Draft:Wood Harvesting and Storage

• Comment: Reads like a proof of concept that should be presented to a board of directors, has no place on Wikipedia in it's current form. _Signed, Pichemist ^{( Contribs | Talk )} 11:28, 6 January 2023 (UTC)

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Wood Harvesting and Storage (WHS) (also known as Wood Harvesting and Sequestration) is a hybrid biological-engineering carbon dioxide removal and storage method where sustainably sourced woody biomass is securely stored in engineered structures called wood vaults. A wood vault maintains anaerobic, cold or dry conditions to prevent wood decomposition, storing carbon for hundreds to thousands of years or longer. The wood is sourced from wood residuals from urban waste wood, forestry residue, fire thinning, land clearing, storm blowndown, or sustainably managed forest. It has been estimated that carbon from 2-10 billion tonnes (gigatonnes or Gt) of CO₂ per year could be stored.

Background

Since the industrial revolution, carbon dioxide concentration in the atmosphere has increased from 280 ppm to 420 ppm (parts per million). According to the IPCC, in order to mitigate the impacts of anthropogenic climate change it is necessary to keep global mean temperature increases below 1.5-2°C. Long-term carbon sequestration via negative emissions technology (NET) are a potential pathway to reduce CO₂ emissions. Carbon sequestration occurs in 2 steps: capturing CO₂ directly from the atmosphere or from industrial sources and then long term storage. Some methods of carbon sequestration and storage include the pumping of CO₂ into the deep ocean, or injecting it into geological formations. Biological sequestration methods rely on the natural process of photosynthesis to capture CO₂ and assimilate the carbon into biomass. Some biological sequestration methods include reforestation, no-till agriculture, and intensive forest management. Wood harvesting and storage is a hybrid of natural and engineering sequestration and storage methods. This allows for continual (no-saturation) and semi-permanent storage.

Storage Methods

With WHS, woody biomass that is minimally processed and free of pollution is buried underground, where it is isolated away from a biologically active environment. The biomass is buried in anaerobic conditions to prevent decomposition that would otherwise occur if the wood was left above ground. WHS takes advantage of the natural process of carbon capture by photosynthesis in the leaves, and prevents it reentering the atmosphere due to decomposition. The sequestered carbon in wood can then be transported and buried using the Wood Vault technology.

Wood Sourcing

There are two types of wood sources that would be put into a Wood Vault: type A and type B. Type A wood sourcing includes woody biomass that is collected from opportunistic sources, or sources that would have co-benefits, like fire risk reduction and waste utilization. Examples of type A wood include urban wood residuals, land clearing for development, logging residue, and thinnings for fire prevention. By using this method there is a potential to prevent up to 1 Gt CO₂ per year globally. The second type of wood, type B, is wood harvested from forests managed for carbon sequestration. Harvesting wood at high intensity, for example in the event of a climate emergency, can sequester around 10 Gt CO₂ and require cutting down about 20% of Earth’s forests (about the size of the United States). However, if the rate that forests are cut down remains at moderate, sustainable levels, putting the wood in a Wood Vault could save on average 0.5-3 Gt CO₂.

Fully Above Ground

There are two variations of the above ground unit: Tumulus and Barrow. Tumulus is partially above ground and partially below ground that is divided into cells. Each cell is then filled with wood and when the last cell is filled, the original topsoil will be placed on top of the vault, allowing for grass and other shallow rooted vegetation to be grown. The Barrow has the same interior design as Tumulus but is completely above ground.

Tumulus Wood Vault

Barrow Wood Vault

Fully underground

There are three variations for a fully below ground vault: pit, quarry, and mine, which utilize either a newly excavated pit or pre-existing mine or quarry for sequestration purposes. The process is the same for all three in which a subterranean structure is filled with woody biomass and sealed off.

Underground Wood Vault

Multi-Tiered Vault

Also called the supervault, it is similar to the above ground units but it would be larger with several smaller vaults making up the inside.

Super Wood Vault

Shelter/warehouse

In this vault, wood is stored in a storage unit built to keep out animals and insects. The shelts can be built out of the wood with an inside layer of mudbrick to shelter from rain. Multiple stockpiles can be put inside the structure acting as baby vaults. These baby vaults can be sealed airtight with adobe or engineered to be ventilated. However, adobe is the better choice as it will then be anaerobic.

