Land-atmosphere feedbacks contribute to crop failure in global rainfed breadbaskets

Area of Science:

• Agricultural Science
• Climate Science
• Atmospheric Science

Background:

• Global crop yields are sensitive to climate variability, with extreme dry and hot years causing major agricultural failures.
• Local land-atmosphere feedbacks, involving soil moisture, evaporation, and temperature, significantly impact crop productivity.
• The influence of upwind regions on crop yields during climate extremes remains under-researched.

Purpose of the Study:

• To investigate the spatio-temporal origins of moisture and heat affecting major rainfed agricultural regions (breadbaskets).
• To quantify the dependency of crop yields on upwind regions and local land-atmosphere interactions.
• To disentangle the combined effects of local and upwind feedbacks on agricultural productivity during low-yield years.

Main Methods:

• Analysis of moisture and heat transport origins for 75 global rainfed breadbaskets.
• Assessment of land-atmosphere interactions in both local and upwind regions.
• Quantification of the impact of anomalous moisture and heat transport on crop yield deficits.

Main Results:

• Crop failure risk increases by approximately 40% when both upwind and local land-atmosphere feedbacks contribute to low moisture and high heat.
• Upwind land-atmosphere feedbacks have a more pronounced impact on productivity deficits in water-limited agricultural regions.
• These regions exhibit a greater reliance on moisture supplied from upwind land areas.

Conclusions:

• Understanding upwind-downwind dependencies in agriculture is crucial for assessing climate change impacts on food security.
• Identifying moisture source regions and their atmospheric connections can inform adaptation strategies.
• Mitigating food shortages requires considering the interconnectedness of land-atmosphere systems across regional scales.