29 maj 2014

Lennart Bengtsson and his media gambit on climate change

Some background and replies to Lennart Bengtsson's post

I am sad to have witnessed the changes in Lennart Bengtsson's media presence over the last few years. At first it was just a few comments in local media such as this article in UNT 2009 stating among other things that a doubling of carbon dioxide in the atmosphere would only result in a temperature increase of about 1 oC as a result of the logarithmic forcing of CO2.  This is misleading, of course, because it ignores feedbacks which increase that number substantially.   He even admits in his comment, that this could be taken as a way of playing down the problem, but at the same time he writes that it should provide perspective.  There are further statements in that article that we will come back to later.

Thus, I do not think his ideas on climate has changed much the last 5 year. What has changed is where and how he communicates them. Over the last years he has been commenting in our biggest newspapers and on Swedish radio (DN, DN, DI and SR) sadly trying to give the impression of providing a fair assessment of the science. Another sad part in this history are his over the top comments on the blog in Sweden which won the “prize” Obscurantist of the Year by the Sceptical Society of Sweden for pushing pseudo science about climate change. Bengtsson joining (thereby supporting) the GWPF was the straw that broke my back. Supporting an organisation that among other things pushed the NIPCC report IMHO shows that you do not have a great desire to provide a fair assessment of climate change. (Just as you would not join a far right party just to teach them about racism.)

Bengtsson makes these statements but does little to show they are grounded in any research.  Therefore I was very happy to see that he tried to publish some of his critiques in the scientific literature. The sad part was Bengtsson's over reaction to the rejection of his arguments when scientifically examined.

In short I and many others have reacted to Bengtsson's claims in different media and felt that they should not stand unopposed. So below I have gathered some statements by Bengtsson on the blogs and in nation-wide media over the last years and explain why they can not be taken as mainstream.

Bengtsson about climate sensitivity and future warming: 
That the earth's climate is slowly getting warmer is a fact, as is the slow rise of the sea level of about 0.03m each year. However, from the end of the last century the earth's temperature has only risen about 0.8 degrees, despite a striking increase of greenhouse gasses. The temperature rise has occurred at an irregular pace including a period of trivial warming during the last 16 years. During this time no warming of the sea surface has occurred.

Individual model simulations have calculated a global warming by 2100 of 6°C or even more, but those have been judged as very improbable by the IPCC (2007). The slow global warming, especially during the last 15 years, reinforces this view.
after facing opposition about the statement by among others Christian Azar and Markku Rummukainen to the answer above Bengtsson replied,

 The IPCC (2007) does not say anything explicitly about how probable a warming of 4 degrees is, but it cites without criticism a study (page 802) that estimates that the probability for a warming on 4 degrees or more is about 5 percent.

We judge the probability as even lower because several studies during the last years point in this direction.

Answer: Well since Bengtsson tried to publish some of his claims on this and the review is open publicly you could just head over there and read why Bengtssons arguments were rejected. This sentence from one reviewer points out what I think is among the largest problems with Bengtssons argument
“Hence the expectation that all expert estimates are completely consistent within a simple energy balance model is unfunded from the beginning.” 
But there is more, go and read the reviews.

Another frustrating part is the use of the temperature record over the last 16 years, talking about sea surface warming when we know that measures of deep ocean heat is showing a temperature increase. We also know that sun, ocean and volcanic variations effect climate in a way that the models can struggle with. Foster and Rahmstorf tried to take that in account and that showed a much clearer trend, an increased temperature trend. There also is new research published by Shindell and Kummer that could explain some differences between models and recent temperatures. So it is not clear at all that temperature record of the last 16 years means that we have a low climate sensitivity. One should also remember that other ways of estimating climate sensitivity exists and some gets higher values than those Bengtsson tries to push. It is troublesome that Bengtsson seems to reject some of those studies without any references to scientific literature.

Moving on to the claim about how probable an increase of 4 degrees is. Well the IPCC quite clearly stated that they did not judge how probable the different scenarios were and Bengtssons claim that they uncritically did so on page 802 in IPCC 2007 report simply is false. I pointed this out in a comment at that time. Go and read for yourself. So how likely is a temperature increase of 4 degrees? Well, doh, it mainly depends on how much fossil fuels we burn which in turn depends on lots of things, but if we continue on this path it seems like we will reach 4 degrees of warming in the future.

