Carpenter’s suit reflects a legal and political dilemma that’s beginning to reverberate around the country: As seas rise and coasts wash away, who owns the land that goes underwater? Versions of that debate are taking place in courtrooms, legislatures, and government offices, raising the question of whether and when climate change justifies seizing private property. The stakes are enormous, affecting not just ownership of offshore mineral and fishing rights but also potentially trillions of dollars of coastal real estate.

A decade after the global financial crisis popularized the term “underwater real estate,” parts of the U.S. are grappling with a new, more literal version of that problem.

“There’s no question it will be a huge fight,” says Holly Doremus, a law professor at the University of California at Berkeley who specializes in environmental law. “We don’t exactly know the boundaries of what the state can do.” For centuries, a body of law called the public trust doctrine has stipulated that, when it comes to coastal property, anything below the average high-tide line is owned by the government for the use and benefit of the public. Those rules also cover what happens when the high-tide line moves. If that movement happens suddenly—for example, if a portion of beach is washed away by a storm—the land owner retains title to the property provided he or she restores it to dry land.

Source: The Fighting Has Begun Over Who Owns Land Drowned by Climate Change