I love it when news articles report instances in which someone had to call in the medievalists. Is it such a stretch to imagine us en masse, swashbuckling our way through the crowds with manuscripts and Latin dictionaries in hand to save the day? Today’s adventure comes courtesy of Paul who sent me a BBC article describing a direct connection between success or failure of Roman society and changes in its climate.  You may also recall how intrigued I am by geology and its relationship to art and history. This week, Mount Etna began to grumble and spew fire, a reminder that the survival of anything– art objects to entire civilizations–is in many ways subject to the forces of nature.
The link between climate change and human achievement in Rome has been deciphered using tree rings from wooden artifacts. Traditionally, dendrochronology (using tree rings to date materials) in archaeology is considered precarious because it tells you the date of the wood, not the object. For instance, the rings on the wooden beam of a church tell you when the tree was cut, not when the church was built. Also, the survival of medieval wooden ships, beams, or furniture is rare. However, the good thing about these elusive medieval tree rings is that trees don’t lie. A tree gets a new ring each year, and the width of that ring is determined by many factors such as temperature, precipitation, fire, wind, species, and habitat. Enough samples have been documented that comparing even partial tree ring evidence to archived samples yields reliable results, and it can be used in conjunction with radiocarbon dating.
In the article, scientists from the Swiss Federal Research Institute for Forest, Snow and Landscape have gathered enough data to deduce that “wet and warm summers occurred during periods of Roman and medieval prosperity. Increased climate variability from 250-600 AD coincided with the demise of the western Roman empire and the turmoil of the migration period.” It’s not particularly surprising that people thrive when nature cooperates, but a study like this adds scientific explanation to common sense theory. Medieval history has added weight to the findings of these paleoclimatologists as well.
The juicy part of all this interdisciplinary intermingling is that so much of history is the writer’s own construction. For instance, there are scholars who would argue that Rome’s ‘chaotic’ migration period could just as easily be seen as one of transition and communication. Lawrence Nees, for instance, promotes art in the early medieval west as that of tradition and transformation, dispelling the notion of “Wandering Tribes” and calling the period “a time of ethnogenesis, the cultural creation of new ‘peoples’, not of the migration of stable populations.” Other scholars concur, saying “the [Roman] empire had never isolated itself from the Germanic peoples they called barbarians, recruiting them as soldiers for the Roman army and developing commercial and diplomatic ties with their leaders.” In other words, the migration period was not necessarily one of constant migration of groups of people, but one of people collectively choosing and asserting their identities. When scholars disagree on the facts, it makes aligning historical events with scientific measurements even more complex. Could measuring climate changes via tree rings compel us to reconsider historical theory?
And how is this remotely useful to an art historian? Right now I’m writing about early Christian baptism, a sacrament that was still evolving in the third century. According to scientist Ulf Büntgen, “distinct drying in the third century paralleled a period of serious crisis in the western Roman empire.” It remains to be seen what impact a drought may have had on art depicting a water ritual, but I like that the discovery is sending my art historical research down a scientific path.
 Mark Kinver, “Roman rise and fall ‘recorded in trees,’” BBC News, January 14, 2011, http://www.bbc.co.uk/news/science-environment-12186245
See also Ulf Büntgen, et al., “2500 Years of European Climate Variability and Human Susceptibility,” Science (January 14, 2011), DOI: 10.1126/science.1197175. Find the abstract online at http://www.sciencemag.org/content/early/2011/01/12/science.1197175.abstract.
 For a fantastic photo by Antonio Parrinello (Reuters), see “Etna Aflame,” National Geographic Daily News, January 14, 2011, http://news.nationalgeographic.com/news/2011/01/pictures/110114-mount-etna-eruption-pictures-italy-volcanoes/.
 A description of the pros and cons of using dendrochronology as evidence can be found in Leslie Brubaker and John Haldon, Byzantium in the Iconoclast Era (c. 680-850): The Sources (Aldershot Hants, England; Burlington, VT: Ashgate, 2001), 5.
See also National Park Service, U. S. Department of the Interior, “Dendrochronology,” Archaeology Program, http://www.cr.nps.gov/archeology/AforI/howfig_abs3.htm.
 Lawrence Nees, Early Medieval Art (Oxford: Oxford University Press, 2002), 14.