Risks of synchronized low yields are underestimated in climate and crop model projections

Simultaneous harvest failures across major crop-producing regions threaten global food security. Concurrent weather extremes, driven by a meandering jet stream, can trigger such events, but their quantification has been lacking. This study analyzes the ability of state-of-the-art crop and climate models to reproduce these high-impact events. The findings reveal an increased likelihood of concurrent low yields during summers with meandering jets, both in observations and models. However, climate models underestimate the associated surface weather anomalies and their negative effects on crop yields, even in bias-adjusted simulations. This highlights significant model uncertainties in assessing regional and concurrent crop losses from meandering jet states, emphasizing the need to account for these model blind spots in climate risk assessments.

Kai Kornhuber, Corey Lesk, Carl F. Schleussner, Jonas Jägermeyr, Peter Pfleiderer, Radley M. Horton