A Methodological Embarassment

May 29th, 2009

Posted by: Roger Pielke, Jr.

I am quoted in today’s NYT on a new report issued by the Global Humanitarian Forum which makes the absurd claim that 315,000 deaths a year can be attributed to the effects of rising greenhouse gas concentrations. Here is what I said:

Roger A. Pielke Jr., a political scientist at the University of Colorado, Boulder, who studies disaster trends, said the forum’s report was “a methodological embarrassment” because there was no way to distinguish deaths or economic losses related to human-driven global warming amid the much larger losses resulting from the growth in populations and economic development in vulnerable regions. Dr. Pielke said that “climate change is an important problem requiring our utmost attention.” But the report, he said, “will harm the cause for action on both climate change and disasters because it is so deeply flawed.”

Strong comments I know. Shoddy work on disasters and climate change is the norm, unfortunately, and something I’ve been closely following for well over a decade. I have no illusions that this latest concoction will be repeatedly cited regardless.

Below are my comments to the NYT upon reading the report (cleaned up and formatted). Caution, strong views ahead.

Let me apologize for the length of this reply. But it is important to be clear and to set the record straight.

Let me say first that human-caused climate change is an important problem requiring our utmost attention. Second, the effects of disasters, particularly in poorer countries, is also an important problem that to some degree has been overlooked, as I have argued for many years.

However, I cannot express how strongly I feel that this report has done a disservice to both issues. It is a methodological embarrassment and poster child for how to lie with statistics. The report will harm the cause for action on both climate change and disasters because it is so deeply flawed.

It will give ammunition to those opposed to action and divert attention away from the people who actually need help in the face of disasters, yet through this report have been reduced to a bloodless statistic for use in the promotional battle over climate policies. The report is worse than fiction, it is a lie. These are strong words I know.

1. Let me first start by noting that the same group that did the analysis for the UN, the Geo-Risks group in Munich Re, earlier this year published a peer-reviewed paper arguing that the signal of human-caused climate change could not presently be seen in the loss data on disasters. They wrote (emphasis added):

It should be noted when assessing the results of both this paper and Schmidt et al. (2008) that it is generally difficult to obtain valid quantitative findings about the role of socioeconomics and climate change in loss increases. This is because of criteria such as the stochastic nature of weather extremes, a shortage of quality data, and the role of various other potential factors that act in parallel and interact. We therefore regard our results as being an indication only of the extent to which socio-economic and climate changes account for the increase in losses. Both studies confirm the consensus reached in May 2006 at the international workshop in Hohenkammer attended by leading experts on climate change and natural catastrophe losses.

I co-organized the Hohenkammer workshop (referred to in the quote above) with Peter Hoeppe of Munich Re and that workshop concluded (among other things):

Due to data-quality issues, the stochastic nature of extreme event impacts, the lengths of the time series, and various societal factors present in the disaster loss records, it is still not possible to determine what portion of the increase in damage may be due to climate changes caused by GHG emissions.


The quantitative link (attribution) between storm/flood loss trends and GHG-induced climate changes is unlikely to be determined unequivocally in the near future.

On p. 84 the GHF report itself says:

However, there is not yet any widely accepted global estimate of the share of weather related disasters that are attributable to climate change.

One would think that would be the end of the story. However, to fill in for the fact that there is no accepted estimate, the report conjures up a number using an approach that is grounded in neither logic, science, or common sense.

2. Specifically, to get around the fact that there has been no attribution of the relationship of GHG emissions and disasters, this report engages in a very strange comparison of earthquake and weather disasters in 1980 and 2005. The first question that comes to mind is, why? They are comparing phenomena with many “moving parts” over a short time frame, and attributing 100% of the resulting difference to human-caused climate change. This boggles the mind. The IPCC itself says that 30 years are needed for the detection of changes in the climate system, and this time frame does not even reach that threshold. More to the point earthquakes and weather events do not have the same variability and earthquake disasters affect only a small part of the total inhabited area of the earth, whereas weather disasters occur much more widely. The assumption that weather disasters should track earthquake disasters is flawed from the outset for both geophysical and socio-economic reasons.

