Fwd: Hurricane Debate Shatters Civility Of Weather Science (WSJ)
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Hurricane Debate Shatters Civility Of Weather Science
Worsened by Global Warming?
Spats Are So Tempestuous,
Sides Are Barely Talking
Charge of 'Brain Fossilization'
By VALERIE BAUERLEIN
Staff Reporter of THE WALL STREET JOURNAL
February 2, 2006; Page A1
The 2,000-plus scientists at this week's annual meeting of the
American Meteorological Society had plenty to talk about, from last
year's droughts to flash floods and wildfires. But the biggest
question at the meeting in Atlanta -- why last hurricane season was
the worst since recordkeeping began 151 years ago -- was almost too
hot to handle.
William Gray, America's most prominent hurricane scientist and an
ardent foe of the belief that global warming has worsened
was supposed to join a panel discussing the storms. So was Greg
Holland of the National Center on Atmospheric Research -- who
disagrees with Dr. Gray. But the organizers withdrew the invitations
after deciding the dispute had grown so nasty it was too risky to
the two in the same room.
"It was looking like it would totally dominate everything else,"
Joe Schaefer, a planner and the director of the National Weather
Service's Storm Prediction Center.
"To hell with it, I'm not going" to Atlanta, said Dr. Gray, a
Colorado State University professor of atmospheric science, after
learning of the cancellation before the conference. He didn't attend.
His adversary Dr. Holland is among a group of prominent scientists
who argue that the recent burst of powerful storms isn't part of a
normal pattern. In a recent article, he and co-authors said that
global warming caused by human activity, while not affecting the
number of hurricanes, appears to be causing more of them to be very
intense. Dr. Holland went to the meeting despite the cancellation of
his joint appearance with Dr. Gray and presented his paper's
conclusions during a session on a wide variety of weather issues.
What is going on with hurricanes like Katrina and the subsequent
Wilma, which was the strongest ever recorded in the Atlantic,
urgently to millions of people wondering whether coastal areas are
safe. Insurers and other companies are trying to calculate future
risks of operating in the vulnerable regions. And policy makers are
wrestling with whether to rebuild some shattered communities.
Dr. Gray, who is 76 years old, has been studying storms for nearly a
half-century. He is the author of seminal early models for
the atmospheric conditions that lead to storms and was a mentor to
doctoral and master's students -- including Dr. Holland.
Dr. Gray hasn't been shy about firing back at his critics. After
Judith Curry, a climatologist at Georgia Institute of Technology in
Atlanta, co-wrote a paper linking global warming and hurricane
intensity, he said: "Judy Curry just doesn't know what she's talking
Dr. Curry, in an interview at her Georgia Tech office, said Dr. Gray
has "brain fossilization." She added: "Nobody except a few groupies
wants to hear what he has to say."
Dr. Gray has said on his Web site and has testified to Congress that
recent storms' intensity wasn't fueled by human-induced global
warming. Natural factors, he says, such as the presence of upper-air
currents that can bat storms from side to side, helped steer them
ashore and thus made them more destructive. Dr. Gray believes the
current era of high activity will eventually end as a result of
changes in salinity and currents in the Atlantic. Sometime in the
next decade or two, he predicts, the earth will enter a cooling
period, as it did in the 1950s.
In October 2004, Dr. Gray's views faced a head-on challenge from
Kevin Trenberth, head of climate analysis at the National Center for
Atmospheric Research, a prominent institute in Boulder, Colo., where
Dr. Holland also works. At a news conference convened by Harvard
Medical School's Center for Health and the Global Environment, Dr.
Trenberth outlined his position that the spate of hurricanes that
slammed the U.S. in 2004 might be linked to global warming caused by
humans. He said rising temperatures weren't necessarily triggering
more hurricanes but might be causing stronger ones, because as
warm they create more water vapor, the fuel for hurricanes.
That news conference roiled the world of weather scientists, several
of whom thought Dr. Trenberth hadn't done sufficient research to
up the provocative claims. Some started new studies aimed at testing
In the July 31, 2005, online edition of the scientific journal
Nature, Kerry Emanuel, a tropical meteorologist at Massachusetts
Institute of Technology, published results of a complicated re-
examination of historic data on wind speed and duration for North
Atlantic and Western North Pacific storms. Hurricane damage
exponentially as wind speeds rise, meaning that a hurricane with
winds of 148 miles per hour may produce as much as 250 times the
damage of a hurricane with 74 mph winds, according to the National
Oceanic and Atmospheric Administration.
To calculate the total power generated over a storm's lifetime, Dr.
Emanuel multiplied each hurricane's maximum sustained wind speed by
itself and then multiplied that result by the wind speed again, a
calculation known as cubing. Then he factored in how many hours the
Dr. Emanuel says he used scientifically accepted formulas to adjust
for years when wind-speed data are most likely to contain errors,
particularly in Atlantic storms from 1949 to 1969, when it is
speed was overestimated. The calculation showed that the intensity
storms had essentially doubled in the past 30 years. He attributed
growing hurricane intensity and destructive power to rising water
temperatures that he said were "at least partially" the result of
At the same time, Dr. Curry and Peter Webster, who is also at
Tech, set out specifically to investigate Dr. Trenberth's
Dr. Webster had co-written a paper in 1998 with Dr. Gray and nine
other scientists in which they didn't find the connections Dr.
