The ocean takes up about 30% of anthropogenic CO2 (about 1.5 PgC/yr from direct air-sea CO2 gradient data plus perhaps another 0.6 PgC/yr background flux). It only becomes clear in the last 10-15 years that the coastal ocean is also a CO2 sink (about 0.2 PgC/yr), which has demonstrated strong regional variability. In this talk I will review sea surface pCO2 and carbonate chemistry data in the global coastal oceans with a focus on the North American margins and discuss the control mechanisms of pCO2, pH and carbonate saturation state distributions in a few better measured regions. While data spans are still quite limited (within 10-20 years in most regions), we are able to demonstrate the highly variable rates of pCO2 change (different than the atmospheric CO2 increase rate) and ocean acidification in various regions. Based on a conceptual model and limited data, I will argue that the coastal ocean is an increasing CO2 sink for the atmosphere and that it will contribute more to the global ocean acidification via cross-margin export of dissolved inorganic carbon to the open ocean.