pages 39-40 here:

    Click to access Rahmstorf_Zedillo_2008.pdf

    Don’t worry Brandon, I won’t ask you to admit that I was right.

  33. Bart Says:


    While the pdf of ocean heat uptake may include zero (as does the pdf of aerosol forcing (*), though barely), I’m quite sure that based on observations zero is not the most likely value. To take values on the extreme edge of the pdf for both aerosol forcing and ocean heat uptake, without offering a good argument as to why those highly improbably values were chosen, to then arrive at a value of climate sensitivity that coincides with a value that the author seems to have a special fondness for, is suspect.

    (*) AR4 has a figure of a pdf of aerosol forcing (based on Monte Carlo simulations), but I’m not aware of one for ocean heat uptake. I base what I wrote here on published estimates of ocean heat uptake, eg as used by Ramanathan and Feng (2009) who use a value corresponding to warming in the pipeline of 0.6 deg C (from memory).

  34. Heiko Gerhauser Says:

    Hi Dana,

    I would rather dispute this “a measured fact” assertion. What Trenberth was talking about it in his much quoted lament about not being able to account for the missing heat, is precisely the fact that recent ocean heat content measurements are awfully consistent with 0 W/m2.

    And on the 2.4C number by 2020.

    It’not nearly as otherworldly and “impossible” as is being made out by a lot of commentary on the issue. Present climate models are consistent with a lot of climate outcomes. Combine a rapid fall in negative aerosol emissions with a high climate sensitivity and a believable, but on the slow side, ocean heat uptake model, and 2.4C sometime in the 2020’s will come out of your climate model without any need to resort to tipping points and the like.

    Modellers falling over themselves to prove that aerosol geoengineering is a right terrible idea, because obviously the right solution must be abstinence and fasting and prayer, hmm, I meant no sinful emitting of CO2 and playing God and all, I know have looked at something like that, namely a rapid fall in aerosol emissions leading to a temperature spike. They of course assumed this for 2050 or 2100 or something like that, after we failed to do what is obviously proper, and merely masked the symptoms, instead of withdrawing from our addiction, and then for some reason instantly stopped resulting in huge warming rates.

  35. Bart Verheggen Says:

    Hey Heiko, you turned rather cynical since you left the sanddunes!

  36. Heiko Gerhauser Says:

    Hi Bart,

    well, I think Lindzen is biased, not biased enough to confuse fact with fiction, but he clearly doesn’t think the probability distributions are quite of the same shape as the majority of scientists do. I haven’t seen a pdf for ocean heat uptake, but lots of discussion of the issue and the difficulties of properly sampling the ocean, and how most of the uptake should be in the top 700 m, or how maybe quite a bit gets sunk in the deep ocean after all.

    A quick google gives me this from Wattsupwiththat:
    Biased as he is, the quoted paper gives a fair idea of the fights over ocean heat content, with Trenberth, Hansen and Pielke Senior all being cited. Especially nice is the overview of the ARGO measurement network.

  37. Dana Says:

    Heiko, John Cook did a nice article on OHC recently. I disagree with your claim that OHC measurements “are awfully consistent with 0 W/m2” and refer you to the article. It addresses the Douglass study referenced in your Watts article.

  38. Heiko Gerhauser Says:

    Hi Dana,

    I see that you do know the ocean heat content wars quite well, so I could have left out the mention of radiation in / radiation out and how heat content is calculated and so forth. It’s all in the link you provide, which is quite nice, though also biased with a different slant.

    I also followed the discussion between Pielke and Trenberth and over on the global change discussion group enquired about the radiation in / radiation out measurements. More recent data for that are presumably covered by the Trenberth paper cited in your link, the abstract of which gives little detail beyond noting that it’s still not possible to properly close the heat balance “Existing observing systems can measure all the required quantities, but it nevertheless remains a challenge to obtain closure of the energy budget.” Maybe, we’ve got a better handle on this than a year or two ago, when I last looked at the satellite radiation balance error bars.

    The sea level line of reasoning is interesting and makes sense, though it needs to be fleshed out a bit, like estimating sources for the rise, calculating what’s left over for thermal expansion and translating that into J and W/m2 with an attached uncertainty range.

    The deep sea explanation also makes sense, though clearly deep sea temperatures are not measured as well as the top 700 m and there’s some disagreement over how likely it is that much heat will end up there.

    I would maintain that the evidence is consistent with 0 and also with anything required to make climate sensitivities of 1.5 to 4.5 W/m2 balance with a range of forcing estimates.

  39. Heiko Gerhauser Says:

    Hi Bart,

    maybe a little, also on the value of some university (especially) and energy research institute energy research (less so)

    I might of course already be corrupted by the fact that I now work in a for profit business …

  40. Brandon Shollenberger Says:

    Dana, this is ludicrous. You made claims about what Lindzen said, and each time I showed them false, you refused to address it. You flat out made things up about what Lindzen said in his essay. When I demonstrated this, you said you weren’t going to play silly games. You then repeated one of the claims despite there being no basis for it (Lindzen never claimed the forcings are equal).

    Then there is the issue of thermal inertia. I’ve already gone over how you handled the discussion of this issue, so I won’t dwell on that. However, I will discuss what new things you now have brought to the issue. First, you say Lindzen has done what you claim he did before, and thus you have been right all along. This is fallacious. Whether or not Lindzen has ignored thermal inertia in the past in no way changes the fact you cannot demonstrate Lindzen ignored thermal inertia here.

    Worse yet, I went ahead and looked at the source you offered. When discussing Lindzen’s supposed claims, he references (amongst other things) Lindzen’s testimony in front of the British House of Lords. While the author of your source claims Lindzen ignores thermal inertia, this is directly contradicted by Lindzen’s testimony which says (in part):

    Even the fact that the oceans’ heat capacity leads to a delay in the response of the surface does not alter this conclusion.

    Now then, there is no way to reconcile your source’s claims with the facts. Your source didn’t say Lindzen was wrong about thermal inertia. It says Lindzen ignored thermal inertia. This is obviously false. Since it is false, it cannot offer support for your claims.

    There is absolutely no evidence Lindzen ignored thermal inertia.

