Poster at the 7th international carbon dioxide conference, Colorado, IUSA, Sept 25-30, 2005. Decline of the sink for atmospheric CO2 in the mid-latitude North Atlantic Ute Schuster and Andrew J. Watson. School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK Abstract Measurements of surface carbon dioxide properties made from commercial ships trading regularly between the UK and the Caribbean show that, across the mid latitudes of the North Atlantic, the flux of CO2 from the atmosphere to the ocean decreased by ~60% from the mid nineties up to 2004. We attribute most of this change to a decrease in the rate of ventilation and mixing between surface and deeper waters in the North Atlantic.