Kill Trees, Save the Planet

Bill Gates and other investors are betting Kodama Systems can reduce carbon dioxide in the air by cutting down and burying trees. Now if only Uncle Sam would get onboard with tax credits, too.

By Chris Helman

Undertaker

No sawmills means no commercial demand for logs from California’s Stanislaus National Forest. That makes these trees prime candidates for burial, says Kodama CEO Merritt Jenkins.

A year ago, Merritt Jenkins moved from Boston to Twain Harte, California, a speck of 2,500 souls in the foothills of the Sierra Nevadas. On his morning commute, he stops at Alicia’s Sugar Shack for a breakfast sandwich (scrambled eggs on rye with avocado), then heads to a 10-acre patch of woods in the Stanislaus National Forest. There, his startup, Kodama Systems, is testing and perfecting its 25-foot-long, 17-ton semiautonomous timber harvesting machine.

Loggers use such machines, known as skidders, to grab tons of cut trees and debris and drag them out of the woods. Kodama’s version is designed to do the job even at night, with fewer workers, using satellite connectivity and advanced lidar (light detection and ranging) cameras, the same type that are used on self-driving cars, to monitor the work remotely. It isn’t easy. “There’s a lot of texture to the trees. Every 10 feet of skid trail is slightly different,” says Jenkins, 35.

But logging in the dark isn’t the most intriguing part of the plans at Kodama, which has raised $6.6 million in seed funding from Bill Gates’ Breakthrough Energy and others. After cutting down the trees, Jenkins plans to bury them–to help slow climate change and to reap salable carbon offsets (and maybe, someday, tax credits too).

Yes, the conventional idea is to plant trees to soak up carbon dioxide from the air and to then sell credits to corporations, private jet owners and others who need or want to offset their emissions. But scientists say burying trees can reduce global warming as well–particularly if those trees would otherwise end up burning or decaying, spewing their stored carbon into the air.

California’s enormous 2020 wildfires drove home the risks to air, property and life posed by overgrown forests. “The orange skies in San Francisco were an inflection point. Now the story resonates,” says Jimmy Voorhis, head of biomass utilization and policy at Kodama. The alarm bells are sounding even louder this year as Canadian wildfires have spread dangerous air conditions to New York, Washington, D.C., and Chicago.

To help address the problem, the U.S. Forest Service aims to thin out 70 million acres of western forests, mostly in California, over the next decade, extracting more than 1 billion tons of bone-dry biomass. It is customary, after such forest thinning, for logs of marketable size to go to sawmills, with most of the rest piled up and later burned under controlled conditions. Kodama wants to bury the leftovers instead–in earthen vaults designed to maintain dry and anoxic (oxygen-free) conditions and protect the wood from rotting or burning.

Along with the VC seed money, Kodama has already received $1.1 million in grants from California’s forest fire agency and others, as well as purchase commitments for the carbon credits tied to the first 400 tons of trees it buries. On the open market, those credits should fetch $200 a ton. Eventually Kodama wants to cut down and bury more than 5,000 tons of trees a year.

A Dartmouth grad with degrees in both engineering and environmental studies, Jenkins started selling used robotic equipment while earning a master’s in robotics at Carnegie Mellon. Then he cofounded a company that uses machine learning to help farmers analyze soil. But in 2019, while earning an MBA at MIT, he concluded there was more opportunity in forestry than in the crowded ag-tech field. He backed away from the AI company and spent months with loggers to understand how they use equipment, and by 2021 had settled on forestry robotics, convinced that labor shortages would drive demand. “There’s not enough workforce,” he says. “We’ll need new training and new technologies” to meet the Forest Service’s clearing goals.

He also saw another “big gap” in the industry: what to do with all that biomass. He had heard about biomass vaults from Yale’s Carbon Containment Lab. Then mutual friends introduced him to Voorhis, a 33-year-old mountaineer, geologist and earth sciences engineer (with an M.S. from Dartmouth), who had become obsessed with the idea of reclaiming old mines as biomass burial sites. They joined forces.