  41. Brandon Shollenberger Says:

    After finding the obvious misrepresentation I mentioned above, I decided to look further into what Rahmstorf was saying about Richard Lindzen. Partly, I was annoyed at having been mislead by him. I don’t understand how Rahmstorf could make such an obviously inaccurate representation while providing a link to the page which showed it wrong. Also though, I was curious at the value Rahmstorf provided regarding thermal intake. He said the value was .6W/m2, a very round number with no error margin. This struck me as odd. To show what I found, let’s first look at what he said:

    Data from about 1 million ocean temperature profiles show that the ocean has been taking up heat at a rate of 0.6 W/m2 (averaged over the full surface of the Earth) for the period 1993–2003.21 This rate must be subtracted from the greenhouse gas forcing of 2.6 W/m2, as actual warming must reflect the net change in heat balance, including the heat flow into the ocean. With an observed temperature increase since the late nineteenth century of 0.8°C (see figure 3-3), and (as Lindzen
    posits, for the sake of argument) assuming this to be caused by greenhouse gases alone, we would infer a climate sensitivity of 0.8°C  (3.7 W/m2) / (2.0 W/m2) = 1.5°C. This is at the lower end of, but consistent with, the IPCC range.

    The abstract of the paper he cites says (in part):

    The time series of globally averaged heat content contains a small amount of interannual variability and implies an oceanic warming rate of 0.86 ± 0.12 watts per square meter of ocean (0.29 ± 0.04 pW) from 1993 to 2003 for the upper 750 m of the water column.

    If you multiply .86W/m2 by 70% (roughly the percentage of Earth covered in water), you get Rahmstorf’s .6W/m2 so that is clearly how he got his number. Now then, if you multiply .8 by 3.7 by .5, you come up with 1.48C. This is not within the range of values given by the IPCC, but after rounding to significant digits it is (1.5C). So this much of Rahmstorf’s position is correct.

    However, Rahmstorf is wrong to simply use .6W/m2. Doing so ignores the margin of error his source lists. Because of the margin of error, his source’s value is actually .74-.98W/m2. Scaling this by 70% gives .52-.69W/m2. Now then, obviously the higher value will produce a result within the IPCC range. However, plugging in the lower value only gives warming of 1.4C.

    This is not within the IPCC range given by Rahmstorf. His claim that Lindzen ignored thermal inertia is not validated by his own method as long as one allows for the margin of error listed by Rahmstorf’s source. The only way Rahmstorf can justify his paragraph is to ignore the margin of error for a value, something which cannot be done.

    In short, not only is there no evidence Lindzen ignored thermal inertia, the evidence which is claimed to show such is mathematically unsound. As before, the more time I spend on this, the more what people say about Lindzen makes no sense.

  42. Dana Says:

    Brandon, you need to stop playing these silly word games. I’m not interested. Saying “I’m aware this effect exists but I’m going to disregard it because I believe it’s inconsequential (even though my references shoe it’s not)” is no different from ignoring the effect. Whether you’re willing to admit it or not, Lindzen’s conclusions were wrong precisely because he ignored these effects in his calculations.

    If you really want to give him credit for mentioning the effects before ignoring them, feel free. I don’t really care. Frankly I think Lindzen’s is playing you for a sucker. The point of my article is that “skeptics” are unwilling to hold their fellow skeptics accountable for their scientific errors. You have proven me right.

  43. Brandon Shollenberger Says:

    Dana, you say:

    Saying “I’m aware this effect exists but I’m going to disregard it because I believe it’s inconsequential (even though my references shoe it’s not)” is no different from ignoring the effect.

    As I have said several times, Lindzen does no such thing. You claimed Lindzen assumed something. You provided no evidence for your claim. I highlighted the lack of evidence for what you claimed.

    You have never refuted what I have said. All you have done is equate my comments with playing word games. Choosing to dispute my comments without ever addressing them is a good way to ensure that nothing will be resolved.

    At this point, our options are simple. We can both repeat ourselves ad nauseam, you can address my comments, or one of us can leave. I would much prefer the second option, but failing that, I promise I will take the third.

  44. Dana Says:

    Brandon, in the section you quote, Stefan appears to be playing Lindzen’s game and simply doing a back-of-the-envelope calculation to show that even ignoring all negative forcings, the thermal inertia of the oceans alone brings the sensitivity into the IPCC range (barely – actually I would argue it doesn’t, because the IPCC puts the likely range at 2-4.5°C for 2xCO2). It’s common practice to take the most likely value and round to only one or two significant digits in such a simplified calculation.

    Regardless, ignoring the ~1 W/m2 of negative forcings is not reality. If you take those into account, the formula becomes 0.8 * (3.7/1.0) = 3 W/m2. Look at that, right on the IPCC most likely value.

    So basically you just confirmed that 40% of Lindzen’s error comes from ignoring thermal inertia, and the other 60% comes from ignoring negative forcings.

  45. Dana Says:

    Geez you need to stop posting new comments while I’m typing.

    Tell you what Brandon, if you admit that Lindzen’s conclusion that we should have seen “much more warming than we have seen thus far” is wrong, then I’ll admit that he didn’t ignore the two factors in question.

  46. Dana Says:

    Oh and one more thing I can’t let slip by. Are you seriously criticizing Stefan for ignoring error bars and taking the most likely value? Hellooo? The error bars on the aerosol/black carbon forcing are much larger than those Stefan neglected. Not only did Lindzen ignore those error bars, but he took one of the *least* likely values, assuming the net forcing was at the very lower possible end at 0 W/m2.

    This is the exact sort of double-standard “skeptics” employ that I talked about in my article. You criticize Stefan while ignoring that Lindzen did the exact same thing, only worse.

  47. Brandon Shollenberger Says:

    Tell you what Brandon, if you admit that Lindzen’s conclusion that we should have seen “much more warming than we have seen thus far” is wrong, then I’ll admit that he didn’t ignore the two factors in question.

    Dana, I don’t think I have the knowledge to make a sound judgment regarding the impact of aerosols. As such, I cannot agree. With that said, I will repeat something I said in my second comment here. I don’t find Lindzen’s comments compelling. I found nothing wrong with his essay, but I don’t think a lack of mistakes in it means climate sensitivity is below 1.5C.

    Bart asked me to respond to two very specific points. Those points are all I am willing to take a position on. Beyond those points, I remain agnostic.