An alternative, more scientifically robust approach would be to look specifically at weather-related disasters, and consider the role of socio-economic changes, and to the extent possible, try to remove that signal and see what trends remain. When that has been done, in every case (US floods, hurricanes, Australia, India TCs, Latin America and elsewhere, all in the peer-reviewed literature) there is not a remaining signal of increasing disasters. In other words, the increase in disasters observed worldwide can be entirely attributed to socio-economic changes. This is what has been extensively documented in the peer reviewed literature, and yet — none of this literature is cited in this report. None of it! Instead they rely on this cooked up comparison between earthquakes and weather related disasters.

(Consider also that in no continental location has there been an observed increase in tropical cyclone landfalls, and yet this accounts for almost all of the windstorm disasters cited in the report. The increase must therefore be due to factors other than geophysical changes. This fact renders the
comparison with earthquakes even more meaningless).

Munich Re’s own peer-reviewed work supports the fact that socio-economic factors can explain the entire increase in global disasters in recent decades.

Consider that in 2005 there were 11 earthquakes magnitude 7 or higher and in 1980 there were 14. by contrast, 1980 was a quiet weather year, and 2005 was very active, and included Katrina.

3. The report cites and undates the Stern Review Report estimates of disaster losses, however, in a peer-reviewed paper I showed that these estimates were off by an order of magnitude and relied on a similar sort of statistical gamesmanship to develop its results (and of course this critique was ignored):

Pielke, Jr., R. A., 2007. Mistreatment of the economic impacts of extreme events in the Stern Review Report on the Economics of Climate Change, Global Environmental Change, 17:302-310. (PDF)

This report is an embarrassment to the GHF and to those who have put their names on it as representing a scientifically robust analysis. It is not even close.

Best regards,


15 Responses to “A Methodological Embarassment”

  1. Jon Frum Says:

    This is how the Boston Globe (owned by the NY Times) covered the story:

    Annan: Climate change causes 300,000 deaths a year
    May 29, 2009

    LONDON—A think-tank led by former U.N. Secretary General Kofi Annan says that around 300,000 people die each year from disasters related to climate change.

    The Global Humanitarian Forum also estimates that global warming seriously affects 325 million people and causes $125 billion in economic losses each year.

    Annan says people in the world’s poorest countries are most affected by changes in the weather and environment.

    The Forum report on climate change released Friday used existing data on weather-related disasters and population trends to draw its conclusions.

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  3. Sean_Wise Says:

    I sent an email and Andrew Revkin and then posted the same message on the DOTEarth blog. The following is what I sent to Mr. Revkin:

    I saw your article on the report of more than 300,000 deaths already due to climate change and applaud your inclusion of Dr. Pielke’s views on the uncertainty. However last year Oxfam estimated that 30 million more people faced starvation as a result of our food crops diversion to biofuels and if even 1% of these people died for lack of food, then most of deaths associated with “climate change” might be attributed to “climate mitigation” strategies instead. I think world leaders should also take this into accout. There is no free lunch when it comes to climate change solutions. All things have an impact on the environment and people’s economic well being, even the “renewable” energy solutions.

    I think there has been a presumption of innocence when it comes to “solutions” for the problems of fossile fuel combustion. If the economic and environmental consequences of each path (renewable vs. fossile) were better defined, it would make for better choices by politicians.

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  5. Benny Peiser Says:


    The GHF study may be the latest ‘poster child for how to lie with statistics.’ But let’s not forget that climate alarmism, for much of the last 20 years, has been entirely based on statistical methods and predictions – not on any empirical observations. Be that as it may, the good news is that after years of listening to crying wolfs, a growing number of policy and law makers in most countries outside the US are no longer relying on this kind of hyperbole. Instead, more and more politicians are well-advised by hard-nosed economic and political experts keenly aware of the significant risk that radical climate policies pose to national insterest and economic stability.

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  7. jae Says:

    Bravo, Roger. Great reply/summary. Indeed, the shrillness and silliness of the extremism is at an all-time high, as the special interests try to influence Congressional action. I think it is actually becoming PC and fashionable in certain circles to see just how big a lie you can get away with!

