杨晓艳 1任世川 1田文锐 1马能伟 1宋增宏 1李国瑞 1张高引1
作者信息
- 1. 云南省高原山地地质灾害预报预警与生态修复重点实验室(筹),云南 昆明 650216||自然资源部高原山地地质灾害预报预警与生态修复重点实验室,云南 昆明 650216||云南省地质环境监测院,云南 昆明 650216
- 折叠
摘要
Abstract
The carbon cycle of the Earth's system coexists with global climate change.Carbon circulates in different forms between different reservoirs,with carbonate rocks actively participating in the global carbon cycling through karst processes.The recovered CO2 accounts for about one-third of the"missing sink",making it an important link between the atmosphere and the sink of CO2.Currently,the dynamic studies on the karst carbon cycling are mainly focused on short time scales such as daily,monthly,seasonal,and annual dynamics,as well as the effects of precipitation.These studies suggest that karst processes are extremely sensitive to environmental changes and are basically synchronized with various climate changes(such as precipitation and temperature)and biological activities,with no significant lag observed.The long-term dynamic changes and responses to climate change are mainly based on carbon isotope records in stalagmites.These records indicate that the changes in carbon content within stalagmites lag behind alterations in atmospheric CO2 concentration by 16 years.Although the IPCC's AR5 and AR6 reports acknowledge the important role of karst carbon sink in sequestering atmospheric CO2,they classify the carbon sink associated with carbonate rock weathering(karst action)as a long-term carbon sink with a time scale of 103-104 years.Furthermore,this process has not been incorporated into the global carbon budget.There is considerable controversy surrounding the timescale of karst carbon sink.Consequently,the long-term dynamics of carbonate weathering,carbon sink,and their responses to climate change necessitate further in-depth research.
The outcropping area of carbonate rocks in the karst area of Southwest China covers 540,000 km2,encompassing three major geomorphic units of the country.This area represents the largest contiguous distribution of exposed carbonate rocks in the world.It benefits from favorable water and heat conditions,along with intense karst processes,which contribute to significant carbon sink effects.The Kunming basin is a water-collecting karst graben basin,with a catchment area of 2,924.5 km2.The outcropping area of carbonate rock layers accounts for about 32%of the total basin area.Karst water in the basin is characterized by abundant amount,concentrated storage,and good water quality.Meanwhile,Kunming,as the capital city of Yunnan Province,has a developed socio-economy.Groundwater monitoring in the area began early and has resulted in a substantial accumulation of foundational data.However,research on karst carbon sink remains relatively underdeveloped.Based on the long-term observation data of karst springs in the Kunming basin,this paper analyzes and calculates the changes in atmospheric CO2 concentration,climate indicators(temperature and precipitation),and data on spring water quality.The response of carbonate weathering to fluctuations in atmospheric CO2 concentration and climate change over the past 40 years,along with its carbon sink effect and contribution to CO2 emission reduction is preliminarily evaluated.The results show that the CO2 consumption rate by carbonate weathering is positively correlated with atmospheric CO2 concentration,exhibiting a lag time of about 20 years,and the rate of change is basically the same.The variations in carbon sink intensity are mainly controlled by changes in precipitation,with no obvious lag time,while also being affected by changes in atmospheric CO2 concentration,with a lag of 20 years.The research findings indicate that the increase in atmospheric CO2 concentration will enhance the dissolution of carbonate rocks,allowing more CO2 to be sequestrated from the atmosphere.This process plays an important role in mitigating global warming.These findings are significant for accurately evaluating the intensity of karst carbon sink,incorporating karst carbon sink into global carbon accounting,addressing the"missing sink"problem,and promoting the achievement of the"dual carbon"goals.关键词
二氧化碳/西南岩溶/昆明盆地/碳酸盐岩风化碳汇/变化响应Key words
carbon dioxide/karst in Southwest China/the Kunming basin/carbonate weathering and carbon sink/response to change分类
天文与地球科学
