09 October 2009

The "Shameful Article": A Review and Update

As the world continues to suffer a "depression" in global tropical cyclone activity with activity at 30-year lows, and hurricane forecasters try to keep busy while watching the listless Atlantic, I thought that for those who haven't been reading this blog for the past 5 years (which I assume is most everyone;-) it would be worth reviewing a bit of the history of the science on hurricanes and global warming, and how that science was ignored by the IPCC.

In 2004 and 2005 (before Katrina), I led an interdisciplinary effort to review the literature on hurricanes and global warming. The effort resulted in a peer-reviewed article in the Bulletin of the American Meteorological Society (here in PDF). Upon its acceptance Kevin Trenberth, a scientist at NCAR here at Boulder and the person in charge of the 2007 IPCC AR4 chapter that reviewed extreme events including hurricanes, said this in the Boulder Daily Camera (emphasis added) about our article:
I think the role of the changing climate is greatly underestimated by Roger Pielke Jr. I think he should withdraw this article. This is a shameful article.
Here is what the "shameful article" concluded:
To summarize, claims of linkages between global warming and hurricane impacts are premature for three reasons. First, no connection has been established between greenhouse gas emissions and the observed behavior of hurricanes . . . Second, the peer-reviewed literature reflects that a scientific consensus exists that any future changes in hurricane intensities will likely be small in the context of observed variability . . . And third, under the assumptions of the IPCC, expected future damages to society of its projected changes in the behavior of hurricanes are dwarfed by the influence of its own projections of growing wealth and population . . . While future research or experience may yet overturn these conclusions, the state of the peer-reviewed knowledge today is such that there are good reasons to expect that any conclusive connection between global warming and hurricanes or their impacts will not be made in the near term.
When Trenberth called the article shameful I responded on Prometheus with this comment:

Upon reading Kevin’s strong statements in the press a few weeks ago, I emailed him to ask where specifically he disagreed with our paper and I received no response; apparently he prefers to discuss this issue only through the media. So I’ll again extend an invitation to Kevin to respond substantively, rather than simply call our paper ’shameful’ and ask for its withdrawal (and I suppose implicitly faulting the peer review process at BAMS): Please identify what statements we made in our paper you disagree with and the scientific basis for your disagreement. If you’d prefer not to respond here, I will eagerly look forward to a letter to BAMS in response to our paper.

Climate change is a big deal. We in the scientific community owe it to the public and policy makers to be open about our debates on science and policy issues. We’ve offered a peer-reviewed, integrative perspective on hurricanes and global warming. I hold those with different perspectives in high regard — such diversity makes science strong. But at a minimum it seems only fair to ask those who say publicly that they disagree with our perspective to explain the basis for their disagreement, instead of offering up only incendiary rhetoric for the media. Given that Kevin is the IPCC lead author responsible for evaluating our paper in the context of the IPCC, such transparency of perspective seems particularly appropriate.
Not surprisingly the IPCC chapter that Trenberth led for the IPCC made no mention of our article, despite it being peer reviewed and being the most recently published review of this topic prior to the IPCC publication deadline (the relevant IPCC chapter is here in PDF). Even though the IPCC didn't see the paper as worth discussing, a high-profile team of scientists saw fit to write up a commentary in response to our article in BAMS (here in PDF) . One of those high-profile scientists was Trenberth. Trenberth and his colleagues argued that our article was flawed in three respects, it was,
. . . incomplete and misleading because it 1) omits any mention of several of the most important aspects of the potential relationships between hurricanes and global warming, including rainfall, sea level, and storm surge; 2) leaves the impression that there is no significant connection between recent climate change caused by human activities and hurricane characteristics and impacts; and 3) does not take full account of the significance of recently identified trends and variations in tropical storms in causing impacts as compared to increasing societal vulnerability.
Our response to their comment (here in PDF) focused on the three points that they raised:
Anthes et al. (2006) present three criticisms of our paper. One criticism is that Pielke et al. (2005) “leaves the impression that there is no significant connection between recent climate change caused by human activities and hurricane characteristics and impacts.” If by “significant” they mean either (a) presence in the peer-reviewed literature or (b) discernible in the observed economic impacts, then this is indeed an accurate reading. Anthes et al. (2006) provide no data, analyses, or references that directly connect observed hurricane characteristics and impacts to anthropogenic climate change. . .

