Climate change and risk scenario in Bangladesh

Bangladesh is vulnerable to climate change because of its geographical position. Many extreme weather events such as floods, cyclones, drought, salinity, hailstorms, river, coastal erosion, etc. affect the country almost every year. Although the whole country is affected by extreme weather events to different degrees, it is important to categorize the zones according to the intensity of impacts from climate-induced losses to delineate mitigation and adaptation strategies. To do this in this study, we employed the global climate risk index (CRI) with the available data at district levels collected by the Bangladesh Bureau of Statistics through a national-level survey to estimate the district-wise CRI of Bangladesh. Moreover, we employed a time series regression model with long-term data collected by the Bangladesh Meteorological Department to estimate the variability of climate parameters (such as temperature, rainfall, humidity). The yearly increment in maximum temperature during 1980–2000 was 0.031 °C and it increased by 0.022 °C per year during 2001–2020. The annual rainfall over the whole period increased by 223 mm. In general, the overall relative humidity increased by 1.16% between the two periods. There were also periodic changes in climate events along with monthly fluctuations in temperatures, rainfall and humidity patterns. Among the 64 districts of Bangladesh, 4 districts were categorized as severe risk (CRI: > 50), 10 as high risk (CRI: 36–50), and 12 as medium risk (CRI: 26–35) based on climate change impacts. The severe climate risk districts are Sunamganj, Bhola, Kurigram and Patuakhali, where there were losses of 520–720 million USD. In general, 41.71% of the people were affected by climate extremes, and 5.55% suffered from hazard-induced sickness and injury. As a consequence of climate change, flooding showed the greatest contribution to household damages and losses in Bangladesh. These findings can help in prioritizing region-specific mitigation and adaptation actions against the impacts of climate change in Bangladesh.