A Heated Debate Are Climate Scientists Being Forced to Toe the Line?

After joining a controversial lobby group critical of climate change, meteorologist Lennart Bengtsson claims he was shunned by colleagues, leading him to quit. Some scientists complain pressure to conform to consensus opinion has become a serious hindrance in the field.
Lennart Bengtsson says he was pressured by colleagues to step down from his role at the controversial Global Warming Policy Foundation.

Lennart Bengtsson says he was pressured by colleagues to step down from his role at the controversial Global Warming Policy Foundation.

News that Lennart Bengtsson, the respected former director of Germany's Max Planck Institute for Meteorology in Hamburg, had joined the Global Warming Policy Foundation (GWPF), sent shockwaves through the climate research community. GWPF is most notable for its skepticism about climate change and its efforts to undermine the position of the United Nations Intergovernmental Panel on Climate Change (IPCC). The tremors his decision sent through the scientific community shocked Bengtsson.

The scientist said colleagues placed so much pressure on him after joining GWPF that he withdrew from the group out of fear for his own health. Bengtsson added that his treatment had been reminiscent of the persecution of suspected Communists in the United States during the era of McCarthyism in the 1950s.

Not all of his fellow climatologists agree. Gavin Schmidt, a climatologist and climate modeler at NASA, described the "alleged connection to McCarthy" as "ridiculous." "As someone who has actually been threatened with criminal sanctions by a United States Senator only because of published science, I don't quite see why Bengtsson's total freedom to associate with anyone he wants -- and let me be clear, he has this freedom -- has in any way been compromised," he said.

But Bengtsson insists that even close colleagues shunned him. He says that one research partner, apparently fearing damage to his reputation, withdrew from a study they had been conducting together. Bengtsson added no further details other than to state that the incident had been hurtful.

NASA's Schmidt also expressed criticism of that claim. "This is so vague as to mean anything, and without an actual example, it is impossible to know what is being alleged."

Clouds Gathered Ahead of Storm

It is now emerging that the clouds of controversy gathered ahead of the current storm. In February, Bengtsson weathered a significant setback. The scientific journal Environmental Research Letters declined to publish a study he had authored predicting a milder greenhouse effect. Peer reviewers described the report's findings as "less than helpful" and added, "actually it is harmful as it opens the door for oversimplified claims of 'errors' and worse from the climate-skeptic media side."

Respected German meteorologist Hans von Storch of the Institute for Coastal Research at the Helmholtz Center, described the justification as "scandalous" and accused the journal of politically motivated decision-making not based on scientific standards. In a statement on the IOP Science website, Publisher Nicola Gulley emphasizes that the study was declined on scientific grounds. She argues that Bengtsson's work failed to meet the journal's high standards.

Climate researchers are now engaged in a debate about whether their science is being crippled by a compulsion to conform. They wonder if pressure to reach a consensus is too great. They ask if criticism is being suppressed. No less is at stake than the credibility of research evidence for climate change and the very question of whether climate research is still reliable.

Bengtsson said in an interview with SPIEGEL ONLINE  that he wanted to open up the climate change debate by joining GWPF. He said that in view of large gaps in knowledge, the pressure to reach a consensus in climate research "does not make sense".

Nevertheless, by joining the political lobby group, Bengtsson opened himself up to criticism that he had taken a position inappropriate for a scientist of his stature.

'We Are not an Interest Group'

University of Washington climatologist Eric Steig says the activities of the GWPF are more reminiscent of McCarthyism than Bengtsson's case. Steig says the GWPF boasts about investigating climate researchers. "They also have published opinion articles on their web site accusing mainstream climate scientists of having 'secret societies' and having political agendas designed with specific left-wing policy aims in mind," he adds. "They have accused British schools of 'brainwashing' students by teaching them about climate change." GWPF, for its part, calls itself a think tank that documents arguments stating why climate change as a problem is being overestimated.

Reto Knutti of the ETH Zürich technical university is also critical. "Organizations like the GWPF contribute to whipping scientific debate into a religious war," he argues. "They distribute pseudo-scientific reports, even though they are actually pursuing a political aim," says Knutti. Jochem Marotzke, who is Bengtsson's successor at the Max Planck Institute for Meteorology, says, "GWPF works deliberately in a selective way. They mention only arguments that suit their purposes. Counterarguments are kept under wraps."

