Longer droughts predicted
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Researchers warn that droughts towards the end of the century could last longer than previously predicted.
A study published in Nature finds that average drought durations could be extended by an additional ten days on average, due to previously underestimated climate model projections.
The research is intended to improve the accuracy of drought forecasts by addressing biases in existing climate models.
The team adjusted projections by calibrating them against historical observations, specifically looking at the longest annual dry spells recorded between 1998 and 2018.
The longest dry spells, also known as the number of consecutive dry days in a year, serve as a critical measure for drought severity.
The recalibrated models showed that by the period from 2080 to 2100, global drought durations could increase by 42 to 44 per cent under both moderate and high-emissions scenarios.
These findings suggest a ten-day increase in the longest dry spells compared to earlier estimates.
This emphasises the need to reassess drought risk globally and develop more reliable projections to improve preparedness for extreme weather events.
One of the key observations from the study was the geographic variability in drought impacts.
In regions such as North America, southern Africa, and Madagascar, the recalibrated models predicted drought lengths that were nearly twice as long as those projected by standard models.
By contrast, parts of Central-East Asia were projected to see shorter dry periods, which may lead to more frequent rainfall and an increased risk of flooding.
The authors highlighted the importance of correcting biases in climate models, noting that the “dry-model-gets-drier” pattern observed in existing models remains an issue that needs further attention.
Without addressing these biases, long-term projections may continue to underestimate the severity of future droughts, leaving societies unprepared for the environmental and societal challenges that prolonged droughts will bring.
The study underscores the urgency of improving drought forecasting, as accurate projections are critical for developing strategies to mitigate the effects of these extended dry periods.