The ocean traps carbon through two principal mechanisms: a biological pump and a physical pump linked to oceanic currents. Scientists have managed to quantify the role of these two pumps in an area of the North Atlantic. Contrary to expectations, the physical pump in this region could be nearly 100 times more powerful on average than the biological pump. By pulling down masses of water cooled and enriched with carbon, ocean circulation thus plays a crucial role in deep carbon sequestration in the North Atlantic....