At 14, Bren Smith dropped out of high school to fish the globe. He witnessed firsthand the industrial havoc factory ships waged on ecosystems in the oceans. After wandering around the globe for years, he began a journey toward ecological sustainability. Nearly 20 years later, he’s the co-founder of Greenwave, a non-profit organization that focuses on regenerative ocean farming — the practice of “growing seaweed and cultivating shellfish that require zero inputs while sequestering carbon and rebuilding ecosystems.”
Smith’s work relies on a tactic to reverse climate change that scientists have now begun to turn their attention to: carbon sequestration, a process taking back the abundance of carbon in our atmosphere. One of the most potent ways to implement carbon sequestration is the farming of kelp in Earth’s oceans.
Kelp is a type of macroalgae — seaweed. Seaweed grows near the shore in rocky conditions and absorbs carbon dioxide before parts of the macroalgae are exported to the deep sea, far away from disturbance, or are consumed by microbes. As parts of the seaweed plant float deeper and deeper into the ocean, protected from harm by “unpalatable elements” it absorbs carbon dioxide through photosynthesis. When seaweed’s gas-filled bladders pop, they sink to the bottom of the ocean, effectively sequestering the carbon in the deep sea.
According to the Energy Futures Initiative’s expert panel, kelp can hold down about 1 billion to 10 billion tons of carbon dioxide per year. For example, kelp’s gas-filled bladders that float on the ocean water for longer periods of time, are exposed to more sunlight and undergo photosynthesis for longer which means more carbon absorption. A 2016 Nature Geoscience paper estimated that seaweed can naturally sequester up to 175 million tons of carbon per year.
This is where Greenwave’s work comes in. The team trains farmers in ocean farming, supports their efforts, and develops technology and research to speed up the process. These farmers cultivate kelp sores in a lab and spray them on ropes — after they begin to look fuzzy, they are dropped into the ocean until they reach maturity.
Kelp farming, when compared to any type of land-based prospect for carbon sequestration, is faster and more efficient. Soil carbon sequestration relies on planting more trees as well as reducing tilling and using more cover crops. The process is a lot slower and requires more resources — water, fertilizers — whereas the plants involved in ocean-based carbon sequestration, including kelp, have higher growth rates.
As much as kelp has begun to be known as a heralded solution to climate change, no one knows for sure how much the seaweed will truly help to reverse global warming.
Warming waters are destroying kelp across the globe and several restoration projects are working to harvest new farms with the help of “super kelp,” a type of giant kelp that seems to be more resistant to warming oceans. But at it’s core, the situation is cyclical — global warming is destroying kelp, but we may need kelp to reverse global warming.
Not only are kelp forests in danger, but no one can truly confirm either the consequences of mass-scale kelp farming or what effect it’s truly going to have on reversing climate change.
The amount of carbon that needs to be pulled down to make a true dent in carbon emissions is impossible for kelp or seaweed to do alone. 50 billion metric tons of greenhouse gasses are emitted into the atmosphere every year. Kelp can reduce that amount significantly but it can’t be the solution to a true reversal. Halting carbon emissions will be the only path to reversing climate change completely.
But increasing the amounts of seaweed could also invite entangling with creatures, upsetting populations in the ocean.
The delicate relationship between kelp, sea otters, and urchins was knocked off kilter when the Sunflower sea star population, urchin predators, decreased rapidly off the West Coast beginning in 2013. This, in combination with a general upward trend in the overfishing of other sea urchin predators meant the urchin population boomed. Purple urchins overgrazed in areas like the Palos Verdes Peninsula, decimating kelp farms. A 2014 ocean heatwave further reduced kelp canopies.
Scientists and researchers have proposed and even implemented in some areas the reintroduction of sea otters to waters where urchins were destroying kelp. This would keep the urchin population in check. The situation is highlighted in detail in an article we wrote last year.
But the introduction of sea otters into waters interrupted food sources for humans who relied on its prey. The issue rages as close to home as Santa Monica Bay, where the Bay Foundation has launched a model program to restore kelp forests off the coast with help from commercial urchin fishermen to help clear urchins. The organization has restored over 55 acres of this vital ecosystem thus far.
No matter how uncertain the issue is, there are forward thinkers and corporations that have taken it upon themselves to commit to kelp farming as, at the very least, a crucial help in reversing climate change.
Ordinary People, Extraordinary Progress
Greenwave isn’t the only initiative that has recognized a need for kelp farming and carbon sequestration. Bren Smith isn’t the only one to witness the destruction of coasts and the need for an efficient carbon removal system.
Fishermen, engineers, scientists, data scientists and more have dedicated themselves to seaweed farming and restoration.
Running Tide Technologies, a Maine-based company concentrated on rebuilding food systems, removing excess carbon, and restoring coasts, has begun to focus on burying kelp at the bottom of the ocean to keep carbon down.
Similar to Smith, the CEO, Marty Odlin, was a fisherman who observed the effects of climate change on fish populations first hand. He started small, with just an oyster farm, but his vision grew.
An inexpensive alternative to high-cost ocean carbon sequestration issues, his goal was to attach a kelp-bearing rope to a biodegradable buoy, relying on it to sink as the kelp absorbed enough carbon to grow heavy and mature. The kelp would fall to the bottom of the ocean
Another start-up, Kelp Blue, focuses on farming kelp specifically. Founded by Daniel Hooft and Caroline Slootweg, Kelp Blue has a sister company in Namibia and is supported by the United Nations Global Compact. Their goal is to pull down 1 million tons of carbon dioxide per year and create more than 400 jobs (more indirectly) by 2029.
They are farming a different type of kelp: macrocystis. Macrocystis works as any other kelp does to sequester carbon, but because of its unique chemical composition, is an “effective biostimulant, a fantastic input material for plastic replacements as well as a sustainable agri-feed.”
Bren Smith isn’t an environmental scientist, nor is he a politician – neither was Marty Odlin, the CEO of Running Tide Technologies. Anyone who chooses to, can tread the path toward clean ecosystems and sustainability, even when it involves systems that seem beyond our reach.
If you want to get involved in any of the organizations mentioned in this article, check out their websites here:
What do you think about the increased focus on kelp farming? Will it really make as much of a difference as companies seem to think it will? Let us know in the comments below!