“Aloha, everyone,” he begins, before breaking into a laugh.
“Hand me those braids,” he says to a person offscreen, before holding up his snipped locks for the camera.
He continues: “Shaving off my hair. Doing it for -”, before breaking into a pained laugh at the close buzz, adding, “Oh, man. I’ve never even felt the wind there!”
The Game of Thrones star goes on to explain that raising awareness about the need to eradicate single-use plastic inspired his decision to cut his hair.
“I'm tired of these plastic bottles,” he says.
“We got to stop [using] plastic forks. All that s***. It goes into our land, into our ocean,” he continues.
“It's just so sad, so please: anything you can do to eliminate single-use plastic in your lives, help me,” he said.
The 43-year-old actor encouraged people to switch to aluminium bottles and canteens, rather than using plastic water bottles.
He captioned the clip: “Here’s to new beginnings. Let’s spread the aloha. Be better at protecting our land and oceans. We need to cut single-use plastics out of our lives and out of our seas. Plastic bottles, plastic bags, packaging, utensils – all of it. Let’s aloha our ‘Äina together. Aloha J.”
Momoa tagged the caption with the water company @mananalu, the aluminium water company he founded in 2019.
“I never thought I’d see the day,” wrote one follower. “Somehow he’s still smoking hot – the man’s got a gift.”
Another added that the Hawaiian native “could have a fundraiser for the ocean selling those braids lol”.
“Hair grows back and it’s for a great cause!” wrote another.
The dramatic change to his famous mane comes just weeks after the actor was spotted handing out bottles of his water to astonished passengers on a Hawaiian Airlines flight.
In a video shared to Instagram, the actor can be seen with a flower tucked behind his ear confirming that the airline is the first to partner with his water company.
He added that he also gave each passenger 10,000 airline miles.
According to Refill, the average UK household uses 480 plastic bottles a year, but only recycles 270 of themâ.
Elsewhere, a landmark survey by Greenpeace and Everyday Plastic published in July found that UK households throw away nearly 100 billion pieces of plastic each year.