  8. 5

    GHF’s head Kofi Annan and report supervisor Andreasen are more interested in “framing” for, as Andy Revkin says, “world leaders, who will meet in Copenhagen in December to negotiate a new international climate treaty”. The only numbers that will have any meaning then will be the capital accounts of the countries participating.

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  11. EDaniel Says:

    Has ‘framing’ become a physical realization of the Orwellian concept of Newspeak?

    And isn’t it a double wammy; ‘framing’ is Newspeak for ‘Newspeak’.

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  13. jasg Says:

    You can readily see why this kind of thing happens. These are all basically good people but when they talk about how to practically end world poverty then they are totally ignored. Yet when they release an error-prone, disaster scenario they get a lot of attention. It’s a sad reflection of our societal priorities.

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  15. dean Says:

    “Dire Predictions” is a laymens book, not a technical journal, and when I went to dictionary.com, ‘projection’ is listed as a synonym for ‘prediction.’ You’re making a mountain out of a molehill here. It would be appropriate for the book to have a note somewhere indicating that the terms have a different meaning in a scientific context, but the intended audience, there is no difference.

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  17. dean Says:

    First of all, apologies for my previous post here which should have been in another blog entry. I’ve had a lot problems posting to this blog recently. [maybe it could be removed?]

    But I generally agree with the criticism of this report. It demonstrates why it is important to go through peer review process, such as has resulted in the current consensus on AGW, which I appreciate Roger reiterating in this blog post.

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  19. Warming and Death - Dot Earth Blog - NYTimes.com Says:

    [...] criticized by Roger A. Pielke, Jr., of the University of Colorado (here’s his full-length critique of the climate-mortality report). Dr. Pielke has a habit of getting under the skin of environmental campaigners. But he has [...]

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  21. Brian Dodge Says:

    In the face of declining Arctic summer ice extent, the inexorable southward march of Antarctic ice shelf collapse, continuing sea level rise(would you like to invest in some nice oceanfront property I have for sale in Bangladesh?), the global decline in glacial ice volume which threatens the water supplies of billions of people, the phenological changes disrupting ecosystems and driving tropical disease into temperate regions, and a myriad other empirical observations of the impact of AGW, it’s a mistake to attribute the deaths to merely “socioeconomic” factors. Further, to wait until the numbers of deaths of victims rise to a level where we have a 90% confidence level that global warming is the cause is as morally reprehensible and ethically indefensible as the “science” of the Tuskegee experiment
    Unfortunately, more and more politicians are ill-advised by idealogically motivated economic and political “experts” who blissfully ignored the signs of the impending economic meltdown in 2008 and are equally myopically unaware of the significant risk that do-nothing climate policies pose to national interest and economic stability.

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  23. Climate mortality by the numbers Says:

    [...] based on shaky data at best.  Roger Pielke, Jr., an expert on climate policy, called the report a methodological embarrassment, largely due to it’s inability to distinguish between deaths due to climate change and deaths [...]

  24. 13
  25. 315,000 | GetAnswers.ws Says:

    [...] Roger Pielke Jr., a policy expert on climate change at the University of Colorado said in his blog that the report was “a methodological embarrassment” because there was no way to [...]

  26. 14
  27. Extracting ‘Climate Refugees’ Out Of Thin Air « The Unbearable Nakedness of CLIMATE CHANGE Says:

    [...] ps Thanks to Ms Warner also for admitting that “the numbers [of potential climate change refugees for the future decades] are all over the place“. I guess there is no shortage of methodological embarassments… [...]

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  29. Scientist calls report of 300,000 climate deaths “an embarrassment” « WeGetIt.org Campaign Says:

    [...] In a comment he sent to The Times, Pielke expanded, calling the report “a poster child for how to lie with statistics.” He referred to a report  from Munich Re, the conclusion of which was that the signal of manmade climate change could not yet be seen in the loss data on disasters. In other words, it’s impossible to tell what deaths should be attributed to climate change and what should be attributed to routine disasters that occur without climate change. [...]