The notion of burying trees sounds simple and low-tech, particularly when compared with the convoluted “carbon capture” technology now being developed to pull CO2 from the air. Thanks to the Inflation Reduction Act Democrats passed in 2022, companies like Occidental Petroleum and ExxonMobil could qualify for tax credits of $85 per ton of CO2 sequestered if they can perfect systems to suck the gas directly from the air and transport it by pipeline before injecting it permanently underground. The IRA further incentivizes some of these projects with tax credits equal to 30% or more of upfront capital invested.

If you want to cut down trees and pelletize them to burn in place of coal, there are tax credits for that too. But not, as of now, for burying them.

“If you need to remove carbon at scale, it’s crazy not to learn from nature or harness nature,” says Lucas Joppa, a former chief environmental officer at Microsoft who is now at Haveli Investments. “We’ve never come remotely close to being as efficient at removing carbon from the atmosphere as evolution has.”

How efficient? University of Maryland atmospheric science professor Ning Zeng, considered the godfather of biomass burial, explains that the average ton of freshly harvested forest is about 50% carbon by weight, and if left to rot or burn it would put the equivalent of one ton of carbon dioxide into the atmosphere. A good rule of thumb, he says: “A ton of biomass in the Earth is a ton of CO2 not in the sky.”

Zeng has his own startup, Carbon Lockdown, which has a contract with the city of Baltimore to pick up 5,000 tons of biomass and bury it near wealthy, leafy Potomac, Maryland. He’s selling the carbon credits generated by that burial at $181 per sequestered ton on Puro.earth (a platform that was built with backing from the Finnish government and became majority-owned by Nasdaq in 2021). Swedish investment company Kinnevik recently bought 1,000 tons. “Nature-based technologies are here and scalable,” says Mikaela Kramer, who oversees carbon credit purchases for Kinnevik. “It doesn’t have to wait another 10 years.”

Still, it’s tough to get large-scale private or government investment in biomass burial because it’s neither replacing a climate-destroying industrial activity nor creating a product that’s of use to people–other than the credits themselves. It also can mean disturbing land.

In Texas, attorney Chris Knop, 43, has already interred more than 4,000 tons of biomass on 45 acres of land his company, Carbon Sequestration, owns near the Louisiana border. The land there is ideal for the anoxic burial required to prevent biomass from decomposing, he says, because of its thick layer of clay. He recently acquired 15,000 tons of debris from landowners north of Beaumont, who are clearing pine forest for real estate development and would otherwise have burned it, enabling him to sell carbon credits for $145 a ton on Puro.

Knop thinks he can break even and was counting on federal tax credits to make the venture profitable. But Congress didn’t explicitly include biomass burial in its tax-credit bonanza. Now Knop and biomass lobbyists are hoping that when the Treasury writes final rules for carbon sequestration credits, biomass will qualify. “I’m just looking for some type of affirmation,” he says.

Knop also has an out-there vision for turning America’s forestlands into carbon sponges by chopping down pine trees, burying them and then replanting with more carbon-thirsty species like bamboo, kenaf or poplar. In the U.S., hundreds of millions of acres are dedicated to cattle grazing or timber production, he says. “Why not switch to carbon farming?”

Back at Kodama, Jenkins is focused on burying wood that needs to be culled anyway for forest health, while Voorhis is aiming to adapt defunct mines and quarries–rather than dig new land–for biomass storage. “We will measure the gas and leachate and completely box off the carbon flows,” Voorhis promises. “If you meet anyone with an old inert rock quarry, let me know.”

HOW TO PLAY IT

By William Baldwin

Grow a tree and then bury it? What a waste! The rational place to store carbon is above ground. The wood could be the two-by-six studs in a house or the laminated beams in a commercial building, and it spares the planet CO2 emissions from steel and concrete. Participate in this environmentally virtuous business by owning shares in forest products companies, such as West Fraser Timber in Canada and Stora Enso in Finland. Earnings will be down this year as homebuilding pauses, but the trees are still growing, and the dividend yields (1.4% and 5%) continue. Recover some or all of the foreign withholding taxes on dividends via a credit on your U.S. return.

William Baldwin is Forbes’ Investment Strategies columnist.

Paul Bunyan 2.0

After thinning trees up to 60 feet tall, Kodama will inter them on more arid land outside the forest.

