Climate models predict that increasing greenhouse gases in the atmosphere will change our climate. However, the range of observations available to assess these model predictions is limited. We have utilized an ocean biogeochemical model to project the impact of climate change on the oxygen cycle in the ocean and the air-sea exchange of oxygen. With climate change, our model predicts an outgassing of oxygen from the ocean. In the model, the Southern Ocean is the region that displays the largest change in the air-sea exchange of oxygen with climate change. The reduced oxygen uptake in the Southern Ocean is dominated by a reduction in convective mixing and in the subduction rate of bottom water which decreases the amount of dissolved oxygen in the Southern Ocean. Our model results suggest that dissolved oxygen is sensitive to changes in Southern Ocean circulation revealing the potential to use dissolved oxygen to test model predictions of climate change. From Southern Ocean observations collected 28 years a part we observed a decrease in dissolved oxygen that was consistent with model climate change simulation. This provides credibility to the climate model predictions. Additional analysis and observations of dissolved oxygen are needed to substantiate our climate model simulations.