Steen Rasmussen: Go cheap, go ancient.

“Biochar!” says Steen out of the blue.

“Say what?” says Erik.

Steen Rasmussen and I are hooped over the bar at McP’s Irish Pub in Coronado with my friend Erik the Song Doctor. (That’s a real thing! People send him their tunes, and for a fee, he equalizes the song, balances it, improves it, gets rid of bum notes, and generally readies it for market.) Erik and I have just met Steen, who’s a financial type, down here on one of his regular visits down from Vancouver. We’re bemoaning the fact that once again, our beaches are closed.

“And it’s getting worse,” says Erik. Seems Border Field State Park was closed every day of 2023, while the beach at IB Pier was closed for 322 days, and Silver Strand for 291 days. I haul up a quote on my iPad from Paloma Aguirre, Imperial Beach’s mayor: in a letter dated June 6th, 2023 to the White House Council on Environmental Quality, she wrote, “The continuous influx of transboundary pollution is wreaking havoc on the local community, economy, and environment along the coastline of San Diego County.”

“What can you do?” I say, mainly to my pint of Ultra. “They throw millions at the pollution problem and it keeps on getting bigger.”

That’s when Steen busts out his biochar bit. “The oldest trick in the Americas. And the cheapest. I’m scaling it up in a project in Namibia, Africa.”

I bite: “Biochar?”

“It’s a stable form of carbon. Cleans out pollution. It’s made by burning, say, wood, while keeping the oxygen supply down to a small roar. Result is a very porous charcoal. It can soak up a lot of toxins and other things out there — like, pretty much everything going on right now in the Tijuana River.” He says biochar is used in remediating mine tailings, and in a bunch of other projects. “So that might be the best solution that I can think of, just offhand, for addressing this issue.”

Deceptively innocent in appearance: mouth of the Tijuana River.

He says the good news is you can use the very things you usually have trouble getting rid of: wood, vegetable, and animal matter. “Waste wood products like biomass from forestry” — say, the dead underbrush that we have in California that makes our wildfires so hot. “You cook it at a certain temperature. I believe it may be upwards of 800 degrees. But you do it in a certain way, where you actually don’t have a flame because you’ve starved it of oxygen. Process is called pyrolysis. The final result is carbon that remains in the ground in a stable form for a long period of time.”

He’s careful to note that it’s not his invention. “The ancient Amazonians were using it to burn their shit thousands of years ago. Biochar is having a resurgence now because people are realizing its efficacy, and because it’s more of a circular economy approach: taking a waste product, and turning it into something that’s useful.”

The Amazonians’ secret, Steen says, was a thing called terra preta (“Black Earth.”) “Amazonian communities would dig a big hole in the ground, take all the waste material they had, all their human waste, everything else. And they would cover it and cook it, by pyrolysis. No flame, oxygen shut out. Results looked like a smoldering campfire the morning after. So all that wood and waste would turn into a stable form of carbon, which is much more fertile than the normal poor soils of the Amazonian jungle. You can see these dark patches of terra preta scattered throughout Amazonia.”

Today, we’d appreciate it more as a way of sequestering carbon. “It’s an answer to our CO2 surplus problem,” says Steen. “Plus it creates that very strong, rich soil, which helps with water retention, which helps with all the minerals in the land, and also agricultural production. So it’s something that they created from their need to get rid of their stuff, and now it’s something we can [use] in our time and place. Except not a lot of people know about it.”

Steen came across it through his work in finance. “I’ve had multiple careers in my life. I was working the capital market side of things, and we raised some money for natural resource projects, and then carbon came up on the radar, so we raised some money for that. And then I noticed that no one knew what carbon was. So we started carboncredits.com, which I oversaw from domain purchase to being the biggest franchise in the sector in that niche industry. And from that, it connected to bring a whole bunch of different people together from different walks of life, people who normally never talk to each other. So I started with them to scale solutions to address these problems.”

Biochar: savior of the TJ River?

Biochar, Steen says, is the cheapest method of carbon dioxide removal, and you can actually put it back in the ground in a stable form. “There’s a massive demand coming [for carbon removal credits], and we’re trying to feed that supply. And companies such as Microsoft are making purchases off of that. Even national governments such as Denmark [are] making purchases. It’s picking up a lot more traction. Essentially, it’s going to be one of the biggest things out there in the world. And every single country that you look at is both a natural resource and a strategic resource going forward. So they’re looking at their woody biomass stocks as an asset because in the pyrolysis process of burning it, you can also recapture some of the gasses that are emitted at the top; you can also actually generate energy off of that as well. So you can have a highly efficient way of essentially cooking wood, and turning it into a soil additive, and this product called biochar. I think it will be more mainstream soon enough.”

And soon enough can’t come soon enough. According to San Diego Coastkeeper, “since October 2023, a staggering 31 billion gallons of raw sewage, polluted stormwater, and trash have flowed down the Tijuana River into the Tijuana River Valley and the Pacific Ocean.” The river’s estuary, one of the few “protected” estuaries left in North America — a “wetland of global importance,” according to the UN’s Ramsar Convention — is turning from coastal marsh into dry land, snowed under by vast volumes of microplastics. The area’s glory of undisturbed biodiversity is starting to wobble. Something different has to be done.

Could Steen’s dream of an ancient Amazonian technique be part of the answer? “Look,” he says, “I’m not a technical science person, but this is my back-of-the-envelope understanding of it: add the biochar towards the slurry, the waste material, and then it will hold it into more stable (and removable) forms. It’d be a start. At least we wouldn’t just be leaving it to political thinkers who sit in think-tanks. We have enough think-tanks. We need more do-tanks.”