Department of Atmospheric and Oceanic Science and Earth System Science Interdisciplinary Center, University of Maryland, College Park, USA.
Carbon Balance Manag. 2008 Jan 3;3:1. doi: 10.1186/1750-0680-3-1.
To mitigate global climate change, a portfolio of strategies will be needed to keep the atmospheric CO2 concentration below a dangerous level. Here a carbon sequestration strategy is proposed in which certain dead or live trees are harvested via collection or selective cutting, then buried in trenches or stowed away in above-ground shelters. The largely anaerobic condition under a sufficiently thick layer of soil will prevent the decomposition of the buried wood. Because a large flux of CO2 is constantly being assimilated into the world's forests via photosynthesis, cutting off its return pathway to the atmosphere forms an effective carbon sink.It is estimated that a sustainable long-term carbon sequestration potential for wood burial is 10 +/- 5 GtC y-1, and currently about 65 GtC is on the world's forest floors in the form of coarse woody debris suitable for burial. The potential is largest in tropical forests (4.2 GtC y-1), followed by temperate (3.7 GtC y-1) and boreal forests (2.1 GtC y-1). Burying wood has other benefits including minimizing CO2 source from deforestation, extending the lifetime of reforestation carbon sink, and reducing fire danger. There are possible environmental impacts such as nutrient lock-up which nevertheless appears manageable, but other concerns and factors will likely set a limit so that only part of the full potential can be realized.Based on data from North American logging industry, the cost for wood burial is estimated to be $14/tCO2($50/tC), lower than the typical cost for power plant CO2 capture with geological storage. The cost for carbon sequestration with wood burial is low because CO2 is removed from the atmosphere by the natural process of photosynthesis at little cost. The technique is low tech, distributed, easy to monitor, safe, and reversible, thus an attractive option for large-scale implementation in a world-wide carbon market.
为了缓解全球气候变化，我们需要采取一系列策略，将大气中的二氧化碳浓度控制在危险水平以下。在这里，我们提出了一种碳封存策略，即通过收集或选择性砍伐的方式收获某些死亡或存活的树木，然后将其埋在沟渠中或储存在地上的避难所中。在足够厚的土层下，这种主要的厌氧条件将防止埋藏木材的分解。由于通过光合作用，大量的二氧化碳不断被同化到世界森林中，因此切断其返回大气的途径就形成了一个有效的碳汇。据估计，木材埋藏的可持续长期碳封存潜力为 10 ± 5 GtC y-1，目前全球森林地表以适合埋藏的粗木质残体形式存在约 65 GtC。热带森林的潜力最大（4.2 GtC y-1），其次是温带（3.7 GtC y-1）和北方森林（2.1 GtC y-1）。埋藏木材还有其他好处，包括最大限度地减少森林砍伐的二氧化碳源，延长重新造林碳汇的寿命，降低火灾危险。尽管存在养分锁定等可能的环境影响，但这些影响似乎是可控的，但其他问题和因素可能会限制这一策略的实施，使得只有部分潜力能够实现。基于北美伐木工业的数据，木材埋藏的成本估计为 14 美元/tCO2（50 美元/tC），低于典型的发电厂二氧化碳捕获与地质储存成本。木材埋藏的碳封存成本较低，因为二氧化碳通过自然光合作用过程从大气中去除，几乎没有成本。该技术具有低技术含量、分布式、易于监测、安全和可逆等特点，因此是在全球碳市场中大规模实施的一个有吸引力的选择。
