21st Century Shifts in Limiting Hazards that Determine Growing Seasons

Abstract:

Weather and climate have major impacts on global agriculture production through both mean conditions and extreme events that can make a crop viable or be the difference between a good or bad year. A slight change in the climate can greatly affect the food security and economy in agricultural regions. Stakeholders are looking for forewarning of shifts in cropping systems. Of particular interest are the factors that will determine crop selection, viable growing seasons, and the potential for multi-cropping. Crops need adequate temperatures, moisture and growing seasons to be healthy, high-quality and high-yielding. Crops may be limited by cold limits during the early and late stages of the growing season while the middle of the season is threatened by drought or heat limits. The magnitude, frequency, duration, spatial extent and timing of these limiting conditions are changing and could potentially pressure farmers to shift growing seasons, crop and livestock selection, and the health of agricultural laborers in the future.

This study focuses on identifying shifts in the beginning, mid-season, and end of season hazards that agriculture regions will have to adapt to in the future. Temperature thresholds for extreme heat exposure and frosts are used to determine shifts in viable growing seasons, drawing upon observations and future climate data from the Coupled Model Intercomparison Project Phase 6 (CMIP6) bias-adjusted by the Inter-Sectoral Impacts Model Intercomparison Project (ISIMIP). The overall goal is to identify regions where the profile of limiting hazards change dramatically over the 21^st century and related uncertainties across RCPs, climate models, crop thresholds, and cropping systems. Results will also be compared against Agricultural Model Intercomparison and Improvement Project (AgMIP) Global Gridded Crop Model Intercomparison (GGCMI) crop simulation model outputs driven by ISIMIP climate data. Results are expected to be of major interest for planning future systems and associated adaptation and mitigation within these agricultural regions