Response to Foxhall Forbes et al. (2026) “Drought, conflict and the use of historical data and methodologies in interdisciplinary paleoclimatic research”

Abstract

We acknowledge the critical engagement of Foxhall Forbes et al. (2026) with our interdisciplinary investigation into the direct and indirect entanglements between droughts and conflicts during the late Roman period (Norman et al. 2025). Aiming towards a non-deterministic interpretation of environmental and societal linkages during the demise of the Western Roman Empire in the 4th and 5th centuries, we compiled and analysed state-of-the-art tree-ring chronologies together with a wide range of written documentary sources. Our qualitative case-study on the ‘Barbarian Conspiracy’ in Roman Britain in 367 CE was supplemented by a continental-wide network approach for the quantitative assessment of possible linkages between climate and conflict across the entire Roman Empire between 350 and 476 CE. Based on the combined, scale-dependent, multi-proxy evidence, we then developed a mechanistic model to explore the susceptibility of past agrarian societies (i.e., how prolonged droughts may have contributed to harvest failures and food shortages that could have led to systematic pressure, societal instability, and eventually even outright conflict).