At one time there were more people per square foot in the Netherlands than in India. The complaint back then was over population. And at the time, the Netherlands had the highest standard of living in the world. They gave all the credit to practically free electricity, all hydro.The Dutch have dealt with land at or below sea level for centuries. They learned to cope. Other places will too. It is far cheaper than trying to change the climate, which we may well lack any ability to influence.
Pro tip: in the future do not build in areas that could be flooded.