A large global soil carbon sink informed by repeated soil samplings

Ruofei Jia; Evan C. Fricke; Avni Malhotra; Yinon M. Bar‐On; Jie Deng; Gervasio Piñeiro; Bruno Bazzoni; Roberto Álvarez; Nicola J. Findlay; Mariska te Beest; Yong Zhou; Thomas W. Boutton; Javid Ahmad Dar; S. Kothandaraman; Andrew S. MacDougall; Nico Eisenhauer; Pablo Luis Peri; Jianqiu Zheng; Sally A. Power; Sasha C. Reed; Petr Macek; Sylvia Haider; Stephen A. Sitch; Michael O’Sullivan; Pierre Friedlingstein; Ben Bond‐Lamberty; Bruce A. Hungate; Robert B. Jackson; Mina Subramanian; Kaizad Patel

doi:10.1101/2025.04.25.650716

EcologybioRxivApr 25, 2025

Preprint

A large global soil carbon sink informed by repeated soil samplings

Ruofei Jia iD, Evan C. Fricke iD, Avni Malhotra iD, Yinon M. Bar‐On iD, Jie Deng iD, Gervasio Piñeiro iD, Bruno Bazzoni iD, Roberto Álvarez iD, Nicola J. Findlay iD, Mariska te Beest iD, Yong Zhou iD, Thomas W. Boutton iD, Javid Ahmad Dar iD, S. Kothandaraman iD, Andrew S. MacDougall iD, Nico Eisenhauer iD, Pablo Luis Peri iD, Jianqiu Zheng iD, Sally A. Power iD, Sasha C. Reed iD, Petr Macek iD, Sylvia Haider iD, Stephen A. Sitch iD, Michael O’Sullivan iD, Pierre Friedlingstein iD, , César Terrer iD

Abstract

Partitioning the terrestrial carbon sink between vegetation and soil is crucial for predicting future climate change, but the role of soils remains poorly quantified. Here, we compiled 3,099 soil organic carbon time series spanning five decades. We found a global soil organic carbon sink of 1.83 {+/-} 0.9 (mean {+/-} SE) petagrams per year from 1992 to 2020, driven by extratropical young forests, boreal old forests, and grasslands, while trends in tropical ecosystems remain uncertain. Our findings suggest the net land sink resides almost exclusively belowground as soil carbon, emphasizing the global opportunity of soil conservation and restoration for climate mitigation.

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