Southern Ocean may flip from carbon sink to carbon source under mitigation scenarios

Plans to limit the global temperature rise to 1.5°C above preindustrial levels depend on reaching net-zero emissions and, in many cases, actively removing carbon dioxide (CO2) from the air. While this helps limit extreme weather, sea level rise, ecosystem loss and the risk of triggering irreversible climate tipping points, a new study, published in Science Advances, finds that reducing CO2 levels may have an unexpected effect. Climate simulations used in the study suggest that the Southern Ocean around Antarctica may switch from being an important carbon sink to being a prolific source of carbon.