President Donald Trump offered a definitively low-tech and maddening solution to rising sea levels amid global warming: Get your mops and buckets ready!

He came up with the snide, unhelpful suggestion in a tweet as he criticized ongoing discussions about the possibility of constructing a sea wall to protect New York City, where low-lying areas have already experienced increased flooding from the encroaching ocean. The president called it an environmentally unfriendly idea that will look terrible.

The proposal by the Army Corps of Engineers for New York would create a six-mile-long barrier of man-made islands with retractable gates . The cost would not be $200 billion, as Trump falsely claimed, but $119 billion, and it would be constructed over 25 years. A finalized proposal isnt expected to be presented to Congress until at least 2022. Some experts fear the massive proposal is already too little too late.

Critics were absolutely gobsmacked by Trumps mocking comeback particularly because the president has his own environmentally unfriendly wall that looks terrible. The environmentally unfriendly president has also won approval to construct two sea walls at his Doonbeg golf resort in Ireland to keep the ocean at bay amid climate change, which Trump has called a hoax, but now says is serious.

CORRECTION: A previous version of this article misidentified the presidents resort as Turnberry, which is his resort in Scotland.