The physics and ecology of mining carbon dioxide from the atmosphere by ecosystems
The physics and ecology of mining carbon dioxide from the atmosphere by ecosystems
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DOI：
10.1111/gcb.14559
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发表时间：
2019-04-01
影响因子：
11.6
通讯作者：
Penuelas, Josep
中科院分区：
文献类型：
--
作者：
Baldocchi, Dennis;Penuelas, Josep
重新造林和管理生态系统已被提出作为减缓全球变暖和抵消人为碳排放的方法。我们这篇观点文章的目的是提供一个关于植物和生态系统固碳能力的视角。单个植物和生态系统从大气中开采二氧化碳的能力，根据速率和累积量的定义，受到物理定律和生态原理的限制。因此，与化石燃料燃烧释放的二氧化碳的速率和数量相比，净碳吸收的速率和数量缓慢而低。管理生态系统以隔离碳也可能导致意想不到的后果。在本文中，我们阐明了一系列关键的要点。首先，一个生态系统可以吸收的潜在碳量以年为基础，以吸收的阳光为尺度，随纬度、叶面积指数和可用水量的变化而变化。其次，改善光合作用的努力将以更多的呼吸为代价。第三，与化石燃料燃烧释放的二氧化碳的速率、数量和速率相比，净碳吸收的速率和数量相对缓慢和低。第四，需要为生态系统提供大量的土地面积，使其成为有效的碳汇，以减轻人为碳排放。第五，利用这些土地作为碳汇的有效性将取决于其作为永久碳汇的能力。第六，将土地转化为森林或湿地可能会产生意想不到的代价，使当地气候变暖，例如改变反照率，增加表面粗糙度或释放其他温室气体。我们的分析基于来自全球155个地点的总碳通量和净碳通量的1163个站点年的直接涡动相关方差测量。
Reforesting and managing ecosystems have been proposed as ways to mitigate global warming and offset anthropogenic carbon emissions. The intent of our opinion piece is to provide a perspective on how well plants and ecosystems sequester carbon. The ability of individual plants and ecosystems to mine carbon dioxide from the atmosphere, as defined by rates and cumulative amounts, is limited by laws of physics and ecological principles. Consequently, the rates and amount of net carbon uptake are slow and low compared to the rates and amounts of carbon dioxide we release by fossil fuels combustion. Managing ecosystems to sequester carbon can also cause unintended consequences to arise. In this paper, we articulate a series of key take-home points. First, the potential amount of carbon an ecosystem can assimilate on an annual basis scales with absorbed sunlight, which varies with latitude, leaf area index and available water. Second, efforts to improve photosynthesis will come with the cost of more respiration. Third, the rates and amount of net carbon uptake are relatively slow and low, compared to the rates and amounts and rates of carbon dioxide we release by fossil fuels combustion. Fourth, huge amounts of land area for ecosystems will be needed to be an effective carbon sink to mitigate anthropogenic carbon emissions. Fifth, the effectiveness of using this land as a carbon sink will depend on its ability to remain as a permanent carbon sink. Sixth, converting land to forests or wetlands may have unintended costs that warm the local climate, such as changing albedo, increasing surface roughness or releasing other greenhouse gases. We based our analysis on 1,163 site-years of direct eddy covariance measurements of gross and net carbon fluxes from 155 sites across the globe.