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Global Warming and the Politicization of Science

On December 26, 2004, a magnitude 9.0 earthquake occurred off the coast of Northern Sumatra. The massive temblor, the largest in 40 years, spawned tsunamis that killed more than 150,000 people. The next day, a colleague at a think tank emailed me to ask if I had any opinions about the new Michael Crichton book, State of Fear.

P.S. - I'm also anxious to see if anyone blames this weekend's tsunami in Indonesia on global warming.

Climate experts warned today that tsunamis could become more common around the world and more dangerous. They cite a number of factors, including a creeping rise in sea levels believed to come from global warming and growing populations along coastal areas.

The reason for the earthquake and a gigantic tsunami which killed several tens of thousands of people in South and Southeast Asia was probably a global climate change...scientists have registered lately a change of the average temperature, which is now growing at fantastic rates. These seemingly insignificant temperature changes allow the atmosphere and oceans to accumulate additional energy...(Anonymous, 2004a).

A cause and effect relationship between anthropogenic activities and climatic warming cannot be demonstrated unambiguously at the present time (Deming, 1995, p. 1577).

The week the article appeared, I came into my office one morning to find a voicemail message from a reporter for National Public Radio. He wanted to interview me concerning my article in Science. Visions of glory danced in front of my eyes. I was going to be on national radio. Surely, it was only a matter of time before I would be a regular guest on the McNeil-Lehrer news hour on PBS. Excited, I called the reporter back. But all of my fantasies were immediately dispelled. The reporter focused in on the last sentence in the Science paper. He asked me, did I really mean to say that? Did I really intend to imply that the warming in North America may have been due to natural variability? Without hesitation, I said "yes". He replied, "Well then, I guess we have no story. That's not what people are interested in. People are only interested if the warming is due to human activities. Goodbye." And he hung up on me. It was my first realization that the media intentionally filter the information the public receives.

A year later, I received a telephone call from an author working on an article for International Wildlife, a magazine published by the National Wildlife Federation, an environmental advocacy group. We discussed some of my work, and talked about the implication of borehole temperature measurements for global warming. Subsequently, the Editor of International Wildlife sent me a draft article for review. I was horrified. My work and comments had been taken out of context and used in such a way as to exaggerate the magnitude of climate change. I made some pointed comments, and the article was toned down a little. I later learned that the author of the International Wildlife article was not a scientist, but a lawyer. I had been naive. I had assumed that everyone was like me--they were interested in the truth. But a lawyer's job isn't to discover truth, it's to win an argument. Neither is an advocacy organization interested in truth--they are committed to advocating a certain position regardless of the facts.

With the publication of the article in Science, I gained significant credibility in the community of scientists working on climate change. They thought I was one of them, someone who would pervert science in the service of social and political causes. So one of them let his guard down. A major person working in the area of climate change and global warming sent me an astonishing email that said "We have to get rid of the Medieval Warm Period."

The Medieval Warm Period (MWP) was a time of unusually warm weather that began around 1000 AD and persisted until a cold period known as the "Little Ice Age" took hold in the 14th and 15th centuries. Warmer climate brought a remarkable flowering of prosperity, knowledge, and art to Europe. As the temperature increased, so did agricultural yields. Marshes and swamps dried up, removing the breeding grounds of mosquitoes that spread malaria. Former wetlands were converted to productive farmland. Infant mortality fell, and the population grew. From 1100 to 1300 AD, the population of Europe increased from about 40 to 60 million (Moore, 1995). The surest sign of the warming climate in Europe was the settlement of Greenland by Vikings from Iceland. The Greenland settlements reached a height of prosperity in the 12th and 13th centuries when 3,000 colonists occupied 280 farms. The settlements came under duress in the late 14th century due to the onset of Little Ice Age cooling; they finally perished in the 15th century. The existence of the MWP was recognized in the climate textbooks for decades. But now it was a major embarrassment to those maintaining that the 20th century warming was truly anomalous. It had to be "gotten rid of".

During the early 1990s, an important reference book for those working in the area of climate change was Climate Change: the IPCC Scientific Assessment (Houghton et al., 1990). The IPCC, the Intergovernmental Panel on Climate Change, was the major international organization concerned with the dangers of global warming. And yet a skeptic could open the IPCC's own reference text and see that 20th century warming was dwarfed by the MWP (Houghton et al., 1990, p. 202). When the 20th century warming was placed into the context of a thousand years of history it appeared to be virtually insignificant. If people were going to be convinced of the danger of global warming, the MWP clearly needed to be erased from history.

