26 January 2010

IPCC Statement on Trends in Disaster Losses

The IPCC has issued a statement in response to the Sunday Times article on errors in the IPCC treatment of disaster losses and climate change. The IPCC statement (PDF) is a remarkable bit of spin and misinformation. Here it is with my comments:
Geneva, 25 January 2010


The January 24 Sunday Times ran a misleading and baseless story attacking the way the Fourth Assessment Report of the IPCC handled an important question concerning recent trends in economic losses from climate-related disasters. The article, entitled “UN Wrongly Linked Global Warming to Natural Disasters”, is by Jonathan Leake.

The Sunday Times article gets the story wrong on two key points. The first is that it incorrectly assumes that a brief section on trends in economic losses from climate-related disasters is everything the IPCC Fourth Assessment Report (2007) has to say about changes in extremes and disasters.
RESPONSE: This is pure misdirection and is irrelevant. The issue here is specific to how the IPCC handled the rising costs of disasters and its relationship to increasing temperature. It is not about the general theme of extremes.
In fact, the Fourth Assessment Report reaches many important conclusions, at many locations in the report, about the role of climate change in extreme events. The assessment addresses both observations of past changes and projections of future changes in sectors ranging from heat waves and precipitation to wildfires. Each of these is a careful assessment of the available evidence, with a thorough consideration of the confidence with which each conclusion can be drawn.
RESPONSE: All of this verbiage is irrelevant to the issue.
The second problem with the article in the Sunday Times is its baseless attack on the section of the report on trends in economic losses from disasters. This section of the IPCC report is a balanced treatment of a complicated and important issue.
RESPONSE: Asserting balance does not make it so. The facts here are what the IPCC should respond to: The IPCC report highlighted a single non-peer reviewed study to make a claim that (a) that study did not support, and (b) that was countered by the entirety of the peer reviewed literature (much of which went uncited). My work was misrepresented in the text and in the IPCC response to reviewers. The latter included an outright lie. The only balance that was achieved was between misrepresentation and error.
It clearly makes the point that one study detected an increase in economic losses, corrected for values at risk, but that other studies have not detected such a trend. The tone is balanced, and the section contains many important qualifiers.
RESPONSE: This statement is remarkable for its untruths. (1) The "one study" did not detect a trend over the full period of record, only a cherrypicked subset, and when that paper was published it explicitly stated that it could not find a signal of increasing temperatures in the loss record, (2) The IPCC report did not note that other studies had not found a trend, except when citing my work in passing, and then undercutting it in error by mistakenly citing the 2004 and 2005 hurricane seasons to suggest something different (and untrue). (3) The Chapter includes the following figure, which has absolutely no scientific support whatsoever:

In writing, reviewing, and editing this section, IPCC procedures were carefully followed to produce the policy-relevant assessment that is the IPCC mandate.
RESPONSE: Carefully followed procedures? Let's review: (a) The IPCC relied on an unpublished, non-peer reviewed source to produce its top line conclusions in this section, (b) when at least two reviewers complained about this section, the IPCC ignored their compalints and invented a response characterizing my views. (c) When the paper that this section relied on was eventually published it explicitly stated that it could not find a connection between rising temperatures and the costs of disasters.
This press release from the IPCC would have been a fine opportunity to set the scientific and procedural record straight and admit to what are obvious and major errors in content and process. Instead, it has decided to defend the indefensible, which any observer can easily see through. Of course there is no recourse here as the IPCC is unaccountable and there is no formal way to address errors in its report or its errors and misdirection via press release. Not a good showing by the IPCC.


MIKE said...

Sounds like WATERGATE more and more. We are in the stonewall stage. I wonder if the Times will seek out a rebuttal.

Ian said...

Excellent dissection, Roger.

In Chapter 10 (p. 489), the IPCC relies entirely on insurance companies (using either non-cited, or non-peer reviewed papers), to estimate future losses arising from climate change.

“ Financial aspects

The cost of damages from floods, typhoons and other climate-related hazards will likely increase in the future. According to the European insurer Munich Re, the annual cost of climate change-related claims could reach US$300 billion annually by 2050.”

In this case, the only source is Munich Re; there actually is NO citation included(though Munich Re's non-peer reviewed papers are referred to elsewhere in WGII, so it presumably is one of those.)

