Mosquitos, malaria and the IPCC "consensus"

This article was brought to my attention by Larry Huldén. It is a memorandum written by Professor Paul Reiter to the UK House of Lords on the widely disseminated idea promoted by the IPCC that climate change will produce increased ranges for mosquito-borne diseases such as malaria and dengue fever.

If people are in any doubt as to the true nature of the IPCC’s "scientific consensus" then Professor Reiter removes that doubt.

Professor Reiter on malaria in the "Little Ice Age":

I wonder how many of your Lordships are aware of the historical significance of the Palace of Westminster? I refer to the history of malaria, not the evolution of government. Are you aware that the entire area now occupied by the Houses of Parliament was once a notoriously malarious swamp? And that until the beginning of the 20th century, "ague" (the original English word for malaria) was a cause of high morbidity and mortality in parts of the British Isles, particularly in tidal marshes such as those at Westminster? And that George Washington followed British Parliamentary precedent by also siting his government buildings in a malarious swamp! I mention this to dispel any misconception you may have that malaria is a "tropical" disease.

All this occurred in a period”¢’‚¬?roughly from the mid-15th century to the early 18th century”¢’‚¬?that climatologists term the "Little Ice Age". Temperatures were highly variable, but generally much lower than in the period since. In winter, the sea was often frozen for many miles offshore, the King could hold parties on the frozen Thames, there are six records of Eskimos landing their kayaks in Scotland, and the Viking settlements in Iceland and Greenland became extinct.

Despite this remarkably cold period, perhaps the coldest since the last major Ice Age, malaria was what we would today call a "serious public health problem" in many parts of the British Isles, and was endemic, sometimes common throughout Europe as far north as the Baltic and northern Russia. It began to disappear from many regions of Europe, Canada and the United States as a result of multiple changes in agriculture and lifestyle that affected the breeding of the mosquito and its contact with people, but it persisted in less developed regions until the mid 20th century. In fact, the most catastrophic epidemic on record anywhere in the world occurred in the Soviet Union in the 1920s, with a peak incidence of 13 million cases per year, and 600,000 deaths. Transmission was high in many parts of Siberia, and there were 30,000 cases and 10,000 deaths due to falciparum infection (the most deadly malaria parasite) in Archangel, close to the Arctic circle. Malaria persisted in many parts of Europe until the advent of DDT. One of the last malarious countries in Europe was Holland: the WHO finally declared it malaria-free in 1970.

I hope I have convinced you that malaria is not an exclusively tropical disease, and is not limited by cold winters!

On the IPCC scientific expertise on the subject of mosquito0-borne vectors in the Second Assesment Review, Professor Reiter lays it bare:

The scientific literature on mosquito-borne diseases is voluminous, yet the text references in the chapter were restricted to a handful of articles, many of them relatively obscure, and nearly all suggesting an increase in prevalence of disease in a warmer climate. The paucity of information was hardly surprising: not one of the lead authors had ever written a research paper on the subject! Moreover, two of the authors, both physicians, had spent their entire career as environmental activists. One of these activists has published "professional" articles as an "expert" on 32 different subjects, ranging from mercury poisoning to land mines, globalization to allergies and West Nile virus to AIDS.

Among the contributing authors there was one professional entomologist, and a person who had written an obscure article on dengue and El NiàƒÆ’à‚Ⱟ, but whose principal interest was the effectiveness of motor cycle crash helmets (plus one paper on the health effects of cell phones).

The amateurish text of the chapter reflected the limited knowledge of the 22 authors. Much of the emphasis was on "changes in geographic range (latitude and altitude) and incidence (intensity and seasonality) of many vector-borne diseases" as "predicted" by computer models. Extensive coverage was given to these models, although they were all based on a highly simplistic model originally developed as an aid to malaria control campaigns. The authors acknowledged that the models did not take into account "the influence of local demographic, socioeconomic, and technical circumstances"

Yes, those much vaunted computer models are driving the IPCC agenda. And who wrote those models? Not the scientists who most know about disease vectors, that’s for sure.

Of course, I would contend that the real point of such models is to produce scary headlines, especially as the models themselves are fundamentally unfalsifiable.

