Wood Vault: remove atmospheric CO2 with trees, store wood for carbon sequestration for now and as biomass, bioenergy and carbon reserve for the future

Table 1 Targets of carbon sequestration amount and example scenarios to achieve them using WHS

Target rate of carbon sequestration	Examples to achieve the goal without expansion of current wood harvest (use only unexploited wood residuals)		Examples with expansion or repurposing of forest management and harvest
Target rate of carbon sequestration			Medium harvest intensity (4 tCO₂ ha⁻¹ y⁻¹)	High harvest intensity (12 tCO₂ ha⁻¹ y⁻¹); fast growing species
1 MtCO₂ y⁻¹	Unused urban wood residue on 25,000 km² (size of MD, or 1/6 of NC) at 0.4 tCO₂ ha⁻¹	Forest thinning for fuel treatment on 25,000 km²	On 2500 km² of forested land (size of two counties in eastern US)	On 800 km² (30 km by 30 km forest, land area of New York City)
1 GtCO₂ y⁻¹	Most unexploited wood residue from 9 Mkm² (temperate forested land the size of US; US wood utilization rate) at 1.1 tCO₂ ha⁻¹ intensity	25% of current world wood harvest rate	2.5 Mkm² of forest	0.8 Mkm² restored Amazon rainforest (area deforested since 1970)
10 GtCO₂ y⁻¹ (27% of 2020 fossil fuel emissions; total NETs needed in IPCC 1.5 °C scenario)			25 Mkm² forest land (about half of total world forest)	8 Mkm² of productive forest land (slightly less than the size of US/China)

MD: the state of Maryland; NC: the state of North Carolina. Mkm²: million square kilometers, or 100 million hectares. A targeted rate can be fulfilled with a specific wood sourcing option listed, but in practice more likely by a combination of multiple choices because the best option depends on the local circumstances

ISSN: 1750-0680