    Incidentally, your offer seems extremely disingenuous. Immediately after making it, you made another comment repeating a claim you offered to retract (if we reached an agreement). This doesn’t make any sense to me, especially since you gave me no opportunity to accept or reject your offer before you made the new comment. This, combined with the fact you still haven’t addressed my actual comments makes me (regrettably) choose the third option now.

    If Bart wants me to comment more here, I’ll respond to him. Otherwise, I see no point in me saying anything further.

  48. Heiko Gerhauser Says:

    Hi Bart,

    being an interesting discussion I’ve looked at the Food Gap report. I don’t think they used the temperature number as an input, or that they tried to make a prediction for temperature.

    The forecast for food production in 2020 is from another study I think. Their own work consists in taking the impact by 2020 on food production from that other study and add in population growth and come to the conclusion there’s a gap, say 4% + 11% = 15%, with the solution being different diets and greenhouse gas reduction, and no mention of increased agricultural productivity as an option. They do mention adaptation, but I think that probably didn’t make its way into their calculation (ie the say 4% I mention in my example is from the other study with adapation excluded).

    So, they probably just don’t understand the IPCC report very well and quoted it poorly, I guess indeed not realising that the 490ppmCO2 equivalent number and 2.4C increase don’t have to go together in 2020 due to aerosols and thermal inertia.

    In a sense, I agree with Dana they are doing the same thing as Lindzen in effect for 2020 that Lindzen is doing for the present. The difference is probably that they are clueless non experts, rather than seriously claiming that aerosol forcing will rapidly drop etc.. and Lindzen is an expert who is a bit out of the mainstream on what he thinks credible. Though, maybe the guy they were relying on for advice on the climate chapter actually is an expert who really is worried about 2.4C because of a combination of a rapid aerosol drop-off, little ocean heat uptake and high climate sensitivity, or maybe he’s just old and incapacitated etc…

    Overall, the Food Gap report doesn’t seem particularly alarmist, a lot of environmental organisations put out similar fare. I don’t see any evidence of bad faith, and can’t say I am disgusted by them not listening to people pointing out supposed errors. It’s poor judgement and cluelessness.

  49. Bart Says:


    Perhaps the disagreement here is due to the word “ignoring”, which would strictly speaking not be correct since Lindzen does mention ocean heat uptake and aerosol negative forcing. However, in his back of the envelope calculation/argument as quoted by Dana upthread, he implicitly assigns a value of ~zero to both (without clearly saying so, but otherwise his argument doesn’t make sense). That is basically the same as the NGO did (though they probably were unaware of these issues rather than picking a value at the extreme outer edge of the pdf. This unawareness of these issues indeed do not apply to Lindzen; on that we seem to all agree. Which makes his committing of that error actually worse imho).

  50. Bart Says:


    Good comment. The report’s conclusions may indeed still apply to when the world actually reaches 2.4 deg above pre-industrial.

    They quote the 2.4 number as a key conclusion though, so I think they probably calculated it themselves, just wrongly so. It cannot possibly have a scientific reference.

    I agree with your last paragraph.

  51. Heiko Gerhauser Says:

    I think I didn’t put this very clearly, I think the report’s conclusions are independent of the 2.4C above pre-industrial. They didn’t use that number for anything, I think at least. What I think they did was to take somebody else’s estimate for the impact of climate change on crop yields by 2020 and then they combined that with an estimate of the increased demand to calculate a food gap. The 2.4C I think is just meant to be background information taken from the IPCC report, not a conclusion of their study. Unless I misread them.

  52. Dana Says:

    Heiko, if that’s true (I haven’t read the report yet), it makes the FEU unwillingness to just change the temp value in 2020 quite dumb. I’ll take a look at it later.

    I agree with Haiko and Bart that Lindzen Knows what he’s doing and FEU seem not to (about temp changes). They consulted with a climate scientist who’s 87 and infirm (according to Gavin), so maybe he was careless. I agree Lindzen is worse for intentionally neglecting these errors, for over three years, too.

  53. Dana Says:

    Yes, I agree with Heiko. The Food Gap did put the incorrect projected temperature changes up front in their very first “Key Finding”. However, the discussions of impacts on agriculture seem to come from the IPCC report and various other UN reports. They seem to be independent of the temperature projection.

    Maybe the FEU weren’t willing to remove the error because it was their #1 key finding, and had probably already gotten significant attention before they were notified of the mistake. But it seems as though they could have just removed that bit of the report without impacting the rest.

    A very poor decision to leave it in.

  54. Brandon Shollenberger Says:

    Bart, let me try providing an example to demonstrate why I think you and Dana are being absurd:

    My tip jar should have more money in it than it does. Fifty people put money in the jar. I noticed the average amount going into the jar was two dollars. My fellow employees say the right amount of money is in the jar because they think some people made change with the tip jar.

    In my example, would you say I am ignoring the possibility of people taking money back out of the jar? I presented both sides of the argument, so how could you?

    Beyond that, would you say I did the same thing as a person who left off the last sentence of my scenario? Of course not. One scenario presents both sides of the technical dispute. The other scenario does not even mention a dispute exists.

    Given this clear and vital difference, how can you equate Lindzen’s action (specifically regarding negative forcings) with the NGO’s action? Also, you say:

    Perhaps the disagreement here is due to the word “ignoring”, which would strictly speaking not be correct since Lindzen does mention ocean heat uptake and aerosol negative forcing.

    It’s a little strange for you to say something about the essay which is so obviously incorrect. Lindzen’s essay never mentioned thermal inertia. The only example of Lindzen mentioning it anyone has discussed was when I pointed out a source offered by Dana (a book by Rahmstorf) falsely claimed Lindzen ignored thermal inertia in his testimony for the British House of Lords. This inaccuracy is compounded when you say:

    However, in his back of the envelope calculation/argument as quoted by Dana upthread, he implicitly assigns a value of ~zero to both

    Nothing in his “calculation/argument,” as quoted by Dana or otherwise, implicitly assigns a value of zero to thermal inertia. Lindzen never mentioned thermal inertia in his essay, but that doesn’t mean he ignored it. Seeing as there were no calculations provided in his essay, there is no evidence he ignored thermal inertia.

  55. Bart Says:


    You lost me there. What are you trying to say?

