RING webinar series

Widespread deployment of CO₂ capture and storage (CCS) in deep geological formations is ‎identified as an essential component of any efforts to mitigate the climate change crisis. Most ‎assessments conclude that CO₂ storage rates in the order of several gigatons per year will be ‎needed to achieve carbon neutrality by 2050. However, concerns exist about the long-term fate ‎of CO₂ underground and the possibility of leakage back to the surface. I will present research ‎that investigates what would happen to CO₂ injected at climate-relevant rates of gigatons per ‎year over geological time scales (million years), much longer than any assessments performed ‎so far. I will discuss the subsurface CO₂ dynamics that can be simplified without loss of ‎generality to vertical CO₂ flow and transport concerning long-term CO₂ migration through ‎geological layers. Such a model enables us to draw reliable constraints on the CO₂ leakage ‎potential over geological time scales at affordable computational costs. Simulation results ‎show that repetitive layering of caprocks, even if pervasively fractured and a few tens of meters ‎thick, will significantly reduce the CO₂ leakage risk, ensuring a secure road toward achieving ‎climate targets.