Abstract：
In 2020, anthropogenic methane (CH4) emissions decreased due to COVID-19 containment policies, but there was a substantial increase in the concentration of atmospheric CH4. Previous research suggested that this abnormal increase was linked to higher wetland CH4 emissions and a decrease in the atmospheric CH4 sink. However, the impact of changes in the soil CH4 sink remained unknown. To address this, we utilized a process-based model to quantify alterations in the soil CH4 sink of terrestrial ecosystems between 2019 and 2020. By implementing the model with various datasets, we consistently observed an increase in the global soil CH4 sink, reaching up to 0.35 ± 0.06 Tg in 2020 compared to 2019. This increase was primarily attributed to warmer soil temperatures in northern high latitudes. Our results emphasize the importance of considering the CH4 sink in terrestrial ecosystems, as neglecting this component can lead to an underestimation of both emission increases and reductions in atmospheric CH4 sink capacity. Furthermore, these findings highlight the potential role of increased soil warmth in terrestrial ecosystems in slowing the growth of CH4 concentrations in the atmosphere.
摘要：
2020年，由于COVID-19遏制政策，人为甲烷(CH4)排放量减少，但是大气中CH4的浓度却大大增加。先前的研究表明，这种异常增加与湿地CH4排放量增加和大气CH4汇减少有关。然而,土壤CH4汇变化的影响仍然未知。为了解决这个问题，我们利用基于过程的模型来量化2019年至2020年间陆地生态系统土壤CH4汇的变化。通过使用各种数据集实现模型，我们一直观察到全球土壤CH4汇的增加，与2019年相比，2020年Tg达到0.35±0.06。这种增加主要归因于北部高纬度地区土壤温度升高。我们的结果强调了在陆地生态系统中考虑CH4汇的重要性，因为忽略该成分可能导致对排放增加和大气CH4吸收容量减少的低估。此外，这些发现强调了陆地生态系统中土壤温暖增加在减缓大气中CH4浓度增长方面的潜在作用。
