Obama bans drilling in parts of the Atlantic and the Arctic

President Obama announced on Tuesday what he called a permanent ban on offshore oil and gas drilling along wide areas of the Arctic and the Atlantic Seaboard as he tried to nail down an environmental legacy that cannot quickly be reversed by Donald J. Trump.

Mr. Obama invoked an obscure provision of a 1953 law, the Outer Continental Shelf Lands Act, which he said gives him the authority to act unilaterally. While some presidents have used that law to temporarily protect smaller portions of federal waters, Mr. Obama’s declaration of a permanent drilling ban from Virginia to Maine on the Atlantic and along much of Alaska’s coast is breaking new ground. The 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 the University of Vermont. “There is no case law on this. It’s uncharted waters.”