Can Climate Forecasts Still Be Trusted?

Confidence melting away: doubts grow in climate change debate.

January 28, 2010, 7:21 AM

Jan. 28, 2010 — -- The Siachen Glacier is home to the world's highest crisis region. Here, at 6,000 meters (19,680 feet) above sea level, Indian and Pakistani soldiers face off, ensconced in heavily armed positions.

The ongoing border dispute between the two nuclear powers has already claimed the lives of 4,000 men -- most of them having died of exposure to the cold.

Now the Himalayan glacier is also at the center of a scientific dispute. In its current report, the Intergovernmental Panel on Climate Change (IPCC) predicts that the glacier, which is 71 kilometers (44 miles) long, could disappear by 2035. It also predicts that the other 45,000 glaciers in the world's highest mountain range will be virtually gone by then, with drastic consequences for billions of people in Asia, whose life depends on water that originates in the Himalayas. The IPCC report led environmental activists to sound the alarm about a drama that could be unfolding at the "world's third pole."

"This prognosis is, of course, complete nonsense," says John Shroder, a geologist and expert on glaciers at the University of Nebraska in Omaha. The results of his research tell a completely different story.

For the past three decades, the US glaciologist has been traversing the majestic mountains of the Himalayan region, particularly the Karakorum Range, with his measuring instruments. The discoveries he has made along the way are not consistent with the assessment long held by the IPCC. "While many glaciers are shrinking, others are stable and some are even growing," says Shroder.

The gaffe over the Himalayan glaciers has triggered an outcry in the world of climatology. Some are already using the word "Glaciergate" in reference to the scandal over a scientifically untenable claim in the fourth IPCC assessment report, which the UN climate body publishes every five years. The fourth assessment report was originally published in 2007. Last week, the IPCC withdrew the erroneous claim and apologized for the error.

German Environment Minister Norbert Röttgen, a member of the center-right Christian Democratic Union (CDU), is also upset about the incident. "The error in the IPCC report is serious and should not have happened," Röttgen told SPIEGEL. "Scientific accuracy is a vital condition to support the credibility of the political conclusions we draw as a result." Although the minister still has confidence in the overall validity of the IPCC report, he wants to see "a thorough investigation into how the error originated and was communicated."

But why wasn't this clearly nonsensical claim noticed long ago by at least one of the 3,000 scientists who contributed to the IPCC report? "What's really amazing is that such a blunder remained uncorrected for so long," says Shroder.

To err is human, say IPCC officials like Ottmar Edenhofer of the Potsdam Institute for Climate Impact Research. "We shouldn't question the credibility of an almost 3,000-page report because of one error."

But other climatologists are calling for consequences. They insist that IPCC Chairman and Nobel laureate Rajendra Pachauri is no longer acceptable as head of the panel, particularly because of his personal involvement in the affair. "Pachauri should resign, so as to avert further damage to the IPCC," says German climatologist Hans von Storch. "He used the argument of the supposed threat to the Himalayan glacier in his personal efforts to raise funds for research." Storch claims that the Indian-born scientist did not order the retraction of the erroneous prediction until it had generated considerable public pressure.

'Best of My Abilities'

Pachauri, for his part, rejects calls for his resignation. "I have a commitment to successfully complete the Fifth Assessment Report, a commitment that I am certainly not willing to set aside," the IPCC chairman said.

The prognosis drama began in 1999. The theory of the disappearance of the Himalayan glaciers by 2035 first appeared in an article in the British popular magazine New Scientist, for which Indian glaciologist Syed Hasnain was interviewed.

As it turned out, the specification of the year 2035 was the result of a simple mistake. In an article published three years earlier, Russian glaciologist Vladimir Kotlyakov did in fact predict a massive decline in the area covered by glaciers, but not until the year 2350. "All of the IPCC's peer-review procedures failed," says Canadian geographer Graham Cogley.

Indian scientist Hasnain's ties to the IPCC chairman have triggered a public relations crisis. The glaciologist now works at The Energy and Resources Institute (TERI) in New Delhi, whose director is none other than Rajendra Pachauri. Could this explain why Pachauri suppressed the error in the Himalaya passage of the IPCC report for so long?

The erroneous prediction of a precipitous end for the Himalayan glaciers was already revealed in November, when a glaciologist working for the Indian environment ministry presented a study on Himalayan glaciers that arrived at completely different conclusions than the IPCC report. But Pachauri dismissed the new study as "voodoo science."

In mid-January, the New Scientist confessed to its own sloppiness, exactly one day after IPCC Chairman Pachauri and his glacier expert Hasnain had announced a joint venture involving TERI, Iceland and the United States to study the Himalayan glaciers, with half a million dollars in funding from the New York-based Carnegie Foundation. "Perhaps Pachauri was so hesitant to look into the matter because he was trying to protect the research projects being conducted by his own institute," says climate statistician Storch. Pachauri, however, claims that he was simply pressed for time: "Everybody in the IPCC was terribly preoccupied with planning for several events that were to take place in Copenhagen," he said, referring to the climate change summit held in the Danish capital in December.

Toyota, the world's largest automaker, also contributed $80,000 to TERI. Last week the Japanese company was awarded the $1.5 million (€1.05 million) "Zayed Future Energy Prize" for its Prius hybrid car. Pachauri was the chairman of the jury, but he explains that he temporarily suspended his chairmanship because of his consulting activities. Nevertheless, he did manage to praise Toyota at the awards ceremony in Abu Dhabi, saying that the company deserves "the fullest appreciation" for bringing about a radical shift in technology.

