The potential for greater air‐sea exchange rates in the northern Atlantic to decrease atmospheric CO2during the ice ages is examined using a simple model of the solubility pump. This potential is shown to depend on whether the modern ocean's region of sinking cold water is reequilibrating with atmospheric CO2at a rate comparable to the poleward transport of warm surface water. If this is the case, it is possible that greater ice age polar ventilation may have produced as much as 60% of the decrease observed in ice cores. In this scenario, the cold surface water CO2partial pressure does not covary with the atmosphere but instead would remain approximately constan