    Your last paragraph doesn’t make any sense to me. Either he mentioned ocean heat uptake but implicitly assigned a value of zero to it, or he didn’t even mention it implicitly assigned a value of zero to it. In the latter case the word “ignoring” would clearly apply; in the former case that could be a point of (semantics) discussion, but not one I’m particularly interested in.

  56. Heiko Gerhauser Says:

    Hi Bart,

    Lindzen’s used variations of this argument in various talks over the years, in some he mentioned ocean uptake, in some he didn’t. I also looked at the link to Ramhstorf provided by Dana, and Rahmstorf refers to another talk of Lindzen. And Rahmstorf was clearly wrong to say that Lindzen didn’t mention ocean uptake when he in fact did. I think you didn’t follow that little side track proffered by Dana.

    I have a rather more charitable view of Lindzen’s argument. Firstly, the guy is convinced there’s heaps of evidence for low climate sensitivity, ie, if some experimental evidence is offered to counter that view he’ll dismiss it unless it is solid.

    I’ve been trying to think of a nice illustration for this behaviour, preferably one avoiding the climate wars: think of cold fusion. If somebody offers evidence that in an experimental set-up heat has evolved, people convinced cold fusion is crap will immediately assume that it must be something else rather than cold fusion, and if the calorimeter is 95% certain to be right, say, I am sure critics of cold fusion will summarily dismiss the whole experiment. And will be mightily unimpressed, if the defenders of cold fusion complain about the obvious error of the critics of choosing a value at the outer edge of the pdf.

    Secondly, I rather sympathise with his concerns about the way aerosols are being used to make model hindcasts work out. And thirdly, I also like attention being brought to the the fact that most warming to date may have been masked and that we only have poor measurements of the actual degree of masking.

    So, in my view it’s not an error, it’s not an attempt to mislead, and the argument is not entirely without merit, but nonetheless I think it’s weak and somewhat circular, ie making real sense only if there are in fact other strong reasons for dismissing a climate sensitivity of 3C as likely.

    You and Dana are far too tempted I think to view Lindzen using this line again and again, as an act of bad faith or a deliberate attempt to mislead.

  57. Bart Says:


    I removed your comment since its sole content was to bash people you disagree with.

  58. Dana Says:

    Sorry guys, I don’t play semantics games. Saying

    “Even the fact that the oceans’ heat capacity leads to a delay in the response of the surface does not alter this conclusion.”

    Is no different than ignoring thermal inertia unless you explain *why* it doesn’t alter the conclusion. We’re talking about science here, not high school Debate class.

  59. Dana Says:

    And to be clear, that is precisely what Lindzen does. He merely says “Even the fact that the oceans’ heat capacity leads to a delay in the response of the surface does not alter this conclusion” with no further explanation.

    This is where Brandon and I are talking past each other. I’m a scientist. To me, waiving your hands in the air and saying “this effect I don’t account for won’t make a difference” is no different than ignoring it. Stefan and I, on the other hand, behaved as scientists and actually quantified the factors which Lindzen claims make no difference. Lo and behold, of the warming Lindzen claims “we should have seen”, the ocean lag accounts for 40% and aerosols account for 60%. And it’s particularly egregious that Lindzen’s reference to justify ignoring aerosols (Ramanathan) says that they are a strong net negative forcing.

    If you really want to play this game of giving Lindzen credit for mentioning these factors that he proceeds to ignore without justification, go right ahead. I’m sure that’s exactly what he was hoping ‘skeptics’ would do by mentioning them. But he was wrong to ignore those factors in his calculations, and it resulted in a completely incorrect conclusion.

    And despite being informed of his errors, Lindzen has continued to make them for over 3 years, periodically publishing media articles with the exact same wrong conclusions, and misleading the general public. That is far worse than FEU making a dumb, but unintentional error.

  60. Herman Vruggink Says:


    We extend our deepest gratitude to Dr. Osvaldo F. Canziani, former Co-Chair of Working Group II, Intergovernmental Panel on Climate Change, for his thoughtful guidance, direction and contributions which made the production of this report possible.

    Guidance? what guidance?

  61. Brandon Shollenberger Says:

    Bart, I give up. I can’t bring myself to care about your claimed confusion given the apparent lack of effort you have put into this exchange. Getting basic facts about the contents of the material being discussed is a bad sign, but tolerable. What I can’t stand is you making a claim while ignoring the fact I have already addressed it. Multiple times.

    At this point, I can see no value in me posting any further on your blog. If I make the same point three or more times, and you still refuse to even acknowledge the fact I have made the point, how could I possibly be expected to continue talking to you? Should I exert more effort just so you can continue to directly contradict me while ignoring what I say? I think not.

    I won’t guess at your motivations or mental processes, but I will say this. You have completely ruined any chance of me taking you seriously.

  62. Dana Says:

    I’d give up in your position too. Semantics arguments simply don’t convince many people. Especially scientists.

  63. Steve Bloom Says:

    No discussion of Lindzen should take place without acknowledging his failure over a twenty-year period to account for paleoclimate even while producing a long string of failed papers trying to prove a mechnaism to explain low sensitivity. [edit. No namecalling. BV]

  64. Peter Wilson Says:

    Steve Bloom

    You trite dismissal of Lindzens papers as “failed” is simply pathetic in light of the long string of proven failures of the IPCC’s models and hypotheses. The fact tat global temperatures have, at the very least plateaued, while CO2 levels and emissions rise faster than ever, indicates a level of success for arguments for low climate sensitivity, in contrast to the falsification of high sensitivity models it implies.

    Success or failure of hypotheses in science is judged against observation, not the acceptance of those with vested interests in the debate. Compared to the verdict of nature, the opinions of all the Team scientists and various august bodies are worthless -its the old evidence versus authority thing again

  65. Dana Says:

    Sorry Peter, but global temperature changes since the mid-’80s are consistent with a climate sensitivity of about 3°C for 2xCO2 (the IPCC’s most likely value).

  66. Dana Says:

    By the way Bart, I hope you don’t mind if I give a little plug. My Skeptical Science post on the subject:

    Has also been picked up by The Guardian:

    Comments in both articles have linked back to this post (in reference to our discussions about Lindzen and “ignoring” aerosols/thermal inertia). That’s where Peter Wilson came from.

