Although the world ocean is known to be a major sink of anthropogenic carbon dioxide, the exact processes governing the magnitude and regional distribution of carbon uptake remain poorly understood. Here we show that Southern Hemisphere winds, by altering the Ekman volume transport out of the Southern Ocean, strongly control the regional distribution of anthropogenic uptake in an ocean general circulation model, while winds and isopycnal thickness mixing together, by altering the volume of light, actively-ventilated ocean water, exert strong control over the absolute magnitude of anthropogenic uptake. These results are provocative in suggesting that climate-mediated changes in pycnocline volume may ultimately control changes in future carbon uptake.