Carbon Capture and Storage (CCS) can help nations meet their Paris CO2 reduction commitments cost-effectively. However, lack of confidence in geologic CO2 storage security remains a barrier to CCS implementation. We present a numerical program that calculates CO2 storage security and leakage to the atmosphere over 10kyr. This links processes of geologically measured CO2 subsurface retention, and estimates of CO2 leakage. We model 12 GtCO2 of cumulative storage based on the EU’s 2050 target, commencing injection in 2020. Realistically well-regulated CCS industry in regions with moderate well densities has a 50% probability that leakage remains below 0.0004% yr-1, with less than 4% of injected CO2 migrating to the atmosphere over 10kyr. An unrealistic unregulated case, with unknown and inadequately abandoned wells shows a 50% probability that leakage is below 0.003% yr-1 over 10kyr, meaning more than 70% of the CO2 is securely retained over 10kyr. Hence, geological storage of CO2 is a secure climate change mitigation option.
- climate change mitigation
- CO2 storage