Climate of doubt: A re-evaluation of Büntgen and di Cosmo's environmental hypothesis for the Mongol withdrawal from Hungary, 1242 CE

In their recent article published in the journal Scientific Reports, Büntgen and Di Cosmo have attempted to solve the historical mystery of the sudden Mongol withdrawal from Hungary after a year-long occupation. We cannot share the authors' viewpoint that environmental circumstances contributed to the decision of the Mongols to abandon Hungary since the hypothesis lacks support from environmental, archaeological and historical evidence. Historical source material in particular suggests that the Mongols were able to settle and sustain their herds in Hungary as is clearly stated in a letter by King Bela IV to the pope. The Mongol army arrived in the kingdom at the end of a severe drought, and we present empirical evidence that the abundant rain in the spring of 1242 CE did not worsen but rather improved their prospects for sufficient food supplies and pasturage. The marshy terrain of the Hungarian Plain likely did not precipitate the Mongol withdrawal as the Mongol high command ultimately stationed their main forces around the marshy Volga Delta. In contrast to what Büntgen and Di Cosmo have suggested, we argue that the reasons for the sudden withdrawal cannot be explained largely by environmental factors.