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 22.76tCO2 km-2 yr-1,which was higher than the global average(15.77tCO2 km-2 yr-1).The total carbonate rock chemical weathering carbon sink(CCS)was 4772.67× 104tCO2,contributing 14.91％of the global CCS through a carbonate rock area of 252.98× 104 km-2.(2)China's CCSF decreased gradually from southeast to northwest,with values of 33.14,12.93,and 7.27tCO2 km-2 yr-1 in the southern karst,Qinghai-Tibetan karst,and northem karst regions,respectively.(3)The overall CCSF in China exhibited an increasing trend from 1991 to 2020,with a rate of increase of 0.16tCO2 km-2 yr1.(4)The contributions of the MAP,MAT,ET,SM,andNDVIto 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 30 years,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 pattems,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.
基金项目
国家自然科学基金(U22A20619)
国家自然科学基金(42077455 &42367008)
Westem Light Crossteam Program of Chinese Academy of Sciences(xbzgzdsys-202101)
中国科学院战略规划重点项目(XDB40000000 &XDA23060100)
贵州省科技计划(2022-198)
High-level Innovative Talents in Guizhou Province(GCC[2022]015-1 & 2016-5648)
Guizhou Provincial Science and Technology Subsidies(GZ2019SIG &GZ2020SIG)
万方数据