A stealth effort to bury wood for carbon removal has just raised millions

A California startup is pursuing a novel, if simple, program for ensuring that dormant trees support c dioxide retired of the ambiance for thousands of years: burying their remains underground.

Kodama Systems, a wood absorption institution based successful the Sierra Nevada foothills municipality of Sonora, has been operating successful stealth mode since it was founded past summer. But MIT Technology Review tin present study the institution has raised astir $6.6 cardinal from Bill Gates’s clime money Breakthrough Energy Ventures, arsenic good arsenic Congruent Ventures and different investors.

In addition, the payments institution Stripe volition uncover connected Thursday that it’s provided a $250,000 probe assistance to the institution and its probe partner, the Yale Carbon Containment Lab, arsenic portion of a broader c removal announcement. That assistance volition enactment a aviator effort to hide discarded biomass harvested from California forests successful the Nevada godforsaken and survey however good it prevents the merchandise of greenhouse gases that thrust clime change. 

It besides agreed to acquisition astir 415 tons of c dioxide yet sequestered by the institution for different $250,000, if that proof-of-concept task achieves definite benchmarks.

“Biomass burial has the imaginable to go a low-cost, high-scale attack for c removal, though determination is simply a request for further probe into its semipermanent durability,” said Joanna Klitzke, procurement and ecosystem strategy pb for Stripe.

For the past respective years, Stripe has pre-purchased tons of c dioxide that startups purpose to yet gully retired of the aerial and permanently sequester, successful an effort to assistance physique up a c removal industry. It has besides helped found a antithetic model for counteracting firm clime emissions that goes beyond simply purchasing c credits from fashionable offsets projects, specified arsenic those that impact planting trees, which person come nether increasing scrutiny.

A fistful of probe groups and startups person begun exploring the imaginable to fastener up the c successful wood, by burying oregon different storing histrion remains successful ways that dilatory down decomposition.

Trees are people businesslike astatine sucking down immense amounts of c dioxide from the air, but they merchandise the c again erstwhile they dice and rot connected the ground. Sequestering trees underground could forestall this. If biomass burial works arsenic good arsenic hoped, it whitethorn supply a comparatively inexpensive and casual mode to propulsion down immoderate stock of the billions of tons of greenhouse state that studies find whitethorn request to beryllium removed to support planetary temperatures successful cheque successful the coming decades. 

But until it’s been done connected ample scales and studied closely, it remains to beryllium seen however overmuch it volition cost, however overmuch c it could store, and however agelong and reliably it whitethorn support greenhouse gases retired of the atmosphere.

Dead wood

Forest experts person agelong warned that decades of overly assertive occurrence suppression policies successful the US person produced dense, overgrown forests that importantly summation the hazard of large conflagrations erstwhile wildfires inevitably occur. Climate alteration has exacerbated those dangers by creating hotter and drier conditions.  

Following a bid of devastating occurrence years crossed the West, a fig of states are progressively backing efforts to wide retired forests to trim those dangers. That includes removing undergrowth, cutting down trees, oregon utilizing controlled burns to interruption up the scenery and forestall fires from reaching wood crowns. 

States are expected to nutrient much and much wood discarded from these efforts arsenic clime alteration accelerates successful the coming years, says Justin Freiberg, managing manager of the Yale Carbon Containment Lab, which has been conducting tract trials exploring a fig of “wood c containment” approaches nether antithetic conditions for respective years.

But today, the harvested plants and trees are mostly piled up successful cleared areas and past near to rot oregon deliberately burned. That allows the c stored successful them to simply instrumentality to the atmosphere, driving further warming. 

Kodama hopes to code some the wildfire dangers and the emissions challenge. The institution says it’s processing automated ways of thinning retired overcrowded forests that volition marque the process cheaper and faster (though it’s not yet discussing this portion of the concern successful detail). After stripping disconnected the limbs from trees excessively tiny to beryllium sold for timber, they’ll load them into trucks and vessel them to a prepared pit.

Small logs and different biomass collected by Kodama.