Warehouse Wood Vault

Aqua Open and Aqua Vault

There are two versions of aquavault: Aquaopen and Aquavault. Aquaopen vaults are when weights are tied to logs and dropped off a barge into low-oxygen waters. Aquavaults are when logs are bundled inside a lining material. The lining material will keep out dwelling organisms.

Aquaopen Wood Vault

Aquavault wood vault

Desert Vaults

There are two versions of the desert vault: Desertopen and desert vault. Desert open is where piles of wooden logs are left open in the desert, piled in a way that allows natural ventilation to extend the life of preservation. Desertvault is when wood piles are protected with a synthetic material and placed under a shelter (similar to the warehouse vaults). The warm and dry desert climate prevents the wood from decaying.

Desert Open Wood Vault

Desert Wood Vault

Freezevaults

Wood piles are stored in cold regions, ideally below freezing, and placed out in the open. The colder environment will act like a natural freezer which prevents decay.

Arctic Wood Vault

Impacts

Environmental Impacts

A Wood Vault has several environmental impacts, both beneficial and detrimental. The primary concerns are material runoff from buried wood, topographical shifts over vaults, and ecological stress from managed forests and plantations.

Material runoff/leaching can be mitigated by ensuring that the only substance entering the vault is organic woody material. This can be done via careful monitoring of the input flows of buried wood. Topographic settling (sinking of land) can occur as buried wood goes through its initial decomposition. As such, it is critical to place Wood Vaults in locations where this settling will have minimal impact (i.e. not in the path of key watersheds or wetlands). This topographic settling can also be mitigated by preemptively adding additional soil on top during burial. Finally, at larger scales, wood harvesting and storage can require managed forests and plantations. It is critical that these managed forests be run sustainably and not interrupt key ecosystems and ecological hot-spots. This can be achieved by primarily utilising portions of large woodland areas where an area of management will cause minimal disruption and isolation.

There are several positive effects of a Wood Vault, including fire suppression and green land use. The fire suppression comes from removing dead wood in the forest underbrush that can cause or intensify wildfires. This wood is removed as part of the waste wood collection process. Additionally, after the land has been given time to settle, the surface can be used for other purposes such as solar farming or other environmentally friendly endeavors. Overall, the negative environmental impacts are small and preventable while the positive impacts can be significant, potentially acting to amplify the sequestration with renewable energy. There are no chemical processes that could cause spills or contamination. Furthermore, the construction of the Wood Vault leads to no large tax on local water or energy supplies.

Social Impact

A Wood Vault has minimal risk to public health. The primary pollutants will come from emissions related to trucking and excavation. While these are not large, especially when compared to the daily operation of a city, they can be mitigated by switching to cleaner and greener fuel sources, reducing harmful emissions.

As a precaution, clean wood is buried by carefully inspecting any materials brought to the burial site. Wood that has been treated or exposed to hazardous chemicals or other pollutants could pose a threat to local ecosystems and groundwater quality if buried. As such, it is critical to ensure that only woody organic material and nothing else is buried in the Wood Vault. This precaution should greatly reduce the risk of contamination that could negatively impact public health.

A Wood Vault project can be a source of significant economic development by providing good jobs and bringing money into the community.

Economic Cost

The cost of land needed for Wood Vault construction ranges from $10,000 to $40,000 per acre, or $25,000-$100,000 per hectare, but can be as low as $2000 per acre in more remote regions. The construction costs are primarily attributable to vault excavation and the sourcing of clay (if local soil is not suitable). The excavation costs are estimated at a unit cost of $4/m3 and the clay sourcing is estimated at $15/m3. Work and quality control will also be a large budget item. Transportation of wood from source to the Wood Vault facility is assumed at a rate of $5/ton for a 25-mile haul . This cost could be zero, or even negative if the facility acts as a wood waste disposal center, which typically is paid for a tipping fee to accept urban waste. The estimated total cost, not including transaction cost, is $10-$50/tCO₂.