Climate scientists already know that the East Coast of the United States could see around a foot of sea-level rise by 2050, which will be catastrophic on its own. But they are just beginning to thoroughly measure a “hidden vulnerability” that will make matters far worse: The coastline is also sinking. … The primary cause of dramatic land subsidence is over-extracting groundwater from it, which makes the terrain collapse like an empty water bottle. In San Jose, California, this has lowered the elevation by as much as 12 feet. The combination of sea-level rise and subsidence could inundate up to 165 square miles of Bay Area coastline by 2100, according to Shirzaei’s previous research.

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