How Carbon Lockdown’s Wood Vault is Pioneering Carbon Removal

During the Climate Vault nonprofit’s 2023 RFP round for Innovative Carbon Dioxide Removal (CDR) projects, the Climate Vault Tech Chamber selected not one, but two, outstanding winners for the 2023 Carbon Dioxide Removal (CDR) Innovation Award. This marks a significant milestone in our CDR journey as this is the first time the Tech Chamber’s rigorous standards for first-of-their-kind CDR solutions have ever been met. Picture this: wood vaults, meticulously engineered to house sustainably-sourced woody biomass, effectively sealing away its carbon footprint for good. This is exactly what our honoree, Carbon Lockdown, is on a mission to do. Carbon Lockdown collects sustainably-sourced woody biomass and buries it in a “wood vault” (see image 1), a specially-engineered underground structure that prevents the decomposition and the re-release of the biomass’ embodied CO2 back into the atmosphere. Carbon Lockdown’s wood vault is pioneering carbon removal.

Image 1: Wood Harvesting and Storage (WHS) and Wood Vault (WV) schematic

Dr. Ning Zeng, the founder of Carbon Lockdown, has been conducting research on wood harvesting and storage (WHS) via wood vault for over 15 years. He is credited as the originator of the idea of carbon sequestration via wood burial. He is also a professor at the University of Maryland and a climate scientist specializing in the global carbon cycle.

We sat down with Dr. Zeng to learn more about Carbon Lockdown’s unique approach to CDR and the verifiable impact Carbon Lockdown’s wood vault is having on the fight against climate change. 

What was the inspiration behind launching Carbon Lockdown and pursuing innovative carbon removal solutions, such as the wood vault?

I was particularly inspired by young people’s effort at fighting climate change, including my own children. I got out of my “ivory tower” in academia to implement solutions that help to solve the climate change problem. The concept behind WHS/WV is simple: sustainably-sourced woody biomass is buried underground a few meters below the surface. The biomass will be preserved for a thousand years or longer because of the oxygen-free condition.

What makes Carbon Lockdown’s approach to carbon removal so unique and credible?

Fundamentally because it hits a sweet spot of natural and engineered solutions. Photosynthesis is ‘free’ carbon capture. Wood vault technology ensures durable preservation of buried biomass, and is akin to the first step of fossil fuel formation. That’s why some people call it ‘reverse coal’ (see image 2). The engineering needed to bury biomass is well established. The whole process is simple, practical, and can be done at very low cost.

Image 2: Concept of wood vault (“Reverse Coal”)

How do you envision your project contributing to mitigating climate change on a global scale?

Each year, the terrestrial biosphere alone captures six times more CO2 than fossil fuel emissions. Utilizing only 5% of that captured CO2 in the form of biomass and storing it durably  can offset 10 gigatons of CO2 (GtCO2), or one-quarter of the current fossil fuel emissions. This is also the negative emissions needed to reach net zero goal by 2050. The 10Gt scale requires major forest management. One to two gigatons of carbon removal can be achieved by utilizing currently unexploited wood residual alone.

Are there other potential benefits, environmental or otherwise, of widespread adoption of your project?

Yes. For example, the wildfire problem in the American West is becoming flammable, literally. A recent study from the Yale Carbon Containment Lab suggests that 0.5-2 GtCO2 equivalent of biomass needs to be thinned in the next 10 years. Most of these thinnings are typically pile burnt, resulting in the release of the biomass’ embodied CO2 back into the atmosphere. Burying them in wood vaults locally may be a low-cost solution with carbon removal co-benefit.

Another potentially larger opportunity is waste wood in the eastern and southern US where forests are highly productive. For instance, in the DC-Baltimore Metro area where I live, many trees are dying—most prominently white oak—the valued Maryland state tree. This is ironically in part due to extreme climate events caused by ‘atmospheric rivers’. The dead wood typically ends up as mulch or goes to landfill, but there is not enough demand for mulch so they are piled up everywhere, generating methane as they decompose, while also posing a fire danger. Our Potomac Project utilizes such urban waste wood from Camp Small, Baltimore.