Bengtsson on sea level rise:
The sea level rise will be between 20, 30 to a bit over 50 cm.  A larger increase would require huge emissions of greenhouse gases which hardly is probable. /.../ so a catastrophic sea level rise of 1-2 m /.../ is improbable.

The IPCC (2013) will say about the same on this as before (he thinks).

During the last 20 years no acceleration of sea level has occurred. Any clear correlation between the sea level and temperature during the last century is not to be found.
Past and future sea-level rise. For the past, proxy data are shown in light purple and tide gauge data in blue. For the future, the IPCC projections for very high emissions (red, RCP8.5 scenario) and very low emissions (blue, RCP2.6 scenario) are shown. Source: IPCC AR5 Fig. 13.27. - See more at: http://www.realclimate.org/index.php/archives/2013/10/sea-level-in-the-5th-ipcc-report/#sthash.bqfnX0iv.dpuf

Answer: Well we all know now that Bengtsson was wrong on what the IPCC might say in its report as they report a upper value of 98 cm with a 66% probability to be in that range (not ruling out larger values). And as Stefan Rahmstorf writes  “As the IPCC also notes, we could end up “several tens of centimeters” higher if the marine-based parts of the Antarctic ice sheet become unstable. Leading ice experts, like Richard Alley and Rob De Conto, consider this a serious risk.”.

About an acceleration of sea level rise and its correlation with temperature, one could argue a bit about the acceleration of sea level rise but I cannot see how one could rule out an acceleration over a longer time scale (why try to find this in only 20 years of data?) and there definitelyis correlation between sea level and temperature in the literature.

Bengtsson on extreme weather events:
Extreme weather events have not gotten worse which can be shown from statistics on tropical storms and extra-tropical storms, tornadoes and various local floods.

Answering the question (in the paper DI); From my point of view, there is a discrepancy between the IPCC's scientific report and its Summary for Policymakers. The later is by comparison dire. How should one understand this?

From my point of view there is an unfortunate tendency, especially in the media but even from some representatives of the IPCC, as we have seen in the last report, to exaggerate weather phenomena and create an atmosphere of exaggeration among the public to gain support for drastic measure to reduce greenhouse gas emissions.

Here it is the scientific results that have had to give way, if they are not dramatic enough. The latest report (2013) is less dramatic than the IPCC's previous ones, playing down extreme weather events and reducing climate sensitivity.

This does not fit the simple catastrophic picture, so therefore they have re interpret this. Some activists even have been able to interpret the extremely cold weather in USA during the last winter as a product of climate change. It is this kind of thing that causes science to lose its credibility.
Answer: Well, some types of extreme weather events have actually gotten more frequent as the IPCC says. The discussion on what can and can not be attributed to climate change will continue. However, a lot of the uncertainty about what kind of events that are increasing globally is due to lack of data which makes it just as wrong to say that they (with lack of data) are not increasing as to say that they are increasing. As for the statement about the Summary for Policymakers being more alarming than the report, where is the evidence for that? I have not found it and if Bengtsson think so he should point out what he is talking about.

When Bengtsson is labeling all of the scientists talking or writing about the cold weather in USA and how it could have come about partly due to climate change, its just sad. Why Bengtsson chose to do that rather than publishing a scientific critique against their published scientific understanding is strange to me.

Bengtsson on pseudoscience in climate science and scientific journals selective publishing:
What is perhaps most worrying is the increased tendency towards pseudo-science in climate research. This is revealed through the bias in publications towards only reporting results that support one climate hypothesis, while refraining from publishing results that deviate. Even extremely cold weather, as this year’s winter in north Eastern USA and Canada, is regarded as a consequence of the greenhouse effect.

Were Karl Popper alive today we would certainly have met with fierce critique of this behavior. It is also demonstrated in journals’ reluctance to address issues contradicting simplified climate assessments, such as the long period during the last 17 years with insignificant or no warming over the oceans, and the increase in sea-ice cover around the Antarctic.
Answer: If Bengtsson really thinks that  pseudo-science exists in climate research he should be specific and point out the articles that are pseudo-science. He does not do this and his claims that journals do not want to address the last 17 years of temperature record, cold weather in Eastern USA or the increase in sea-ice cover around the Antarctic is just false. We have papers doing that but it might not support his own theory, that so far has failed the scientific process of peer review.

