Invoking a rarely used provision in federal law, the
The ban relies on the Outer Continental Shelf Lands Act of 1953, which says the president "may, from time to time, withdraw" federal waters from oil and gas development that are not already leased. It was announced as part of a joint action with Canada, where Prime Minister Justin Trudeau also made long-term, though not permanent, commitments to protect the Arctic from drilling.
Obama cited the Arctic's "unique ecosystem," the risk of damage from a spill, the high cost of working in the remote and frigid region and concerns about climate change.
"It would take decades to fully develop the production infrastructure necessary for any large-scale oil and gas leasing production in the region – at a time when we need to continue to move decisively away from fossil fuels," the president said in a written statement.
The announcement, coming one month to the day before Obama is to be succeeded by President-elect
Trump made clear his intentions for robust new drilling during the campaign, and his appointment to key cabinet posts of longtime loyalists to the oil industry has alarmed environmentalists. Major conservation groups had been pushing Obama in recent weeks to put the offshore areas off limits in perpetuity.
Past presidents, including Dwight D. Eisenhower, have invoked the law to issue temporary bans. Obama's action appears to be the first time the law has been used to impose a permanent drilling ban – and it is almost certain to be challenged.
A senior administration official said Tuesday that the White House was "quite confident" that the decision could not be undone by Trump, noting that the law specifies no provision for reversal. The official suggested that overturning the ban could require years of legal action and the passage of a bill in Congress.
Some oil industry leaders said they believed the next administration could easily reverse it. They cited a 2008 memorandum by President George W. Bush that lifted a temporary ban in certain offshore areas imposed by President Clinton.
"Fortunately, there is no such thing as a permanent ban, and we look forward to working with the new administration on fulfilling the will of American voters on energy production," wrote Erik Milito of the American Petroleum Institute.
Yet environmental groups say the 2008 reversal left intact other permanent changes Clinton made.
Under the 1953 law, a presidential order that explicitly states that it is intended to be permanent, and is designed to address an "articulated purpose," would likely stand up to legal challenges, lawyers for two conservation groups, Earthjustice and the Natural Resources Defense Council, wrote in a legal brief on the issue last month.
The Trump transition team did not immediately respond to a request for comment.
How much the decision might change the situation in the Arctic is unclear. Only one company,
Last year, after spending more more than seven years and $7 billion preparing, Shell abandoned its plan after a single summer of drilling, citing disappointing results.
On Tuesday, an administration official estimated it could take decades — and a doubling or tripling of the price of oil — to make drilling in the Arctic appealing to many companies.
The administration emphasized that oil and gas exploration have thrived in other parts of the country at far less expense. While the Arctic is believed to hold vast reserves, it currently provides 0.1% of the nation's crude oil production. None of the companies that hold the 42 active leases in the Arctic's Beaufort Sea is currently pursuing drilling.
Still, with Trump promising to unleash a wave of fossil fuel development, the announcement is another example of Obama moving to shield his legacy of environmental protection. If and how Trump might undo various policies have been constant questions. Some rules are fairly easily reversible; others could require years of regulatory processes to change.
Trump has suggested he could walk away from the landmark agreement on global warming Obama signed with other countries in Paris last year, as well as scrap the Obama administration's signature effort to curb greenhouse gas emissions from U.S. power plants.
Trump has promised to champion coal power, eliminate subsidies for green energy programs and broadly relax federal environmental regulations. His pick to head the Environmental Protection Agency, Oklahoma Attorney General Scott Pruitt, is a climate change skeptic who has led state efforts to resist the agency's authority. His choice for Energy Secretary, former Texas Gov. Rick Perry, has also expressed doubts about human-caused climate change and is a close ally of the oil industry.
Canada's role in the announcement on Tuesday follows a commitment Obama and Trudeau made in March to collaborate on Arctic issues as declining sea ice from climate change is stirring new interest and posing new risks in the region. While Canada also banned drilling in its Arctic region, its ban would be reviewed after five years.
The nations also pledged to work together to define "low-impact shipping corridors" to protect the Arctic's endangered whales and other species as well as the subsistence hunting and fishing practices of indigenous people.
The announcement includes a ban on drilling in large parts of the Atlantic, from New England to the Chesapeake Bay, where the U.S. administration is seeking to protect underwater canyons, some deeper than the Grand Canyon. Many are what scientists call biodiversity "hot spots," providing homes to corals, beaked whales, fish, sponges and crabs. Officials say preserving the canyons will ensure better health for commercial fish populations.
But the big news was in the Arctic, long a stage for conservation battles. While 3.8 million acres are being protected in the Atlantic, 115 million are set aside in the Arctic. The ban there includes all of the Chukchi Sea and the vast majority of the Beaufort off the coast of Alaska, leaving out a portion near state waters and the onshore drilling fields of the North Slope. That area, the administration noted, includes known oil reserves, and its proximity to existing infrastructure and spill-response equipment somewhat reduces risks of serious damage from a drilling mishap.
That area already had not been designated for leasing in the federal government's upcoming five-year program for the Outer Continental Shelf, which begins in 2017. Just last month, the administration said it would not sell new leases for drilling in the Arctic and Atlantic through 2022. That announcement also blocked expansion in the Pacific, leaving the Gulf of Mexico as the primary offshore production area.
While many lawmakers on the East Coast supported Tuesday's decision, Alaska's three-member congressional delegation sharply criticized it and other moves by the administration that have restricted oil development in that state, including previously announced protections for a wide swath of western Alaska and Bristol Bay, home to one of the world's largest runs of wild salmon.
The vast majority of Alaska's budget is funded through revenue from oil production, which has been in steady decline as production on the North Slope and the price of oil have declined. Many Alaskans view offshore drilling as a potential economic lifeline — and lawmakers said Tuesday's decision would leave them with even fewer options.
"President Obama has once again treated the Arctic like a snow globe, ignoring the desires of the people who live, work, and raise a family there," said Sen. Lisa Murkowski, chairwoman of the Senate Committee on Energy and Natural Resources. "I cannot wait to work with the next administration to reverse this decision."
Halper reported from Washington and Yardley from Seattle.
7:55 p.m.: Updated with additional background on Obama's decision and the government's leasing program.