In a second criticism, Anthes et al. (2006) point out (quite accurately) that Pielke et al. (2005) failed to discuss the relationship between global warming and rainfall, sea level, and storm surge as related to tropical cyclones. The explanation for this neglect is simple—there is no documented relationship between global warming and the observed behavior of tropical cyclones (or TC impacts) related to rainfall, sea level, or storm surge. . .

A final criticism by Anthes et al. (2006) is that Pielke et al. (2005) “does not take full account of the significance of recently identified trends and variations in tropical storms in causing impacts as compared to increasing societal vulnerability.” Anthes et al. (2006) make no reference to the literature that seeks to distinguish the relative role of climate factors versus societal factors in causing impacts (e.g., Pielke et al. 2000; Pielke 2005), so their point is unclear. There is simply no evidence, data, or references provided by Anthes et al. (2006) to counter the analysis in Pielke et al. (2000) that calculates the relative sensitivity of future global tropical cyclone impacts to the independent effects of projected climate change and various scenarios of growing societal vulnerability under the assumptions of the Intergovernmental Panel on Climate Change.
This series of exchanges was not acknowledged by the IPCC even though it was all peer-reviewed and appeared in the leading journal of the American Meteorological Society. As we have seen before with the IPCC, its review of the literature somehow missed key articles that one of its authors (in this case Trenberth, the lead for the relevant chapter) found to be in conflict with his personal views, or in this case "shameful." Of course, there is a deeper backstory here involving a conflict between my co-author Chris Landsea and Trenberth in early 2005, prompting Landsea to resign from the IPCC.

So almost five years after we first submitted our paper how does it hold up? Pretty well I think, on all counts. I would not change any of the conclusions above, nor would I change the reply to Anthes et al. Science changes and moves ahead, so any review will eventually become outdated, but ours was an accurate reflection of the state of science as of 2005. However, you won't find any of this in the IPCC.

Papers and links

Anthes et al. 2006, Hurricanes and global warming: Potential linkage and consequences, BAMS, Vol. 87, pp. 623-628.

Pielke, Jr., R. A., C. Landsea, M. Mayfield, J. Laver and R. Pasch, 2005. Hurricanes and global warming, Bulletin of the American Meteorological Society, 86:1571-1575.

Pielke, Jr., R. A., C.W. Landsea, M. Mayfield, J. Laver, R. Pasch, 2006. Reply to Hurricanes and Global Warming Potential Linkages and Consequences, Bulletin of the American Meteorological Society, Vol. 87, pp. 628-631, May.


  1. But you bizarrely accept IPCC AR4 WG1. What makes you think that the other WG1 chapters are any less biased? Briffa was lead author of the Paleoclimate chapter, for example. Lead authors are dominated by activists who promote their own views and work. Inconvenient peer reviewed papers are ignored. IPCC AR4 should be in the toilet, not on policymakers desks!

  2. Thanks for posting this. I always enjoy seeing updates on these things.

    After the hurricane season is over, maybe we can see an update on the Risk Management Solutions "forecasts" on insured losses from hurricane activity. As I remember, their original forecast for 2006-2010 was off to a rocky start last time I heard about it in 2007.

  3. Paul-

    My issue here is with Chapter 3 of the WG1 report. In the end the SPM got this issue just about right:


    Not due to our work, but thanks to the heroic efforts of a WMO assessment group led by John McBride. Maybe if Chapter 3 had better reflected the actual literature the WMO effort would not have had to play such a key role. Things could have turned out differently, but in this case at least, the problem was in the process not the outcome.

