Wood Vault Concerns

What is a Wood Vault?

The wood vault is a new concept within the “hybrid nature-engineering method to combat climate change” which builds on storage of harvested wood for carbon sequestration. The most typical nature-engineering outcome is a forest product (i.e. construction or furniture), however, the wood vault would sequester woody debris that is not turned into wood products. Depending on the startup company working on the project, the wood can be stored either deep underground or in a mound. To date, wood vaults have only been purpose-tested in small demonstration projects but ambitious prototypes are being produced that would occupy 2.47 square acres, (1 hectare) of surface land, be 65 feet tall (20 meters) and collect unused wood residuals from an area the size of 10 typical U.S. counties or 9,600 square miles (25,000 km2).

What are the problems with Wood Vaults?

1)  Wood vaults create a perverse incentive for increased logging:

a. The carbon trade market has encouraged speculation and Ponzi-schemes. Currently, wood vault startups can pre-purchase carbon credits and then log, according to what they may need to fill the vault to ‘sequester’ the carbon – not according to any management a forest may potentially need. These carbon credits are then sold to big polluters, enabling additional pollution instead of making them clean up existing sources. Logging also destroys our most important real carbon capture and storage mechanism: our forests, and hinders them from maturing and continuing to actively draw down pollution and sequestering it in their mass and soils.

b. Some wood vault companies have created automated logging operations (“automated ways to thin forests, making it cheaper and faster to log, strip limbs off the trees, and select usable timber, then bury the rest.”) Logging in general should be a very careful and discriminating operation.

c. While the Forest Service states that forest management is necessary to keep our forests healthy, it also just co-authored the Maryland Forest Stewardship Disalignment Report which warns current “sustainable management” is too aggressive since “harvest allowances built into the stewardship plans may preclude forest landowners from participating in certain ecosystem markets.”  The fact is that forests are dynamic and constantly change by themselves – they don’t need humans to help them. Mature and old-growth forests (the most valuable ones for carbon capture and biodiversity) can mostly self-regulate and do not require logging – in fact, the ‘no-management’ option is the best one for climate change as it maximizes carbon capture and storage. In the mid-Atlantic region, the main management activities should be invasive species abatement and deer management, in addition to nature recovery efforts whereby we help forests regenerate (plantings) and reconnect wildlife corridors – not logging.

As we can see in the graphic below taken from "Forest carbon storage in the Northeastern United States: effects of 6 harvesting frequency and intensity including wood products" by Nunery and Keeton (2009), the most climate smart forest management practice is no management as it stores the most CO2.

d. Wood vaults are being planned for land that was placed in preservation easements. The wood vault would disrupt the protected lands, potentially polluting them, and simply generate additional funds for the land owner or easement holder.

2)  Wood vault proponents do not take into account all emissions:

a.   For each ton of CO2 sequestered in wood products, we emit up to 13 tons of CO2 in its production. Therefore, the emissions from the by-product, the waste wood or woody biomass that would be buried in a vault, would produce similar amounts of CO2– up to 13 times as much CO2 than it sequesters. It would make more sense to just leave forests be.

b.  Logging is one of the most polluting industries in the world: A July 2023 paper in Nature (The Carbon Costs of Global Wood Harvest) finds that the world’s yearly wood harvests are likely to emit 3.5 to 4.2 billion tons of carbon dioxide equivalent per year, more than 10% of recent global annual emissions of carbon dioxide. It also finds that these emissions are typically not counted in either scientific papers or public policies. This level of emissions is more than three times the annual emissions from aviation.

c.   Loss of Soil-C and Arbuscular Mycorrhizal Fungi Network (AMF) die off are not accounted for: The world's forests store approximately 861 gigatons of carbon, with 44 percent in soil (to one-meter depth), 42 percent in live biomass (above- and below-ground), 8 percent in dead wood, and 5 percent in litter. When we log the trees (less than 42% of live biomass – only the above ground) we unfortunately also kill off below ground biomass and the symbiotic AMF (44% of carbon in the soil), in addition to –arguably- the 5% in litter.

d.  What are the emissions from the construction of the (Pit, Quarry, or Mine)/ Super Vault/ Shelter/AquaOpen or AquaVault/ DesertOpen or DesertVault or FreezeVault (see article from the CBM Journal above)?

e.   Additional emissions from collecting, transporting (via truck?), sorting, and testing woody biomass from up to nearly 10,000 square miles (9,652.554) to fill the vault are also not accounted for.

3)  Wood vaults don't distinguish which wood to store:  (i.e. old growth v. invasive species). “Woody biomass” for wood vaults is sometimes defined as “vegetation that does not contain any toxic chemicals or other contaminants that are unsuitable for long-term burial; and is sourced from wood residuals unfit for market; and, if not buried in a wood vault- would be mulched, burned, or otherwise disposed of, resulting in the release of carbon within 20 years if not sequestered.” That’s pretty much anything that grows – yet wood does not usually decompose in 20 years (see below.)

4)  Wood Vaults would have to store wood for centuries: The wood vault would hold “woody biomass that otherwise would release CO2 back into the air within 20 years.” Yet, a log or tree from conifer species decomposes over 57 to 124 years. Hardwood species typically take 46 to 71 years, and this decomposed wood is now fertile soil. How does one test the potential effects wood vaults could have over centuries? 

a.   A wood vault would do nothing for carbon or methane capture and storage within 20 years when decomposition can take over 100 years.

b.  Removing decomposing wood from the forest/forested lands also removes habitat for many animals, millions of micro-organisms, and impedes the generation of healthy soils.

c.   We are not in a fire-prone region where dead wood could conceivably become a fire hazard – and forest thinning for fire is questionable in the many cases.

d.  The best forest management strategy to help avoid the dual catastrophe of climate emergency and biodiversity die off is forest protection, preservation/proforestation, nature recovery, and rewilding according to the International Panel on Climate Change, the International Union for the Conservation of Nature, the Center for Biological Diversity, and others who are not seeking to profit from timber. A pivotal study on carbon capture in different forest management styles in Northeastern Forests by Nunery and Keeton, makes it absolutely clear that no-management is the most effective for carbon storage (see attached chart.)

5)  Wood Vault permits copy existing insufficient permitting for landfills and incinerators. The wood vault is a new concept and we don’t know what it may entail yet. That said, it has become clear that existing regulations, specifically air permits and some water permits, are insufficient to keep communities safe from landfills and incinerators.

In our opinion, it makes more sense to leave the forests to grow old than to log them. Any woody debris should be left to generate fertile soils. Since there is so much invested in the concept already, we would like to clarify that the only potential safe path forward for Wood Vaults would require strict guard rails including:

1)  Burial of biomass from invasive species only to avoid incentivizing logging;

2) Ensure that no carbon credits can be gained through wood storage in any vault; 

3)  Small “farm sized” wood vaults for invasive species which would not require hundreds of miles of transportation;

4)  Prohibit automation of any logging;

5)  Require third party inspections of what is being buried, where, and how;

6)  Siting in already compromised areas, not in protected landscapes;

7)  Clear regulations regarding depth, height, size, duration of the vault, etc.;

8)  Strict monitoring of any effects over the entire duration of the vault; and

9)   Strong air and water permits.