They also rely on a non-peer reviewed paper of the Association of British Insurers for the following:

“The Association of British Insurers examined the financial implications of climate change through its effects on extreme storms (hurricanes, typhoons and windstorms) using an insurance catastrophe model (ABI, 2005). Annual insured losses from hurricanes in United States, typhoons in Japan and windstorms in Europe are projected to increase by two-thirds to US$27 billion by the 2080s. The projected increase in insured losses due to the most extreme storms (with current return periods of 100 to 250 years) by the 2080s would be more than twice the reported losses of the 2004 typhoon season, the costliest in terms of damage during the past 100 years.”

In both cases, the claim is that climate change related damage will increase dramatically in the future. There are no caveats attached to these statements - no attempt to control for additional development or inflation.

Eric said...


I think there is a typo in your last RESPONSE (b)

I believe you want to say "MIS-characterizing your views".

thank you for pursuing this. The IPCC needs to act quickly and decisively to regain confidence lest it become a joke and a liability.

PaulM said...

What strikes me immediately as most dishonest about the IPCC response is the repeated use of the word 'baseless'. In fact the criticisms have a very solid base which you have set out very clearly on your blog.

The 'response' completely fails to address any of the issues you have raised.

In the section where the graph is shown, there is no balance, no qualifiers, just a single graph from an un-refereed report written by one of the chapter authors himself.

The other dishonest aspect of the report is its vagueness in talking about 'the section' - what section are they talking about? The aim is to confuse and mislead rather than to inform.

intelligert said...

Would you still call 'tefan Rahmstorf, Michael Mann, Rasmus Benestad, Gavin Schmidt, and William Connolley. "Hurricanes and Global Warming - Is There a Connection?"' a good a article? (http://www.realclimate.org/index.php/archives/2005/09/hurricanes-and-global-warming/comment-page-1/#comment-4129)

What do you think of wikipedia's treatment on 'extreme weather' topics.

best wishes.

bernie said...

Who wrote and/or contributed to this press release? Names I believe are going to be important in unravelling the connections between the IPCC an advocacy groups. As was the case with Hansen et al and Jones et al, there is a circling of the wagons. It is an embarrassment to all who continue to lend the support and scientific prestige to what now amounts to no more than a political pressure group. Not even the late Michael Crichton could make this stuff up.

Malcolm said...

It would appear that Bob Ward is more of an expert on your science than you are.



Hans Erren said...

what bernie says: who wrote it?

mcculloch.2 said...

Interesting. However, the graph that you state has no scientific basis cites what appears to be Muir Wood et al., 2000(?) as its source.

Does that reference actually contain this graph? Is this a published scientific article or is “Muir Wood” just a Sierra Club affiliate? Why do you say it has no validity?

(Assuming the data is correct, it looks to me like there’s a positive correlation, though it’s hard to say if it would be significant after adjustment for serial correlation. Also, absolute real losses should increase over time just because the real economy is growing over time. Losses/GDP would be more relevant. As would a longer time period, since temps generally dipped between the 1940s and 1960s.)

– Hu McCulloch

(I had trouble posting this at first, and meanwhile Ian and RomanM have replied on CA. However, I'm still unclear why you say this graph is invalid.)

kmye said...

I came here to quote Ward in the Guardian piece, too. The last paragraph is pretty amusing:

"But even if the 2% a year trend is not correct, Pielke's own data suggest there is cause for alarm, said Ward. 'He is right that an increase in the number of valuable properties in high-risk areas is overwhelmingly the cause of increased financial losses from extreme weather events over the past few decades,' he said. 'That in itself is a worrying conclusion given that climate change is expected to lead to changes in the occurrence and severity of such events.'"

David said...

I'd send a link to this to the Times, but I don't want to register. Anyone interested? I'm sure the Times will be :-)

Roger Pielke, Jr. said...

-9-Hu McCulloch

No the graph did not appear in Muir-Wood et al. 2006. I don't know where it was from, perhaps an IPCC AR4 production.

There is a correlation between disaster losses and temperature. The issue is causation.

Once adjusted for societal change (wealth or building stock or the like) everywhere that scholars have look (Europe, US, Asia, Australia, Central America, Caribbean, India, China, etc.) there is no residual trend in losses once these factors are accounted for.

Hence the IPCC's use of a figure to suggest otherwise is misleading.

mcculloch.2 said...

