In the 20 February 2006 issue of The New Republic, John B. Judis has an article about how the issue of hurricanes and global warming has been handled by NOAA. Judis is engaging in scientific McCarthyism by arguing that certain perspectives on science are invalid because they are viewed as politically incorrect by some.

The transformation of this part of climate science into pure politics is fully embraced by those on the political left and the right, and most troubling is that this transformation is being encouraged by some leading scientists who have taken to criticizing the views of other scientists because they happen to work for the federal government. These scientists know full well how such accusations will be received. What ever happened to sticking to the science? Read on for background and analysis.


Judis alleges that scientists and political appointees in the National Oceanic and Atmospheric Administration or NOAA (pronounced “Noah”) are together conspiring to suppress scientific knowledge about a linkage of hurricanes and global warming,

Many respected climate scientists, including some who work for NOAA, believe the organization’s official line on the link between global warming and hurricanes is wrong. What’s more, there is reason to believe that NOAA knows as much. In the broader scientific community, there is grumbling that NOAA’s top officials have suppressed dissenting views on this subject–contributing to the Bush administration’s attempt to downplay the danger of climate change. Says Don Kennedy, the editor-in-chief of Science, the journal of the American Association for the Advancement of Science, “There are a lot of scientists there who know it is nonsense, what they are putting up on their website, but they are being discouraged from talking to the press about it.”

The notion that NOAA has an “official line” on hurricanes put up on their website apparently comes from this press release from 29 November 2005 which includes the following statements:

The nation is now wrapping up the 11th year of a new era of heightened Atlantic hurricane activity. This era has been unfolding in the Atlantic since 1995, and is expected to continue for the next decade or perhaps longer. NOAA attributes this increased activity to natural occurring cycles in tropical climate patterns near the equator. These cycles, called “the tropical multi-decadal signal,” typically last several decades (20 to 30 years or even longer). As a result, the North Atlantic experiences alternating decades long (20 to 30 year periods or even longer) of above normal or below normal hurricane seasons. NOAA research shows that the tropical multi-decadal signal is causing the increased Atlantic hurricane activity since 1995, and is not related to greenhouse warming.

There is consensus among NOAA hurricane researchers and forecasters that recent increases in hurricane activity are primarily the result of natural fluctuations in the tropical climate system known as the tropical multi-decadal signal.

Judis argues that the scientific consensus has moved on:

NOAA’s official position reflects what used to be the conventional wisdom on the relationship between global warming and hurricanes. Until recently, most empirical climate studies had focused on the frequency of hurricanes; and most researchers concluded that there wasn’t a link to global warming–the frequency was connected to cyclical trends. But, in the last year, two important studies have suggested that there is an observable link between global warming and the growing intensity of hurricanes.

The studies that he refers to are familiar to readers of this bog, Emanuel in Nature and Webster et al. in Science, hereafter E05 and W05. What Judis doesn’t tell his readers is that neither E05 nor W05 are attribution papers – that is, neither paper conducted a rigorous analysis to explain the trends that they have documented. Here is what those papers actually say about attribution:

Emanuel et al. 2005 expresses some doubt as to the cause of the trends that he observes: “Whatever the cause, the near doubling of power dissipation over the period of record should be a matter of some concern”

Webster et al. 2005 more explicitly eschew attribution: “attribution of the 30-year trends [in hurricane intensity] to global warming would require a longer global data record and, especially, a deeper understanding of the role of hurricanes in the general circulation of the atmosphere and ocean, even in the present climate state.”

Now to be fair, Emanuel and the Webster et al. team have stated frequently in public that they firmly believe that the trends that they have documented are in fact caused by global warming. Why is there a difference between the cautious statements these scientists have made in their peer-reviewed publications and what they have said in public? The difference is that between rigorous research and hypotheses about what future research will show. Neither E05 nor W05 fully explain the trends that they see, but as we suggest in or 2005 BAMS review (here in PDF), they are “suggestive” of a linkage. Further peer-reviewed research may indeed demonstrate attribution, but it has not yet, and for those of us without expertise in the science it is probably best to rely on what the peer reviewed literature says rather than picking sides in an unfolding debate yet to appear in the peer-reviewed literature.

Judging by a quote in the Judis article, Donald Kennedy of Science thinks that this issue is important enough to violate his own magazines embargo policy when he says that, “According to Kennedy, forthcoming papers by Emanuel and by Kevin Trenberth of NCAR could strengthen the case for a link between hurricanes and global warming.” Of course it seems obvious that even if such papers are soon to appear, it makes no sense for scientists who are unaware of them to reflect what they say. [My guess is that these papers will offer competing theories to explain recent trends.] But I suppose that the logic here is that such studies merely confirm what those evil NOAA scientists should have known in the first place.

