Projected migration. Regional variation is significant across Asia. By one estimate, in South Asia, internal climate migrants  are projected to be 40 million by 2050  under high warming . While methodological critiques remain on projected migration estimates, what is certain is that some countries will be more affected that others; it is estimated that in southern Bangladesh, SLR could displace 0.9-2.1 million people by direct inundation by 2050 . In South Asia, migration hotspots include the Gangetic Plain and the Delhi-Lahore corridor, and coastal cities such as Chennai, Chittagong, Dhaka and Mumbai, which will be simultaneously exposed to climate-change impacts, major migration destinations and amplified rural-urban migration . Importantly, there is low agreement on projected numbers  with uncertainties around how local policies and individual behaviours will shape migration choices. Even in high-risk places, people might choose to stay or be unable to move, resulting in 'trapped' populations . There is currently inadequate evidence to ascertain the nature and numbers of trapped populations currently or in the future.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report