Jürchott et al. (2025): Direct cooling effect of artificial upwelling dominates over its marine carbon dioxide removal potential
Malte Jürchott, Andreas Oschlies, Nadine Mengis, Ivy Frenger and Wolfgang Koeve, IN: Environmental Research Letters, https://doi.org/10.1088/1748-9326/ae0054
Artificial upwelling (AU) is investigated as a marine carbon dioxide removal (CDR) method with a strong focus on its potential impact on Earth’s carbon cycle, in particular enhanced air-sea CO₂ flux. The overarching goal of marine CDR methods is to contribute to offsetting remaining CO₂ emissions as a means to stabilize global mean surface air temperature (SAT). However, AU also directly affects ocean heat uptake (OHU) through the upwelling of cold ocean interior water to the surface and the simultaneous backflow of warm surface water into the ocean interior. In this study, the authors challenge the carbon centered perception of AU. They simulate large-scale AU in an Earth system model of intermediate complexity between the years 2025 and 2100 with and without its direct impact on OHU under low, medium and high future CO₂ emission scenarios. Thus, they can quantify the individual contributions of AU-induced carbon and heat effects to changes in global mean SAT.