  67. Heiko Gerhauser Says:


    I think the word isn’t ignore, but dismiss. Lindzen dismissed aerosols and ocean uptake.

    “Ignore” implies Lindzen actually believes that aerosols and ocean uptake are the explanation, rather than low climate sensitivity, and that he chooses not to present that information, even though he thinks it credible.

    Let me suggest another thing. Most “skeptics” on blogs have good intentions, just like most “alarmists”. Leave aside for the moment, what you need to believe to fall into one or the other group, or what label to attach to the two groups that people are being pigeonholed into by “you are either with us or against us” logic.

    For most, there is no financial game in deception or lying, and the presumption I have is that they participate in the climate wars because of a combination of the fun factor and because they want to do some good. Heavy verbiage on how all the members of the dark side are are the same and can’t be trusted, I find rather offputing.

  68. Dana Says:

    I think “dismiss” is a fair description, Heiko. It’s still just a minor semantics issue. I think “neglected” is accurate too (in terms of his calculations).

    Anyway, at some point in the (hopefully near) future I’ll do an article that actually looks at the numbers and uncertainties. Given the uncertainties in aerosols and thermal inertia, I’ll try to come up with a range of surface temperature changes that we “should have seen”, like Lindzen should have. That will allow for a quantitative evaluation of his statements. But I’ve got a few more ‘Monckton Myths’ to work on first.

    So much misinformation, so little time.

  69. Jeffrey Eric Grant Says:

    I have read through these posts to try to get a glimmer of what real scientists spend their time on. I am a retired engineer and this reminds me way back when I was a member of the US Society of Naval Architects and Engineers, they had rousing discussions over one or two words in an ‘official’ offering ready for publication.

    I didn’t like that then, and I am put-off by the discussion now.

    My interest is in the technical side. I have been watching ‘weather forecasts’ intently for my entire life. And I do know the difference between those and the global climate process; my problem is that while I have been studying the climate process intently for the past three years or so, I have yet to have that ‘aha’ moment where I finally have a gut understanding of the problem.

    So far, I just don’t agree that we are living at a time where the global temperatures will get so hot that it will cause a mass extinction (or the seal levels will get so high they will render sea-side cities uninhabitable). I mean, we are not even close….

    Please, can you give me a little guidance? Do you think we can design an experiment and measure heat flux coming onto the earth as well as measure the radiation going out, directly? Since the climate system is contantly changing, I wouldn’t think the two numbers are identical, but knowing that would help steer the discussion in a more direct way. It would also assist me in knowing whether I should be alarmed, or not.

    Thanking you in advance.

  70. Dana Says:

    Jeffrey, satellites have measured the heat flux in/out. See Trenberth et al. 2009. The difference is about 0.9 Watts per square meter more going in than out.

  71. Heiko Gerhauser Says:


    thanks for the paper. If I read it right, the errors in the radiation balance are still huge compared to those 0.9 W/m2 and he actually bases that number on climate models.

    “There is a TOA imbalance of 6.4 W m−2 from
    CERES data and this is outside of the realm of current
    estimates of global imbalances (Willis et al. 2004;
    Hansen et al. 2005; Huang 2006) that are expected
    from observed increases in carbon dioxide and other
    greenhouse gases in the atmosphere. The TOA energy
    imbalance can probably be most accurately determined
    from climate models and is estimated to be 0.85 ±
    0.15 W m−2 by Hansen et al. (2005) and is supported by
    estimated recent changes in ocean heat content (Willis
    et al. 2004; Hansen et al. 2005).”

  72. Bart Says:

    I think Heiko is correct. In his 2010 Science perspective article, Trenberth writes:

    The difference between the incoming and outgoing energy—the planetary energy imbalance—at the top of the atmosphere is too small to be measured directly from satellites. Nevertheless, the satellite measurements are sufficiently stable from one year to the next, so that by measuring incoming solar radiation and outgoing infrared radiation, it is possible to track changes in the net radiation.

    Both sentences are important here.


    Some good overviews of what the problem entails are e.g. this RealClimate post outlining the CO2 problem and at SkepticalScience the big picture by Dana. In the latter you’ll see e.g. references to satellite and ground based measurements that show the increasing greenhouse effect: Thosed wavelengths where CO2 absorbs are increasingly being radiated back to the earth’s surface.

    Btw, we most probably won’t witness sea levels inundating large parts of the world in our lifetimes. But our actions or inactions do have a profound effect on the chance of that happening to those who come after us. See e.g. my two recent posts on sea level changes (and sea level vs temperature).

  73. Herman Vruggink Says:


    ” it only takes a quick look at the IPCC projections to figure that out. ”

    As a non atmospheric scientist i take a quick look and i know the IPCC’s conclusions. If i take a quick look, the first thing i do is reading the graph, and what is my conclusion? : almost 1 degree between 2000 and 2020. Nobody told me : “do not use this graph for scaling or consult a atmospheric scientist for conclusions”

    At first i was laughing about the silly NGO but i am slightly changing my mind:
    Should i blame this person? One of the IPCC conclusions : World temperatures could rise by between 1.1 and 6.4 °C (2.0 and 11.5 °F) during the 21st century, depending on the emission reductions.
    In what way is the NGO thinking? : Did the World take serious action the past 10 years? : No, the world did not. Is it likely people will take serious actions to reduce CO2 emissions? It doesn’t look like it at all. So : we have to follow the upper scenario.

    Another misleading thing is the non use of a clear reference year. “Before industrial times” is very misty and is making reference to a uncertain year with an unknown global temperature. The Cancun deal “not more than 2 degrees ” is doing the same, smuggling a half degree of non CO2 related heating in the period 1850 – 1950.

    Dana is trying to escape to change subject and start a discussion about Richard Linzens interpretation of science. Although this is a interesting subject indeed (another posting?), i think this is not the subject of this article. I think the subject : “What can we predict for 2020? ” is interesting enough to me.

    As i am a non atmospheric scientist i have the following questions to you Bart as a specialist :

    *If 2,4 warmer is a wrong conclusion, what can we predict for 2020 to your opinion?
    *Somewhere in IPCC 2007 there is mentioned a 0.2 degree per decade mentioned to work with: is this correct?
    * Can i predict 0.4 degrees warmer in 2020 than 2000?

    I suggest scientist leave the first 20 years blank in a prediction graph if they can’t say a thing about this period.

