Cyclones in a changing climate: the case of Bangladesh

This paper integrates information on climate-change, hydrodynamic models, and geographic overlays to assess the vulnerability of coastal areas in Bangladesh to larger storm surges and sea-level rise (SLR) by 2050. The approach identifies polders, coastal populations, settlements, infrastructure, and economic activity at risk of inundation, and estimates the damage from storm surge inundation versus the cost of several adaptation measures. A 27-centimetre SLR and 10% intensification of wind speed resulting from global warming suggest that the vulnerable zone increases in size by 69% given a +3-metre inundation depth, and by 14% given a +1-metre inundation depth. Estimates indicate investments including strengthening polders, foreshore afforestation, additional multi-purpose cyclone shelters, cyclone-resistant private housing, and further strengthening of the early warning and evacuation system would cost more than $2.4 billion, with an annual recurrent cost of more than $50 million. These estimates can serve as a prototype in climate negotiations of the adaptation costs of extreme weather events.