| January 19, 2010 |  |
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.
UPDATE: 1/20/2009 – The IPCC released a statement (pdf) on this issue. It says, in part, "The Chair, Vice-Chairs, and Co-chairs of the IPCC regret the poor application of well-established IPCC procedures in this instance."
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 rapidly.
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. Overall, about 90 percent of the world's glaciers that scientists have measured 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 largely considered the effects that thermal expansion has on the ocean.
New analyses indicate that the shrinking land-based ice 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
Although individual scientists can make mistakes, the scientific process corrects 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 or simply repeat debunked arguments.
Because climate contrarians cannot ignore 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 are using 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.
The Union of Concerned Scientists puts rigorous, independent science to work to solve our planet's most pressing problems. Joining with citizens across the country, we combine technical analysis and effective advocacy to create innovative, practical solutions for a healthy, safe, and sustainable future.
