Prompt rewetting of drained peatlands reduces climate warming despite methane emissions
Prompt rewetting of drained peatlands reduces climate warming despite methane emissions
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DOI：
10.1038/s41467-020-15499-z
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发表时间：
2020-04-02
影响因子：
16.6
通讯作者：
Couwenberg, John
中科院分区：
文献类型：
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作者：
Guenther, Anke;Barthelmes, Alexandra;Couwenberg, John
泥炭地因其无与伦比的碳储量而成为减缓气候变化的战略区域。排水的泥炭地将这些碳以二氧化碳（CO2）的形式释放到大气中。泥炭地重新湿润有效地阻止了这些二氧化碳的排放，但也重新建立了甲烷（CH4）的排放。从根本上说，管理必须在排干的泥炭地的CO2排放量和重新湿润的泥炭地的CH4排放量之间作出选择。这一选择必须考虑到这两种气体的辐射效应和大气寿命，二氧化碳是一种微弱但持久的温室气体，甲烷是一种强烈但短暂的温室气体。因此，由此产生的气候影响与时间密切相关。我们使用辐射强迫模型来比较未来泥炭地管理的全球情景的强迫动态，使用来自全球泥炭地数据库的面积数据。我们的研究结果表明，CH4辐射强迫不会破坏泥炭地再湿润的气候变化减缓潜力。相反，推迟复湿会通过持续的二氧化碳排放增加长期的变暖效应。排干的泥炭地是二氧化碳的来源，虽然重新湿润可以减少排放，但这种策略会导致甲烷释放量增加。在这里，作者模拟了泥炭地的排放情景，并表明尽管潜在的甲烷增加，但再润湿是缓解气候变化的关键方法。
Peatlands are strategic areas for climate change mitigation because of their matchless carbon stocks. Drained peatlands release this carbon to the atmosphere as carbon dioxide (CO2). Peatland rewetting effectively stops these CO2 emissions, but also re-establishes the emission of methane (CH4). Essentially, management must choose between CO2 emissions from drained, or CH4 emissions from rewetted, peatland. This choice must consider radiative effects and atmospheric lifetimes of both gases, with CO2 being a weak but persistent, and CH4 a strong but short-lived, greenhouse gas. The resulting climatic effects are, thus, strongly time-dependent. We used a radiative forcing model to compare forcing dynamics of global scenarios for future peatland management using areal data from the Global Peatland Database. Our results show that CH4 radiative forcing does not undermine the climate change mitigation potential of peatland rewetting. Instead, postponing rewetting increases the long-term warming effect through continued CO2 emissions. Drained peatlands are sources of CO2, and though rewetting could curb emissions, this strategy results in elevated methane release. Here, the authors model peatland emissions scenarios and show that rewetting is a critical way to mitigate climate change despite potential methane increases.