Sunday, December 29, 2019

"The Science of Roman History: Biology, Climate, and the Future of the Past"

Another one* from Inference Review:
A Means to an End
From the seven essays presented in The Science of Roman History it seems that there has never been a better time to be a Roman historian. This is the rosy outlook described by Walter Scheidel and the array of historians, archaeologists, and scientists assembled for this volume. Complex and longstanding questions about the Roman era, such as the impact of slavery, wealth distribution, health and nutrition, and the costs of trade are now being reexamined using data-driven approaches. For the first time, the ancient Mediterranean climate can be reconstructed in detail, offering insights beyond the standard ancient literary sources and archaeological evidence. In short, it would seem that we are narrowing the multimillennial gap between ourselves and the Romans. These are claims that merit careful consideration.

In their opening chapter, entitled “Reconstructing the Roman Climate,” Kyle Harper and Michael McCormick promise a deeper understanding of the role played by climate in shaping Roman history. Their deployment of scientific data and historical reasoning is nonetheless surprisingly subjective, frequently undermining the conclusions they reach. The authors see stability in the main climate-forcing mechanisms, solar and volcanic activity, throughout the Roman era. Yet the four diagrams used to illustrate this point also depict numerous dramatic and often widely spaced peaks and troughs.1 Harper and McCormick correlate a peak that falls during the Imperial Crisis of the third century (235–284 CE), a period in which there were 25 emperors in just 50 years, to a hypothetical disruption of food supplies caused by a major volcanic event that occurred in 266 CE.2 In doing so, they do not adequately explain the correlation and downplay the well-documented political, military, economic, social, and moral causes of the crisis. This flirtation with something akin to environmental determinism is also evident in the concluding section. The authors call for “sophisticated thinking about exactly how climate can affect an ancient economy,” before immediately raising the familiar specter of food production.3 This leap in logic does not reflect sophisticated survival strategies involving land management practices and surplus harvests that have been documented by ethnographers.4

“Both climate change and social impact,” Harper and McCormick caution, “are complex and multidimensional phenomena that usually cannot be reduced to unilinear cause and effect.”5 At times, the authors struggle to follow their own advice. The Roman Warm Period (200 BCE–150 CE), an interval of generally warmer temperatures throughout the Mediterranean basin, is viewed as a factor that favored the formation of the Roman Empire during that period.6 This is not a causal connection. At best, it is merely an interesting coincidence. By contrast, the period of greatest political expansion and cultural efflorescence in the Etruscan era (ca. 700–250 BCE) coincided with a time of relatively cool temperatures in Tuscany.7 Climate datasets from around the Roman Empire do not reflect the level of uniformity implied by the authors. A detailed geological and geomorphological study of Ostia Antica, the harbor of ancient Rome, concluded that, “over the last 2,000 years, the most important progradation phases of the delta [first century BCE to second century CE] were produced by increases in sediment load caused by environmental changes, i.e., cool, moist climatic periods.”8 A generalized empire-wide model can never hope to capture the true complexity of environmental change. Historical questions are best formulated at the local and regional levels, where the climate data are most robust, and include archaeological data derived from field surveys and excavations.9
The second chapter is entitled “Archaeobotany: The Archaeology of Human-Plant Interactions,” and explores what can be learned from botanical remains recovered in archaeological excavations.

Contributed by Marijke van der Veen, the strongest sections of this chapter examine the trade and distribution of foodstuffs and the relationship between food and identity.10 Both sections feature a selection of well-chosen examples. Although van der Veen correctly emphasizes that “both humans and plants have agency, and that both affect one another,” her examples mostly comprise lists of finds and exhibit a notable anthropological emphasis.11 She does not examine causal links between changes in the availability and desirability of specific foods and larger historical forces. Rather than simply noting that imperial quarry workers at Mons Claudianus and Mons Porphyrites in Egypt had a relatively rich and varied diet, it would be worthwhile to examine the means by which these foods were provided to people of presumably humble social origin and how this changed over time.12
Van der Veen’s chapter has some notable shortcomings. The ancient Roman agricultural texts, crucial evidence describing the types of plants cultivated at the time, are mentioned only to note their evidently limited applicability.13 Elsewhere, tobacco is erroneously listed among the Old-World plants introduced to the Americas for cultivation in plantations.14 There are also digressions of questionable value on modern issues, such as the effects of globalization and a high-sugar diet on health, and the description of the correct archaeological methods for collecting samples is misplaced in a volume targeted at historians. Perhaps the most glaring problem is that many of the examples chosen to illuminate the discipline of archaeobotany are not even Roman, either in chronology or location. This chapter is a long way from the detailed environmental reconstructions that have enriched our archaeological and historical understanding of the Greek and early Roman periods at Metaponto in southern Italy.15

*Friday: "Vaclav Smil: 'Good Eats'"