The IPCC SAR didn’t lose the opportunity to produce those scary headlines

In summary, the treatment of this issue by the IPCC was ill-informed, biased, and scientifically unacceptable. The final "Summary for Policymakers stated:

"Climate change is likely to have wide-ranging and mostly adverse impacts on human health, with significant loss of life . . . Indirect effects of climate change include increases in the potential transmission of vector-borne infectious diseases (eg malaria, dengue, yellow fever, and some viral encephalitis) resulting from extensions of the geographical range and season for vector organisms. Projections by models . . . indicate that the geographical zone of potential malaria transmission in response to world temperature increases at the upper part of the IPCC-projected range (3-5ºC by 2100) would increase from approximately 45 per cent of the world population to approximately 60% by the latter half of the next century. This could lead to potential increases in malaria incidence (on the order of 50-80 million additional annual cases, relative to an assumed global background total of 500 million cases), primarily in tropical, subtropical, and less well-protected temperate-zone populations".

Professor Reiter goes on to talk about the IPCC’s use (or should I say abuse) of the notion of "consensus" as a means of driving the debate. After mentioning the "Trojan numbers" of the number of "world’s leading scientists" who wrote the entire report, he writes:

The issue of consensus is key to understanding the limitations of IPCC pronouncements. Consensus is the stuff of politics, not of science. Science proceeds by observation, hypothesis and experiment. Professional scientists rarely draw firm conclusions from a single article, but consider its contribution in the context of other publications and their own experience, knowledge, and speculations. The complexity of this process, and the uncertainties involved, are a major obstacle to meaningful understanding of scientific issues by non-scientists.

In the age of information, popular knowledge of scientific issues”¢’‚¬?particularly issues of health and the environment”¢’‚¬?is awash in a tide of misinformation, much of it presented in the "big talk" of professional scientists. Alarmist activists operating in well-funded advocacy groups have a lead role in creating this misinformation. In many cases, they manipulate public perceptions with emotive and fiercely judgmental "scientific" pronouncements, adding a tone of danger and urgency to attract media coverage. Their skill in promoting notions of scientific "fact" sidesteps the complexities of the issues involved, and is a potent influence in education, public opinion and the political process. These notions are often re-enforced by attention to peer-reviewed scientific articles that appear to support their pronouncements, regardless of whether these articles are widely endorsed by the relevant scientific community. Scientists who challenge these alarmists are rarely given priority by the media, and are often presented as "skeptics".

The democratic process requires elected representatives to respond to the concerns and fears generated in this process. Denial is rarely an effective strategy, even in the face of preposterous claims. The pragmatic option is to express concern, create new regulations, and increase funding for research. Lawmakers may also endorse the advocacy groups, giving positive feedback to their cause. Whatever the response, political activists”¢’‚¬?not scientists”¢’‚¬?are often the most persuasive cohort in science-based political issues, including the public funding of scientific research.

In reality, a genuine concern for mankind and the environment demands the inquiry, accuracy and skepticism that are intrinsic to authentic science. A public that is unaware of this is vulnerable to abuse.

Professor Reiter echoes Dr Richard Lindzen’s comments on the ideological pressure placed on himself and others to make "authoritative pronouncements" by people who had "little or no knowledge of our speciality" in writing the Third Assessment Report (TAR).

He was obliged to resign from the IPCC process in order to concentrate on the US assessment report.

For the Fourth Assessment Report, Professor Reiter was passed over as a Lead Author, despite being an expert in his field and strongly recommended by the US Government as such. The IPCC put others in charge:

It will be interesting to see how the health chapter of the fourth report is written. Only one of the lead authors has ever been a lead author, and neither has ever published on mosquito-borne disease. Only one of the contributing authors has an extensive bibliography in the field of human health. He is a specialist in industrial health, and all his publications are in Russian. Several of the others have never published any articles at all.

Professor Reiter concludes:

The natural history of mosquito-borne diseases is complex, and the interplay of climate, ecology, mosquito biology, and many other factors defies simplistic analysis. The recent resurgence of many of these diseases is a major cause for concern, but it is facile to attribute this resurgence to climate change, or to use models based on temperature to "predict" future prevalence. In my opinion, the IPCC has done a disservice to society by relying on "experts" who have little or no knowledge of the subject, and allowing them to make authoritative pronouncements that are not based on sound science. In truth, the principal determinants of transmission of malaria and many other mosquito-borne diseases are politics, economics and human activities. A creative and organized application of resources is urgently required to control these diseases, regardless of future climate change.

I recommend the entire article for closer study.