Example of silly comments from Bengtsson on the Swedish blog that was used by the organisation winning the “prize” Obscurantist of the Year by the skeptical society in Sweden.

We already have written about the one where he talks about sending people to North Korea.

And here we have three comments in threads discussing the green roots and their connection to Nazism.

Reminding all enthusiasts of the green movement of its roots are very important. /.../ They resemble the enthusiasms that existed in the National Socialist movement, nature and origin. Hitler and some of his closest associates were vegetarians, cared about nature and animal life. The German peasant society was the ideal, as many today also believe. German and Swedish Romanticism have much in common and have a life force that has over lived many. To be aware of this dubious history is a necessity.The unfortunate thing in our time is that this is not done and this is unfortunately a consequence of the lack of historical knowledge. The risk is that it as before can degenerate. I recommend reading of Hitler's table talk in the bunker where similar remarkable ideas were discussed."
"An excellent compilation that could develop into a article if our dear journalists dare to take this into. To translate into Swedish society today, there are certainly distinct features of green folk roots, as in Germany and the parties that follow this clearly are the Sweden Democrats, Green Party and the Centre Party. One might ask oneself the rhetorical question, where would these parties have stood in the 1930s. Perhaps these three parties might finally find their common roots?"

(The Swedish Green Party is one of the strongest critics of today's right wing populists the Sweden Democrats in which some of its founders had connections to Nazism-parties, a party that today is mostly about trying to stop migration.)
And here is one where he criticize a whole field (temperature reconstructions) and Michael Mann
"To reconstruct climate from proxy - observations is a complex activity that one must approach critically. There is even a challenge to reconstruct the global temperature distribution before World War II because then we are missing observations from the free atmosphere. In some regions such as Europe we have made good progress but Europe represent only about 2 % of the earth's surface. To produce graphs of the earth's temperature 10,000years back is probably based more on creative thinking and imagination than on solid data that is clearly linked to the basic meteorological parameters. An experiment which I have not seen would be to reconstruct the climate of the last 75 years and only do this with the help of proxy observations including error estimates, I have not seen this anyway. Just do a thought experiment to reproduce this past winter's weather from proxy data? Or how many have realized that Europe's temperature is only weakly correlated with global temperature and Iceland, Greenland and Northern Scandinavia hardly at all! Here, in my view, both Mann and Co. as well as their detractors got way too much attention despite the fact that one can not find much substance in their writings . This calls for anew research approach."

Personally I think both Mann and Marcott has defended their published articles in a good way. And while one can agree that reconstructing climate from prxies is complex it seams like Bengtsson needs to learn the basics in proxy calibration before he lectures the experts in the field.


As I have shown, Bengtsson has been wrong at several points in our national media with his predictions and statements before. Joining an organisation like the GWPF some of whose members clearly push climate nonsense and the way the whole organisation has behaved lately was only the last step in a long chain that made it impossible to longer ignore his biased reporting to media.

(Read the links, they support the claims I make. If a blog is linked they often have links to relevant scientific papers.)

16 kommentarer:

  1. And some other important news today:
    IPCC co-chairman says scientists being intimidated by climate change deniers

    Speaking to The Irish Times prior to giving a public lecture in Dublin, he said claims that there had been no global warming for 15 years were “quite a clever way to divert the attention of policymakers from the broader perspective of climate change”.


    1. "He said natural variability could explain the current “hiatus”. Thus, IPCC scientists were looking at a longer “climatological period”.

      From APS: http://www.aps.org/policy/statements/upload/climate-review-framing.pdf

      "This IPCC text lists internal variability, forcing inadequacies, and model over-responsiveness as all possibly contributing to the stasis, but without a quantitative resolution. To what would you attribute the stasis?
      • If non-anthropogenic influences are strong enough to counteract the expected effects of
      increased CO2, why wouldn’t they be strong enough to sometimes enhance warming trends, and in so doing lead to an over-estimate of CO2 influence?
      • What are the implications of this stasis for confidence in the models and their projections? "

      Well according to Stocker then, APS surely must be one of those "denier" organisations pushing the "wrong" questions, trying to divert the attention, no? Drop the subject, you are painting yourself in a corner.
      /JPC Lindstrom

    2. You should read the links in the post. There are papers that try to take this in to account, of course they look at both variability that slows and enhance the global temperature. As you can see if you actually would have read the links in the post there are also other ways that could give higher climate sensitivity then natural variability.

