There is a paper in this week’s Science magazine by a long list of authors led by Ulf Büntgen from the Swiss Federal Research Institute for Forest, Snow and Landscape Research that unabashedly throws political commentary into the conclusions of their scientific research paper (i.e., it is not an opinion piece).
The work largely is an unremarkable retelling of the climate social history of Western Europe over the past two millennia or so, with a rather remarkable conclusion.
Anyone familiar with the history of European civilization and how is has been shaped by climate—a story that has been well known for some 30 or 40 years (and probably longer)—will find little new in the Büntgen et al. work.
Factually, that is.
What will come as a surprise to climate history buffs is their take of this well-known story and its implication for the future.
Büntgen et al. reconstruct the western European climate for the past twenty-five hundred years from a large collection of tree ring series collected from oak trees from central Europe. Figure 1 (below) shows their reconstruction of spring precipitation (blue series, top) and summer temperature (orange series, bottom) and their added annotations (between the two series) of what was going on with human populations at various intervals during the past 2,500 years.
Figure 1. Reconstructed AMJ precipitation totals (top) and JJA temperature anomalies (bottom) with respect to the 1901–2000 period. Error bars are +/-1 RMSE of the calibration periods. Black lines show independent precipitation and temperature reconstructions from Germany (19) and Switzerland (18). Bold lines are 60-year low-pass filters. Periods of demographic expansion, economic prosperity, and societal stability are noted, as are periods of political turmoil, cultural change, and population instability (Figure and caption from Büntgen et al., 2011).
Look long and hard at Figure 1 and see what you think the relationship is between climate and society.
No matter how we look at it, we see these general things—periods of population growth and prosperity (which are generally denoted by the horizontally oriented green typeface, i.e., Late Iron Age, Roman Period, Medieval Period) in the figure are associated with a relatively warm climate, while periods of unrest and all out societal downfall (which are generally indicated by the vertically oriented dark grey typeface, e.g., Migration Period, Great Famine, Black Death, etc.) are associated with relatively cold climates.
This warmer=better/colder=worse view is not in any way new as it has been the general knowledge for some 40 years, encapsulated in such works as Le Roy Ladurie’s (1971) Times of Feast, Times of Famine: A History of Climate since the Year 1000, and Hubert Lamb’s (1972) Climate: Past, Present and Future.
Nothing whatsoever in the just-published Büntgen et al. paper changes this understanding one iota.
Yet, through some strange interpretation of these facts, Büntgen et al. conclude—and, we hasten to add, Science magazine accepts and publishes—the following:
“Such historical data may provide a basis for counteracting the recent political and fiscal reluctance to mitigate projected climate change.”
That certainly requires novel interpretation and wishful thinking.
Apparently this is one way to get published in Science—submit a paper that presents a collection of well-known facts and relationships, but spin them in a manner that is 180 degrees from what is generally accepted.
Instead of using the historical relationships to suggest that anthropogenic global warming seems a beneficial trend (and certainly one that portends a better situation than a cooling trend would), Büntgen et al. tell us that history should guide us to be very afraid of a warming climate. And, that this fear should be used as a tool to break up the political logjam that is apparently preventing serious steps to mitigate human-caused climate change (which all involve making energy more expensive—we can only imagine how Büntgen et al. would spin the results of an investigation into the relationship between the fate of human societies and the amount of cheap energy that they had available to them).
We wonder what would have been the fate of their paper had they not included the suggestion as to how their results could be used in the current political situation.
We offer up this conjecture…
Had we presented the exact same data, and concluded something much more in line with the general way of thinking, something like:
“Such historical data may provide a basis for the support of the recent political and fiscal reluctance to mitigate projected climate change.”
our paper would have been rejected out of hand and the reviewers would have tsked tsked about our using the paper for “political purposes” as we are “wont to do.”
However, Büntgen et al. can and do explicitly call for the use of their paper for political purposes, and not only is that OK, but it is probably the reason that it is appearing Science magazine.
The facts haven’t changed, only the political message.
Büntgen, U, et al., 2011. 2500 Years of European Climate Variability and Human Susceptibility. Science, 331, 578-582.