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STORY: These volunteers aren't simply out for a stroll along this popular beach in Japan's Yokohama.

They’re hoping to fight climate change with these clumps of eelgrass

wrapping them in clay, and planting them among the waves.

The group wants to try and help restore Japan’s ecosystem

and in turn help achieve Japan’s goal of going carbon-neutral by 2050.

But will efforts like these be enough?

(This Earth)

Hideaki Kanke, brings people together for days of planting the eelgrass, a variety of the seagrasses that grow in shallow coastal waters.

(Hideaki Kanke, Organizer)

"Dig a hole, put it all the way in, then cover it over with some sand. You did it."

Kanke says the shallow waters around Tokyo Bay were once filled with beds of eelgrass.

However, as the area developed and greater Tokyo grew, the plants died off.

Japan's recent Greenhouse Gas Inventory, submitted to the UN’s climate change effort this month,

factors in carbon absorbed by seagrass and seaweed beds for the first time.

However in 2022, Japan's Ministry of the Environment found that

the amount of so-called ‘blue carbon’ stored by the country’s coastal ecosystems

was only about .03 percent of what it emits every year.

Marine scientist Keita Furukawa says seagrasses could change that.

(Keita Furukawa, Assoc. for Shore Environment, Creation Marine Scientist)

"If eelgrass were to grow in every shallow area of the sea it's possible for it to grow, I think it could absorb perhaps 10 or 20 percent of human emissions. As things currently stand, it can take in maybe a few percent at most so it's not going to have a swift impact as a measure against global warming."

But Gregory Nishihara, a marine algal ecology professor at Nagasaki University says relying on the plants alone for carbon capture is impractical.

(Gregory Nishihara, Professor of Marine Algal Ecology, Nagasaki University)

"So I did some calculations and I think, if my calculations are correct, if we wanted to capture all those emissions just using seaweeds we need to use 10 percent of Japan's EEZ (Maritime Exclusive Economic Zone), so that's like 433 million hectares. I don't know how big that is but I'm pretty sure that's huge, so, that's a lot of space."

According to the Environment Ministry data, Japan's seagrass and seaweed beds have shrunk,

making the task of reforesting the sea floor even more challenging.

They are now only estimated to cover less than 200,000 hectares, or around half a million acres,

down from a little over 850,000 acres over the course of three decades.