Durable carbon dioxide removal efficiency of wood vault-enhanced afforestation

[Geoengineering News]

https://link.springer.com/article/10.1007/s11367-026-02734-w

Authors: Jerome Ignatius T. Garces, Raymond R. Tan, Kathleen B. Aviso, Michael Angelo B. Promentilla & Carla Mae J. Pausta 

27 August 2026

Abstract

Purpose

Afforestation is widely considered a technologically mature negative emissions technology (NET) for short-term carbon dioxide removal (CDR). Coupling it with anoxic wood burial in vaults can help address its durability limitations. However, the CDR potential of this wood vault-enhanced afforestation (WVEA) system has not yet been systematically evaluated. This study addresses this research gap by evaluating WVEA using an ex-ante cradle-to-grave life cycle assessment (LCA) to benchmark its CDR potential.

Methods

Climate Repair Value (CRV) was used to account for CDR durability. A 1-ha afforestation-only (AO) scenario served as the baseline against which the 1-ha WVEA system was compared over a 500-year timescale. Two tree species with different growth rates and wood harvesting schemes, Mahogany (Swietenia macrophylla) and Bagalunga (Melia dubia), were considered. Net CDR and cradle-to-grave inventory flows, including logistical processes such as wood harvesting, transportation, and vault construction, were modeled in SimaPro and characterized using the Global Warming Potential (GWP) metric of ReCiPe 2016 Midpoint (H) method, with a single-impact focus on climate change. Sensitivity analysis was conducted to assess the sensitivity of the results to operational parameter assumptions, wood vault durability, and impact assessment methodological assumptions.

Results and discussion

The results indicate that WVEA can achieve a CRV-weighted net CDR of 4.83 to 18.45 ktCO2e ha−1, when evaluated over a 2,000-year permanence horizon, while the AO baseline results in a CRV-weighted net emission of 0.28 to 1.07 ktCO2e ha−1. This highlights the significant long-term advantage of adopting wood burial to complement afforestation. For both tree species, CDR durability of the buried biomass relative to the exposed biomass accounted for this advantage, resulting in stable CDR efficiencies across multiple centuries. The net CDR advantage of WVEA is realized earlier for the faster-growing Bagalunga versus Mahogany, due to its more aggressive harvest and replanting cycle, coupled with wood vaulting. Biomass decomposition was identified as the dominant source of emissions for AO, underscoring the advantage of wood vaulting in preventing these emissions.

Conclusions and recommendations

This study demonstrates the potential of adopting engineered wood vaults coupled with afforestation-harvest cycles as a durable CDR strategy. Wood vaulting can amplify the climate change mitigation benefits of afforestation substantially at climate-relevant timescales. Future work should focus on improving model robustness by incorporating experimental data on the durability of buried biomass, additional constraints, such as soil nutrient depletion, and other impact factors to provide a full view of the overall environmental co-benefits and burdens of WVEA.

Source: Springer Nature Link