Climate Change during and after the Roman Empire: Reconstructing the Past from Scientific and Historical Evidence

TLDR

Modern climate science, combined with unevenly distributed written and archaeological records, offers a complex foundation for investigating the environmental history of the Roman Empire and its successor societies. The authors synthesize written records and multi‑proxy natural archives to reconstruct climate change and variability across western Eurasia from roughly 100 BC to 800 AD. Their reconstruction shows that the Roman Empire rose during a stable, favorable climate that deteriorated during the third‑century crisis, experienced a brief recovery in the fourth century, and that regional climate differences paralleled the divergent fates of eastern and western Empires while climate beyond its borders influenced Nile agriculture and prompted migrations and invasions from Central Asia.

Abstract

Growing scientific evidence from modern climate science is loaded with implications for the environmental history of the Roman Empire and its successor societies. The written and archaeological evidence, although richer than commonly realized, is unevenly distributed over time and space. A first synthesis of what the written records and multiple natural archives (multi-proxy data) indicate about climate change and variability across western Eurasia from c. 100 b.c. to 800 a.d. confirms that the Roman Empire rose during a period of stable and favorable climatic conditions, which deteriorated during the Empire's third-century crisis. A second, briefer period of favorable conditions coincided with the Empire's recovery in the fourth century; regional differences in climate conditions parallel the diverging fates of the eastern and western Empires in subsequent centuries. Climate conditions beyond the Empire's boundaries also played an important role by affecting food production in the Nile valley, and by encouraging two major migrations and invasions of pastoral peoples from Central Asia.