CO2 source-sink in karst processes in karst areas of China

The CO 2 source-sink of atmospheric greenhouse has a close relationship with karst processes.The corrosion of carbonate rocks leads to the sink of atmospheric CO 2 , whereas the deposition of carbonate rocks gives off CO 2 into atmosphere, which is one of the sources of atmospheric CO 2 .According to the exposed areas of carbonate rocks in China, the flux of atmospheric CO 2 consumed in karst processes is estimated at about 1.77×10 13 g CO 2 /a.Considering the global karst area, the flux of atmospheric CO 2 consumed in corrosion may be an important part of the missing sink.And the sink has a tendency of continuous increase.The release of CO 2 from karst water is usually less than the sink of atmospheric CO 2 consumed in karst processes.But in active tectonic zone the release of high CO 2 concentration of mantle source in the geothermal karst water should not be neglected.