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Controversies Create Opening For Climate Critics

The spate of recent controversies about climate research has given fresh voice to a group of scientists who question the mainstream view that human activity is warming the planet to dangerous levels.

Very few scientists disagree that the earth’s climate has warmed since 1850. But some have long argued that there are too many uncertainties about man’s role in the warming, and that other factors, such as solar activity and the greenhouse effect of clouds, could account for a large part of the observed warming trend. Among this group are researchers who have criticized the limitations of past temperature records and mathematical models used to forecast future effects.

Such views are getting a fresh airing on the heels of two recent controversies dogging climate researchers. A United Nations group, the Intergovernmental Panel on Climate Change, or IPCC, has been heavily criticized for publishing an unsubstantiated claim that Himalayan glaciers would entirely melt away by 2035. A recent report also included several other claims later found to lack a scientific basis, including predictions of the impact of climate change on agriculture in Africa and the retreat of Amazonian rain forests, among others.

News of those discrepancies followed a scandal in Britain where the publication of hacked emails of climate scientists suggested they had declined to share their data with fellow researchers and tried to squelch dissenting views about climate change.

It’s too soon to tell whether the critics’ views will force the scientific community to revisit the prevailing view of man-made climate change. Many of their colleagues remain resolute in their stance that global warming is caused mainly by humankind. The IPCC in recent interviews has said its errors, while serious enough to make the organization re-examine its procedures, do not change the central point of its influential 2007 report, which concluded that evidence for the human role in global warming is “unequivocal.”

“It’s important to say that the scandals we’ve had don’t change the fundamental point that global warming is man-made and we need to tackle it,” says Bjorn Lomborg, a Danish academic and environmental writer.

The political fallout from the IPCC’s mistakes was evident Tuesday when Texas authorities announced the state was taking legal action against the Environmental Protection Agency’s efforts to curb greenhouse gases under the Clean Air Act. In its filing, the state argued that the information the EPA used to make its decision is based on data from the IPCC. Alfredo “Al” Armendariz, EPA regional administrator for Texas and other nearby states, said he expected the agency’s efforts to withstand a court challenge.

Virginia’s attorney general Kenneth T. Cuccinelli II said Tuesday he also asked the EPA to delay final consideration of that finding so “newly available information” can be reviewed, reported the Associated Press.

Among the most vocal of the cadre of scientists who have questioned some of the IPCC’s recent work is John R. Christy, director of the Earth System Science Center at the University of Alabama-Huntsville and a former contributor to a big 2001 IPCC report. He, like several other of the critics, was repeatedly criticized in the hacked emails.

Dr. Christy spent years comparing temperature data from satellites with ground stations. He concluded that the reliance on a few well-known ground-based measuring stations may vastly overstate how much temperatures have risen. He suggests that surface temperatures are actually measuring an increase in human development—more and bigger cities, more asphalt, more air-conditioning—and not rising temperatures in the atmosphere. Most climate scientists, by contrast, ascribe rising temperatures largely to man’s introduction of greenhouse gases into the atmosphere.

Some dissenters have focused on the complex effect of clouds. Richard Lindzen, a professor of meteorology at the Massachusetts Institute of Technology and a past contributor to an IPCC report, says that the role of clouds and water vapor—the main greenhouse agents in the atmosphere—is one of the least understood factors in climate science. It’s a limitation that the IPCC acknowledges.

Prof. Lindzen says the key issue is “climate sensitivity”—how much will temperatures rise when carbon-dioxide levels double. He asserts that current climate models include a “positive feedback” effect whereby clouds and water vapor act to amplify CO2’s greenhouse effect. In response to a doubling of carbon-dioxide levels, the IPCC has found climate sensitivity to be between 1.5 degrees and five degrees Fahrenheit. Prof. Lindzen says those figures, derived from models, overstate the case.

Prof. Lindzen recently published a study based on radiation measurements taken from satellites—not models—and concluded that climate sensitivity as a result of clouds and water vapor was more likely in the 0.3 degrees to 1.2 degrees range, much lower than the figure accepted by most climate researchers. “The observational analysis implies that the models are exaggerating climate sensitivity,” he concludes in a second, yet-to-be published paper on the same subject.

Dr. Willie Soon, a professor at Harvard University, believes that changing levels of solar radiation, especially the amount that hits the Arctic, are driving huge, slow changes in the earth’s climate—much as they did in past centuries. The theory rests on the fact that the sun emits different amounts of energy at different times.

George Kukla, a retired professor at Columbia University, says even longer-term climate cycles explain the current warming trend. His work is based on the idea that ice ages and warmer interglacial periods are driven by periodic variations in earth’s orbit around the sun, known as the Milankovich cycle after the scientist who studied them.

Shifting momentum in the climate debate

NOV. 17, 2009

Senate Democratic leaders announce they will put off debate on a big climate-change bill until spring, citing a desire to first address legislation on health care and financial regulation.

NOV. 19, 2009

Emails and documents hacked from the Climate Research Unit at East Anglia University in the U.K. are cited by global-warming skeptics who say they call into question the validity of U.N.-sponsored reports contending that the earth is heating up and that it’s largely because of human activity.

DEC. 19, 2009

A summit on climate change in Copenhagen, Denmark ends with a final statement that calls on countries to “enhance our long-term cooperative action to combat climate change,” but doesn’t legally obligate any country to meet a specific target for reducing emissions.

JAN. 18, 2010

U.N. body on climate change says it is studying how its landmark 2007 report came to include a statement that Himalayan glaciers would disappear by 2035.

FEB. 5, 2010

As a huge snowstorm bears down, the Virginia Republican Party releases an ad that mocks Democrats for supporting legislation to fight global warming.

APRIL 17, 2009

The administrator of the Environmental Protection Agency declares that emissions of carbon dioxide and other greenhouse gases threaten public health and welfare, the legal prerequisite for regulating such emissions under the Clean Air Act.

MAY 19, 2009

Flanked by representatives of the auto industry and environmental groups, President Obama announces that the EPA and the Department of Transportation will craft rules aimed at boosting the fuel economy of U.S. automobiles and reducing their emissions of greenhouse gases.

JUNE 26, 2009

The U.S. House of Representatives passes legislation by a 219-212 vote that calls for cutting U.S. industrial emissions of greenhouse gases by 17% from 2005 levels by 2020, including by requiring companies to buy permits for emissions.

NOV. 26, 2009

China announces it will aim to cut its ‘carbon intensity’—or the amount of greenhouse gas it emits per unit of gross domestic product—by 40% to 45% below 2005 levels by 2020.

The Wall Street Journal, 17 February 2010