Abstract
Bangladesh stands out as a climate change hot spot due to its unique geography, climate, high population density, and limited adaptation capacity. Mounting evidence suggests that the country is already suffering from the effects of climate change which may get worse without aggressive action. Here, we use an ensemble of high-resolution (10 km) regional climate model simulations to project near-term change in climate extremes, mainly heat waves and intense rainfall, for the period (2021–2050). Near-term climate projections represent a valuable input for designing sound adaptation policies. Our climate projections suggest that heatwaves will become more frequent and severe in Bangladesh under the business-as-usual scenario (RCP8.5). In particular, extremes of wet-bulb temperature (a temperature and humidity metric important in evaluating humid heat stress) in the western part of Bangladesh including Bogra, Ishurdi, and Jessore are likely to exceed the extreme danger threshold (according to U.S. National Weather Service criterion), which has rarely been observed in the current climate. The return periods of extreme heat waves are also significantly shortened across the country. In addition, country-averaged rainfall is projected to increase by about 6% during the summer months, with the largest increases (above 10%) in the eastern mountainous areas, such as Sylhet and Chittagong. Meanwhile, insignificant changes in extreme rainfall are simulated. Our results suggest that Bangladesh is particularly susceptible to climate extremes in the near future, in the form of extreme heat waves over the western part of the country.
Highlights
Scientific evidence has shown that rising anthropogenic greenhouse gas (GHG) concentrations due to human activity are unequivocally accelerating global warming (IPCC 2013)
We investigate the changes in extreme heat stress and rainfall in response to the business-as-usual near-term climate change scenario based on ensemble of projections using the high-resolution (10 km) MIT Regional Climate Model (MRCM), allowing a more detailed representation of topography, coastlines, physical processes, and extreme climatic events
We assume that the MRCM has sufficient skill for use in this study to project climate change over Bangladesh based on comparison with temperature and rainfall observations (Figs. 2 and 3)
Summary
Scientific evidence has shown that rising anthropogenic greenhouse gas (GHG) concentrations due to human activity are unequivocally accelerating global warming (IPCC 2013). Based on future climate projections using General Circulation Models (GCMs), southwest Asian countries are likely to be exposed to deadly weather extremes including heat waves and extreme heavy rainfall in the future (OECD 2003; May 2004; Sillmann et al 2013; Kirtman et al 2013; Coffel et al 2018). In our earlier study by Im et al (2017a), we projected changes in wet-bulb temperature over south Asia towards the end of the century using a regional climate model at 25-km resolution. We investigate the changes in extreme heat stress and rainfall in response to the business-as-usual near-term climate change scenario based on ensemble of projections using the high-resolution (10 km) MIT Regional Climate Model (MRCM), allowing a more detailed representation of topography, coastlines, physical processes, and extreme climatic events
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