15 Comments

  1. JerryB
    Posted Aug 30, 2005 at 6:27 AM | Permalink

    Another interesting Reiter article is:

    From Shakespeare to Defoe: Malaria in England in the Little Ice Age

    http://www.cdc.gov/ncidod/eid/vol6no1/reiter.htm

  2. John Cross (John C)
    Posted Aug 30, 2005 at 9:09 AM | Permalink

    Not my field, but I believe that Dr. Reiter presents a slight bias in his case. As far as I know, the main malarial disease agent in Britain during the LIA was vivax which is the least lethal form of the disease (mind you even this form is unpleasant).

    I was a little confused by his mention of “IPCC THIRD ASSESSMENT REPORT, WORKING GROUP II. CHAPTER 18. HUMAN POPULATION HEALTH” since this chapter does not exist by this name. I believe that he was referring to Chapter 9 – Human Health. Anyway, I found the comments about the accuracy of the models in this chapter to be appropriate. I also found no mention of the 16 C limit on transmission that he discussed.

    However while I disagree with some of what he says, I agree fully with his last sentence.

    John

  3. John A
    Posted Aug 30, 2005 at 10:08 AM | Permalink

    Re #2:

    The limitation of 16C was given in the Second Assessment Report, and it was to that report he was referring. I don’t know if the SAR is online (and if not, why not?) so I can’t check the exact quote.

    The temperature sensitivity of two types of mosquito in conjunction with yet another computer model is given here. If you look at Table 1, you’ll find that Dr Reiter was accurate in his assessment of this figure being used.

  4. John Cross (John C)
    Posted Aug 30, 2005 at 10:47 AM | Permalink

    That was my point in mentioning it (the fact that it was in the second). Rather than discuss what the position was 10 years ago, don’t you think it is better to discuss what the current position is? The 3rd report contains no mention of the 16C so I don’t think it is all that relevant to bring it up now. The paper you linked to is over 10 years old and thus from the same era. Perhaps this was accepted then, the main point is that it is not currently accepted by the IPCC.

    Science is constantly changing and old ideas are replaced with new and (hopefully) better ones. I was just surprised that Dr. Reiter did not seem to want to acknowledge this.

  5. John A
    Posted Aug 30, 2005 at 11:35 AM | Permalink

    Re #4

    Perhaps this was accepted then, the main point is that it is not currently accepted by the IPCC.

    Science is constantly changing and old ideas are replaced with new and (hopefully) better ones

    John, you may not have noticed, but on this weblog that contention has been shown to be utterly false. The science of the IPCC, if anything has gotten worse over time even as it’s message has become ever more strident and shrill.

    Be that as it may, the TAR carries exactly the same contention as to the minimum temperatures at which vectors for malaria survive. If you check Table 9-3 of "Temperature thresholds of pathogens and vectors" in the report from Working Group II you’ll find that the T_min for malaria is given as 16-19 degrees for Plasmodium falciparum and 14.5-15 degrees for Plasmodium vivax

    I have no idea what the "slight bias" that Dr Reiter is displaying, other than he’s an expert in his field, he knows the IPCC ideological bias from the inside, and he knows bad science as it relates to that expertise when he sees it.

  6. John Cross (John C)
    Posted Aug 30, 2005 at 12:15 PM | Permalink

    John: Which contention has been shown to be utterly false by this weblog? Was it number 1: “Perhaps this was accepted then, the main point is that it is not currently accepted by the IPCC.”. Or was it number 2: “Science is constantly changing and old ideas are replaced with new and (hopefully) better ones”?

    You may have a point in regards to number 1 since table 3 does indicate that 16 is a threshold for one type of malarial agent but I was not aware that this was the function of this blog. In regards to number 2, some may feel that this blog does try to show that the statement “old ideas are replaced with new and better ones” is false, but I actually don’t share this point of view.

    Anyway, on to some real discussion. The temperature threshold for the vivax is indeed lower than 16. The problem is that Dr. Reiter was not specific in which agent he was refering to. Likewise, in his presentation he does not differentiate between the different types of malaria. This is what I was refering to in my comment about bias. I would have thought an expert like Dr. Reiter would have distinguished between the types.

