This book discusses the economic costs and benefits of unilateral and regional actions on climate change adaptation in ADB’s six South Asia DMCs, namely Bangladesh, Bhutan, India, the Maldives, Nepal, and Sri Lanka. It provides an estimate of the total economic loss throughout the 21st century to the South Asia DMCs. The study takes into account the different scenarios and impacts projected across vulnerable sectors and estimates the magnitude of funding required for adaptation measures to avert such potential losses.