The fight against climate change has long focused on scaling back humanity’s emissions of planet-warming carbon-dioxide. But a movement is growing to think bigger and find ways to actually pull existing CO2 out of the air and lock it up somewhere safe.
One Maine startup has an innovative approach that’s drawing attention from scientists and investors: grow massive amounts of seaweed and then bury it at the bottom of the deepest sea, where it will sequester carbon for thousands of years.
On a fishing boat a few miles out in the Gulf of Maine, Capt. Rob Odlin and Adam Rich are tossing buoys into the water. Each is tethered to a rope entwined with tiny seeds of kelp, a fast-growing seaweed.
“We’re just fishing for carbon now, and kelp’s the net,” Odlin says.
The project is experimental R&D for a company called Running Tide Technologies, based on the Portland waterfront.
Marty Odlin, the boat captain’s nephew and the CEO of Running Tide, explains the company’s mission.
“Essentially what we have to do is run the oil industry in reverse,” he says.
Odlin wants to mimic the natural processes that turned ancient plants into carbon-storing fossil fuels — and do it in a hurry. He sees individual kelp microfarms floating hundreds of miles offshore, over the deepest parts of the world’s oceans.
The kelp soaks up carbon, via photosynthesis, and grows. After about seven months, the mature blades get too heavy for their biodegradable buoys, and sink.
“The kelp will sink to the ocean bottom in the sediment, and become, essentially, part of the ocean floor,” Odlin says. “That gets you millions of years of sequestration. So that’s when you’re making oil. That’s got to be the ultimate goal.”
This year’s goal is more modest: just 1,600 buoys deployed to demonstrate that in principle, the system could safely and economically be expanded to a global scale: millions of microfarms floating in the open sea, moving billions of tons of carbon from sky to ocean floor every year.
“On geologic time scales it can remove 400 gigatons, 800 gigatons of carbon from the atmosphere. That will happen. So what we’re trying to do is just give it a nudge, and accelerate it,” Odlin says.
With climate change’s effects accelerating, deep-pocketed corporations are setting aggressive goals to offset their emissions. Some, like Microsoft, are pledging to go carbon negative, pulling more CO2 from the air than the company’s operations have emitted since its founding.
Last year Microsoft pledged $1 billion to the effort, and some of that money will be used to purchase carbon offset credits generated by large sequestration projects. High-tech 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.
Venture capital funds have already invested millions in Running Tide. But Shopify will be the first to buy carbon-offset credits from the company as part of its corporate commitment to address climate change.
Kauk says the approach holds unique promise for rapid, even exponential growth, and at a price that businesses and governments that aim to “decarbonize” their economies could afford, while making a profit for the entrepreneurs.
“They’re not relying on expensive equipment, or energy-intensive processes. It’s very simple, and the economies of scale associated with that make Running Tide’s solution have huge potential,” she says.
If the technology were to reach that potential though, it could bring problems. What might happen, after all, when a multitude of little kelp farms floats free?
“We need to basically catalog all of the possible environmental impacts,” says Brad Ack, who directs Ocean Visions, a consortium of top research institutions such as MIT, the Smithsonian Institution and the Woods Hole Oceanographic Institution. This month, the group chose Running Tide as the first carbon-removal project that it would advise and evaluate.
That vetting includes analysis of potential environmental damage — whether rope might entangle whales, whether bunched-up microfarms might hinder shipping traffic. And what happens to seafloor ecosystems when they receive a big pulse of biomass from above?
“But we have to compare them against the no-action alternative,” he says, “and in this case, the no-action alternative is very grim.”
Odlin says it will take a World War II-level effort to knock back CO2 levels in the Earth’s atmosphere to something like a preindustrial state, through his and other big-thinking projects. You could reopen all of Maine’s defunct paper mills, he says, just to produce the biodegradable buoys needed for the Running Tide effort.
“Kind of in a cage-match with it at this point. Because if we don’t bring it down, every ecosystem on Earth will face collapse, period,” he says.
Running Tide started out a few years ago as a comparatively modest aquaculture operation, focused on restoring oyster habitats. Now its staff has grown to more than 30 engineers, scientists, site workers and mariners. Come spring, they plan to sink the first experimental kelp crop 1,000 meters deep — hopefully to stay there for millennia.
This story is part of the New England News Collaborative; it was originally published on Maine Public's website.
This segment aired on February 16, 2021.