TNR’s Judis appears to acknowledge a “scientific debate” but then writes as if the previous scientific paradigm has been overturned and anyone who says differently must be in cahoots with the Bush Administration’s spin machine or conservative commentators. Bizarrely, Judis criticizes NOAA scientists for making statements fully supportable by peer-reviewed science, and in some cases work that those scientists have published.

NOAA officials have sometimes included carefully crafted caveats designed to deflect criticism from scientists who know about the controversy. But, because they don’t acknowledge the debate explicitly, the general public is likely to miss the caveats’ significance. Appearing before a subcommittee of the Senate Commerce Committee on September 20, for instance, Max Mayfield, the director of NOAA’s National Hurricane Center, said, “The increased activity since 1995 is due to natural fluctuations and cycles of hurricane activity, driven by the Atlantic Ocean itself along with the atmosphere above it and not enhanced substantially by global warming.” NOAA officials also resort to clever ambiguities that elude the public.”

If there is a scientific debate as Judis suggests, should Mayfield have the right to express his views on the science? Didn’t we just go through this with James Hansen? Is it that Mayfiled’s views are not politically correct and so therefore he must be lying to the public? Judis is encouraging scientific McCarthyism.

Judis continues to pile on NOAA administrators and scientists for making statements that are either consistent with existing science or their own personal views on the science,

They deny, for instance, any link between global warming and hurricane “activity”–a term that glosses over the distinction between frequency and intensity. The November issue of NOAA’s online magazine declares that “NOAA attributes recent increase in hurricane activity to naturally occurring multi-decadal climate variability” (italics added). In settings where scientists are not likely to be listening, NOAA officials have even dropped the hedged and ambiguous language. On August 30, Conrad Lautenbacher, the head of NOAA, said in Weldon Spring, Missouri, “We have no direct link between the number of storms and intensity versus global temperature rise.” The next month, when CBS’s “Face the Nation” host Bob Schieffer asked Mayfield whether the hurricanes had “something to do with global warming,” he replied unequivocally, “Bob, hurricanes, and especially major hurricanes, are cyclical.” And, at the NOAA press conference, Bell said simply of hurricane intensity: “It’s not related to greenhouse warming.”

Bell has an impressive record of scientific research. Is he not allowed to speak to his conclusions and hypotheses, or are only certain perspectives allowed in today’s politics of the climate debate? If we are going to advocate that James Hansen can speak his views on climate science, which are not universally shared, on what basis is Judis criticizing Bell for expressing his views?

Judis even endorses scientific McCarthyism by associating the views of certain scientists with conservative commentators, suggesting that certain views should be evaluated by who refers to them,

As expected, Rush Limbaugh, Rich Lowry of National Review, The Washington Times, and other conservative voices have cited NOAA to attack what Limbaugh has called “the global warming crowd.” But NOAA’s and Mayfield’s statements have also influenced mainstream commentators. Citing Mayfield, USA Today editorialized against “global warming activists” who were turning the “storms into spin.” CNN correspondent Ann O’Neill counseled against attributing hurricanes becoming “bigger and meaner” to global warming. “Don’t rush to blame it on global warming, experts warn,” she wrote. And two of the experts she quoted were Mayfield and Chris Landsea, Mayfield’s colleague at the National Hurricane Center. Citing Mayfield, a Chicago Tribune editorial issued a similar admonition against linking hurricanes with global warming.

Judis goes on to discuss the state of public relations in NOAA, a subject on which I too have heard rumors of a clamp down. As I understand things the alleged clamp down affects all NOAA employees, not just those who want to assert a linkage between global warming and hurricanes (Who are these folks? Judis does not name names.). This is indeed an important subject and it would benefit from some hard evidence (muzzled NOAA employees contact me: pielke@colorado.edu!). But to suggest that any such clamp down on media interactions has contributed to a stifling of discussion of hurricanes and global warming is absurd. This subject has received far more attention than is warranted by its policy significance. The great irony here is that Judis is trying to stifle the voices of those who he disagrees with.

For its part, NOAA should never put out an official agency position on a scientific subject, unless it has some formal mechanism for arriving at such a position (as does the FDA, for instance). Individual scientists, whether they are in NOAA and NASA, should be able to voice their views on science in which they have expertise. If many scientists within NOAA happen to think that the linkage of hurricanes and global warming is overstated by others, there is no need to ascribe this to the politics of the Bush Administration or to lying or deceit. Every NOAA scientist quoted in the Judis story has had a career that began long before Bush took office. Each is an accomplished scientist. They are deserving of our respect, even if their views are not received as politically correct.

The reality is that the last word on the science of hurricanes and climate change has yet to be written. And as far as the peer-reviewed literature is concerned, the debate really hasn’t even begun. There are differing expectations from very smart people about what future research will say. This is a recipe for an increase in our collective uncertainty. For the foreseeable future there will be conflicting statements made by qualified scientists. How people choose sides in this debate is likely to be much more a function of politics and ideology than anything else. Expect to see more scientific McCarthyism.