中国科学院地质与地球物理研究所白晓永团队的最新研究，探明了中国碳酸盐岩区岩溶无机碳的储量、形态及影响因素。2024年2月26日，国际知名学术期刊《中国科学：地球科学》发表了这一成果。

研究人员收集了中国不同流域已发表的离子浓度的现场数据，并使用经典热力学溶解模型，重新评估了1991-2020年中国CCSF的潜力和时空模式。研究量化了温度(MAT)、降水(MAP)、蒸散发(ET)、土壤水分(SM)和归一化植被指数(NDVI)对CCSF的贡献。结果表明：(1)中国的CCSF为22.76t CO₂km^-2yr^-1，高于全球平均水平(15.77t CO₂km^-2yr^-1)。碳酸盐岩化学风化碳汇(CCS)总量为4772.67×10⁴t CO₂通过面积为252.98×10⁴km²的碳酸盐岩，贡献了全球CCS的14.91%。

(2)中国的CCSF由东南向西北逐渐降低，在南方喀斯特区、青藏喀斯特区、北喀斯特区分别为33.14、12.93和7.27t CO₂km^-2yr^-1。(3) 从1991-2020年，中国的总体CCSF呈增加趋势，增长速率为0.16t CO₂km^-2yr^-1。(4) MAP、MAT、ET、SM和NDVI对CCSF的贡献率分别为63.3%、3.02%、27.5%、3.1%和3.05%。其中，降水增加是近30年中国CCSF增加的主要原因。而ET的增强抵消了降水增加对CCSF的部分正贡献。综上所述，本研究的结果为中国长期CCS的数量、模式和影响因素的系统量化。研究结果对我国和全球碳中和能力的诊断和差距分析具有重要的参考意义。

据介绍，碳酸盐岩化学风化碳汇减缓了大气CO₂浓和全球变暖的增长率。然而，碳酸盐岩化学风化碳汇通量(CCSF)的估算结果仍存在不确定性，气候变化和生态恢复对CCSF的贡献尚不明确。

附：英文原文

Title: Storage, form, and influencing factors of karst inorganic carbon in a carbonate area in China

Author: Chaochao DU, Xiaoyong BAI, Yangbing LI, Qiu TAN, Cuiwei ZHAO, Guangjie LUO, Luhua WU, Fei CHEN, Chaojun LI, Chen RAN, Sirui ZhANG, Lian XIONG, Fengjiao SONG, Biqin XIAO, Zilin LI, Yingying XUE, Mingkang LONG, Qing LUO, Xiaoyun ZHANG, Minghui LI, Xiaoqian SHEN, Shu YANG

Issue&Volume: 2024/02/26

Abstract: Carbonate rock chemical weathering carbon sinks reduce the rate of increase of the atmospheric CO₂ concentration and global warming. However, uncertainty still exists in the estimation results of carbonate rock chemical weathering carbon sink fluxes (CCSF), and the contributions of climate change and ecological restoration to the CCSF are not clear. To this end, we compiled published site data on ion concentrations in different watersheds in China and used a classical thermodynamic dissolution model to reassess the potential and spatial and temporal patterns of the CCSF in China from 1991 to 2020. We quantified the contributions of temperature (MAT), precipitation (MAP), evapotranspiration (ET), soil water (SM), and the normalized difference vegetation index (NDVI) to the CCSF. The results revealed that (1) China’s CCSF was 22.76t CO₂km^-2yr^-1, which was higher than the global average (15.77t CO₂km^-2yr^-1). The total carbonate rock chemical weathering carbon sink (CCS) was 4772.67×104t CO₂, contributing 14.91% of the global CCS through a carbonate rock area of 252.98×10⁴km^-2. (2) China’s CCSF decreased gradually from southeast to northwest, with values of 33.14, 12.93, and 7.27t CO₂km^-2yr^-1 in the southern karst, Qinghai-Tibetan karst, and northern karst regions, respectively. (3) The overall CCSF in China exhibited an increasing trend from 1991 to 2020, with a rate of increase of 0.16t CO₂km^-2yr^-1. (4) The contributions of the MAP, MAT, ET, SM, and NDVI to the CCSF were 63.3%, 3.02%, 27.5%, 3.1%, and 3.05%, respectively. Among them, the increase in precipitation was the main contributor to the increase in the CCSF in China over the last 30years, while the enhancement of ET offset part of the positive contribution of the increase in precipitation to the CCSF. In conclusion, the results of this study provide a systematic quantification of the magnitude, the patterns, and the influencing factors of CCS over a long time series in China. The results are of great significance and provide a reference for the diagnosis and gap analysis of the national and global carbon neutrality capacities.

DOI: 10.1007/s11430-023-1249-9

Source: https://www.sciengine.com/10.1007/s11430-023-1249-9