Microsoft bets on algae to mitigate its growing carbon footprint

Like all of its peers in the tech industry, Microsoft has a carbon pollution problem.

The software giant’s emissions are on the rise, in spite of a pledge from the company to be carbon negative by 2030. This ticking clock explains Microsoft’s latest deal to address its environmental toll: It’s turning to Running Tide to offset some of its emissions via the ocean.

Running Tide, which also works with Stripe and Shopify, aims to use this money to lock away massive quantities of carbon dioxide. Running Tide has said it will do this through efforts such as growing a whole lot of kelp on biodegradable buoys, intending for the algae to eventually sink to the ocean floor. The startup has a white paper on its work, but if you’re looking for just a tad more detail, here is what business development head Jordan Breighner told TechCrunch today:

“We combine wood and alkaline minerals to form a small carbon buoy that we can seed with algae seed and deploy deep into the open ocean,” said Breighner. “The buoy floats, the alkaline minerals dissolve, reducing ocean acidification and removing carbon through a process called ocean alkalinity enhancement. The algae grows rapidly, absorbing CO₂. After less than three months the buoy and the algae and the embodied fast carbon sink to the bottom of the ocean, and if they sink below 1,000 meters the carbon is gone for roughly 1,000 years.”

“However, not all buoys are seeded,” Breighner added. “That is based on ocean conditions that are optimal for algae growth.”

On the whole, the carbon removal business is still early in its development. It has not yet proved it can lastingly draw down carbon at the scale it eventually aspires to reach. Some scientists also worry that fully developed, venture-backed sequestration schemes, such as gigantic kelp farms, could unintentionally harm ocean ecosystems, MIT Technology Review reported last year. 

So far, Breighner said that Running Tide has “only removed less than 1,000 tons of carbon in test and research deployments.” The startup intends to remove up to 12,000 tons over two years for Microsoft alone.

The deal is valued in the single-digit millions, Running Tide said. A Microsoft spokesperson declined to comment on the price.

Microsoft’s most recent sustainability report showed a 21.5% increase in emissions from 2020 to 2021. The software giant attributed this to scope 3 emissions, which it said were linked to data center development and more customers using its products more often. In other words, Microsoft grew its cloud and gaming businesses, and its net emissions rose in tandem. The company aims to be carbon negative in the next seven or so years, and its plan to get there hinges on carbon removal.