  7. mikep
    Posted Aug 30, 2005 at 12:42 PM | Permalink

    ry this link for a clear explanation of Paul Reiter’s views. Temperatureis but one of the factors explaining the incidence of infectious disease and not necessarily the most important. And its easier to reduce the incidence of disease by public health measures than by trying to influence the cliamte.

    http://www.policynetwork.net/main/press_release.php?pr_id=13

    If you read his evidence to the House Of Lords you will find that he discusses the third as well as the assessment second report, and gives it only marginally higher marks.

  8. John A
    Posted Aug 30, 2005 at 12:57 PM | Permalink

    Which contention has been shown to be utterly false by this weblog? Was it number 1: “Perhaps this was accepted then, the main point is that it is not currently accepted by the IPCC.”. Or was it number 2: “Science is constantly changing and old ideas are replaced with new and (hopefully) better ones”?

    Both. The IPCC (as I’ve shown) has not changed its viewpoint on the simplistic and erroneous assumptions of outbreaks of malaria being a function of temperature. As I said (and I’ll emphasize here the salient part):

    The science of the IPCC, if anything has gotten worse over time even as it’s message has become ever more strident and shrill.

    As for the second part…

    …some may feel that this blog does try to show that the statement “old ideas are replaced with new and better ones” is false, but I actually don’t share this point of view.

    …unless you think that the promotion of the Mann Hockey Stick over the previous plot of global mean temperature, Medieval Warm Period and all, to be an improvement then it’s clear that I’m not going to agree with you. Science, like other forms of human endeavor, often goes down blind alleys, and continues down them by force of “consensus” until some genius pops up to redirect them. I’m sure you can think of lots of examples.

    Likewise, in his presentation he does not differentiate between the different types of malaria. This is what I was refering to in my comment about bias. I would have thought an expert like Dr. Reiter would have distinguished between the types.

    This is what in biblical terminology is called “straining at gnats and swallowing camels“. There is no point of Dr Reiter demonstrating the slightly different minimum temperatures for two different types of malarial vector to the House of Lords, when his main thrust is that to posit temperature rise as a key factor in malarial transmission as the IPCC does so (and continues to do so), when it “ain’t that simple”.

    That’s not bias, that’s called “not getting bogged down in pedantry but getting to the meat of the matter”. The IPCC’s analysis in Reiter’s particular area of expertise was done by people not particularly competent to write it, under large and not-very-subtle political pressure to make expansive and authoritative statements which conform to a narrow political agenda.

  9. John Cross
    Posted Aug 30, 2005 at 4:54 PM | Permalink

    Both. The IPCC (as I’ve shown) has not changed its viewpoint on the simplistic and erroneous assumptions of outbreaks of malaria being a function of temperature.

    John: you have not shown this at all. In fact the IPCC is quite clear that it does not consider malaria to be a function of many things including temperature, precipitation and humidity. Furthermore, quoting from the document you linked to:

    An important criticism of biological
    models is that undue emphasis is placed on temperature
    changes, without consideration to other ecological complexities”¢’‚¬?
    including those influenced by rainfall, humidity, and host
    exposure”¢’‚¬?that influence transmission dynamics.

    Or this one:

    None of the modeling to date has
    i n c o rporated the modulating effect of public health strategies
    and other social adaptive responses to current or future malaria
    risk (Sutherst et al., 1998).

    Or to quote from the article by Dr.Reiter:

    The 2001 report is much more comprehensive, more accurate, and gives a much better perspective of the diseases and their dynamics. The selection of references was biased towards models that predict an increase in range and prevalence of mosquito-borne disease, but there were refreshingly frank statements on the fundamental limitations of such models.

    I am surprised that you disagree with my comment about science working by old ideas being replaced by new and better ones. I would have thought that you feel that Steve’s GRL paper was an improvement on MBH, but I guess not.

    I am somewhat bothered by your comment about “not getting bogged down in pedantry”. You may not feel that it is important whether you get a fatal or non-fatal version of a disease, but I suspect that others would disagree.

    Finally, I suspect that Dr. Reiter would disagree with your statement: The IPCC’s analysis in Reiter’s particular area of expertise was done by people not particularly competent to write it. He states that one of the authors “a colleague of mine”¢’‚¬?was an established authority on vector-borne disease.” Or am I being pedantic again?

  10. John Cross
    Posted Aug 30, 2005 at 4:58 PM | Permalink

    MikeP:

    In fact I tend to agree with a great deal of what Dr. Reiter says. But I would disagree with your comment about the fact that he gives only marginally better marks to the third. To quote again from his paper:

    The 2001 report is much more comprehensive, more accurate, and gives a much better perspective of the diseases and their dynamics.

