Upscaling DAC Hubs with Wind Energy and CO₂ Mineral Storage: Considerations for Large-Scale Carbon Removal from the...

Continued fossil fuel emissions will increase CO₂ concentrations in the atmosphere and could require removal of 10 Gt of CO₂ per year or more to reach IPCC global climate goals. Large-scale construction of direct air capture (DAC) hubs to scrub CO₂ from the atmosphere paired with geological storage is a prominent approach to potentially meet this target. We consider one location for theoretical scale-up of a DAC hub: the Kerguelen plateau in the Southern Indian Ocean which has high-potential renewable energy resources (wind) and large volumes of basalt rock for mineral storage. With consistent wind, previous studies indicate a hub in this location could collect approximately 75 Mt of CO₂ annually, with conservative storage resources for 150-300 Mt of CO₂ each year. Even with its immense wind and storage potentials, 14 Kerguelen-scale hubs would be needed to capture and store 1 Gt of CO₂ per year. This brings into focus the important social, economic, and environmental trade-offs that must be considered in finding an acceptable balance between climate solutions, renewable energy requirements, and nature. Engaging public groups on these trade-off considerations will be crucial for gigaton scale-up of CO₂ removal in just and responsible ways.