  4. -2-T.I.M.

    Sure, I'll add it to the list. The RMS forecasts are bust.

    Meantime, I discuss some of the technical aspects of the RMS forecast in the paper I posted up earlier:


  5. Not terribly comforting! IPCC AR4 should be an objective review of published science - no 'heroic efforts' should be required. The rest of the SPM lacked heroes!

  6. Look just at literature from 2006 and later, many papers have appeared on this subject which generally support your stated conclusions.

    A sampling of references:

    Klotzbach, P.J. and W.M. Gray. 2008. Multidecadal variability in North Atlantic tropical cyclone activity. Journal of Climate, 21, 3929-3935.
    Vecchi, G. A., et al., 2008. Whither Hurricane Activity? Science, 322, 687-689.
    Kuleshov, Y., et al., (2008), On tropical cyclone activity in the Southern Hemisphere: Trends and the ENSO connection, Geophysical Research Letters, 35, L14S08, doi:10.1029/2007GL032983.
    Chan, J.C.L. 2007. Decadal variations of intense typhoon occurrence in the western North Pacific. Proceedings of the Royal Society, A., 464, 249-272.
    Elsner, J.B., et al., 2008. Comparison of hurricane return levels using historical and geological records. Journal of Applied Meteorology and Climatology, 47, 368-374.
    Briggs, W.M. 2008. On the changes in the number and intensity of North Atlantic tropical cyclones. Journal of Climate, 21, 1387-1402.
    Zuki, Z. M., and A. R. Lupo. 2008. Interannual variability of tropical cyclone activity in the southern South China Sea. Journal of Geophysical Research, 113, D06106, doi:10.1029/2007JD009218.
    Englehart, P. J., et al., 2008. Defining the frequency of near-shore tropical cyclone activity in the eastern North Pacific from historical surface observations (1921–2005). Geophysical Research Letters, 35, L03706, doi:10.1029/2007GL032546.
    Wang, C., and S.-K. Lee (2008), Global warming and United States landfalling hurricanes, Geophysical Research Letters, 35, L02708, doi:10.1029/2007GL032396.
    Vecchi, G.A. and B.J. Soden. 2007. Effect of remote sea surface temperature change on tropical cyclone potential intensity. Nature, 450, 1066-1071.
    Li, Y., et al., 2007. Analysis and prognosis of tropical cyclone genesis over the western North Pacific on the background of global warming. Acta Oceanologica Sinica, 26, 23-34.
    Swanson, K.L, 2007. Impact of scaling behavior on tropical cyclone intensities. Geophysical Research Letters, 34, doi:10.1029/2007GL030851.
    Bengtsson, L., et al., 2007. How may tropical cyclones change in a warmer climate? Tellus, 59A, 539-561.
    Chan, J.C.L. 2007. Interannual variations of intense typhoon activity. Tellus, 59A, 455–460.
    Vitart, F. and F. Doblas-Reyes. 2007. Impact of greenhouse gas concentrations on tropical storms in coupled seasonal forecasts. Tellus, 59A, 417-427.
    Wu, Y., et al., 2007. The impact of tropical cyclones on Hainan Island’s extreme and total precipitation. International Journal of Climatology, DOI: 10.1002/joc.1464.
    Vecchi, G.A. and B. J. Soden, 2007. Increased tropical Atlantic wind shear in model projections of global warming. Geophysical Research Letters, L08702, doi:10.1029/2006GL028905.
    Michaels, P. J., et al., 2006. Sea-surface temperatures and tropical cyclones in the Atlantic basin, Geophysical Research Letters, 33, L09708, doi:10.1029/2006GL025757.
    Kossin, J.P., et al., 2007. A globally consistent reanalysis of hurricane variability and trends. Geophysical Research Letters, 34, L4815, doi: 10.1029/2006GL028836.
    Landsea, C.W., et al., 2006. Can We Detect Trends in Extreme Tropical Cyclones? Science, 313, 452-454.
    Yoshimura, J., et al., 2006. Influence of greenhouse warming on tropical cyclone frequency, Journal of the Meteorological Society of Japan, 84, 405-428.
    Ren, F., et al., 2006. Changes in tropical cyclone precipitation over China, Geophysical Research Letters, 33, L20702, doi:10.1029/2006GL027951.
    Klotzbach, P.J., 2006. Trends in global tropical cyclone activity over the past twenty years (1986-2005). Geophysical Research Letters, 33, L010805, doi:10.1029/2006GL025881.

