《Nature communications》| Varney et al：土壤碳周转对全球变暖敏感性的空间突发性约束

摘要：碳循环反馈在气候变化预测中存在着很大的不确定性，而土壤碳对气候变化的响应是其中最大的不确定性。土壤碳的变化取决于植物的凋落物和根系输入的变化，特别是在随着温度的升高而土壤碳的周转时间减少的过程中。可以从使用CMIP6和CMIP5地球系统模型（ESM）所作的预测中诊断出表层土壤碳（ΔC_s，τ）的近似项，发现即使在全球变暖2°C时，其覆盖范围也很大（−196 ± 117 PgC）。在本研究中，我们提出了一个对ΔC_s，τ的约束，它利用了当前的异养呼吸和从观测中推断的τ的空间变异性。这种空间出现约束使我们可以将ΔC_s，τat2°C的不确定性减半至-232 ± 52 PgC。

Abstract:  Carbon cycle feedbacks represent large uncertainties in climate change projections, and the response of soil carbon to climate change contributes the greatest uncertainty to this. Future changes in soil carbon depend on changes in litter and root inputs from plants and especially on reductions in the turnover time of soil carbon (τ_s) with warming. An approximation to the latter term for the top one metre of soil (ΔC_s,τ) can be diagnosed from projections made with the CMIP6 and CMIP5 Earth System Models (ESMs), and is found to span a large range even at 2 °C of global warming (−196 ± 117 PgC). Here, we present a constraint on ΔC_s,τ, which makes use of current heterotrophic respiration and the spatial variability of τ_s inferred from observations. This spatial emergent constraint allows us to halve the uncertainty inΔCs,τat2°C to−232 ± 52 PgC.

《Nature communications》为nature集团旗下的子刊，最新影响因子为12.121，是在线出版的多学科杂志，专门发表生物学、物理学和化学等各领域的高质量研究论文。

原文链接：

https://doi.org/10.1038/s41467-020-19208-8

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