596 Net Benefits to Crop Yields from Intensifying Hourly Rainfall

Tuesday, 14 January 2020
Hall B (Boston Convention and Exhibition Center)
Corey Lesk, Columbia Univ., New York, NY; Columbia Univ., Palisades, NY; and E. D. Coffel and R. M. Horton

Many varieties of short-duration extreme weather pose a threat to global crop production, food security, and farmer livelihoods. Hourly exposure to extreme heat has been identified as detrimental to crop yields, however the influence of hourly rainfall intensity and extremes on yields remains unknown. We show that while maize and soy yields are severely damaged by the rarest hourly rainfall extremes, they benefit from heavy rainfall up to 20 mm hr-1, roughly the heaviest downpour of the year on average. We also find that yields decrease in response to drizzle (0.1-1 mm hr-1), revealing a complex pattern of yield sensitivity across the range of hourly intensities. We project that crop yields will increase by up to 2-3% on average due to projected future rainfall intensification under climate warming, with the benefits of more heavy rainfall hours outweighing the damages due to additional extremes. Our results challenge the view that increasing rainfall intensity poses an unequivocal risk to crop yields and provide insights that may guide adaptive crop management and improve crop models.
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