Vulnerability Assessment of Wheat Yield Under Warming Climate in Northern India Using Multi-model Projections

Climate change impact on crop production using different climate model projections varies considerably and it is challenging to choose a suitable climate scenario for risk assessment. This study aims to assess the climate change impact on the wheat crop in nine agro-climatic zones (ACZs) of Uttar Pradesh (UP) in Northern India using the CERES-Wheat crop model, driven by high resolution projected climate from different regional climate models (RCMs). The results show that the vegetative growth period would be shortened across the ACZs and scenarios where higher reductions will be witnessed under RCP 8.5 viz., up to 10 days in the 2050s (2040-2069), and 14 days in the 2080s (2070-2099). Also, in the 2080s shortening up to 17 days will be observed in the total growth period under RCP 8.5. When elevated CO2 concentration was not considered the wheat yields were found to reduce up to 20.5 and 30% under RCP 4.5 and RCP 8.5, respectively, in the 2050s. In the 2080s, the losses will be more pronounced reaching up to 41.5% under RCP 8.5. With the consideration of CO2, the yield reductions will be up to 14 and 18% under RCP 4.5 and RCP 8.5 respectively in the 2080s. Uncertainty associated with climate model revealed that ACCESS 1-0 and MPI-ESM-LR predicted higher mean yield reductions while CNRM-CM5 has shown a mild effect. Present study concluded that eastern UP is a vulnerable region for wheat production in the 21st century. The results suggest that there is an urgent need for developing suitable adaptation strategies to ameliorate the adverse effects on wheat production in UP through regional policy planning.