Global Warming and Sea Level Rising: Impact on Agriculture and Food Security in Southern Coastal Region of Bangladesh

Abstract

Climatologically, the entire southern coastal belt of Bangladesh is most vulnerable than the other parts of the country due to its spatial geo-morphological settings. Global warming and sea level rise are already observed and predicted to be occurred more with time. These bring real negative consequences on the agricultural production and food security, and livelihood for the people live in the coastal areas. Therefore, the study was conducted to analyze the effect of global warming and sea level rise on the agriculture and food security in southern coastal areas of Bangladesh. Both primary and secondary sources of information were collected. Stakeholder consultation, direct field visits and interview of climate affected people in the coastal region were carried out for collecting information on land-use and cropping patterns and adaptation measures to be taken to boost crop production against global warming and sea level rise. By the middle and end of the twenty first century, global annual mean temperature is predicted to be increased about 1.5oC and 2.5oC, respectively. These projected warming will lead to about 14, 32 and 88 cm sea level rise by 2030, 2050 and 2100, respectively which would cause inundation of about 8, 10 and 16 percent of total land masses in Bangladesh. Most of the coastal parts and associated islands of Khulna and Barisal divisions and western part of Chattagram division lie within one meter from sea level where incursion of saline water is common. It is predicted that these areas will be inundated and unsuitable for crop production due to upcoming sea level rise. The predominant crop in entire coastal belt is transplanted Aman with sporadic occurrences of Aus rice. The land in Boro rice season either loosely occupied by mungbean, grass pea, cowpea, groundnut, soybean, potato, sweet potato, chili etc or remained fallow until the following monsoon. A systemic analysis of all of the cyclones that originated from the Bay of Bengal since 1961 indicated that most devastating cyclones formation occurred from last quarter of April through May and from middle of October to November just prior to the harvest of Boro and Aman crops, respectively. Therefore, Boro and Aman rice harvests are mostly unpredictable every year posing great threat to the food security of the coastal people. These areas are criss-crossed by innumerable water canals or channels especially in Barisal and Khulna divisions which can be utilized for Boro rice cultivation in dry season despite some levels of salinity. Cultivation of salt-tolerant crop varieties could mitigate such hindrances. Introduction of saline tolerant Boro rice in coastal cropping patterns and/or advancing the harvesting times by a fortnight in both Aman and Boro rice seasons to avert cyclonic havoc not only ensure food security but also turn the entire coastal belt into a food surplus region.