BY GUEST BLOGGER|SEPTEMBER 22, 2020
By Seung Hun Baek, Jason Smerdon, George-Costin Dobrin, Jacob Naimark, Edward Cook, Benjamin Cook, Richard Seager, Mark Cane and Serena Scholz
A global pandemic is a good time to reflect on the reality that history is full of much more misery and strife. For example, even by the standards of Medieval Europe, when deadly wars, famines, and diseases were common, the 14th century is particularly heartbreaking. Among many notable and terrible events of that age, the Great Famine, the Hundred Years’ War and the Black Death all stand out as infamous events in one of Europe’s most miserable centuries.
A new paper from our team at Columbia University’s Lamont-Doherty Earth Observatory, published in Communications Earth & Environment, specifically revisits the infamous and devastating European Great Famine of 1315-1317. During this period, much of Europe experienced unrelenting rains that were compared to the fulfillment of Noah’s Ark prophesy. Historical records report that excessively wet conditions made planting difficult, crop yields poor, and frequently made it difficult to transport what could be harvested to market. The consequence was massive crop and market failures, which led to widespread death and starvation; in some places infanticide and cannibalism were reported, which purportedly gave rise to the Hansel and Gretel fairy tale. Famine spread across the British Isles, France, the low countries and Germany, and approximately 10-25% of Europe’s population perished.
It has long been known that miserable weather played a key role in the events that gave rise to the Great Famine, particularly the heavy rains. But it was not known, relatively speaking, how wet the years during the Great Famine actually were. That is where our paper comes in. Using the Old World Drought Atlas (OWDA), which reconstructs soil moisture conditions over Europe and was developed at Lamont by Ed Cook and colleagues, our team estimated that 1314-1316 was the fifth wettest 3-year period from 1300 to 2012. Among individual famine years, 1315 and 1314 were the first and second wettest years between 1300-2012, respectively.
The Old World Drought Atlas includes data collected from the wooden beams of old structures in Europe, including Dragon Hall, a medieval trading center in Norwich, U.K. The tree rings measured from these beams provide valuable information about past soil moisture conditions in the regions where the trees were harvested. Photo: Martin/Flickr CC
Most interestingly, our team placed the conditions during the Great Famine in a larger context; we identified a pattern in the soil moisture data (see EOF1 in the image below) that is strongly expressed in the region’s wettest years — including during the Great Famine; when the pattern is reversed, it is also associated with the driest years. For centuries, this climate pattern characterized a large portion of Europe’s soil moisture variability, but the dominance of the pattern has waned during the 20th century. It is not clear why, and whether that will continue to be true. These findings leave open critical questions about how to interpret the risks of droughts and deluges into the next century, and how they will be influenced by both natural variability and the ever-evolving effects of human-caused climate change.
The new paper characterizes a ‘mode of climate variation’ over Europe. This pattern of soil moisture (EOF1) was strongly expressed during the Great Famine and other wet years through the last millennium, whereas when the pattern is reversed, the region experiences drier conditions. The self-calibrating Palmer Drought Severity Index, scPDSI, is a normalized estimate of soil moisture; positive values around 2 and 4 are abnormally wet and extremely wet, respectively, whereas values of -2 and -4 are dry and extremely dry.
If these questions get answered it will most likely be because engaged and interested students will continue the charge. The Great Famine paper was ultimately carried out by intrepid students working over multiple years. George-Costin Drobin and Jacob Naimark were both undergraduate Earth Institute interns who worked with Jason Smerdon to compare the conditions in the OWDA to historical accounts of the weather during the Great Famine. Seung Hun Baek, a former DEES graduate student (now a postdoctoral fellow at Yale University), picked up where Costin and Jacob left off, and in a fortuitous twist of fate, Hun interacted with a Lamont summer intern, Serena Scholz, who was working with Richard Seager on patterns of hydroclimatic variability over Europe. Hun’s and Serena’s discussions ultimately led us to think about how the hydroclimatic pattern they were characterizing for the Great Famine connected to the long-term dynamics of Europe and their relevance for the future. These stories of student involvement are thus a testament to the importance of student engagement in the scientific enterprise at Lamont, and the free and spontaneous exchange of ideas that is so vital to making collaborative research possible.
This post contains material from a blog post originally published by Springer Nature.