Climate change impacts in the Late Roman Empire: a quantitative analysis

Abstract

The study of past societies’ relation with climate is a precious resource to contextualize our own struggles with the current climate crisis, but the field has been left largely unexplored by both historians and climatologists. In this project, we aim at providing a contribution to fill this gap. Our focus is on the late Roman Empire, from the onset of the third century crisis (235 AD) to the fall of the Western Roman Empire (476 AD). This period coincided with climatic change in Europe, as it represented the transition between the Roman Warm Period and the Dark Ages Cold Period. We are interested in exploring the relation between climate change and the Empire’s crisis, through the use of a computational simulation of the Empire’s agricultural productivity and food staples economy. The project was divided in two phases. First we constructed a simulation that reproduced the known historical trade patterns around 200 AD to a reasonable level of accuracy. In a second phase, we tested this simulation through a different reconstructed climate forcing and evaluated the anomaly between them. We found that the climate transition caused a significant rise in grain import costs in several cities of the Roman East, which could justify some of the Empire’s socio-economic issues starting around the 3rd century AD.