  74. Dana Says:

    Herman, I can answer those questions.

    1) The IPCC projects somewhere in the ballpark of 0.4-0.6°C warming between 2000 and 2020.

    However, the shorter the timeframe, the larger role short-term noise plays. For example, between 2000 and 2010 we expected to see about 0.2°C warming, but saw a bit less than 0.1°C.

    2) Yes, the current warming rate is around 0.2°C per decade.

    3) 0.4°C is within the range of projected temperature increase between 2000 and 2020, but if making predictions, it’s smart to give the full range of possible values.

  75. Herman Vruggink Says:

    Thanks Dana, So we will see at least 0.3 °C in the next 9 years.

  76. Dana Says:

    No, I wouldn’t say that. The natura short-term factors which slowed the cooling of the surface the past decade could continue to slow it over the next decade too. There’s a nice graph here which shows just how much short-term temperatures can vary while still remaining consistent with the range of climate model projections:

    The most likely warming over the next decade is somewhere around 0.3°C, but there’s a fairly wide range of possible values.

  77. Bart Says:

    Dana, Herman,

    I wouldn’t say trhat the most likely amount of warming over the next decade would be 0.3 degrees. The rate of wareming over the past 30 years has been around 0.17 deg/decade. It’s perhaps possible that it would nearly double in the next decade, but not ‘most likely’. Also in the model projections, it takes until later this century for the warming rate to really pick up speed.

  78. Dana Says:

    Good point. Most likely from now to 2020 should be about 0.2°C. The fact that 2001-2010 was below the average rate doesn’t necessarily mean we should expect 2011-2020 to be above the average rate.

    I should also correct my previous statement. It’s tough to eyeball that IPCC temperature projection graph, but the projected change by 2020 does look like about 0.4°C above 2000.

  79. Herman Vruggink Says:

    Okay, 0.2°C

    I suggest to follow the IPCC specific calibrated sense:virtually certain > 99 %,
    very likely 90-99 % , very high confidence > 90 % , likely 66 – 90 % high confidence ± 80 %

    Most likely = Very likely ? So Cooling is very unlikely 1 – 10 % ? Fine with me if you even want to use likely, but if the slowed warming scenario will be the case in the next years, somewhere between 2020 and 2030 it must change virtually certain to a rapid warming.

  80. Heiko Gerhauser Says:

    Hi Herman, Dana and Bart,

    Looking at the past, warming rates above 0.2C seem unlikely, but at some stage we need more to get to 5C between 2000 and 2100. This more comes from a combination of high sensitivity and aerosols no longer keeping up with greenhouse gases. And with greenhouse gases having long residence times, the potential for suddenness then hangs on aerosols.

    At least, on the no tipping point or major non-linearities view of climate sensitivity, which also says that it matters little, whether the forcing is solar or CO2 or aerosols. Not that it’s presumed that there are no differences, or that this would hold for wildly differing climates (roughly speaking, more than 10C removed from the present).

    On the view that these simplifications hold, a fall by 2020 would be due to aerosols going up unexpectedly, and a rise of 1C would be due to aerosols going down.

    That leaves out “natural variations”. Solar is small, and cloud cover and the like are subsumed under feedbacks, I can only see ocean heat uptake variability as a reasonable explanation. In other words, cold water rising to the surface for a decade would give a greater heat uptake of the oceans in W/m2 and a lower global surface mean temperature increase by 2020, and slower heat transfer for a decade the inverse. I think the conventional view of natural variability also boils down to saying that this ocean heat uptake variability can act on scales of days, months and up to two or three decades, but knock off no more than 0.2C or so from the decadal trend dictated by climate sensitivity and the defined forcings.

    Now, to predict 2020 even on the conventional view we need a good picture of aerosol forcing changes, but we’ve got a terrible idea even of how aerosols have changed over the last 100, 30 or 10 years. Bart is the expert there, and I gather that calculating sulphur emissions in millions of metric tonnes from tonnes of coal and heavy fuel oil burnt times their sulphur content is not enough. You need to know aerosol size, residence time and location, with some places very effective (supposedly ship emissions over the tropical ocean) and in other places, aerosols making maybe little difference. So, changes like banning high sulphur fuel oil or making high chimneys mandatory or a building boom for coal fired plants in particular tropical countries all could have an outsize impact on world temperature by 2020. Hey, they could be the main reason for the rapid warming between 1980 and 2000 and the somewhat slower warming over the last decade.

    And finally, while I think the conventional view has merit, in my mind, I assign a somewhat unknowable probability to significant non-linearities and randomness coming from clouds, water vapour and the like. I can both accept the possibility of thermostat like effects and for runaway warming of the boil away the oceans and turn the Earth’s surface into a pressure cooker of a few hundred C and a few hundred bar steam pressure variety. Or that climate can move up or down by 1.5C over a hundred years without any change in CO2 or solar forcing, with the physical explanation lying in changes to cloud reflectivity or the water vapour content of the upper atmosphere.

    Back to Herman’s question: Take the decadal changes over the last 150 years and a conservative forecast is that we are going to see a repeat of one of those changes, and no upward or downward outlier. There could always be a trendbreak, but when? That’s hard now.

  81. Herman Vruggink Says:

    @Heiko says:

    ” Take the decadal changes over the last 150 years and a conservative forecast is that we are going to see a repeat of one of those changes, and no upward or downward outlier.”

    This might be the most reasonable approach but i don’t think this is in line with the IPCC predictions. It’s not a casino where your chance for black is 50% even you have hit the red colour already 15 times in a row. The climate play table is out of balance. If we have seen 15 times stable years or very slow warming, the chance for real warming is growing every year. Because we are not able to implement effective ways of reducing emissions in the next decade, we will see up going CO2 for sure. We must see warming the next decade or admit that the IPCC predictions were a little bit over the top.

    Looking back on the warmest decade ever measured, 0.1°C warming (in average) between 2010 – 2019 is very spectacular to me already: It means we have to see between two and seven new warm global Temp records ( the last decade we didn’t seen one, if we consider 1998 still the warmest). I think the IPCC only needs a 0.1°C warming the next decade to stay in the game.

    Global warming is a fact, the influence of CO2 is a fact. The only remaining and most important question is: how fast?