    That sounds fairly solid to me.

    John

  11. Paul Penrose
    Posted Aug 30, 2005 at 6:48 PM | Permalink

    When it comes to computer models I like to remind people that all models are wrong, but some are useful. Over reliance on models is one of my biggest beefs with the IPCC. These types of chaotic models are not reliable over large time scales, especially when they don’t yet understand all the forces involved (like the effects of clouds on temperature), yet they perport to predict small temperature changes over many decades.

    Paul.

  12. Ed Snack
    Posted Aug 30, 2005 at 7:29 PM | Permalink

    John, selective quoting can make the 2001 report appear better than what Dr Reiter seems to be saying.

    Quote “Thus, despite the improved quality of the Third Assessment Report, the dominant message was that climate change will result in a marked increase in vector-borne disease, and that this may already be happening. The IPCC message has been repeated in the publications of other Agencies, often with inaccuracies that appear to have their origin in the Second Assessment Report.”

    So although there are more caveats and some recognition of the shortcomings of their methodology in the TAR, the IPCC persist in promoting what appears to be a false or at best highly uncertain conclusion.

  13. Ross McNaughton
    Posted Aug 30, 2005 at 7:34 PM | Permalink

    I am sorry am I missing something? The way I read this article was that the UK and Europe both had malaria when it was colder than now. It has now got warmer and it has been eradicated, therefore the control of malaria can be acheived even in a warming climate.
    Secondly the predicitons by the IPCC do not take into account any effort to control or erradicate the disease. I would hope that 100 years from now mankind would have developed methods to control and eradicate this disease regardless of whether it is warmer or not. Now if that means taking the money off scientists drilling holes in trees trying to work out if the temperature 2000 years ago was colder or warmer now to an accuracy of 10ths of a degree then I say go for it. Surely that is a much better way to spend our research money.
    Finally if we are talking about science progressing then the following comments from the article do not fill me with confidence:

    For the Fourth Assessment Report, Professor Reiter was passed over as a Lead Author, despite being an expert in his field and strongly recommended by the US Government as such. The IPCC put others in charge:

    It will be interesting to see how the health chapter of the fourth report is written. Only one of the lead authors has ever been a lead author, and neither has ever published on mosquito-borne disease. Only one of the contributing authors has an extensive bibliography in the field of human health. He is a specialist in industrial health, and all his publications are in Russian. Several of the others have never published any articles at all.

  14. Larry Huldén
    Posted Aug 30, 2005 at 11:13 PM | Permalink

    It is a fact that both Plasmodium vivax, P. falciparum and P. malariae occurred in Europe in previous times. Falciparum (the most dangerous species) caused serious epidemics for example in Archangelsk region by the White Sea in northern Russia in the 1920’s.

    Climate had nothing to do with the “rise and fall” of malaria in Europe or northern America. Malaria is not spreading because of a possible increase in the mean temperature. Malaria is present in a human population only because of human behaviour (including housing conditions). Annual malaria cases varied locally in Finland (in the 18th and 19th century) according to the mean temperature of June and July (= varying number of mosquitoes). However, the temperature had no effect on the trends of malaria through times. Malaria spread and declined in Finland independently of the trends of mean temperature. Malaria disappeared from Finland during an increasing mean temperature (1860-1930). There were no actions against malaria during this time, still it disappeared.
    A part of the results from Finland are available at:

    http://www.malariajournal.com/content/pdf/1475-2875-4-19.pdf

    More results will soon be published concerning the common cause of decline of malaria in the industrialised world (these will be a surprise for many people in Europe and USA).

  15. Posted Aug 23, 2010 at 8:16 PM | Permalink

    I agree with a previous comment regarding “old ideas” being replaced by new and better ones”. That is so true and we call that reinventing but with innovation.

    Just about everything you see continues to get reinvented but with innovation added.

    Bill Gates (founder of Microsoft-billionaire) and one of his charities has contributed 100’s of millions of dollars for the fight of Malaria disease and other infections diseases throughout the world. I would say that’s a SOLID start.

    Martha

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  1. […] Climate Audit Mosquitos, malaria and the IPCC consensus This article was brought to my attention by Larry Huld n. It is a memorandum written by Professor Paul Reiter to the UK House of Lords on the widely disseminated idea promoted by the IPCC that […]

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