Reply to Strunz and Braeckel: Agricultural failures logically link historical events to extreme climate following the 43 BCE Okmok eruption.

We report (1) ice core evidence that unambiguously identifies massive sulfur fallout over much of the Arctic, attributed using tephra geochemistry to eruption of Alaska’s Okmok volcano, with climate model simulations indicating 2 y of extreme temperatures and precipitation throughout the Northern Hemisphere starting in early 43 BCE. This climate event occurred in the waning years of the Roman Republic and Ptolemaic Kingdom during a period of well-known social, political, and economic stress including food shortages, epidemic disease, and unusually inclement weather reported in ancient sources (Fig. 1). We contend that such a climate anomaly—corroborated by paleoclimate proxies—undoubtedly contributed to historical events primarily through disruptions in food production in the Mediterranean region. Without offering any specific criticisms or … [↵][1]1To whom correspondence may be addressed. Email: Joe.McConnell{at}dri.edu. [1]: #xref-corresp-1-1