Abstract
The global crop ecosystem is critically dependent on snow availability, which has diminished in numerous snow-dependent regions due to increasing snow droughts associated with warmer winters. However, our understanding of crop yield sensitivity to snow droughts and how this sensitivity evolves remains limited. In this study, we find that from 1960 to 2020, approximately 51% of winter wheat croplands have experienced a significant increase (5.3−6.7% per year) in the frequency of snow droughts. To assess the sensitivity of winter wheat yield to snow droughts, we utilized explainable machine learning, gridded yield datasets, and the standardized snow water equivalent index (SWEI) from 1982 to 2016. Our findings reveal a positive association between yield anomalies and SWEI under snow drought conditions and a significant increase in the sensitivity of yield to SWEI over 24% of Northern Hemisphere winter wheat croplands. Additionally, enhanced accumulation of growing degree days, increased vapor pressure deficit (VPD), a slight decrease in total precipitation, and increased heavy rainfall are identified as dominant factors amplifying yield sensitivity to snow droughts. These findings highlight an increasing vulnerability of crop systems to snow droughts over the past three decades, which is crucial for informing risk management and adaptation of agriculture to a warming future with less snow.