Professor Myles Allen, a climate researcher at Oxford, says, "The problem is their anti-science agenda, clearly illustrated by the fact that they refused point blank to submit their recent report criticizing the IPCC 5th Assessment Report to the same kind of open peer review that the IPCC report was itself subjected to."

GWPF Director Benny Peiser challenges assertions like that. "We are not an interest group; our scientists have no official or collective opinion -- to any topics. If there were no taboos in climate science or climate policy, the GWPF would probably not exist."

'Stealth Advocates'

Roger Pielke Jr., an environmental scientist at the University of Colorado and professor long critical of the politicization of the climate debate, says the group uses science to cloak its political agenda. Pielke emphasizes, however, that as a lobbying group GWPF "has every right to advance whatever arguments it wants. It often focuses on stealth advocacy -- hiding its politics in science -- a strategy common across the climate issue, found on all 'sides,' and is pretty common across many issues."

Von Storch agrees that other political camps, such as environmental groups, also use "stealth advocates" to influence scientific debate. Pielke elaborates, "In a democracy people will organize around all sorts of shared interests, as they should, and many will share values that I don't. So what? Bengtsson's justifications for associating with GWPF are perfectly legitimate. That he was pressured by his peers with social and other sanctions reflects the deeply politicized nature of this issue."

He argues that scientific research must be held to higher standards than lobby groups, but even those standards now the subject of greater scrutiny.

Many climatologists have been tacitly complaining about harassment and exclusion for years. But is the situation any worse in this scientific discipline than it is in others? Roger Pielke Sr., a senior research scientist at the University of Colorado and Pielke Jr.'s father, says, "Unfortunately, climate science has become very politicized and views that differ at all from those in control of the climate assessment process are either ignored or ridiculed. From my experience, I agree 100 percent with the allegations made by the very distinguished Lennart Bengtsson."

But who is doing the politicizing? Knutti says that it is pretty easy to tell. "If you are on the left politically, you believe in global warming," he says. "If you are on the right, that is much less likely." He adds that the line between opinion and fact is often blurred, even among scientists.

'Dirty, Nasty, Destructive'

"Each side maintains the other is politicizing the debate," explains Werner Krauss, an environmental ethnologist at the Helmholtz Center for Materials and Coastal Research in Geesthacht, Germany. He says climate research is dominated by "strongmen" who know how to exploit the media whenever they like. Krauss claims Bengtsson stage managed his move to GWPF in the media and alleges that climate research has fallen into the throes of the scientific equivalent of religious fervor. He says it is no wonder Bengtsson came under heavy fire for his decision.

At the same time, Heinrich Miller of the Alfred Wegener Institute for Polar and Marine Research says, "I find the way his colleagues reacted shocking. Apparently there is now pervasive disappointment because a shining scientific example is making his scientific doubts public," he says. Miller adds that the Bengtsson case reminds him about how politicians use "dirty tricks" to muzzle opponents.

Pielke Jr. confirms that climate research is a tough business. "We see hardball politics," he says. "I have personally seen very strong social and professional pressures over the years. These include threats to my job, professional ostracism, public misrepresentations of my research and views, efforts to prevent me from speaking publicly and personal threats, many of which have been publicly documented." He advises that "anyone who wishes to participate in the public debate on climate change should do so knowing how the politics are played today -- dirty, nasty, destructive."

'Global Warming Is Taken as Dogma'

Climatologist Michael Mann even speaks of "climate wars." For years, he says he was the subject of attacks by conservative groups skeptical of climate change, especially after the "Climategate"  scandal, when his e-mail correspondence was published illegally. The other side is not pulling any punches either -- at least when it comes to vitriol. One Austrian professor has gone so far as calling for the death penalty for climate skeptics.

Miller says that scientists were politicized more than anything else by having to seek a consensus on results for the 5th IPCC report. "Global warming is taken as dogma. Anyone who doubts it is bad," says the renowned researcher, who was branded a "climate skeptic" after questioning the scientific validity of computer simulations.

Knutti, by contrast, warns about overemphasizing the lack of certainty about the evidence. He says Bengtsson's stringent criticism of climate change forecasts is misleading, explaining that the models provided useable results that were tested on historical climate change. The 5th IPCC Report that took hundreds of scientists years to produce, says Knutti, comprehensively documents the range of results. He says that sitting back and waiting until all the questions are answered is not an alternative, and describes a large portion of what has come to be called skepticism as deliberate deception.

Translated from the German by Taryn Toro

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