  82. Heiko Gerhauser Says:

    If all that’s holding back the warming temporarily is cold water from the deep ocean, while the forcing is steadily building up, then yes we should see steadily increasing likelihood of a warm spurt.

    If it’s not just CO2 that’s increasing but also aerosols due to explosive growth in the developing world and all the successes in fighting pollution there ending up mainly affecting black, ie warming, aerosols, then why shouldn’t we see a repeat of say the 1970’s in terms of trend warming?

    Two of my related blog posts:

  83. Jeffrey Eric Grant Says:

    Dana, thanks for the report by Trenberth. Do you think the uncertainties will be cleared up soon? For me, a net positive net radiation (inbound) certifies that we are in a warming period, regardless of cause. Also, it seems that the heat sinks are on the surface and there is no heat build up in the atmosphere or above.

    Bart, you seem to be saying that the heat balance at the top is very nearly zero, certainly within any error bandwidth. How could we have a net inbound increase at the surface and be nearly zero at the top?

  84. Bart Says:


    No, I wouldn’t put it that way. I think that there is a positive radiation imbalance at the top of the atmosphere, but it’s not directly measureable from space because the required accuracy is missing. The reasons I think there is a positive radiation imbalance are that 1) the globe is warming (according to many different metrics), 2) the oceans are still taking up heat (even though the heat uptake in the upper 700 metres seems to have slowed in recent years) and 3) the radiative forcing is still increasing and climate response is not instaneous.

  85. Jeffrey Eric Grant Says:

    OK, from what I have read the atmosphere is VERY SLOW to display the forecasted increase of temperatures. 0.1C/decade is extremely slow to me; the IPCC is stating that we want to stay lower than 2C rise in the next century. So far, so good!
    BTW, if in fact the earth is warming, I would EXPECT every year to be warmer than the last!

    Dana stated that TOA net increase of radiation is about 6.4 watts per square meter (per year?), but Bart states that it cannot yet be measured, presumably because the sensors are not sensitive enough.

    So, if there is no direct proof what the net radiation is, how can we certain exactly where we stand? Can someone explain or reference a paper that addresses a study that directly measured the net radiation? How has it changed over time?

    In the meantime, I have a nagging feeling that even with all the $Billions spent on this research, we have not progressed to a definitive answer. After all, if we were at that point, we would be talking more about what needs to be done to mitigate or adapt to the consequences.

    I’m sorry…..I’m just trying to be practicable. I am an engineer, so I am focussed on what to do. To keep hashing and rehashing the AGW theory to me is a waste of time (if we have progressed from there). If Al Gore was correct in stating that the debate has ended, why are we still having the debate? I mean, really….let’s get on with it.

    My understanding concerning the recent meeting at Cancun the delegates put together a document which transfers all authority on what to do to the UN. In my mind, that just about cements in what will be done. All that is needed are the signatures of the member states. We don’t need to debate those actions because that action is not a democracy and our input is not welcomed.

    So, let’s get back to our discussion here: first (1), I would want to ‘prove’ that the earth has entered a period of catastrophic warming (with a direct measurement). Then (2) I would want to establish a theory as to why; what mechanism comes close to explaining the reason for the warming. Lastly (3), I would want to come up with a science based affordable plan to address the warming.

    Can this be done in a reasonable period? It seems like we have spent all of our time on the second part, and try to use that as justification for the third part, without ever measuring the first part.

    I live in Connecticut and can state that this year may become the ‘worst’ winter on record for most snow, lowest average temperature, most naturally caused financial losses…etc. Looks a lot like the pictures I’ve seen from the ‘Little Ice Age’.

    Don’t get me wrong, I am a conservationalist. I joined the Sierra Club when I was in High School. I spent many days up on Mt. Rainier skiing and snowshoeing. I was an Environmental Engineer for quite a few different companies. I have used those CFL lamps ever since they became available. I purchased carbon credits from before they were popular. I love the sight of windmills….

    and yet, I want to do what is right. Science based solutions are the only way to go. To state that Polar Bears are in jeapardy and may become extinct because I happen to drive a Cadillac is just not science based to me.

    I’ll keep an open mind. I’ll keep reading as much as I can. I still have not has that ‘aha’ moment when I finally understand the underlying principles of this endeavor.

  86. Dana Says:

    “0.1C/decade is extremely slow to me”

    The current temperature rise is closer to 0.2°C per decade, and projected to accelerate unless we reduce GHG emissions.

    “Dana stated that TOA net increase of radiation is about 6.4 watts per square meter (per year?)”

    No it’s around 0.9 W/m2, but as Bart said, we can’t measure it precisely. Suffice it to say we know there is an energy imbalance.

    “if we were at that point, we would be talking more about what needs to be done to mitigate or adapt to the consequences….why are we still having the debate?”

    That depends who you mean by “we”. Climate scientists do talk about solutions. The problem is the “skeptic” movement is trying very hard to prevent that discussion.

  87. Bart Says:


    Summer is warmer than winter, yet I’m sure you don’t expect every single day between winter and summer to be warmer than the preceding day, do you?

    SkepticalScience could be a good resource for you, e.g. here. The increased greenhouse effect (IR being “trapped”) can be measured both from space and from the surface.

    “Catastrophic” is in the eye of the beholder, and different people favour different ways of dealing with climate change. Those are not really in the realm of science (which doesn’t mean they’re not important, mind you; to the contrary)

  88. Herman Vruggink Says:


    ” the IPCC is stating that we want to stay lower than 2C rise in the next century.”

    If this is the statement of the IPCC than i agree, but i think they mean 2C rise from 1850. This is still very unclear to me.

    “how can we certain exactly where we stand? ”
    I don’t think we know where we stand, i think we will know more after 10 years time.

    “If Al Gore was correct in stating that the debate has ended”
    I think after AL Gore’s ‘An Inconvenient Truth’ the debate started.

    “I’ll keep an open mind. ” That’s the best thing you can do, but it will be clarified as “sceptical”


    “That depends who you mean by “we”. Climate scientists do talk about solutions. The problem is the “skeptic” movement is trying very hard to prevent that discussion. ”

    Is the “skeptic” movement trying to prevent the discussion? I don’t think so.
    Perhaps you are turning some things around here?

  89. RickA Says:

    Herman Vruggink at February 3, 2011 at 23:27:

    You indicated the 2C rise was measured from 1850.

