Forget what you've read in the press or
heard on television: There is no scientific consensus on global
In recent months, there has been much
talk in the national news media about a scientific consensus on
global warming. A page one story appearing in The Washington Post
on November 12, for example, blared, "Consensus Emerges Earth
is Warming -- Now What?"
But precisely how did The Washington Post
and other papers conclude that a scientific consensus exists?
Did they poll climate scientists? Perhaps they, like Vice President
Gore and other administration officials, relied on various letters
supporting the global warming theory signed by self-proclaimed
One such letter, "Scientists' Statement
on Global Climatic Disruption," was circulated by a Washington,
D.C.-based group called Ozone Action. It purported to have as
signatories 2,611 scientists from the U.S. and abroad endorsing
the idea that the scientific evidence of global warming was conclusive.
The only problem is, most of the signers have little or no background
in climate science. According to Citizens for a Sound Economy,
only about 10% of the letter's signers have experience in fields
connected with climate science. What's worse, the letter includes
as signers two landscape architects, ten people with backgrounds
in psychology, one person trained in traditional Chinese medicine
techniques and one person trained in gynecology. There is a world
of difference between a gynecologist and a climatologist. Still,
a number of journalists actually took the Ozone Action letter
Or, perhaps The Washington Post and others
determined there was a consensus based upon the Second Assessment
Report of the United Nations Intergovernment Panel on Climate
Change (IPCC) released in 1995. The report, which purports to
be the culmination of some 2,000 scientists' work, found that
the "balance of evidence suggests a discernible human influence"
on climate. But this is misleading: While many scientists did
indeed work on the Second Assessment Report, they did not necessarily
support the conclusions of the final report. As Dr. John W. Zillman,
one of the scientists who participated in the process noted, "[The
IPCC was] meticulous in insisting that the final decision on whether
to accept particular review comments should reside with chapter
Lead Authors. This was at variance with the normal role of journal
editorial boards and led to suggestions that some Lead Authors
ignored valid critical comments or failed to adequately reflect
dissenting views when revising their text."
Surveys of climate scientists and meteorologists
don't lend much credibility to the argument that a consensus exists
A survey of over 400 German, American
and Canadian climate researchers conducted by Dennis Bray of the
Meteorologisches Institut der Universitat Hamburg and Hans von
Storch of GKSS Forschungszentrum and reported in the United Nations
Climate Change Bulletin, for example, found that only 10% of the
researchers surveyed "strongly agreed" with the statement
"We can say for certain that global warming is a process
already underway." Further, 35% of those surveyed either
disagreed with the statement or were undecided. Perhaps even more
interesting, 67% of the researchers either disagreed or were uncertain
about the proposition that climate change will occur so suddenly
that a lack of preparation would devastate certain parts of the
world -- the underlying assumption on which the talks in Kyoto,
Japan were based. Close to half of the researchers -- 48% -- indicated
that they don't have faith in the forecasts of the global climate
models, the strongest argument in favor of quick, decisive, international
action to counter the threat of global warming. Another 20% expressed
uncertainty about these models.
Another survey, conducted by American
Viewpoint for Citizens for a Sound Economy, found that, by a margin
of 44% to 17%, state climatologists believe that global warming
is largely a natural phenomenon. The survey further found that
58% of the climatologists disagreed with President Clinton's assertion
that "the overwhelming balance of evidence and scientific
opinion is that it is no longer a theory, but now fact, that global
warming is for real," while only 36% agreed with the assertion.
Thirty-six of the nation's 48 official state climatologists participated
in the survey.
There is, therefore, no scientific consensus
on global warming.
But perhaps even more important than whether
or not scientists have reached a consensus, however, is whether
or not the scientific data backs up the theory. Data collected
from NASA's TIROs series of weather satellites show a slight cooling
trend of .04 degrees Celsius over the past 18 years. These findings
have been confirmed by weather balloons.
Even if scientists haven't developed a
consensus on global warming, the scientific data has: Global warming
is not occurring.
-David Ridenour is vice president of
The National Center for Public Policy Research. Comments may be
sent to him at [email protected]