President Obama invoked the 1953 Outer Continental Shelf Lands Act to "permanently" ban drilling along the Arctic and Atlantic seaboards. The sudden move ahead of Donald Trump's assumption of the role of President cannot be easily undone without Republicans amending the 1953 Act. While this Act does give the President the power to make decisions unilaterally, it has only ever been invoked for temporary matters and may not stand should it be challenged in court.
https://www.nytimes.com/2016/12/20/us/obama-drilling-ban-arctic-atlantic.html