Little Big Picture

WOOD WORK

America has plenty of trees–nearly 300 billion of them, according to the U.S. Forest Service’s “tree census.” Good thing, since wood products are used in a variety of products including cigarette filters and Parmesan cheese. Here’s how much you can wring out of a single 30-foot tall, 1.5-foot-wide tree.

7 million toothpicks

Birch

4,000 wine corks

Cork Oak

1.2 bowling lanes

Pine

1/40th of a 65-foot Viking longship

Oak

Framing for 1/20th of a 2,000-square-foot home

Douglas Fir

FINAL THOUGHT

“If a tree falls in the forest and nobody is there to hear it, doesn’t it just lie there and rot?”

–Chuck Palahniuk

Photograph by Ethan Pines for Forbes

Ethan Pines for Forbes (top); Getty Images (5)

When people think about the risks of climate change, the idea of abrupt changes is pretty scary. Movies like “The Day After Tomorrow” feed that fear, with visions of unimaginable storms and populations fleeing to escape rapidly changing temperatures.

While Hollywood clearly takes liberties with the speed and magnitude of disasters, several recent studies have raised real-world alarms that a crucial ocean current that circulates heat to northern countries might shut down this century, with potentially disastrous consequences.

That scenario has happened in the past, most recently more than 16,000 years ago. However, it relies on Greenland shedding a lot of ice into the ocean.

Our new research, published in the journal Science, suggests that while Greenland is indeed losing huge and worrisome volumes of ice right now, that might not continue for long enough to shut down the current on its own. A closer look at evidence from the past shows why.

Blood and water

The Atlantic current system distributes heat and nutrients on a global scale, much like the human circulatory system distributes heat and nutrients around the body.

Warm water from the tropics circulates northward along the U.S. Atlantic coast before crossing the Atlantic. As some of the warm water evaporates and the surface water cools, it becomes saltier and denser. Denser water sinks, and this colder, denser water circulates back south at depth. The variations in heat and salinity fuel the pumping heart of the system.

If the Atlantic circulation system weakened, it could lead to a world of climate chaos.

Ice sheets are made of fresh water, so the rapid release of icebergs into the Atlantic Ocean can lower the ocean’s salinity and slow the pumping heart. If the surface water is no longer able to sink deep and the circulation collapses, dramatic cooling would likely occur across Europe and North America. Both the Amazon rain forest and Africa’s Sahel region would become dryer, and Antarctica’s warming and melting would accelerate, all in a matter of years to decades.

Today, the Greenland ice sheet is melting rapidly, and some scientists worry that the Atlantic current system may be headed for a climate tipping point this century. But is that worry warranted?

To answer that, we need to look back in time.

A radioactive discovery

In the 1980s, a junior scientist named Hartmut Heinrich and his colleagues extracted a series of deep-sea sediment cores from the ocean floor to study whether nuclear waste could be safely buried in the deep North Atlantic.

Sediment cores contain a history of everything that accumulated on that part of the ocean floor over hundreds of thousands of years. Heinrich found several layers with lots of mineral grains and rock fragments from land.

The sediment grains were too large to have been carried to the middle of the ocean by the wind or ocean currents alone. Heinrich realized they must have been brought there by icebergs, which had picked up the rock and mineral when the icebergs were still part of glaciers on land.

The layers with the most rock and mineral debris, from a time when the icebergs must have come out in force, coincided with severe weakening of the Atlantic current system. Those periods are now known as Heinrich events.

As paleoclimate scientists, we use natural records such as sediment cores to understand the past. By measuring uranium isotopes in the sediments, we were able to determine the deposition rate of sediments dropped by icebergs. The amount of debris allowed us to estimate how much fresh water those icebergs added to the ocean and compare it with today to assess whether history might repeat itself in the near future.

Why a shutdown isn’t likely soon

So, is the Atlantic current system headed for a climate tipping point because of Greenland melting? We think it’s unlikely in the coming decades.

While Greenland is losing huge volumes of ice right now – worryingly comparable to a midrange Heinrich event – the ice loss will likely not continue for long enough to shut down the current on its own.

