日本高知大学海洋核心研究所Sano, Yuji研究团队报道了从全球板块构造看深层碳循环。该研究于2024年4月12日发表于国际一流学术期刊《国家科学评论》杂志上。

研究人员概述了现代板块构造体系中深部碳循环的情况，特别关注用于评估全球碳质量平衡的汇聚板块边缘。最新的通量汇编表明，在不确定的范围内，深层碳外流和俯冲碳内流之间大致平衡，但碳向对流地幔的回流非常有限。如果正确的话，碳将随着时间的推移逐渐在岩石圈中积聚——(i)大规模的地下碳储存主要发生在大陆岩石圈，从汇聚边缘到大陆内部；(ii)由于向大气排放高通量深层二氧化碳，而持续存在的海底表面碳汇。

对全球碳质量平衡的进一步评估，需要更新俯冲驱动的碳循环路径的通量，并减少深层碳外流的不确定性。从全球板块构造的角度出发，研究人员特别强调大陆改造是重新活化大陆地壳，和次大陆岩石圈地幔中地质封存碳的重要机制。结合近年来的研究进展，建议未来的研究侧重于通过观测、实验和数值模拟的综合方法，更好地了解深层碳循环的储库、通量、机制和气候效应，以从深层碳循环的角度解读地球系统的自我调节及其可居住性。

据介绍，板块构造在地球内部和表面之间重新分配生命必需的挥发性元素方面，起着至关重要的作用，因此，我们的星球在其历史的大部分时间里一直保持着宜居性。

附：英文原文

Title: Deep carbon recycling viewed from global plate tectonics

Author: Zhang, Maoliang, Xu, Sheng, Sano, Yuji

Issue&Volume: 2024-04-12

Abstract: Plate tectonics plays an essential role in the redistribution of life-essential volatile elements between Earth's interior and surface, whereby our planet has been well tuned to maintain enduring habitability over much of its history. Here we present an overview of deep carbon recycling in the regime of modern plate tectonics, with a special focus on convergent plate margins for assessing global carbon mass balance. The up-to-date flux compilation implies approximate balance between deep carbon outflux and subduction carbon influx within uncertainty but remarkably limited return of carbon to convecting mantle. If correct, carbon would gradually accumulate in the lithosphere over time by (i) massive subsurface carbon storage occurring primarily in continental lithosphere from convergent margins to continental interior and (ii) persistent surface carbon sinks to seafloors sustained by high-flux deep CO₂ emissions to the atmosphere. Further assessment of global carbon mass balance requires updates on fluxes of subduction-driven carbon recycling paths and reduction in uncertainty of deep carbon outflux. From a global plate tectonics point of view, we particularly emphasize that continental reworking is an important mechanism for remobilizing geologically sequestered carbon in continental crust and sub-continental lithospheric mantle. In light of recent advances, future research is suggested to focus on a better understanding of the reservoirs, fluxes, mechanisms, and climatic effects of deep carbon recycling following an integrated methodology of observation, experiment, and numerical modeling, with the aim of decoding the self-regulating Earth system and its habitability from the deep carbon recycling perspective.

DOI: 10.1093/nsr/nwae089

Source: https://dx.doi.org/10.1093/nsr/nwae089