The highest potential exists in tropical countries where wood vault can be implemented as an element of mixed-use forest management strategies. It can benefit global south countries as local communities control and manage their resources sustainably for livelihood while benefiting the climate.

What have been some key milestones or breakthroughs for Carbon Lockdown?

Two earlier projects: the Gemstone Project and the Montreal Project (see image 3), conducted by research at the University of Maryland, demonstrated the high durability of buried wood. Carbon Lockdown is a tech spinoff from research. These projects laid the foundation for the development of a woody biomass burial project methodology, under which Carbon Lockdown’s 5,000 tonne Potomac Project was the first listed. 

Image 3: Montreal Project sequence (March 22, 2013)

The Potomac project is considered the world’s first commercial-scale wood vault implementation. Carbon Lockdown is working with local NGOs, university, state legislators and agencies to develop a permitting process specifically for wood vault.

Carbon Lockdown’s effort at implementing the Potomac Project has put the idea of biomass burial on the radar screen of CDR platforms including the Rocky Mountain Institute (RMI), XPRIZE, DOE/FECM, and the State of CDR. Last July, Carbon Lockdown sold its first 1,000 tonnes to Kinnevik AB. Last November, attendees of the DOE BiCRS/WHS workshop had the opportunity to visit Potomac Project sites (see image 4). 

Image 4: Potomac Project site in Maryland—the Kilby Farm

Can you share some of the main challenges you’ve encountered during the development of your project and the lessons you have learned along the way?

A major challenge has been to communicate the validity and efficacy of this apparently simple idea. A typical response is dismissal as either too crazy: ‘What a waste? Why don’t I use [the wood] for furniture’, or the solution is simply ignored as not ‘techy’ enough to be attractive. It tends to fall through the ‘crack’ of nature-based methods and technology-based methods, but this is changing. The simple answer to the first question is ‘by all means, but there is still more wood residual of no good use and is valuable as carbon storage’.

While the idea of wood vault is conceptually simple, we have encountered major obstacles in practice, including funding and permitting. Additional research will also be needed to support the continued evolution of best practice.

Given that it’s “easily applied” (quote National Academy of Sciences), a good strategy is to “quickly implement a number of pilot projects” (quote Rudy Kahsar of Rocky Mountain Institute) to test out different wood sourcing and burial conditions because this is a very local thing. 

Another characteristic of this method (and hybrid nature-engineering method in general) is the finite biospheric productivity. Only a fraction each year can be utilized sustainably, but if we don’t use it, the carbon goes back into the atmosphere. 

An analogy I like to use is: we are raising chickens not just for the chicken, but for the eggs. Keeping our chicken (forest) healthy is a prerequisite, but if we don’t harvest the eggs, the opportunities are wasted.

What is your hope for the future of carbon removal technologies, and how does Carbon Lockdown fit into that vision?

A safe climate will require multi-gigaton carbon removal, which would be a trillion-dollar industry. I think biomass burial can contribute a big ‘wedge’. Carbon Lockdown has been a trailblazer in this area, and will continue to do so. We also support other implementers via partnership.

Here at Climate Vault, we couldn’t be more excited to welcome Carbon Lockdown as one of the inaugural CDR solutions to have their technology validated by the Climate Vault Tech Chamber as trustworthy for credibly removing CO2 from the atmosphere. Carbon Lockdown stands as a true trailblazer in the realm of carbon capture and removal. We can’t wait to see the impact we have together on combating the worst effects of climate change in the coming years.

Want to learn more about Carbon Lockdown and its potential impact on the CDR space? Register to attend our webinar and hear from Dr. Zeng firsthand about the first-of-its-kind wood vault.