KODAMA SYSTEMS

The cardinal volition beryllium to guarantee that what the institution refers to arsenic a “wood vault” keeps retired oxygen and h2o that would different accelerate decomposition and prevents greenhouse gases from leaking out.

In the tract effort with Yale researchers, expected to statesman successful the 3rd 4th of adjacent year, the institution intends to make a burial mound successful the Nevada godforsaken that’s 7 yards high, 3 yards deep, and 58 yards agelong and across.

They program to screen the biomass with a geotextile liner and past hide that nether ungraded and a furniture of autochthonal vegetation selected to sorb moisture. Given the region’s adust conditions, this volition make a contained strategy that prevents “agents of decomposition from acting connected the buried wood mass,” ensuring that the c stays successful spot for thousands of years, says Jimmy Voorhis, caput of biomass utilization and argumentation astatine Kodama. 

Freiberg adds that they’ll besides permission wood exposed astatine the tract and make smaller broadside vaults designed successful antithetic ways. The teams volition proceed to show them and comparison decomposition rates and immoderate greenhouse-gas leakage for years. The teams expect to beryllium capable to extrapolate semipermanent c retention estimates from that data, on with different studies and experiments.

Burial costs

Other startups and probe efforts are taking antithetic approaches to the problem. 

The Australian institution InterEarth believes that allowing trees to soak up salty groundwater earlier burying them volition efficaciously pickle the wood, preserving it for extended periods.

The Carbon Lockdown Project, a nationalist benefits corp founded by University of Maryland prof Ning Zeng, has projected creating pits that are lined with clay oregon different materials with debased permeability.

In a paper this year, Zeng and a workfellow besides highlighted a fig of different imaginable approaches, including storing biomass successful frozen sites, underwater, oregon adjacent successful above-ground shelters. His earlier enactment recovered that harvesting and storing wood could perchance region several cardinal tons of c dioxide a twelvemonth astatine a outgo of well below $100 a ton.

But determination are inactive galore unknowns.

“We person to admit that the subject of wood harvesting and retention is inactive evolving,” says Daniel Sanchez, main idiosyncratic for biomass c removal and retention astatine Carbon Direct, which evaluates c removal efforts and firm clime plans. “Most importantly, our knowing of what drives oregon doesn’t thrust decomposition of wood needs to beryllium refined.”

On apical of that, residents and environmental groups are often opposed to wood thinning. Sawing down trees and removing them from the steep slopes of dense forests is simply a laborious and costly process that volition beryllium hard to automate effectively. Hauling astir bulky histrion remains and digging large holes is besides costly and requires a batch of energy.

The clime emissions produced by removing, transporting, and burying wood volition request to beryllium cautiously tallied and counted against the full c stored.

KODAMA SYSTEMS

Finally, there’s the question of acquiring the indispensable discarded biomass.

A 2020 study by Lawrence Livermore National Lab recovered plentifulness to spell astir for these sorts of purposes today, estimating that 56 cardinal “bone dry” tons of discarded biomass are produced each twelvemonth conscionable successful California from agriculture, logging, occurrence prevention, and different activities. (Wood is astir 50% c by mass.)

But demands for it are acceptable to emergence arsenic startups similar Kodama, Mote Hydrogen, and Charm each question retired these sources for assorted biomass-related c removal efforts and the satellite races to execute ambitious clime targets.

There’s immoderate hazard that yet each these efforts could make perverse incentives to region much trees oregon cultivation worldly than indispensable for occurrence prevention oregon steadfast for ecosystems. After all, removing biomass besides reduces the levels of nutrients that forests and farms get from rotting plants.

Kodama says it has done economical and c assessments for its afloat process. It’s assured that it tin execute costs beneath $100 a ton of carbon, and estimates that emissions from the aviator task volition lone trim the nett magnitude of c yet sequestered by astir 15%.

Merritt Jenkins, the company’s cofounder and main executive, says they program to gain gross from their wood thinning work, arsenic good arsenic by selling usable timber and c credits from its burial projects.

But Yale’s Freiberg stresses that the captious ngo of the infinitesimal is to usage that Stripe assistance to assistance reply these “big technological questions astir burial biomass … and show that this is so a solution worthy backing.”