cm" class=MsoNormal>In order to calculate the atmospheric COB>2 sink formed in karst processes, the karst area of China can be divided into four types of karst regions: South China karst region, North China karst region, Tibet Plateau karst region and the buried karst region. The area of the above regions is 564 800 km2, 325 800 km2, 556 000 km2 and 2 001 000 km2, respectively. Based on the data from recent geologic survey and statistics of the other research results, the atmospheric CO2 sinks formed in karst processes of the above-mentioned four karst regions are estimated. Therefore, the total atmospheric CO2 sink formed in karst processes of China is 3 699.1×104 t CO2/a.ce prefix = o ns = "urn:schemas-microsoft-com:office:office" />