In 1998, Michael Mann, a climate researcher at the University of Massachusetts, published a paper in Nature where he and his colleagues claimed that temperatures in the late 20th century were warmer than any time since the year 1400. A year later, the same authors extended their analysis back to the year 1000 (Mann et al., 1999). In the Mann et al. (1999) reconstruction of temperature, the MWP simply vanished. The analyses by Mann et al. (1998, 1999) resulted in graphs of mean global temperature over the last 1000 years that had the shapes of hockey sticks. The graphs showed that mean global temperatures were uniformly monotonic over the last millennium, abruptly rising in the 20th century.

The 10 warmest years on record have occurred in the past 15 years...Clearly something is happening to Earth's climate, and according to the scientific consensus, that "something" probably has two arms, two legs and two or three cars in every garage (Anonymous, 1999).

...the consensus view among paleoclimatologists is that the Medieval Warming Period was a regional phenomenon, that the worldwide nature of the Little Ice Age is open to question and that the late 20th century saw the most extreme global average temperatures.

The conclusions of Natural Science are true and necessary, and the judgment of men has nothing to do with them (Galilei, 1953, p. 63).

The crowd of fools who know nothing is infinite (Drake, 1957, p. 239).

The data set of [Mann et al., 1998]...contains collation errors, unjustifiable truncation or extrapolation of source data obsolete data, geographical location errors, incorrect calculation of principal components, and other quality control defects (McIntyre and McKitrick, 2003, p. 751).

The particular "hockey stick" shape derived in the [Mann et al., 1998] proxy reconstruction..is primarily an artifact of poor data handling, obsolete data and incorrect calculation of principal components (McIntyre and McKitrick 2003, p. 751).

The centennial variability of the Northern Hemisphere temperature is underestimated by the regression-based methods applied here, suggesting that past variations may have been at least a factor of 2 larger than indicated by empirical reconstructions (von Storch et al., 2004, p. 679).

In an interview, the lead author, Hans von Storch, was less tactful. In the October 4, 2004, issue of the German magazine Der Spiegel, he referred to the "hockey stick" graphs of Mann et al. (1998, 1999) as "quatsch." The German word quatsch translates into English as rubbish, hogwash, balderdash, bilge, bunk, hooey, malarkey, or nonsense (Anonymous, 2004b).

There is nothing left to vindicate the myth that individually owned guns were a source of American freedom and greatness (Wills, 1999, p. 31).

Critics of Bellesiles' thesis seemed to be confined to a community of ignorant zealots and gun fanatics who circulated ad hominem attacks on the internet. Writing in the Atlanta Journal-Constitution on March 18, 2001, Bellesiles claimed that he had become the victim of a hate campaign waged over the world wide web (Bellesiles, 2001).

The first intimation in the mainstream press that there might be anything wrong with Bellesiles' scholarship occurred on October 3, 2001. The Boston Globe reported that Emory University had asked Bellesiles to write a detailed defense of his work. Among the charges against Bellesiles was that he claimed to have relied upon San Francisco probate records that had been destroyed in the 1906 fire (Mehegan, 2001). A year later, it was all over. An investigative panel assembled by Emory concluded that Bellesiles "was guilty of both substandard research methodology and of willfully misrepresenting specific evidence" (de la Merced, 2002). Bellesiles resigned, but without admitting any culpability. In an effort to save face by rewriting history, Columbia University retroactively rescinded Bellesiles' Bancroft Prize (Anonymous, 2002).

Personally, I had doubts about the Mann et al. (1999) claims from the beginning. Only a few years earlier, the existence of a world-wide MWP had been documented by an important paleoclimate study, Huang et al.'s (1997) analysis of borehole temperature data. As Lachenbruch and Marshall (1986, p. 696) pointed out many years ago, borehole temperatures are the most robust paleoclimate indicator we have because they are not a proxy, but a direct thermophysical record of temperature changes occurring at the surface.

The Huang et al. (1997) study was originally submitted to Nature. I was one of the reviewers of the manuscript. I told the Nature editors that the article would surely be one of the most important papers they published that year. But it never appeared in print. Nature asked the authors to revise the paper twice and then, after a long delay, ended up rejecting it. While writing this essay, I learned that McIntyre and McKitrick's manuscript had received similar treatment at Nature. Apparently, it is not enough for the editors at Nature to simply reject an article that is politically incorrect, they have to delay its inevitable publication in another journal by tying it up in the review process for several months.

Not only does the analysis by Huang et al. (1997) show a well-developed MWP, it also reveals that mean surface global temperature over most of the last 10,000 years was significantly warmer than the late 20th-century value. But this paper received virtually no attention in the press. After all, it wasn't "what people are interested in."

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