Unfortunately, the questions about the IPCC and its president come at a time when the credibility of climatologists has already suffered, partly as a result of the theft of confidential e-mail messages written by scientists, the content of which has led critics to claim that data were manipulated. Although none of these incidents negate the evidence supporting climate change, facts ceased to be the focus of the acrimonious debate long ago. Instead, it now revolves around questions of belief.

"Confidence in the authority of the science of climatology is currently eroding in the public consciousness," says Roger Pielke Jr., an American social economist and expert on natural disasters. Environmental economist Richard Tol agrees, saying: "Criticism of climate research has become fashionable." And the British science journal Nature warns that climatologists can no longer assume that solid evidence alone will convince the public.

New Ammunition from an E-Mail Scandal

For years, malaria expert Paul Reiter of the Paris-based Pasteur Institute has criticized the warning, as expressed in the third IPCC report, that climate change will lead to the spread of malaria, saying that there is no evidence to support such a claim. Reiter accuses many climatologists of perceiving themselves too strongly as activists who are more interested in spreading an alarmist message.

Scientists already feel that the second part of the IPCC report, which addresses the consequences of global warming, is not as sound as the first part, which deals with the underlying physical factors contributing to climate change. This could, in fact, explain how the erroneous Himalayan prognosis slipped into the report in the first place. The report's lead author, Murari Lal, defends himself by saying that "the melting of the glaciers is such a huge threat to so many people" and, for that reason, had to be included in the report. According to malaria researcher Reiter, it is precisely this passion that is so dangerous to science.

The e-mails hackers stole from the Climatic Research Unit at the University of East Anglia last November and placed on the Internet have also provided critics with new ammunition. An e-mail exchange between climate modelers that took place in the fall of 1999 suggests that the scientists were biased.

The exchange involved the validity of a controversial temperature curve. The so-called hockey stick graph was intended to prove that the average global temperature in the last 1,000 years was never as high as it is today. To arrive at the date, several groups of researchers reconstructed past temperatures, to a large extent based on tree-ring data.

But one of the graphs differed markedly from the rest, leading to a controversy in the run-up to a conference of paleo-climatologists in Tanzania in September 1999. The abnormal temperature graph was "a problem and a potential distraction/detraction from the reasonably consensus viewpoint we'd like to show," paleo-climatologist Michael Mann wrote in an e-mail, adding that he didn't want to be the one to offer "the skeptics … a field day." The lead author of the IPCC chapter, Chris Folland, wrote in another e-mail that the divergent data set "dilutes the message rather significantly."

Keith Briffa, whose team reconstructed the contradictory temperature graph, was furious, and wrote: "I know there is pressure to present a nice tidy story as regards 'apparent unprecedented warming in a thousand years or more in the proxy data.'"

For the IPCC report that was written at the time, the scientists eventually resorted to an underhanded solution to downplay the data behind Briffa's graph, which showed temperatures falling since the 1960s: the graph was simply cut off at 1960 in the IPCC report. "This sort of approach is considered problematic in science," says climate scientist Storch.

Controversial Passages

Briffa's unusually declining temperature graph points to a serious conundrum that no one has been able to explain yet: Since the 1960s, the tree-ring data no longer reflect actual temperature changes. But why, then, should tree-ring data be valid for periods before that?

At least the fourth IPCC report, published in 2007, discusses the problems with the tree-ring data at length. But even the current, valid report contains controversial passages.

Chapter 1.3.8, for example, contains a discussion of the possible relationship between climate change and the increased incidence of natural disasters, which, after Hurricane Katrina in the United States, have now become a politically charged issue.

At the IPCC report, the damage associated with such events "are very likely to increase due to increased frequencies and intensities of some extreme weather events" (italics in original). The report cites as evidence a study that supposedly demonstrates precisely this trend.

The only problem is that the study in question had not been subjected to outside peer review before the IPCC report went to press. This has since been done, and the conclusions are surprising: "We find insufficient evidence to claim a statistical relationship between global temperature increase and normalized catastrophe losses," read the report published in the compendium "Climate Extremes and Society."

Roger Pielke, a leading expert in this field, wrote in his blog: "The claims were not just wrong. The claims were based on knowledge that just doesn't exist."

Representatives of the insurance industry hold a completely different view, which presents an additional problem for the IPCC. Reinsurers, such as Munich Re, calculate their premiums on the basis of risk, so that an increase in the frequency and severity of natural disasters can translate into additional profits when new policies are concluded.

"We see, in our databases, significant evidence for a correlation between climate change and the increase in natural disasters," says Ernst Rauch, director of German insurer Munich Re's "Corporate Climate Centre." Unlike scientists, he adds, the insurance industry cannot wait until all doubts have been set aside. "We are a business operation that has to act today," says Rauch. He also points out that his company is "extremely satisfied" with the conclusions of the IPCC report. This is hardly surprising: A 2005 publication by Munich Re served as one of the sources for the IPCC's cautionary predictions.

Climatologists are now calling for reforms. Pielke, for example, is concerned about the way authors and peer reviewers work, how they are appointed by the IPCC and how literature is used that, as in the case of the Himalayan glacier, does not come from peer-reviewed professional journals.

One of the problems is that working for the IPCC is a time-consuming honorary appointment for scientists. "This means that it is not always the best people in their field who are willing to contribute their time and effort," says epidemiologist Reiter.

On the other hand, the community is sometimes reluctant to include troublesome critics in its efforts. For instance, when the IPCC recently set up a special working group to address natural disasters, the US government nominated ecologist Pielke. The IPCC declined to appoint him.

Translated from the German by Christopher Sultan

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