On Tuesday, President Obama announced a groundbreaking ban on offshore oil and gas drilling. In doing so, the U.S. President invoked an obscure 1953 law to unilaterally declare a permanent ban on offshore drilling from Virginia to Maine and along much of Alaska’s coast. As Coral Davenport reports for The New York Times, the unusual declaration’s fate will almost certainly be decided by the federal courts.

“It’s never been done before,” said Patrick Parenteau, a professor of environmental law at Vermont Law School. “There is no case law on this. It’s uncharted waters.”

As Davenport reports, “Tuesday’s announcement would ban drilling in about 98 percent of federally owned Arctic waters, or about 115 million acres, a pristine region home to endangered species including polar bears and bowhead whales. It would also block drilling off the Atlantic Coast around a series of coral canyons in 3.8 million acres stretching from Norfolk, Va., to the Canadian border.”