Image: Bjørn Christian Tørrissen

A start-up company in Maine is testing the feasibility of combatting climate change by growing kelp to capture carbon dioxide. Once the kelp is mature, it will sink to the bottom becoming part of the sediment and trapping the carbon for millions of years. The company, Running Tide Technologies is prototyping the concept this winter.

One often hears the recommendation to plant more trees to help reduce climate change. Saltwater plants like mangroves and seagrasses are estimated to take up 20 times more CO2 per acre from the atmosphere than land-based forests. Kelp could potentially capture far more.

Running Tide’s larger goal is to remove 40 gigatons of CO2 in the next decade. As noted by NPR, this year’s goal is more modest: an on-the-water experiment, floating about 1600 single-buoy “micro-farms” to gather data and prove the concept. 

The company is part of a new wave of big-thinking about removing carbon from the atmosphere at a planetary-scale.

Microsoft last year committed a billion dollars to kick-start research and development in the emerging field of carbon-removal tech. It also promised to find ways to remove all the CO2 its operations have put in the air since it was founded.

High-tech carbon-removal innovations are emerging around the world. Towering banks of fans that can pull CO2 from the sky. Pumps injecting plant-based biofuels into the earth. But Running Tide seems to be capturing attention — and investment — because of its low-tech elegance.

“When we started learning about Running Tide’s approach, I was blown away by the simplicity,” says Stacy Kauk, who directs sustainability efforts at Shopify, a $150-billion e-commerce company that will be Running Tide’s first customer for carbon-capture credits.

She says Shopify is willing to pay a premium for the credits now, in hopes the technology can ultimately be brought to a price-point that would attract broad buy-in from other businesses and governments.

“They’re not relying on expensive equipment or energy-intensive processes,” she says. “It’s very simple, and the economies of scale associated with that make Running Tide’s solution have huge potential.”

On a large scale, Running Tide is mindful there could be unwanted consequences. It’s modeling whether, for instance, a multitude of free-floating micro-farms could entangle whales, hinder shipping, or foul beaches.

Outside experts are pitching in: A consortium of oceanographers from MIT, Stanford and other top research outfits will review the project and its environmental risks. But executive director Brad Ack says all that will be weighed in the context of the urgency of combating climate change.