Microsoft has signed an agreement with Ebb Carbon to remove up to 350,000 tons of CO2 from the ocean over the next 10 years.
The ocean is the world’s largest carbon sink. It has absorbed around 30% of all CO2 emitted since the Industrial Revolution. But to sustain life, it must keep a pH of around 8.1. CO2 is acidic and is throwing off that balance.
Historically, this balance has been managed through a natural process that occurs over geologic timescales as alkalinity is produced through the slow weathering of rocks. These alkaline minerals flow into the ocean where they convert CO2 in seawater into bicarbonate and carbonate ions that securely store carbon for more than 10,000 years. The resulting CO2 deficit is quickly rebalanced as surface waters in the ocean draw down additional CO2 from the atmosphere. But the rapid acidification from increased CO2 makes it impossible to wait for this process.
Ebb is one of several companies working to pull the CO2 out of the ocean to help it continue to function as a carbon sink. Founded in 2020, Ebb works with aquaculture farms, desalination plants, ocean research labs, and other industrial sites that process seawater. The company said its Electrochemical Ocean Alkalinity Enhancement (OAE) process mimics the natural process, using bipolar electrodialysis (BPED) technology to separate seawater into acidic and alkaline streams. The alkaline stream is then returned to the ocean, where, like natural alkalization, it converts CO2 in seawater into bicarbonate ions and enables the ocean to absorb additional CO2 from the atmosphere.
The company said BPED is a low-energy consumption, mature and well-developed technology deployed at scale in industries such as winemaking and wastewater treatment. The agreement calls for Ebb Carbon to deliver an initial 1,333 tons of removals with options to purchase an additional 350,000 tonnes potentially available over 10 years.
“The ocean is a critical part of the carbon cycle,” said Brian Marrs, Senior Director of Energy & Carbon Removal at Microsoft. “Ebb has developed technology to leverage the natural attributes of the ocean – its massive surface area and natural ocean processes that already pull CO2 from the atmosphere – to durably remove and store large volumes of atmospheric carbon. We are pleased to collaborate with Ebb to both accelerate the scientific foundation for ocean-based carbon dioxide removal and explore the potential of ocean-based carbon removal solutions at scale.”
To measure, report, and verify CO2 removed with its technology, Ebb will utilize Isometric’s recently-announced OAE protocol which the company said will ensure that Ebb Carbon’s credit deliveries to Microsoft meet the highest standards of scientific rigor and transparency.
“Isometric’s protocol requires measurements and the use of internationally recognized ocean models to quantify carbon removal so buyers and suppliers can be sure one credit equals one tonne of carbon dioxide removed from the atmosphere,” Stacy Kauk, P.Eng., Chief Science Officer, Isometric. “This is another step towards creating trust and transparency in carbon markets.”
Removing marine carbon may be increasingly important as scientists say land-based carbon sinks have been absorbing less carbon over the recent years and the ocean’s carbon absorption is impacted by melting glaciers.
“This agreement underscores the potential of Ebb Carbon’s technology to contribute meaningfully to gigaton-scale carbon removal in the years ahead,” said Ben Tarbell, CEO of Ebb Carbon
Ebb raised a $22 million Series A last year and is operating a pilot facility in partnership with the Department of Energy’s (DOE) Pacific Northwest National Laboratory (PNNL) in Sequim, Washington. The company is also a semi finalist for DOE’s carbon removal purchase prize and a finalist for the XPrize.
