Preliminary regional estimation of carbon sink flux by carbonate rock corrosion: A case study of the Pearl River Basin

Abstract

The formation of carbonate rocks has had a dramatic sink effect on atmospheric CO2 throughout geological time. The wide global distribution of carbonate rocks and their strong sensitivity to climate change mean that carbonate rock corrosion consuming air/soil CO2 can play an important role in the global carbon cycle. The carbon sink accounts for 12. 00%-35. 29% of the "missing carbon" in the global carbon cycle. Using the Pearl River Basin as a case study, we analyzed comprehensively the factors impacting karstification and the carbon sink, collected existing monitoring data, and established a regression equation incorporating corrosion rate, annual precipitation, soil respiration rate and net primary productivity from typical observation sites. We used Arcview 3.3 software to estimate spatially the atmospheric CO2 sink flux in the Basin's karst region by combining the distribution of carbonate rock categories. We determined annual CO2 consumption due to carbonate rock corrosion to be 1.54×107 t CaCO3 a-1, equal to 1.85×106 t C a-1. © 2011 The Author(s).