In the race to stall or even reverse global warming, new efforts are in the works to pull carbon dioxide out of the air and put it somewhere safe.
One startup in Maine has a vision that is drawing attention from scientists and venture capitalists alike: to bury massive amounts of seaweed at the bottom of the ocean, where it will lock away carbon for thousands of years.
The company is called Running Tide Technologies, and it's prototyping the concept this winter. On a recent day in the Gulf of Maine, boat captain Rob Odlin says the task itself isn't much different from any other in his seafaring career, whether chasing tuna or harvesting lobster.
"We're just fishing for carbon now, and kelp's the net," he says.
Running Tide CEO Marty Odlin — the boat captain's nephew — comes from a long line of Maine fishermen, and once imagined he would continue the tradition. But he watched as the warming climate drove major shifts in fish populations, while regulators put a lid on how much could be taken from the sea.
"It just got really hard for me to go into crazy debt to buy a boat to catch fish that were swimming away," Odlin says.
The Dartmouth-trained engineer did start an oyster farm. But he also started thinking about how to stop the damage in the Gulf of Maine, one of the fastest warming bodies of water on the planet.
"Essentially what we have to do is run the oil industry in reverse," he concluded.
As Odlin notes, the fossil fuels we burn for energy started out as plants millions of years ago. Much of it was ocean algae that sank to the bottom of ancient seas, where chemistry and water pressure transformed it into oil, over geologic timescales.
Odlin wants to mimic those natural processes, and do it in a hurry. He envisions an armada heading hundreds of miles offshore each fall, to deploy millions of free-floating cellulose buoys, each tethered to a kelp-bearing rope.
The kelp will soak up carbon — gigatons of it — via photosynthesis. Months later the mature plant blades will grow too heavy for their biodegradable buoys.
"So the kelp will sink to the ocean bottom in the sediment, and become, essentially, part of the ocean floor," Odlin says. The ultimate goal is that it will stay there, sequestrated for millions of years, turning back into oil.
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.
Low-tech elegance
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 which 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."
At a large scale, though, 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.
"We have to compare them against the no-action alternative," he says. "And in this case, the no-action alternative is very grim."
Running Tide's Marty Odlin says it will take a World-War II level mobilization to remove a major chunk of some 200 years' worth of humanity's CO2 pollution, whether via his model or any others that show real-world promise.
"We're kind of in a cage-match with it right now," he says. "I'm not in this to give Godzilla a paper-cut."
For now, from his uncle's re-purposed lobster boat off Maine's coast, the Running Tide team is tending the buoys, making sure they survive the winter storms. They'll return in the spring to sink this test-crop of carbon-removing kelp a thousand meters deep, hopefully to stay there for millennia.
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