Markandya and González-Eguino  have estimated the adaptation costs and residual adaptation costs accrued due to insufficient adaptation using integrated assessment models. Using the residual damages as a measure of loss and damage, the authors have estimated adaptation costs and residual costs under scenarios of high damages-low discount rate and low damages-high discount rate. The estimates suggested adaptation costs of 182 and 193 billion USD by 2050, and 737 and 783 billion USD by 2100 for South Asia and East Asia, respectively, under the scenario of high damages-low discount rate. The residual costs for the same scenario were 289 and 76% for 2050 and 238 and 62% for 2100 for South Asia and East Asia, respectively. Estimates for low damages-high discount rate were significantly lower adaptation costs and residual costs for both of these sub-regions of Asia.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report