Icebergs are much more effective at disrupting the current than meltwater from land, in part because icebergs can carry fresh water directly out to the locations where the current sinks. Future warming, however, will force the Greenland ice sheet to recede away from the coast too soon to deliver enough fresh water by iceberg.

The strength of the Atlantic Meridional Overturning Circulation, or AMOC, is projected to decline 24% to 39% by 2100. By then, Greenland’s iceberg formation will be closer to the weakest Heinrich events of the past. Heinrich events, in contrast, lasted 200 years or so.

Instead of icebergs, meltwater pouring into the Atlantic at the island’s edge is projected to become the leading cause of Greenland’s thinning. Meltwater still sends fresh water into the ocean, but it mixes with seawater and tends to move along the coast rather than directly freshening the open ocean as drifting icebergs do.

That doesn’t mean the current isn’t at risk

The future trajectory of the Atlantic current system will likely be determined by a combination of the decelerating but more effective icebergs and the accelerating but less influential surface runoff. That will be compounded by rising ocean surface temperatures that could further slow the current.

So, the Earth’s pumping heart could still be at risk, but history suggests that the risk is not as imminent as some people fear.

In “The Day After Tomorrow,” a slowdown of the Atlantic current system froze New York City. Based on our research, we may take some comfort in knowing that such a scenario is unlikely in our lifetimes. Nevertheless, robust efforts to stop climate change remain necessary to ensure the protection of future generations.

In addition, the payments company Stripe will reveal on Thursday that it’s provided a $250,000 research grant to the company and its research partner, the Yale Carbon Containment Lab, as part of a broader carbon removal announcement. That grant will support a pilot effort to bury waste biomass harvested from California forests in the Nevada desert and study how well it prevents the release of greenhouse gases that drive climate change.

It also agreed to purchase about 415 tons of carbon dioxide eventually sequestered by the company for another $250,000, if that proof-of-concept project achieves certain benchmarks.

“Biomass burial has the potential to become a low-cost, high-scale approach for carbon removal, though there is a need for further investigation into its long-term durability,” said Joanna Klitzke, procurement and ecosystem strategy lead for Stripe.

For the last several years, Stripe has pre-purchased tons of carbon dioxide that startups aim to eventually draw out of the air and permanently sequester, in an effort to help build up a carbon removal industry. It has also helped establish a different model for counteracting corporate climate emissions that goes beyond simply purchasing carbon credits from popular offsets projects, such as those that involve planting trees, which have come under growing scrutiny.

A handful of research groups and startups have begun exploring the potential to lock up the carbon in wood, by burying or otherwise storing tree remains in ways that slow down decomposition.

Trees are naturally efficient at sucking down vast amounts of carbon dioxide from the air, but they release the carbon again when they die and rot on the ground. Sequestering trees underground could prevent this. If biomass burial works as well as hoped, it may provide a relatively cheap and easy way to pull down some share of the billions of tons of greenhouse gas that studies find may need to be removed to keep global temperatures in check in the coming decades.

But until it’s been done on large scales and studied closely, it remains to be seen how much it will cost, how much carbon it could store, and how long and reliably it may keep greenhouse gases out of the atmosphere.

Dead wood

Forest experts have long warned that decades of overly aggressive fire suppression policies in the US have produced dense, overgrown forests that significantly increase the risk of major conflagrations when wildfires inevitably occur. Climate change has exacerbated those dangers by creating hotter and drier conditions.

Herds of horses, bison and reindeer could play a significant part in saving the world from an acceleration in global heating. That is the conclusion of a recent study showing how grazing animals can slow down the pace of thawing permafrost in the Arctic.

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The study — a computerized simulation based on real-life, on-the ground data — finds that with enough animals in the Arctic used, 80% of all permafrost soils around the globe could be preserved through 2100.

The research was inspired by an experiment in the town of Chersky, Siberia featured on CBS News’ “60 Minutes.” The episode introduces viewers to an eccentric scientist named Sergey Zimov who resettled grazing animals to a piece of the Arctic tundra more than 20 years ago.

Zimov is unconventional, to say the least, even urging geneticists to work on resurrecting a version of the now-extinct woolly mammoth to aid in his quest. But through the years he and his son Nikita have observed positive impacts from adding grazing animals to the permafrost area he named Pleistocene Park, in a nod to the last Ice Age.

