Simulating the impact of projected climate change on rice (Oryza sativa L.) yield and adaptation strategies in major rice growing regions of India

Global mean air temperatures are projected to increase by 1.8 to 4.0 oC by the end of this century. Higher temperatures coupled with increased CO2 levels could result in altered growth and productivity of crops. Since rice is sensitive to high temperatures, a simulation analysis was carried out to quantify the impact of increased temperatures (1, 2, 3, 4 and 5 oC) and elevated CO2 (369, 450,550 and 650ppm) alone and in combination on the yield using InfoCrop-RICE model. An assessment is also provided on the possible gains due to change in planting time and crop duration. Though elevated CO2 alone increased the rice yields, increase in temperature by 1oC (even at 369 ppm CO2 concentration) reduced irrigated rice yield by 6.6 to 11.1 % and rainfed rice yields by 4.6 % to 9.4 %. The combined impact of increased temperature and elevated CO2 resulted in net decline in yield in spite of CO2 fertilization. Planting cultivars in future with matching crop duration of current cultivars and change in planting time may reduce the adverse impacts of climate change on rice yields.