Radiocarbon constraints imply reduced carbon uptake by soils during the 21st century
Radiocarbon constraints imply reduced carbon uptake by soils during the 21st century
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DOI：
10.1126/science.aad4273
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发表时间：
2016-09-23
期刊：
影响因子：
56.9
通讯作者：
Randerson, James T.
中科院分区：
文献类型：
--
作者：
He, Yujie;Trumbore, Susan E.;Randerson, James T.
土壤是最大的陆地碳库，可以影响碳循环-气候反馈的信号和大小。许多地球系统模型（esm）估计到2100年土壤碳汇将显著增加，但决定这一响应的潜在碳动力学尚未根据观测结果进行系统测试。我们使用了157个全球分布土壤剖面的C-14数据，采样深度为1米，结果表明，esm低估了土壤碳的平均年龄6倍以上（430 +/- 50年与3100 +/- 1800年）。因此，esm高估了土壤的固碳潜力近两倍（40 +/- 27%）。这些不一致性表明，在模拟未来大气二氧化碳动力学时，esm必须更好地代表缓慢和被动储层的碳稳定过程和周转时间。
Soil is the largest terrestrial carbon reservoir and may influence the sign and magnitude of carbon cycle-climate feedbacks. Many Earth system models (ESMs) estimate a significant soil carbon sink by 2100, yet the underlying carbon dynamics determining this response have not been systematically tested against observations. We used C-14 data from 157 globally distributed soil profiles sampled to 1-meter depth to show that ESMs underestimated the mean age of soil carbon by a factor of more than six (430 +/- 50 years versus 3100 +/- 1800 years). Consequently, ESMs overestimated the carbon sequestration potential of soils by a factor of nearly two (40 +/- 27%). These inconsistencies suggest that ESMs must better represent carbon stabilization processes and the turnover time of slow and passive reservoirs when simulating future atmospheric carbon dioxide dynamics.