This startup is helping the ocean absorb more harmful carbon emissions

Removing carbon from the atmosphere is a growing field of business in the fight against global warming, but it’s not just big air vacuums doing the work. New technology is targeting an even bigger potential resource: the ocean. 

The ocean, often likened to the lungs of the planet, is the world’s largest natural carbon sink. It generates half of all the oxygen we need and absorbs a quarter of all carbon dioxide we don’t. A buffer against the effects of climate change, it has also fallen victim to it, as excess heat and carbon dioxide make it more acidic and less able to do its job.

Now, companies such as Equatic, Captura, Running Tide and a startup called Ebb Carbon are using new technology to restore ocean chemistry and speed up its natural abilities.

“We’re restoring the balance in the ocean chemistry and enabling the ocean to absorb CO2 and convert it to a safe stable form,” said Ben Tarbell, co-founder and CEO of Ebb Carbon. Tarbell said he anticipates the company will remove upward of a million tons of CO2 per year in the coming five years, simply by improving the ocean’s own natural capabilities.

Here’s how it works: Ebb sets up its modules near ocean water — this first one by Sequim Bay in Washington state. The seawater flows through the Ebb system, which uses an electrochemical process to remove acid. Free of acid, it is returned to the ocean much better able to absorb CO2 again and store it as bicarbonate naturally.

“We can install our modules anywhere, and, as we scale, we’ll be installing systems at existing industrial facilities on the coast that process ocean water,” Tarbell added.

That potentially lowers costs substantially. Ebb is selling its carbon removal service to companies such as Stripe, which are looking for offsets to meet their net-zero goals. The potential for such sales makes it attractive to investors such as Prelude Ventures.

“Right now, there are very large voluntary carbon markets, large corporations willing to pay to remove carbon from the atmosphere to offset emissions in other parts of their business. Those markets alone are a multibillion-dollar market opportunity,” said Gabriel Kra, managing director at Prelude Ventures.

Right now, Tarbell says his technology costs over $100 per ton of CO2 removed, but as it scales to more locations, he says he expects that cost to drop significantly.

“Because we’re coupling our systems with existing infrastructure, like desalination plants and coastal power plants, we can leverage the cost of that existing infrastructure to enable benefits for them while also reducing our costs,” Tarbell said.

In addition to Prelude, Ebb Carbon is backed by Evok Innovations, Congruent Ventures and Propeller. The company says it has raised $27.75 million to date.

CNBC producer Lisa Rizzolo contributed to this piece.