    3. That was not my point at all. Most models "try" to take natural variability into account but evidently they fail miserably if the "hiatus" is due to natural variability.. Stocker thinks focusing on the "hiatus" is in line with "denier"-thinking according to the interview.. APS is doing a serious review on AR5 including the "hiatus". The main question neither You or Stocker answer is this: "If non-anthropogenic influences are strong enough to counteract the expected effects of increased CO2, why wouldn’t they be strong enough to sometimes enhance warming trends, and in so doing lead to an over-estimate of CO2 influence?" (from APS). To spell it out for you: that would imply that the fast rise in global temperatures before 1997 could have a larger component of natural variability than previously thought. Meaning that the implications for an imminent climate disaster are less. /JPC Lindstrom

    4. Jan, you misunderstand. Models do not capture all natural variability. That lead to that during times they will be over the mean and during some time under it. So this might help you to understand why natural variability solve your problem: http://www.realclimate.org/index.php/archives/2013/12/the-global-temperature-jigsaw/

    5. In particular, the models cannot predict e.g. when an El Nino or a La Nina will occur, or how strong it will be.

      If one enters the observed El Nino/La Nina patterns into a model (as Kosaka and Xie did), global surface temperatures are reproduced with higher accuracy.

  2. The study using paleo data to reconstruct the recent instrumental period already exists:
    Global warming in an independent record of the past 130 years.

    The above is a sad story and in case of Bengtsson you cannot explain it away with stupidity. Very very sad.

  3. Here is a taste of what goes on at the Swedish 'skeptic' blog which Bengtsson likes to frequent.

    This is a comment made by a Swedish professor in Philosophy of Science, and one of the writers of the blog. The subject is a distinguished Swiss climate scientist.

    "Karln är uppenbarligen galen och lider svårt av paranoia, liksom übermobbaren Michael Mann."

    Translation: "The man is obviously insane and suffers severely from paranoia, like the über bully Michael Mann."

    There is more of the same stuff.

  4. "Bengtsson needs to learn the basics in proxy calibration before he lectures the experts in the field."

    Perfect! Please Magnus Westerstrand or someone else from this blog, name someone that you consider to be an "expert" in climatology so that we can compare their resumes to Bengtssons. It would also help if you described why you value some individuals opinions high (Azar and Rummukainen) while disregarding others (Hans von Storch that commented on the other post). Which ones are to be trusted when it comes to evaluations in this specific scientific field?

    1. The field here would be paleoclimatology. As far as I know, none of the people you mention is an expert in that field.

    2. "Individual model simulations have calculated a global warming by 2100 of 6°C or even more, but those have been judged as very improbable by the IPCC (2007). The slow global warming, especially during the last 15 years, reinforces this view.

      after facing opposition about the statement by among others Christian Azar and Markku Rummukainen to the answer above..."

      Magnus was advising Bengtsson not to lecture experts in the field. Seems to me exactly what Magnus is doing to Bengtsson?

    3. You miss the important part "Bengtsson needs to learn the basics in proxy calibration" Which is the point....

      As mentioned a study to reproduce "modern" times has been done... and the proxies is chosen to reflect global climate... basic stuff Bengtsson seams to not know (or which is just as bad, omit). Still he criticizes one of the leading experts in the field. If Bengtsson was serious he could for example point out what is wrong with Manns method http://www.pnas.org/content/suppl/2008/09/02/0805721105.DCSupplemental/0805721105SI.pdf#nameddest=STXT

  5. Please Magnus Westerstrand or someone else from this blog, name someone that you consider to be an "expert" in climatology so that we can compare their resumes to Bengtssons.

    1. Jag håller med Magnus 12:29 nedan: "Why?" Det du föreslår, cdi brt, är en tämligen meningslös excercis, då vetenskapliga frågor inte avgörs genom akademisk k*kmätning eller "min pappa är starkare än din"-tjafsande. Lennart Bengtssons klimatvetenskapliga meriter är utmärkta (dock inte enastående), men goda vetenskapliga meriter är ingen garanti mot att tappa omdömet, och Bengtsson är nog varken den förste eller siste framstående forskare som drabbas av det. Till och med Nobelpristagare har drabbats.

  6. cdi brt, pleaee have a look at these lists compiles by James W Prall in 2010.. For comparison, Bengtsson's most cited paper has 617 citations according to Google scholar. That is good, but not among the very best.


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