Six-times more carbon dioxide (CO 2 ) is removed each year by terrestrial photosynthesis than fossil fuel emissions. However, the carbon is mostly returned to the atmosphere by decomposition. We found a 3775-year-old ancient wood log buried 2 meters belowground that was preserved far beyond its expected lifetime. The wood had near-perfect preservation, with carbon loss less than 5% compared to a modern sample. The lack of decay is likely due to the low permeability of the compact clay soil at the burial site. Our observation suggests a hybrid nature-engineering approach for carbon removal by burying woody biomass in similar anoxic environments. We estimate a global sequestration potential of up to 10 gigatonnes CO 2 per year with existing technology at a low cost of $30 to $100 per tonne after optimization.

中文翻译：

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拥有 3775 年历史的木葬支持“木拱顶”作为一种耐用的除碳方法


陆地光合作用每年去除的二氧化碳 （CO 2） 是化石燃料排放的六倍。然而，碳大部分通过分解返回到大气中。我们发现了一根埋在地下 2 米处的 3775 年历史的古老原木，其保存时间远远超过了其预期的寿命。这种木材的保存效果近乎完美，与现代样品相比，碳损失不到 5%。没有腐烂可能是由于墓地致密粘土的低渗透性。我们的观察表明，通过将木质生物质掩埋在类似的缺氧环境中，可以采用混合自然工程方法去除碳。我们估计，使用现有技术，优化后每吨 30 至 100 美元的低成本，全球每年可封存高达 10 吉吨的 CO2。