Crop Yield Loss Risk Is Modulated by Anthropogenic Factors.

Area of Science:

• Agricultural Science
• Climate Change Adaptation
• Global Food Security

Background:

• Extreme weather events cause significant crop yield variation, impacting global food production and creating system vulnerabilities.
• Understanding the link between adaptive capacity and crop yield variability is crucial for mitigating these shocks.
• Existing research is predominantly local-scale, lacking a comprehensive global assessment.

Purpose of the Study:

• To conduct a global assessment of crop yield variation for wheat, maize, soybean, and rice from 1981-2009.
• To evaluate the explanatory power of anthropogenic factors (adaptive capacity measures) on yield variation.
• To identify how these factors influence yield loss risk and performance during climate shock years.

Main Methods:

• Assessed crop yield variation using yield loss risk and changes during dry/hot shock years.
• Employed the XGBoost machine learning algorithm for analysis.
• Utilized gridded indicators of anthropogenic factors (HDI, irrigation, fertilizer use) at 0.5° resolution within climatically similar regions.

Main Results:

• Anthropogenic factors explained 40%-60% of yield loss risk variation globally over the study period.
• Explanatory power of these factors was lower (5%-20%) during extreme shock years.
• Factors explained a high proportion of yield loss risk variation (up to 80%) on continental scales, particularly in Europe and Africa.

Conclusions:

• Anthropogenic factors play a significant role in explaining global crop yield variation, though their influence diminishes during extreme climate shocks.
• Global-scale assessment provides critical knowledge for targeting adaptation strategies to enhance food security.
• Findings support the development of region-specific adaptation measures to build resilience in the global food system.