  7. This thread fits will with the global warming as religion thread.

    Roger, your paper was heretical, and all heresy is shameful.

    The logical fallacy that leads to that conclusion is the “appeal to consequences of belief”. The consequence of belief in your paper is the rejection of a tenet of Global Warming. The belief that Global Warming causes more hurricane damage has been accepted as part of the AGW doctrine. The concept is even in the Boxer/Kerry cap and trade bill as settled science justifying the extreme cost of the bill.

    Meanwhile both sides of the argument are tightly focused on how climate affects hurricanes. What the field needs is a left handed climate scientist to investigate how hurricanes affect climate. A single hurricane removes about 200 trillion joules per day from the ocean and transports thousands of tons of water high into the troposphere where it is free to radiate energy into space and exchange CO2 between the ocean and the atmosphere. But I have no faith in the government funding such a study.

  8. Roger - What on earth is going on? I just looked in the IPCC report (AR4-WG2-Chap1). On page 110, section, titled Tropical Cyclones, this is the first thing it says: "While overall number of tropical cyclines worldwide have shown little variation over the past 40 years (Pielke et al, 2005) . . ."

    They also refer to you 2006 paper with Hopp in the next section about economic losses, again in the first paragraph.

    So how do you justify saying that the IPCC doesn't mention your report when I see it mentioned as the first paper cited in the section on cyclones?

  9. -8-Dean

    This post is about IPCC WG1 Chapter 3. Confusing, I know, apologies.

    IPCC WG2 has its own issues with my work, and that is a separate matter. I discuss WG2 here:


    It is funny that the impacts working group sees fit to cite my work with colleagues related to the physical science but ignores much of my impacts work ;-)

    The IPCC WGs work essentially independently of one another.

  10. So your paper is used in the IPCC report - fairly prominently I might add, but not in the WGI section. Though WGI does refer to WGII regarding impacts. I also note that a paper that your father participated in (Chase et al 2003) is cited in the same section that you wanted to be cited in.

    Further, some of the conclusions that you have come to are similar in that chapter. In the sidebar it comments on how increases in the economic costs of storms is probably due to human factors.

    I can't comment on Trenberth's own statements or personal opinions of your paper. But given the above, I don't see any evidence a problem with bias in these examples from the AR4. The Pielke name is not hard to find in AR4 citations.

  11. -10-Dean

    I can understand why you would come to this conclusion. I do wish it were as simple as a name appearing somewhere in the IPCC.

    As I have said, in the end (SPM) the IPCC WG1 got things just about right on hurricanes. But this does not mean that the process could not be improved.

    WGII however is a completely different story ...

  12. I suppose my point was that you use Trenberth's statements to claim that he brings a bias to the IPCC chapter you say he led. But then you say that the conclusions of that chapter are "just about right." So how can the IPCC be biased if they basically agree with you?

  13. -12-Dean

    The IPCC Summary for Policymakers got things right, the IPCC WG1 Chapter 3 did not. Trenberth was in charge of Chapter 3.

    They are different documents prepared at different times by different groups (with some overlaps).

    Sorry for any confusion, it is complicated!

  14. Gee I don't want to cause any hurricanes. Does this mean I can heat my house this winter? I almost froze to death last winter trying to prevent hurricanes and global warming.