While most of official Washington was captivated with the fight on the Senate floor to pass an energy bill before Congress left town for its August vacation, a vicious campaign was under way behind the scenes to smear two leading scientists for pointing out serious flaws in the science behind the theory of human-caused climate change.
The targets were Willie Soon and Sallie Baliunas, both astrophysicists at Harvard, who were characterized as fringe scientists whose work should be ignored. What did they do to attract such characterizations? They had the audacity to pull back the curtain on the wizard of global warming.
The issue focuses on a paper by them that supports the widely held view that the climate of the last millennium has been quite variable and includes a Medieval Warm Period and subsequent Little Ice Age. This is only controversial because it, and the wider body of scientific literature that exists, directly contradicts recent research by Michael Mann, a leading global warming proponent. Mr. Mann argues global air temperatures have been stable over the last 1,000 years, with the exception of the last 100. It is the "Mann-made" warming to which Mr. Soon and Ms. Baliunas have objected.
While most of these arguments are confined to academic discussions that the general public would find less than boring, this fight played out recently in front of the U.S. Senate Committee on the Environment and Public Works. It has also been echoed in several news accounts from academic journals to the New York Times.
Mr. Mann testified before the Senate committee that his research is the "mainstream view" because it is featured in a chapter of the U.N. Nations Intergovernmental Panel on Climate Change (IPCC) report, of which Mr. Mann was a lead author. Mr. Soon and Ms. Baliunas challenged Mr. Mann's claim by reviewing the large body of literature that shows his claims to be unsubstantiated and his research to be fatally flawed. In truth, Mr. Mann's work is the scientific outlier -- the one study that does not fit with the wealth of scientific evidence.
Mr. Soon and Mr. Baliunas argue that Mr. Mann's conclusions rest on a dubious manipulation of data. While many of the problems in Mr. Mann's work require scientific expertise to understand, one flaw is so basic that everyone can understand it. Mr. Mann and his colleagues compiled a historical climate reconstruction -- called the "hockey stick" because of its shape -- primarily using tree ring records to infer air temperature trends. Their use of proxy data is not novel, but the methods they used and thus the results, certainly are. For example, Mr. Mann and his colleagues simply attached the surface temperature record of the 20th century to the end of the proxy record. This is an apples-to-oranges comparison as air temperature readings are not directly comparable to proxy records. However, putting the two different sets of data together in this way makes a stunning visual display for the average reader.
Also, in his analysis for the Northern Hemisphere prior to 1400, Mr. Mann uses data from nine locations in addition to statistical summaries derived from data for the Western United States only. Four of these additional locations are in the Southern Hemisphere, including Tasmania and Patagonia.
The widespread acceptance of this revisionist history was possible because the global-warming community was eager to accept the "hockey stick" as proof of human-caused climate change.
If it remained merely a disagreement about science and research methods, there wouldn't be much of a story -- or reason for concern. Unfortunately, it turned into a scientific lynching of Mr. Soon and Ms. Baliunas and anyone associated with them. For example, Chris de Freitas, the editor of Climate Research that published the paper, was criticized for having failed in his responsibilities of quality control, even though the paper passed an extensive peer-review process and the publisher defended Mr. de Freitas' handling of the paper. It was argued Mr. de Freitas should be removed from his position simply for having published it. Even Mr. Mann, in his Senate testimony, dismissed Mr. de Freitas' credentials solely because he "frequently publishes op-ed pieces in newspapers attacking IPCC and attacking [the] Kyoto [protocol]."
Why is all this important? Global warming alarmists would have governments impose significant regulations with tremendous economic implications. The Bush administration is under attack simply for stating that the science is uncertain whether human-induced global warming is occurring. At the same time, scientists that add credence to that assertion are being silenced.
Yet if recent global warming is largely a result of natural climate variability, policies to reduce global warming would be unnecessary, costly and ineffective. Before we are asked to incur the pain, we should better understand whether there would be any gain.
David R. Legates is an adjunct scholar with the National Center for Policy Analysis and an associate professor and director of the Center for Climatic Research at the University of Delaware.