Overview

• By screening global sedimentary basins, the team reduced a physical reserve of about 11,800 GtCO₂ to a prudent 1,460 GtCO₂ by excluding seismically active, shallow or deep, protected, or densely populated areas.
• Even if all prudent capacity were dedicated to removing CO₂ from the air, the study estimates the maximum temperature benefit at roughly 0.7°C.
• If used to bury ongoing large emissions after net zero, practical storage could be effectively exhausted around the year 2200, the authors warn.
• Current storage is about 49 million tonnes of CO₂ per year, versus roughly 8.7 gigatonnes per year by mid‑century in some Paris‑aligned scenarios, underscoring an enormous scale‑up gap.
• Reporting highlights uneven regional capacity and intergenerational equity concerns, with outside experts split on whether the new estimate is too conservative or still optimistic given political and economic barriers.