    I thought it was measured from the last IPCC report (2007).

    In other words, I thought they wanted to keep the future increase from 2007 to 2100 below 2C.

    Maybe that isn’t right?

  90. Dana Says:

    The IPCC did not set a ‘danger limit’ or specific warming target. The internationally-accepted value is 2°C above pre-industrial levels. See here:

    Herman – yes, the “skeptic” movement is trying very hard to keep the discussion in the realm of whether or not humans are causing global warming. What we should be discussing is the appropriate action in response to the known human-caused warming. But by denying that anthropogenic warming is established, “skeptics” can avoid this difficult discussion (which invariably ends in the conclusion that carbon pricing is necessary – precisely what “skeptics” want to avoid).

  91. TimG Says:


    Sceptic opinions are varied but most agree that humans are causing some warming but suspect the magnitude has been greatly exagerrated. Of course, AGW activists don’t like to argue that point because it is complex. They prefer to beat up strawmen by claiming that the debate is about whether humans are causing warming. It is not.

    From my perspective I can accept that CO2 is a plausible risk but it is only one among many. But the biggest problem with CO2 is economical alternatives do not exist and are not likely to exist any time soon. A carbon tax is not a magic wand and will not change that.

    Lastly, what many skeptics oppose is not a ‘carbon price’ but the mountains of red tape that would come with any regulation – red tape that is inevitable when dealing with an invisible substance that is undetectable once it is released into the atmosphere (i.e. it is really easy to cheat on CO2 regulations and get away with it).

    It is not clear that the harm caused by over regulation of the economy will be less than the harm caused by climate change itself.

  92. Herman Vruggink Says:


    @Dana says: ” The internationally-accepted value is 2°C above pre-industrial levels. ” pre-industrial =before 1850. This is including non CO2 related warming (natural). So: 1°C left. But how fast? is this discussed? 1°C increase in 250 years is very much acceptable to me, but 1°C in 25 years? …..

    There are deniers and there are skeptics.
    Not all believers in AGW (i do) do not automatically accept carbon pricing as a use full solution ( i don’t )

  93. Jeffrey Eric Grant Says:

    Dana: “There is a TOA imbalance of 6.4 W m−2 from
    CERES data ” from Heiko on 1/28/11 up-thread, while computer models show an imbalance closer to 0.9 w/m-2 – but I am not looking for model data, I am looking for radiation actually measured.

    Bart:”Summer is warmer than winter, yet I’m sure you don’t expect every single day between winter and summer to be warmer than the preceding day, do you?”
    No, of course not. However, when averaging out annual global mean temperatures, I would expect them to increase every year, unless there was some forcing which had not already been taken into consideration.

    Herman: I would expect to be labelled a “skeptic” because I am still looking for my ‘aha’ moment. The evidence I have seen so far does not lead me to an earth catastrophy.

    I have yet to see a definitive carbon budget for earth. We all do better with energy use. I do know that my ‘carbon footprint’ is orders of magnitude lower than a jet-setter, or Al Gore – for that matter. As I currently understand what CO2 is not wanted (where the C is from stores in the form of coal, oil and natural gas), I believe I would release more CO2 by burning wood. I looked into heating my home with geothermal energy – but it is extremely expensive, so I have not done it. I looked into a roof top solar collector, but I hate to cut down all those trees to give me a good look at the sky. I used to be for wind turbines until I looked at it closely and found that a fossil fuel plant was needed for back-up when the wind did not blow. I love hydro-electric as an electrical source, but we have run out of un-tapped rivers; they are already fully developed. Nuclear is the way to go (at this point), but the environmentalists have all but blocked them from being built.

    So, if atmospheric CO2 will continually increase (and, thus temperatures), how could it be possible to change this increase to a decrease? Or, maybe adding aerosols to the atmosphere could counter the CO2 effect. I think we should address this so temperatures will not continue to rise.

    Only thing left is limiting the need for energy (conservation or population contraction, or nomadic living).

  94. Herman Vruggink Says:

    In fact we can say : Dana and Bart you are right in all things but then the question is: and now what?

    TimG Says:
    “It is not clear that the harm caused by over regulation of the economy will be less than the harm caused by climate change itself.”

    and Jeffrey Eric Grant Says:
    “Only thing left is limiting the need for energy (conservation or population contraction, or nomadic living).”

    Even if we forget that the evidence we have seen so far does not lead us to an earth catastrophy, and we all accept Global warming is a problem, we don’t have a solution. We have to reduce emissions at least with 80% to have a change on some result without guarantee.

    People wants to consume more and more. With a growing population and a growing need for everything i fail to see how on earth we are able to reduce CO2

  95. Bart Says:

    It seems like we’re getting somewhere!

    In fact we can say : Dana and Bart you are right in all things but then the question is: and now what?

    Who am I to disagree ;-)

    As I mentioned before, “catastrophic” is a judgment call; not a scientific fact. But we seem to have some agreement across the spectrum of participants in the discussion here that the real debate ought to be concerned with the question: So what do we do? And naturally, different people come to different answers on that one. As long as we don’t bend the science around to fit a preferred policy, all is good and well IMO.

  96. Dana Says:

    I agree, the real debate is “what should we do about it”? Achieving 50-80% reductions in global GHG emissions by 2050 is a pretty monumental task. That’s why international negotiations are critical. Every country can say “our emissions are too small to make a difference” (even the USA), but if everyone agrees to reduce emissions, then you can make progress.

    How each nation decides to accomplish this is up to them. The key component is a price on carbon emissions. What each country does with the funding from carbon pricing, whether it be returning it to the public through other tax cuts or investing in green tech R&D or something else is up to them.

    As for the costs vs. benefits, I’m working on an article on that subject right now. Should be published on Skeptical Science sometime next week. Spoiler alert – the benefits of carbon pricing (the amount of damage avoided) almost certainly outweigh the costs, by a significant amount.

  97. Dana Says:

    Oh I almost forgot, I published a quantitative assessment of Lindzen’s errors and how much warming we “should have seen” when accounting for all factors. It comes out to about 0 to 2°C with a most likely value of 1°C, so it’s simply not correct to say “we should already have seen much more warming than we have seen thus far”. The amount of warming thus far is well within the range of what we “should have seen”.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: