Assessing impacts of climatic variations on foodgrain production in Bangladesh

Abstract

A simulation study was conducted to assess the vulnerability of food grain production in Bangladesh to potential climate change. Simulation runs were made for high yield varieties of rice for Aus (March-August), Aman (July-November), and Boro (February-July), the traditional growing seasons, using the CERES-Rice model. Simulation runs were made for wheat, which is grown from November through March, using the CERES-Wheat model. Three scenarios (baseline, Canadian Climate Centre Model, and Geophysical Fluid Dynamics Laboratory) and sensitivity analyses for temperature increases of 2 and 4°C at three levels of CO2 (330, 580, and 660 ppm) were used. In the simulation, increased CO2 levels increased rice yields over baseline, and considerable spatial and temporal variations were noted. Higher temperatures reduced the yields in almost all study locations and in all seasons, and it was particularly pronounced with a 4°C increase. The detrimental effect of temperature rise was observed even with increased CO2 levels. Wheat yields increased with increased CO2 level in all three locations. The adverse effects of increased temperature were more pronounced for wheat than for rice at all levels of increased CO2. In the scenarios of the Canadian Climate Centre Model and Geophysical Fluid Dynamics Laboratory, both rice and wheat yields were decreased (35% and 31%, respectively) over baseline in all seasons, especially in the Aus season, and in all locations. The adverse effects of the climate under the Geophysical Fluid Dynamics Laboratory scenario were more pronounced for wheat than for rice. The greatest reductions in aggregated production for both crops were noted at 330 ppm CO2 with a 4°C temperature rise. The greatest increases in aggregated production for rice and wheat were observed at a 660 ppm CO2 with no temperature increase.