In 1998, the journal Nature published an article by Michael Mann, Raymond S. Bradley, and Malcolm K. Hughes (MBH). It included a graph that showed a recent, steep rise in the Earth's surface temperature. The article presented evidence that the recent temperature was as high as it has been since the fifteenth century. In 1999, the journal Geophysical Research Letters published another paper by Mann, Bradley, and Hughes that extended the data back to 1000 A.D. In 2001, the Intergovernmental Panel on Climate Change, included their graph in its third Assessment Report. While the graph illustrated only one piece of research that supported the claim that the Earth's climate was rapidly changing, it was a striking "infographic" which helped to focus attention on the developing climate crisis. It also triggered a surprising backlash from conservative pundits and politicians. Global Warming and Political Intimidation is Raymond Bradley's account of the ensuing controversy over the MBH or "hockey stick" graph.
From time to time, conservative pundits and politicians seize upon a minor error, a cautious qualification, or a poorly phrased statement made by climate scientists to discredit the growing body of research that has demonstrated that our climate is changing at a catastrophic rate. Their attacks also are sometimes tied to the work of a small number of contrarian scientists or others with vaguely related academic credentials. In this instance, the excuse for criticism of the MBH graph came from an article written by Stephen McIntyre (an economist) and Ross McKitrick (a mathematician). Their article was initially published in an obscure journal Energy & Environment and latter published in Geophysical Research Letters, though GRL did not apply its normal review process before publishing the article.
Since then, MM's critique has been shown to be unfounded, but it was sufficient to prompt the Wall Street Journal to publish an article making reference to the critique. This, in turn, prompted two conservative congressional representatives to Joe Barton, chair of the House Energy Committee, and Ed Whitfield, chair of the Subcommittee on Oversight and Investigation, to write letters to Mann, Bradley, and Hughes asking for an enormous amount of information related to their research and its financial support, not just for their 1998 Nature paper, but for all the work they had conducted in the course of their career. Clearly, a frivolous investigation was now underway, aimed at obstructing their work and possibly smearing their scientific reputations. It was comparable to a lawyer's massive discovery motion aimed at burdening the opposing litigants.
In the end, Mann, Bradley, and Hughes were able to avoid the worst possible outcomes of this partisan governmental intrusion into science, because the Republican chair of the House Committee on Science, Sherwood Boerlert, objected to Barton and Whitfield's harassment of scientists. The standoff between powerful Republicans was widely covered in the national and foreign press and eventually led to the National Academy of Science investigating the issue and larger issues related to climate change research. Unsurprisingly, the National Academy of Science found the MBH graph supported by "an array of evidence." Barton continued to harass Mann, Bradley, and Hughes over the graph, but the real threats to their work were largely over.
This incident is merely one of many efforts by the climate crisis deniers to attack the scientist who are working to understand the dangers we face with the continued pollution of our atmosphere with greenhouse gases. While it is quite valuable to read Bradley's insider account of the "hockey stick" debate, one is left wishing he had included more information about other incidents. He does provide some detail on the theft of emails from several climate scientists (most prominently Phil Jones) that were made public just prior to the Copenhagen UN climate summit in 2009. Bradley also briefly describes the harassment of Ben Santer, the lead author of Chapter 8 of the second IPCC Assessment Report (1996). Chapter 8 focused on the causes of climate change. Its qualified conclusions were that "the balance of evidence suggests that there is a discernible human influence on global climate." We now know this beyond any doubt, but this was one of the first times that anthropogenic climate change was so publicly endorsed. The reaction was swift and ruthless from the carbon industry lobbyists and libertarian bloggers. Santer's work was said to be the result of a "corruption of the peer-review process." Fortunately for Santer, the criticisms did not result in governmental harassment as occurred in the "hockey stick" and stolen email affairs and the overwhelming evidence of the human impact on the climate has made his critics look utterly foolish, but not before causing him a great deal of headache and unnecessary distraction.
It is commendable perhaps that Bradley sticks to his first hand experiences with his Nature graph, but asking Jones and Santer to give him a brief account of their experiences that he could fold into his book would have helped establish his main argument that partisan political intrusions into the conduct of science is common and significant and that in order for public policy on climate change to be based on an accurate understanding of the physical world, we must insist that politicians stay out of the scientific debates. We must allow the tried and true methods of scientific enquiry to light our way toward solutions to our mounting environmental problems.
Bradley's book is a welcome contribution to understanding how politics is interfering with science. Perhaps the best book on this subject,however, is Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming by Naomi Oreskes and Erik M. Conway (reviewed in this blog).