Factcheck: Contrarians Attack IPCC Over Glacier Findings, But Glaciers are Still Melting

Climate contrarians are inflating the importance of an erroneous
reference to Himalayan glaciers in a 2007 U.N. Intergovernmental Panel
on Climate Change (IPCC) report to attack the scientific body and its
chairman, Rajendra Pachauri. The Union of Concerned Scientists (UCS)
expects ideological bloggers, some members of Congress, and fossil-fuel
industry front groups to try to exploit this relatively small error in
the report to bolster conspiracy theories about the IPCC and climate
scientists.

The second of three 2007 IPCC reports included a statement that the
likelihood that Himalayan glaciers will disappear "by the year 2035 and
perhaps sooner is very high." It is not clear how this unsupported
assertion made it into the report, although it was openly challenged by
some researchers during the review and editing process. Rajendra
Pachauri, the IPCC chairman, said this week that the IPCC will
investigate the matter.

Each of the three IPCC 2007 reports was written by a different
working group. The reports, which covered climate science, the
consequences of climate change, and potential strategies for reducing
emissions and adapting to climate change, included discussions of
nearly every climate study available from the scientific literature at
the time. The working groups also issued shorter documents called
"summaries for policymakers" that highlighted their most solid
conclusions.

Regardless of how the statement remained in the full report after
the review process, it is important to put it into scientific and
political context, UCS experts said. The claim was part of the full
review of climate science and impacts provided in the dense, 3,000-page
report, but was not mentioned in its highly visible summaries for
policymakers. Presumably the working group did not consider the 2035
Himalayan glaciers claim to be reliable enough for its policymaker
summary. The statement in the summary was much less specific. "If
current warming rates are maintained," it stated, "Himalayan glaciers
could decay at very rapid rates."

Given the sprawling nature of the IPCC, it is not surprising to find
relatively minor errors. Such mistakes do not undermine the overall
conclusions of the organization's reports, which are subject to an
exhaustive review process. The IPCC reports reference as many as 20,000
documents and the writing and review process involved more than 2,500
expert scientific reviewers.

GLACIERS ARE RETREATING WORLDWIDE

What should not get lost in this manufactured controversy is the
fact that glaciers around the world are melting more rapidly than the
IPCC projected.

A 2005 global survey of 442 glaciers
from the World Glacier Monitoring Service found that only 26 were
advancing, 18 were stationary, and 398 were retreating. In other words,
90 percent of the world's glaciers are shrinking as the planet warms.

Because scientific understanding of how fast snow and ice is
responding to global warming is still developing, the IPCC left the
effect of melting glaciers and ice sheets out of its sea-level rise
projections in 2007 and only considered the effects that thermal
expansion has on the ocean.

New analyses indicate
that meltwater from ice on land could lead to a sea-level rise of 2.6
feet (0.8 meter) by the end of the century; and, although 6.6 feet (2.0
meters) is less likely, it is still physically possible.

Melting glaciers and the resulting sea-level rise are a threat to
coastal communities around the world. According to the U.S. Global
Change Research Program's 2009 review of climate impacts in the United States,
"Sea-level rise and storm surge place many U.S. coastal areas at
increasing risk of erosion and flooding, especially along the Atlantic
and Gulf Coasts, Pacific Islands, and parts of Alaska. Energy and
transportation infrastructure and other property in coastal areas are
very likely to be adversely affected."

Melting glaciers also will threaten drinking water supplies. An August 2008 Geophysical Research Letters study
that examined the impact of the melting Himalayan Naimona'nyi glacier
concluded, "If Naimona'nyi is characteristic of other glaciers in the
region, alpine glacier meltwater surpluses are likely to shrink much
faster than currently predicted with substantial consequences for
approximately half a billion people."

SCIENTISTS CORRECT THEMSELVES; CONTRARIANS DON'T

Scientists admit when they make mistakes and correct them. That's
one important way science moves forward. Climate contrarians often
cherry-pick minor points like this one then inflate their importance to
attack the broader science.

The rare times contrarians have proven scientists wrong, scientists have corrected the error and gone back to work.
When scientists prove contrarians wrong--which happens all the time in
and out of the scientific literature--contrarians tend to ignore them
and move on to other points.

Because climate contrarians cannot account for the overwhelming
evidence that heat-trapping emissions from human activity are driving
global warming, they have resorted to conspiracy theories and attacks
on scientists to try to explain away reality. Climate contrarians
likely will use this small error to try to undermine confidence in the
IPCC and climate science generally. They also will use it to attack
Pachauri personally. It is incumbent upon journalists to resist giving
these attacks more credence than they deserve and avoid confusing the
public about the real threat of global warming.