migration was estimated to be optimal in terms of economic costs . Considering coastal migration as part of the solution space could lower global costs in investment and maintenance for SLR protection by a factor of 2-4 in the 21st century, but would result in large land losses and high levels of migration for South and Southeast Asia in particular, and in relative terms, small island nations would suffer most. The need to consider place attachment, community relationships, livelihoods and the spiritual and cultural significance of settlements limits the application of BCR as a tool for coastal adaptation decisions in these contexts . Moreover, there is limited knowledge on trade-offs, including BCR, of alternative adaptation options and pathways at a global to regional scale, in particular over the long term .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report