Probabilistic Assessment of Extreme Heat Stress on Indian Wheat Yields Under Climate Change

Abstract

AbstractThe wheat belt along the Indo‐Gangetic Plains (IGP) in India is an emergent hotspot of climate change‐driven crop loss threatening local food security. Using statistical Generalized Linear Models, observed temperature and wheat production data, we show an increase in magnitude, frequency and areal extent of heat stress episodes in the IGP region during 1967–2018. Such episodes comprise of temperatures exceeding a senescence‐inducing threshold. Further, using a copula‐based multivariate framework, we probabilistically assess wheat production conditioned on heat stress indicators, both in the historical period and also in the Coupled Model Intercomparison Project (CMIP6) future projections. Probabilistic estimates of below‐average wheat production under scenario‐averaged heat stress conditions are expected to rise by 8%–27% under the SSP5‐8.5 scenario, with Punjab showing the largest increase. Quantitative links between heat stress indicators and loss of crop yield highlight increased agricultural vulnerability in India under climate change.