Much of past research on hurricanes had been limited to storms in
Atlantic, which spawns those that hit the U.S. The Georgia Tech
researchers, along with Dr. Holland, broadened their scrutiny to all
hurricanes -- known as tropical cyclones and typhoons in the Pacific
and Indian oceans -- anywhere in the world since 1970.
"It's not rocket science," says Dr. Curry, 52, who says the
researchers counted the number of Category 4 or 5 storms, or those
with sustained wind speeds of at least 131 mph. They found that the
total number of storms world-wide stayed fairly constant, but the
number of intense ones had doubled since 1970. About two weeks after
Katrina barreled into the Gulf Coast as a Category 3 storm, an
article by Drs. Curry, Webster and Holland laid out their conclusion
in the journal Science. They say the rise in ocean temperatures
related to natural causes and appears to be associated with global
warming, most likely related to a rise in greenhouse gases.
Dr. Gray's views on the natural cycle of storms in the Atlantic are
strongly supported by the weather establishment. The National
and Atmospheric Administration, which runs the National Hurricane
Center, took the unusual step in November of saying it is the
consensus view among NOAA scientists that global warming related to
human activity isn't causing either more storms or greater storm
intensity. "Increases in hurricane activity are primarily the result
of natural fluctuations in the tropical climate system," the
Most serious weather and climate researchers, including Dr. Gray,
agree the planet has gradually warmed in recent decades. Last year
was the warmest year since 1880, climatologists at National
Aeronautics and Space Administration's Goddard Institute for Space
Studies said recently. All sides also agree 2004 and 2005 were
unusually active years for big storms.
The sides disagree about how much global warming is attributable to
natural cycles and how much to human activity such as the release of
greenhouse gases from burning fossil fuels. Among meteorologists who
say humans are behind global warming, many contend there isn't
evidence to link it to increased hurricane intensity.
Further complicating things: Climate change can be studied based on
tree-ring and ice-core samples dating back thousands of years, but
specific data on hurricanes has been gathered for only about 150
years. Even that is primarily in the Atlantic. Modern hurricane
science began about 60 years ago, when daredevil pilots first flew
into the storms. Until then, hurricanes' strength had to be
extrapolated from damage and from data collected by ships and on
land. Some storms in remote places may not have been recorded at
Satellites improved the quality of information starting in the
and meteorologists wrote and rewrote formulas for calculating wind
speed in an effort to smooth out the historical record.
Dr. Gray responded sharply to the new research tying hurricane
intensity to human-caused climate change, and the once-intimate
circle of hurricane researchers erupted in turmoil. In Senate
testimony in late September and in papers on his Web site, Dr. Gray
said the new conclusions were irreparably flawed by the inferior
of earlier years. He says he had seen weather information being
gathered haphazardly when he visited remote Pacific outposts in the
1970s. "The satellites were down or the people weren't trained," he
Dr. Gray attacked the Science article on his Web site, agreeing that
ocean temperatures were climbing but maintaining that the rise was
largely attributable to long-term heating and cooling trends. The
rise in water temperature has negligible connection to the
hurricanes, he argued. He complained that "the near universal
reference to this paper over the last few weeks by most major media
outlets is helping to establish a false belief among the general
public...that global warming may be a contributing factor" to
devastation such as that from Katrina.
Worse, he said in a separate paper on his Web site, flaws in wind-
speed calculation are magnified when the numbers are cubed, as in
Emanuel's study. In an email widely circulated among climate
researchers in November, Dr. Gray wrote: "How were Emanuel and
Webster et al. able to see trends in the global data that the rest
us long-time (tropical-cyclone) researchers presently working on
these same data sets do not find?"
Dr. Curry says her study used only data collected since 1970, after
satellites were in global use, minimizing the possibility of errors.
She says Dr. Gray's prominence in the field has overshadowed
new research. Meteorologists trained by him had looked at the data
for so long and in such a prescribed manner, she argues, that they
missed red flags about increasing intensity.
Dr. Holland, the scientist who was supposed to appear with Dr. Gray
Tuesday night, once was a student under Dr. Gray. At the Atlanta
meteorological conference, he said seasonal forecasts, especially
Gray's, are rarely correct. An ally of Dr. Gray, Chris Landsea, of
the National Hurricane Center, presented a critique of the global-
warming hurricane theories, but the two scientists weren't in a
that allowed debate.
Dr. Gray says his forecasts are accurate and improving each year. As
for his resistance to the new challenges, it is based on experience
and solid science, not his age, he said. "I don't feel I'm
fossilized. If half my ex-Ph.D. students say I'm senile, then I'll
quit. They have not."
Scientists on both sides say they expect follow-up studies proving
they are right to be published before the next hurricane season
starts in June. Drs. Trenberth and Emanuel are submitting separate
studies to major journals arguing that the influence of natural
cycles has been greatly overestimated, a mutinous theory in
established hurricane science. Dr. Landsea says he has submitted his
own analysis to a major journal confirming the natural ebb and flow
of storms argued by Dr. Gray. Both sides are waiting to see which
papers will be accepted.
Meanwhile, a new panel discussion featuring the highest-profile
hurricane scientists is being planned for an April conference in
Monterey, Calif. Drs. Emanuel and Webster already have said they
won't participate if Dr. Gray is there.
Write to Valerie Bauerlein at valerie.bauerlein@...
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