Permafrost is a thick layer of soil that remains frozen year-round. Because of the rapidly warming climate in Arctic regions, much of the permafrost is not permanently frozen anymore. Thawing permafrost releases heat-trapping greenhouse gases that have been buried in the frozen soil for tens of thousands of years, back into the atmosphere.

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Permafrost in the Arctic is thawing- a new study shows how grazing animals could help with this (Photo by: Jefferson Beck/NASA ).

Scientists are concerned that this mechanism will act as a feedback loop, further warming the atmosphere, thawing more soil, releasing more greenhouse gases and warming the atmosphere even more, perpetuating a dangerous cycle.

Last year their fears were confirmed when a study led by scientists at Woods Hole Research Center revealed that the Arctic was no longer storing as much carbon as it was emitting back into the atmosphere.

In winter the permafrost in Chersky, Siberia stays at about 14 degrees Fahrenheit. But the air can be much colder, dropping down to 40 below zero Fahrenheit. Typically there is a thick blanket of snowfall in winter which insulates the soil, shielding it from the frigid air above and keeping it milder.

The idea behind Zimov’s on-the-ground Pleistocene Park experiment was to bring grazing animals with their stamping hooves back to the land to disperse the snow, compress the ground and chill the soil.

Turns out, it worked. The 100 resettled animals, across a one-square-kilometer area, cut the average snow cover height in half, dramatically reducing the insulating effect, exposing the soil to the overlying colder air and intensifying the freezing of permafrost.

In an effort to see what impact this method could have on a much larger scale, beyond the confines of Pleistocene Park, Professor Christian Beer of the University of Hamburg conducted a simulation experiment. His team used a special climate model to replicate the impact on the land surface throughout all of the Arctic permafrost soils in the Northern Hemisphere over the course of an entire year.

The results, published in the Nature journal Scientific Reports, show that if emissions continue to rise unchecked we can expect to see a 7-degree Fahrenheit increase in permafrost temperatures, which would cause half of all permafrost to thaw by 2100.

In contrast, with animal herds repopulating the tundra, the ground would only warm by 4 degrees Fahrenheit. That would be enough to preserve 80% of the current permafrost though the end of the century.

“This type of natural manipulation in ecosystems that are especially relevant for the climate system has barely been researched to date, but holds tremendous potential,” Beer said.

CBS News asked Beer how realistic it is to expect that the Arctic could be repopulated with enough animals to make a difference. “I am not sure,” he replied, adding that more research is needed but the results are promising. “Today we have an average of 5 reindeers per square kilometer across the Arctic. With 15 [reindeer] per square kilometer we could already save 70% permafrost according to our calculations.”

“It may be utopian to imaging resettling wild animal herds in all the permafrost regions of the Northern Hemisphere,” Beer concedes. “But the results indicate that using fewer animals would still produce a cooling effect.”

Rick Thoman, a climate specialist at the International Arctic Research Center in Alaska, agrees that snow disturbed and trampled by animal herds is a much less efficient insulator, but he has his doubts about implementing this idea. “Unless the plan is to cover millions of square kilometers with horses, bison and reindeer, how could this possibly have any significant impact? I certainly would not call it ‘utopian’ to destroy permafrost lands as we know them by having these animals in the distribution and numbers required.”

Beer and his team did consider some potential side effects of this approach. For example, in summer the animals would destroy the cooling moss layer on the ground, which would contribute to warming the soil. This was taken into account in the simulations, but the cooling impact of the compressed snow effect in winter is several times greater, they found.

“If theoretically we were able to maintain a high animal density like in Zimov’s Pleistocene Park, would that be good enough to save permafrost under the strongest warming scenario? Yes, it could work for 80% of the region” said Beer.

As a next step, Beer plans to collaborate with biologists in order to investigate how the animals would actually spread across the landscape.

Featured image by: Flickr

This story originally appeared in CBS News and is republished here as a part of Earth.Org’s partnership with Covering Climate Now, a global collaboration of more than 250 news outlets to strengthen coverage of the climate story.