Is it really possible to determine the change in global temperatures over the last 1,000 years by examining tree rings?
We may finally learn the answer, thanks to the efforts of Congressman Joe Barton, R-Texas -- who has had everything but the kitchen sink thrown at him by the global warming lobby in its fierce opposition to his recent inquiry.
On June 23, Rep. Barton, chairman of the House Committee on Energy and Commerce, sent letters to the climate researchers responsible for developing the notorious “hockey stick” graph, which purports to show a dramatic rise in global temperatures during the 20th century after a millennium of supposedly little change in global temperature.
The hockey stick graph has been key weapon in the arsenal of the global warming alarmists in their efforts to scare the U.S. into signing the Kyoto Protocol and clamping down on greenhouse gas emissions and energy use.
The graph has been criticized for many reasons, including its reliance on dubious estimates of historic temperatures based on the size of tree rings. Not only is temperature merely one factor that contributes to tree growth (as evidenced by the ring size), but a 15th century portion of the hockey stick graph is based on tree ring measurements from a single tree.
Noting that “sharing data and research results is a basic tenet of open scientific inquiry” and that the hockey stick research was paid for with public funds, Chairman Barton asked Dr. Michael Mann of the University of Virginia for the computer code used to generate the hockey stick graph. Dr. Mann had previously refused to provide his computer code to other climate researchers who had requested it.
Dr. Mann apparently decided that he cannot withhold his data and computer code any longer from the public and agreed in a letter to post his data and computer code on the Internet -- but not without squealing about it first. Before Dr. Mann turned over his data, virtually the entire spectrum of global warming alarmists attacked Chairman Barton for requesting access to the data and code.
The American Association for the Advancement of Science, long a proponent of global warming alarmism, chided Chairman Barton in a July 13 letter that Dr. Mann’s hockey stick had already been accepted by the United Nations’ global warming organization and that Congress ought not interfere with that process.
Although the AAAS apparently believes that the UN should be the final arbiter on scientific matters, it’s not at all clear that political organizations have any special insight into what constitutes scientific fact.
Dr. Ralph Ciccerone, the president of the National Academy of Sciences, wrote in a July 15 letter to Chairman Barton that “a focus on individual scientists can be intimidating.”
But congressional committees send out requests for information from private parties routinely. Moreover, I doubt that Dr. Mann felt “intimidated.” He has previously testified in person before Congress about global warming without complaining of any intimidation. It’s more likely that Dr. Mann doesn’t want to run the risk of more criticism directed at his hockey stick graph.
Rep. Sherwood Boehlert, the Chairman of the House Science Committee, melodramatically wrote Chairman Barton claiming that, “The only conceivable explanation for the investigation is to attempt to intimidate a prominent scientist and to have Congress put its thumbs on the scales of a scientific debate… The precedent your investigation sets is truly chilling.”
But Chairman Barton merely asked Dr. Mann to provide some information to Congress, including his computer code – something that Dr. Mann had previously refused to do when asked by private parties. Chairman Barton isn’t trying to influence scientific debate. He’s trying to make scientific debate possible -- a good thing in a free society. What’s chilling is Dr. Mann’s past stonewalling and utter refusal to permit the public to see how he concocted the hockey stick -- research that was paid for by the public and that is being used by global warming advocates to restrict the public’s access to affordable energy.
In his request for information, Barton had also asked Dr. Mann to provide records of the grants and other sources of funding that had financed his research, no doubt fueling suspicion about the intentions of Barton's investigation. But these records would have established that the research and methodology that Dr. Mann was refusing to share had been publicly funded.
The Washington Post seized upon this point when it chimed in on the debate with an editorial likening Chairman Barton’s request for information to a “witch hunt.” The Post added that “… to pretend that [Chairman Barton] is going to learn something useful by requesting data on 15th century tree rings is ludicrous; to demand decades worth of financial information from scientists who are not suspected of fraud is outrageous.”
Well, a scientist’s refusal to provide colleagues with his data and methodology is suspicious. Chairman Barton’s request for publicly funded scientific data concerning a major public policy issue isn’t ludicrous; but estimating global temperature data based on a single tree certainly is.
The global warmers are trying to demonize Chairman Barton to make him the bad guy out to harass and intimidate Dr. Mann, now a martyr for global warming hysteria. But it appears that just the opposite is the case.
For the sake of national energy policy and the global economy, let’s all thank Chairman Barton for his reasonable inquiry into the questionable hockey stick.
Steven Milloy publishes JunkScience.com and CSRwatch.com, is adjunct scholar at the Competitive Enterprise Institute, and is the author of Junk Science Judo: Self-defense Against Health Scares and Scams (Cato Institute, 2001).