Abstract
[HN14] Thanks to international efforts, COconcentrations in the atmosphere are monitored at ~100 sites worldwide. By comparison, very few decade-long ocean COrecords exist, and consequently very little is known about the variability of COconcentrations in the surface ocean. In his Perspective, Quay highlights the report of Gruber, Bates, and Keeling, who present an 18-year record of surface-ocean COconcentrations near Bermuda. The study provides much-needed observational data for testing models, but more such records are needed to predict how much anthropogenic COwill be taken up by the ocean.