President Barack Obama on Tuesday moved to indefinitely block drilling in vast swaths of U.S. waters.
The president had been expected to take the action by invoking a provision in a 1953 law that governs offshore leases, as CNBC previously reported.
The law allows a president to withdraw any currently unleased lands in the Outer Continental Shelf from future lease sales. There is no provision in the law that allows the executive's successor to repeal the decision, so President-elect Donald Trump would not be able to easily brush aside the action.
Trump has vowed to open more federal land to oil and natural gas production in a bid to boost U.S. output. Obama on Tuesday said he would designate "the bulk of our Arctic water and certain areas in the Atlantic Ocean as indefinitely off limits to future oil and gas leasing," though the prospects for drilling in the affected areas in the near future were already questionable.
U.S. Outer Continental Shelf
The lands covered include the bulk of the Beaufort and Chukchi seas in the Arctic and 31 underwater canyons in the Atlantic. The United States and Canada also announced they will identify sustainable shipping lanes through their connected Arctic waters.
Canada on Tuesday also imposed a five-year ban on all oil and gas drilling licensing in the Canadian Arctic. The moratorium will be reviewed every five years.
"These actions, and Canada's parallel actions, protect a sensitive and unique ecosystem that is unlike any other region on earth," Obama said in a statement.
"They reflect the scientific assessment that, even with the high safety standards that both our countries have put in place, the risks of an oil spill in this region are significant and our ability to clean up from a spill in the region's harsh conditions is limited."
The action potentially tees up a battle that touches on hot-button issues: environmental protection, energy independence, climate change, and the scope of executive power.