Geoscience Reference
In-Depth Information
in different regions were synchronous. The authors therefore hadn't accounted for likely off setting
fluctuations—the typical sort of seesaw patterns one often encounters with the climate, where certain
regions warm while others cool.
An additional problem with the study is readily evident from Monastersky's characterization
above. Rather than assessing whether there was overall evidence for widespread warmth, the authors
were asking a completely different, practically tautological question: Was there evidence that a given
region was either unusually warm, or wet, or dry? The addition of these two latter criteria
undermined the credibility of the authors' claim of assessing the relative unusualness of warmth
during the medieval period. These two criteria—were there regions that were either wet or dry—
could just as easily be satisfied during a global cool period!
A third problem is that the authors used an inadequate definition of modern conditions. It is only
for the past couple of decades that the hockey stick and other reconstructions showed warmth to be
clearly anomalous. Many of the records included in the Soon and Baliunas meta-analysis either end in
the mid-twentieth century or had such poor temporal resolution that they could not capture the trends
over the key interval of the past few decades, and hence cannot, at least nominally, be used to
compare past and present.
There was yet a fourth serious problem with the Soon and Baliunas study. The authors in many
cases had mischaracterized or misrepresented the past studies they claimed to be assessing in their
meta-analysis, according to Monastersky. Paleoclimatologist Peter de Menocal of Columbia
University/LDEO, for example, who had developed a proxy record of ocean surface temperature from
sediments off the coast of Africa, indicated that “Mr. Soon and his colleagues could not justify their
conclusions that the African record showed the 20th century as being unexceptional,” and told
Monastersky, “My record has no business being used to address that question.” To cite another
instance, David Black of the University of Akron, a paleoclimatologist who had developed a proxy
record of wind strength from sediments off the coast of Venezuela, indicated that “Mr. Soon's group
did not use his data properly”; he told Monastersky pointedly: “I think they stretched the data to fit
what they wanted to see.”
26
That such a deeply flawed paper not only was published in peer reviewed journals, but was then
immediately promoted so widely and uncritically by those with a clear policy ax to grind, including
people within the highest circles of our government, was cause for widespread concern. It was
certainly a cause of concern at Harvard University, where a number of faculty members were
uncomfortable with the way their institution's imprimatur had been used to serve what appeared to be
a partisan political agenda. For example, John Holdren, the Heinz professor of environmental policy
who went on to become president of the American Association for the Advancement of Science
(AAAS) and presidential science adviser in the Obama administration, voiced the opinion
27
that “The
critics are right. It's unfortunate that so much attention is paid to a flawed analysis, but that's what
happens when something happens to support the political climate in Washington.”
28
There was little doubt that a response from the climate research community was needed, and
various colleagues encouraged me to initiate the effort. A group of twelve leading climate scientists
joined me in authoring a rebuttal to Soon and Baliunas in
Eos,
the official newsletter of the American
other recent work in the field, basically pointed out the flaws noted above. The American
Geophysical Union considered our rejoinder important enough to issue a press release entitled
