A study on the possible impacts of climate change on food security in the central coastal area of Bangladesh

Global and local climate changes can affect crop yields in the future. Recent increase of weather related stresses and damages are resulting from an increase in the frequency of climate hazards. However, agriculture in both developing and developed countries depends highly on climate factors (temperature, solar radiation and precipitation) that act as a main driver of rice production. Nevertheless, the relationship of climate variability and rice production could vary in different regions across the world. Bangladesh is perhaps one of the most climatic vulnerable countries because of geographical location and large Gnga-Meghna-Brahmuptra river systems. The costal belt of Bangladesh covers 30% of the total agricultural land in Bangladesh, and plays an important role in the country’s GDP. The close dynamic relationship between climate variability and rice yield could be useful to identify yield losses or gains at different spatial scales. This relationship can have differences in their patterns as well as in magnitude at different spatial and temporal scales. This study consisted of a review of climate change issues for Bangladesh, an analysis of crop yield variations over the years 1990-2008 and some preliminary modeling of rice yields with changing climate parameters. Generally, three seasonal rice crops(Aman, Aus and Boro) have been cultivated in the study area. Based on correlation analysis, for the country’s central coastal belt, no or negative relationships have been indentified between climate parameters and yield. Although there are significant uncertainties in the predicted climate parameters, DSSAT 4.5 crop simulation model is an effective tool to show the potential impacts of predicted climate change on yields. For deriving DSSAT4.5 simulation model, climate parameters and management inputs is important to predict yield under the basis of planting period investigation. Model results indicate that as climate parameters like temperature increase, farmers could get lower yields in their cropping systems. Lower yields were estimated for the heavy rainfall period when plants could be washed away plant after planting. A 2˚C rise in minimum temperature will lead to a lowering of yields of around 800 to 1000 Kg/hectare in every seasonal rice crops in the study area. As a result, changing climate parameters in the central coastal belt area of Bangladesh could lead to lower yields in every rice season. Any lowering of yields due to climate change is important for the densely populated coastal belt area in Bangladesh as this could result in food insecurity for the region.