How many people will be forced to migrate as a result of climate change? Figures range from tens of millions to hundreds of millions, but the multiple entanglements of climate change make it difficult to get accurate estimates. People may move because of drought, violence, degradation of local ecosystems, war or job loss. Poverty, adverse effects of globalisation and conflict may get worse with climate change, which is why it is often referred to as a threat multiplier.
Getting accurate sea level rise (SLR) projections has also always been difficult. Along with expansion of warm waters and melting of glaciers, subsidence of land also increases relative SLR. Models for glacier melt are not as well developed as other models that study global warming. SLR projections going beyond 2050 are therefore not as accurate as those until mid-century. There is broad agreement that if high emissions of greenhouse gases (GHGs) were to continue, average global SLR could be as high as two metres by the end of this century.
Most of the people found to be at risk from coastal events live in Asia residing in countries like China, Bangladesh, India, Vietnam, Indonesia, Thailand, the Philippines and Japan.
Very large fractions of coastal populations in these countries will be vulnerable. Other than Asia and the Netherlands, there are 20 countries (13 of which are small island nations) in which more than a tenth of their population are expected to reside below the high tide line by 2100, and this is with deep cuts to emissions. Coastal cities, such as Alexandria, Ho Chi Minh City, Basra and Shanghai are among the most vulnerable and large portions of Mumbai and Kolkata will be fully submerged by 2050.
2019, THG PUBLISHING PVT LTD.