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Sea-level rise may make some low-lying nations uninhabitable by the end of this century, if not before. If a country is under water, is it still a state? Does it still have a seat in the United Nations? What is the citizenship, if any, of its displaced people?

These questions take on increasing urgency as the world continues doing too little to avert catastrophic climate change. Many climate policy analyses agree the goal should be to keep global average temperatures within 1.5°C (2.7°F) above pre-industrial temperatures. That is the level that the small island states have demanded, as a matter of survival, at the annual United Nations climate conferences since the 15th Conference of the Parties in Copenhagen in 2009. However, the world appears to be on a path to between 2.6°C and 2.9°C by 2100. An increase of 2.5°C would likely lead to a rise of global mean sea level of fifty-eight centimeters — or about two feet — with an uncertainty range of between thirty-seven and ninety-three centimeters by 2100, with sea levels continuing to rise after that. In 2021, the Intergovernmental Panel on Climate Change warned that, under continued high greenhouse gas emissions levels, sea-level rise approaching two meters by 2100 and five meters by 2150 “cannot be ruled out due to deep uncertainty in ice-sheet processes.”


Environmental Law | Law


Sabin Center for Climate Change Law