SeaCURE and the New Wave of Ocean Carbon Removal

A Pilot Project with Big Potential

On the south coast of England, something quietly powerful is happening. A small pilot project named SeaCURE is pulling carbon straight out of the ocean—and sending it back to sea, ready to absorb even more. It sounds like science fiction, but it could be part of our real solution to climate change.

Backed by £3 million from the UK Government, SeaCURE is one of 15 projects exploring carbon removal tech. Unlike air capture, this one taps into the ocean's natural ability to soak up CO2—and could eventually help cut global emissions in a big way.

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Why the Ocean?

Turns out, seawater has higher CO2 concentrations than air. The SeaCURE team is leaning into that. Their pilot plant, located in Weymouth, tests how well ocean water can be processed to extract carbon at scale.

Some early concerns popped up around marine life, since dissolved carbon is essential for many ocean species. But the team is working on mitigation, like pre-dilution and alkalinity balancing, to reduce risks.

The ocean is already doing a lot of the heavy lifting. Each year, it absorbs billions of tons of CO2 from the atmosphere. SeaCURE just wants to help it do more—without harming what lives in it.

How the Technology Works

The process is surprisingly low-tech in theory, though the science is solid. Here's how it goes:

1. Seawater is pulled to shore

Water from the ocean surface is piped to a processing facility. This happens near the coast, minimizing energy use.

2. Acidity is raised to release CO2

By adjusting the water's pH, naturally dissolved carbon is released in the form of gas—just like bubbles in soda.

3. CO2 is collected and filtered

That gas is pulled out and passed through charred coconut husks, a natural filter that concentrates it into a usable CO2 stream.

4. Water is treated and returned

The treated seawater gets an alkali boost to restore its balance before heading back out to sea. There, it absorbs even more CO2 naturally.

It’s a closed loop. And it's powered by floating solar panels, making the whole process even cleaner.

Tiny Pilot, Huge Possibilities

Right now, SeaCURE removes about 100 metric tons of CO2 per year—about the same as 100 transatlantic flights. That’s tiny. But the team sees serious scale in their future.

Their pitch to the UK government? If they could treat just 1% of the ocean's surface water, they might remove up to 14 billion tons of CO2 annually. That’s a number that could actually change the game.

That scale would make SeaCURE one of the most promising carbon removal pathways available, especially for hard-to-decarbonize industries like shipping and steel.

A Race with Time

Dr. Jennifer Johnson, a marine biogeochemist at the University of Southampton, said in a 2024 climate forum: "Ocean-based carbon removal has the potential to buy us time while we transition to cleaner technologies. The key is making sure it's done safely and responsibly."

SeaCURE’s team seems to agree. They’re careful not to overstate results while remaining hopeful. Their focus is on proving the science works—and that scaling up won't hurt the planet more than it helps.

As they test and tweak, they’re also building public trust. No one wants to see a repeat of failed geoengineering experiments. That’s why SeaCURE's approach feels different: it’s slower, more transparent, and based on the ocean’s own rhythm.

Not Just a UK Effort

Globally, ocean-based carbon removal is gaining traction. The Carbon to Sea Initiative and similar programs are exploring the same idea. They’re looking at how ocean alkalinity enhancement and electrochemical methods might help reduce CO2 on a larger scale.

There’s competition, of course, from more headline-friendly technologies like direct air capture plants. But for many scientists, the sea still holds the most promise.

David King, former UK Government Chief Scientific Adviser, once said: "The oceans are the lungs of our planet. Any solution that works with them rather than against them is worth exploring."

The Bottom Line

SeaCURE might not be flashy. But it’s a quiet contender in the carbon removal race—using simple chemistry, floating solar power, and the sea’s natural rhythm to chip away at a massive problem.

The goal isn’t just removal. It’s safe, scalable, and sustainable removal.

And if they can prove that even a fraction of the ocean can help us breathe easier? Then this little pilot in Weymouth might be one of the biggest climate moves we’ve seen yet.

To learn more about SeaCURE, visit seacure.org.uk.