The Oceanic Sink for Anthropogenic CO2

Using inorganic carbon measurements from an international survey effort in the 1990s and a tracer-based separation technique, we estimate a global oceanic anthropogenic carbon dioxide (CO) sink for the period from 1800 to 1994 of 118 ± 19 petagrams of carbon. The oceanic sink accounts for ~48% of the total fossil-fuel and cement-manufacturing emissions, implying that the terrestrial biosphere was a net source of CO to the atmosphere of about 39 ± 28 petagrams of carbon for this period. The current fraction of total anthropogenic CO emissions stored in the ocean appears to be about one-third of the long-term potential.