Artificial Upwelling - A New Narrative

The current narrative of artificial upwelling (AU) is to use ocean pipes to pump nutrient rich deep water to the ocean surface, thereby stimulating the biological carbon pump. This simplistic concept of AU does not take the response of the solubility pump or the CO2 emission scenario into account. Using global ocean-atmosphere model experiments and several idealized model tracers we show that the effectiveness of almost globally applied AU from the year 2020 to 2100 to draw down CO2 from the atmosphere is strongly dependent on the CO2 emission scenario and ranges from 1.01 Pg C / year under RCP 8.5 to 0.32 Pg C / year under RCP 2.6. The solubility pump becomes equally effective compared to the biological carbon pump under the highest emission scenario (RCP 8.5), but responds with CO2 outgassing under low CO2 emission scenarios. Key Points: • Artificial Upwelling effectiveness to draw down CO2 from the atmosphere is strongly dependent on the future CO2 emission scenario. • The solubility pump becomes as effective as the biological carbon pump under high emission scenarios. • Organic matter transfer efficiency decreases under artificial upwelling, likely due to higher water temperatures below the ocean’s surface