On November 29, top officials at the National Oceanic and Atmospheric Administration (NOAA), which includes the National Weather Service, held a press conference in Washington, D.C., to sum up this year’s disastrous hurricane season. The first question from a reporter was one the press had been asking since Hurricane Katrina reached land three months before: “I was wondering if one of you can talk about what extent, if any, global warming may have played in the storms this year?” NOAA’s chief hurricane forecast scientist, Gerry Bell, stepped forward to answer. Bell denied that “greenhouse warming” had any effect on the hurricanes. The hurricanes, he insisted, were merely part of “the 20- to 30-year cycles that we’ve seen since 1950.”
Aren’t there recent reports, the reporter then asked, that “global warming may have been responsible for the intensity of the storms”? No, Bell said, the storms’ intensity was “part of the multi-decadal signal that we see. It’s not related to greenhouse warming.” According to Bell, there was simply no conceivable connection between global warming and hurricanes. And Bell’s denial of a link echoed the statements of other top NOAA administrators and those posted on the organization’s website. These statements by NOAA officials were widely cited in columns and editorials debunking claims of a link between global warming and hurricanes.
There’s only one problem: 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.”
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. In August, Kerry Emanuel of MIT, one of the nation’s most respected climate scientists, published a study in Nature concluding that global warming may lead “to an upward trend in tropical cyclone destructive potential.”
Emanuel was not arguing that global warming caused any particular hurricane, including Katrina. “It’s statistically impossible to say this, just as it is impossible to say that a very warm day is a result of global warming,” he explains. “All you can say is that the odds of having a day like that increase when you have global warming.” In other words, global warming didn’t necessarily cause Katrina, but it may be increasing the odds that hurricanes like Katrina will occur.
In September, Peter Webster, H.-R. Chang, and Judith Curry of Georgia Tech and G.J. Holland of the National Center for Atmospheric Research (NCAR) published a study in Science that bolstered Emanuel’s conclusions. They found “a thirty-year trend toward more frequent and intense hurricanes,” which coincided with global warming. While they were careful not to draw final conclusions from the limited period they studied, what they found, the researchers wrote, “is not inconsistent with recent climate model simulations that a doubling of CO2 may increase the frequency of the most intense cyclones.” One of the simulations the researchers cited was done by a NOAA scientist. Thomas R. Knutson of NOAA’s Geophysical Fluid Dynamics Laboratory at Princeton and Robert E. Tuleya of Old Dominion University had shown that “if the frequency of tropical cyclones remains the same over the coming century, a greenhouse gas-induced warming may lead to a gradually increasing risk in the occurrence of highly destructive category-5 storms.”
These findings have sparked an intense debate among climate scientists. In response to criticism, Emanuel has modified part of his theory without discarding the whole. 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. In the meantime, however, NOAA, which has never before taken an official position on such a raging scientific controversy, is making pronouncements suggesting that there is no debate at all.
In making these statements, 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. 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.”
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.
According to The New York Times, officials at the National Aeronautic and Space Administration (NASA) have attempted to discourage its chief climate scientist, James Hansen, from speaking out on global warming. The same thing may be happening to scientists at NOAA. Francesca Grifo, the head of the Scientific Integrity Program at the Union of Concerned Scientists, says a NOAA scientist complained last year of “being what we now call Hansenized.” Emanuel, who regularly talks with NOAA scientists, says, “Scientists who don’t toe the party line are being intimidated from talking to the press. I think it is a very sad situation. I know quite a few people who are frightened, but they beg me not to use their name.”
The main instrument of suppression seems to be NOAA’s policy on contact with the press. Since June 2004, NOAA, which is part of the Department of Commerce, has had a policy that its employees have to notify a public affairs officer if a member of the press contacts them for an interview. But the policy was often ignored. Then, on September 29, in the midst of growing public debate over hurricanes and global warming, public affairs official Jim Teet issued a memo requiring that “any request for an interview with a national media outlet/reporter must now receive prior approval by DOC [Department of Commerce].”
NOAA Public Affairs Director Jordan St. John insists that Teet’s memo merely restated the existing policy, but, by requiring approval and not merely notification, Teet’s order—first publicized by reporter Larisa Alexandrovna of “The Raw Story”—erected an entirely new hurdle in the face of NOAA scientists who want to talk to the press. NOAA employees, speaking on background, described the policy to me as “strange” and “unfortunate.”
Georgia Tech’s Curry, who also serves as a NOAA adviser on its Climate Working Group, thinks that what is happening at the organization is an “absolute disgrace.” Curry knows of NOAA scientists who disagree with NOAA’s position on hurricanes and global warming but are being told not to talk to the press.”They are being muzzled,” she says. Curry also says that officials have been trying to prevent certain scientists at the National Climactic Data Center from even working on the problem of hurricanes and global warming. “You hear about Hansen, but NASA is not really that bad. NOAA is really, really bad,” she says.
Perhaps the most telling indictment of NOAA comes from Jerry Mahlman. Mahlman joined NOAA in 1970, the year it was established, and served from 1984 to 2000 as the director of the Geophysical Fluid Dynamics Laboratory. Retired from NOAA, he is now a senior research associate at NCAR in Boulder, Colorado. Mahlman, who has continued contact with NOAA scientists, says that dissenting scientists are being intimidated from talking to the press and that their papers are being withheld from publication. Mahlman tells me, “I know a lot of people who would love to talk to you, but they don’t dare. They are worried about getting fired.”
According to Mahlman, the architect of NOAA’s policy on global warming and hurricanes is its director, Lautenbacher, not underlings like Mayfield and Bell. Lautenbacher, a former naval officer with a Ph.D. in applied mathematics whom Bush nominated to head NOAA in September 2001, has been an administration point man on global warming at international conferences, where he justifies the administration’s rejection of the Kyoto treaty. At a U.N. climate conference in Milan in December 2003, Lautenbacher declared, “I do believe we need more scientific info before we commit to a process like Kyoto.”
Lautenbacher’s predecessors regularly voiced their opinions on scientific subjects, but they usually tried to steer clear of politics, and they didn’t pretend to be presenting an official position on a scientific controversy. But, under Lautenbacher, NOAA has been plunged into Bush administration politics. With the issue of hurricanes and global warming, the organization has entered the even murkier realm of scientific censorship. NOAA, which once exemplified the constructive relationship between science and government, has become an instrument of what author Chris Mooney calls “the Republican war on science.” And, in this war, the public is the real casualty.
This article appeared in the February 20, 2006 issue of the magazine.