RE RPJr #12,
"Hence the IPCC's use of a figure to suggest otherwise is misleading."

"Misleading" is an understatement. The graph sounds dubious even if it had a published source, but the IPCC's first problem is that they printed a graph that was completely unsourced (in that it did not even come from the draft report they cited). They should be challenged do come up with whatever the actual source of this was, to prove that they did not just make it up out of thin air. Errors happen, but the burden is now on them to prove they did not fabricate it.

Roger Pielke, Jr. said...


You'll find lots on this site to show that "misleading" is indeed an understatement.

Good luck getting the IPCC to respond, see:


I have no idea what the source is, and I assume that the IPCC just made it up.

itisi69 said...

We are way past the tipping points already.

They are called: credibility, authority, consensus, independent science. The IPCC is acting very hard to bring down their own sandcastle. Hardly surprising with a chairman called Pachauri who apparently has never followed a seminare about Crisis Management.

Utterly self destructing.

Ian said...

I spent some time parsing through the FOD, SOD and related comments for this portion of Chapter 1 of the WGII report.

The graph that Hu McCulloch asks about, and which Roger criticizes above, initially appeared as part of the text in the SOD as figure 1.5. It was a scatter graph, with a “Fitted Values” trend line drawn in. At that point, the source was being cited as “Miller et al. 2006” rather than Muir-Wood; I assume, however, that it is the same source (the full reference was: “Miller, S., R. Muir-Wood, et al. 2006: Weather related catastrophe loss trends and the impact of climate change,. In lit. (to be circulated prior to publication).”) (See p. 91 of Ch. 1 of the SOD)

The use of the “Miller” paper drew a number of comments from the expert reviewers. One of those experts was Annick Douguedroit of University de Provence, who commented (http://ipcc-wg2.gov/AR4/SOD_COMMS/Ch01_SOD_Expert.pdf at p. 122)

“Fig 1,5 is not reliable from a statistical point of view because the significant trend is pulled upward by "outliers" (especially 3 points with losses >100000 ) which provoque a pseudo-significancy as it is suggested by the authors themselves in lines 18-21 [of the SOD] "Removing......entirely". So I propose "Since 1970 the global normalized results do not show any statically significant correlationn with global temperatures." and to remove the end of the paragraph and the figure 1,5 because it can mislead a reader not familiar with correlation."

The response from the “Writing Team” was:

“Figure moved to Supplementary Figure and employed a different plot that smoothes catastrophe losses and shows these alongside temperature. After smoothing (that thereby removes the peaks noted) the correlation remains. The text now provides a balanced commentary on this.”

So, it is clear that the graph seen in the supplementary materials to Chapter 1 of WGII, was the creation of “Writing Team”. Perhaps Roger can answer whether the original graph (as shown in the SOD) was the work of Muir-Wood.

Concerns were also raised by Indur Goklany (US Dept of the Interior), Francis Zwiers (Can. Centre for Climate Modelling and Analysis) and Nathan Gillet (University of East Anglia).

Zwiers commented (pp. 121-22):

“I’m wondering if too much space is devoted to Miller, given the inference one draws from Fig 1.5 is senstive to the inclusion of individual outliers (as pointed out in the text) and that it is acknowledged that early data are incomplete. Some additional comment on data quality, beyond just completeness, is probably in order (I'm not expert, but this type of data would presumably be influenced by all kinds of factors, including varying political influences and changes in reporting practices, that might confound any climate signal).

To which the response was: “Agreed – will restate the conclusions of this work judiciously to summarize what is revealed and what is uncertain.”

Gillett was concerned about the statistical underpinnings (p. 122):

“Is the statistically significant correlation purely a result of the trend in both series? Does the correlation remain statistically significant if both are de-trended? If not, then this merely tells us that both series contain a trend. More fundamentally, why correlate losses with global temperature? Some justification is needed.”

To this, the Writing Team responded:

“Losses can be correlated with year and also with global temperatures. The correlation with T is a function of both series containing trends with time over this period.”

I’ll leave it to the stats types to argue over whether the answer was actually responsive.

Brooks said...

Thank you for an excellent critique of the IPCC response. Your graphic is perfect.

David said...

Well struck.

I also would like to say that I enjoyed the picture of the pick wielding pile of dirt.

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