President Barack Obama announced Tuesday that he would permanently protect parts of the Arctic and Atlantic from offshore drilling. That includes 3.8 million acres in the north and mid-Atlantic Ocean.

“These actions…protect a sensitive and unique ecosystem that is unlike any other region on Earth,” he said in a statement.

Green groups welcomed the announcement and credited grassroots climate justice movements.

Jacqueline Savitz, senior vice president at Oceana, said the president

“has taken a key step in protecting important areas of the Atlantic Ocean from offshore drilling…The people of the Atlantic coast refused to allow their way of life to be compromised and we commend their hard work making their voices heard in Washington.”

Rachel Richardson, director of Environment America’s Stop Drilling program, also said, “This is a win for all who spoke out in support of putting our oceans off limits to oil extraction once and for all. President Obama just gave us an incredible victory in the fight to protect our oceans and climate from reckless offshore drilling and spilling.”

Earlier:

President Barack Obama is expected to announce as early as Tuesday that he will restrict offshore drilling indefinitely in parts of the Arctic and Atlantic, according to two officials familiar with the matter.

The president is reportedly planning to invoke a rarely-used provision in a 1953 law that lets him withdraw federal waters from future oil and gas leases. Although Obama issued an order earlier this year banning new lease sales in parts of the Arctic, Atlantic, and Pacific from 2017 to 2022, the upcoming move would protect certain portions of U.S. waters from oil exploration and production indefinitely.

Bloomberg reports:

Obama’s withdrawals would block the sale of new oil and gas leases in portions of the U.S. Atlantic and most of the Chukchi and Beaufort seas north of Alaska. They are not expected to affect drilling or production under existing leases, including 42 parcels that Royal Dutch Shell Plc, Hilcorp Energy Co., Eni Spa, Repsol Sa, and other companies own in the Beaufort, according to a government registry last updated in June.

The action also doesn’t affect waters under state jurisdiction, including part of the Beaufort Sea where a Texas company recently trumpeted a potential 6 billion barrel discovery.

“If the reports are right, then this is a gift to the public and to our kids that will rank with any in the history of American conservation,” Niel Lawrence, Alaska director of the Natural Resources Defense Council (NRDC), told Bloomberg.

Obama’s move reportedly comes in response to efforts by the climate activists who collectively operate the “keep it in the ground” movement to secure important environmental protections before President-elect Donald Trump takes office. Dozens of scientists in November also urged him to do the same.

Although it’s possible Trump would rescind the order, the provision does not have a process for reversal, meaning any effort to overturn it would likely involve a lengthy court battle.

“I see no evidence that Congress ever intended for these withdrawals to be reversible; courts should respect that,” Lawrence told Bloomberg.

While green groups welcomed the announcement, they cautioned that wide swaths of land and sea remain open to plunder—which is particularly worrying in light of the coming administration, which is stuffed to the brim with climate change deniers.

As 350.org executive director May Boeve said Tuesday,

“This is an important move, but we’re still looking forward to the day when all communities are protected from fossil fuel development. Everyone deserves the right to safe environment and the benefits of a clean energy economy. That includes those in the Gulf and other areas facing dangerous oil, gas, and coal expansion.”

“During the Obama presidency, the ‘keep it in the ground’ movement transformed our public conversation about fossil fuels and made announcements like today’s possible. Now, we must redouble our resistance to Trump and the industry’s drill-baby-drill agenda. Our climate and communities depend on it,” Boeve said.