Global record-shattering breadbasket droughts emerge from moderately extreme regional events

TL;DR

This study shows that global droughts in major maize regions are becoming more likely due to moderate droughts happening at the same time, not just extreme ones.

Contribution

The paper reveals that global droughts emerge from concurrent moderate droughts, not just extreme regional events.

Findings

Global record-shattering droughts are projected to occur with 52% probability under an intermediate emission scenario by 2099.

Droughts in Brazil, Europe, and the USA drive the increased risk of global droughts.

Moderately extreme droughts across regions, not record-breaking ones, cause global shocks.

Abstract

Simultaneous droughts across multiple maize-producing regions can strike record-shattering portions of the global maize agricultural area, threatening global food security as the system is poorly adapted to large shocks. Yet the future probability of such global droughts remains unknown. Here, we close this gap by analyzing surface soil moisture data from large ensemble climate models under future emission scenarios. During 2026-2099, the chance of at least one such event is 52% (32–80%, range across models) under an intermediate emission scenario and 60% (32–100%) under high emissions, about seven to eleven times higher than expected if there were no long-term trends in soil moisture. These elevated probabilities are primarily driven by long-term drying in Brazil, Europe, and the USA. Interestingly, global record-shattering droughts do not emerge from simultaneous regional record-shattering events, but they mostly occur when several regions simultaneously face moderately extreme droughts relative to the new climate. These results demonstrate a high potential for an upcoming global record-shattering drought in crop-producing areas, an under-recognized risk for food security.

The study shows that global record shattering droughts across major maize producing regions become more likely this century and typically arising from concurrent moderately extreme droughts rather than simultaneous regional records.

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