Geological Storage and Sequestration of Carbon Dioxide

Geological storage and sequestration of carbon dioxide involves the permanent injection of CO₂ into deep subsurface formations to mitigate atmospheric emissions. Suitable targets include deep saline aquifers, depleted hydrocarbon reservoirs and unmineable coal seams, each offering distinct porosity, permeability and trapping characteristics. Upon injection, CO₂ is initially contained by structural and stratigraphic seals and cap rocks. Over time, physical and chemical processes secure the gas: residual trapping immobilises droplets within pore spaces; solubility trapping dissolves CO₂ in formation brine; and mineral trapping transforms dissolved CO₂ into stable carbonate minerals. Numerical modelling, field pilot studies and monitoring technologies—such as seismic imaging, tracer tests and pressure–temperature sensors—ensure containment integrity and inform capacity estimates. The global potential for storage is vast, with theoretical capacities exceeding hundreds to thousands of gigatonnes of CO₂, yet practical deployment depends on regional geology, infrastructure, regulatory frameworks and public acceptance. Integration with carbon capture and transport networks, alongside enhanced oil recovery and emerging subsea approaches, underscores the multifaceted role of geological sequestration in achieving near- and long-term climate targets.

Research from Nature Portfolio

Recent studies have quantified the feasibility of scaling geological CO₂ storage to gigatonne levels by mid-century using geographically resolved growth models. Findings suggest a theoretical maximum of around 16 GtCO₂ yr⁻¹ by 2050 under optimal development in regions with abundant storage sites, but a more pragmatic global benchmark of 5–6 GtCO₂ yr⁻¹ aligns with current technology roadmaps and uneven regional contributions. Parallel work has advanced quantitative assessments of long-term storage security, combining subsurface retention models with estimates of surface leakage over 10 000 years. These results indicate that well-regulated storage in moderate well-density regions can retain over 98% of injected CO₂, affirming the robustness of geological sequestration as a climate mitigation option while highlighting the need for stringent site governance and monitoring to resolve remaining uncertainties.

Geological Storage and Sequestration of Carbon Dioxide publication trend

The graph below shows the total number of articles in geological storage and sequestration of carbon dioxide across all publications each year (not limited to Nature Index journals).

Technical terms

Carbon capture and storage (CCS): Process of capturing CO₂ at point sources, transporting it to a storage site and injecting it into geological formations for long-term isolation.

Deep saline aquifer: Porous, water-bearing rock formation saturated with brine and overlain by impermeable cap rock, offering extensive capacity for CO₂ injection.

Structural trapping: Containment mechanism in which impermeable rock layers or geological folds prevent upward migration of injected CO₂.

Residual trapping: Immobilisation of CO₂ as disconnected droplets within pore spaces, formed when advancing brine displaces injected gas.

Solubility trapping: Dissolution of CO₂ into formation water, increasing fluid density and reducing buoyancy-driven leakage risk.

Mineral trapping: Long-term geochemical reaction of dissolved CO₂ with host minerals to form stable carbonate precipitates.

Enhanced oil recovery (EOR): Technique in which CO₂ is injected into depleted oil reservoirs to improve hydrocarbon recovery while storing CO₂ in the pore space.

References

1. Carbon capture utilization and storage in review: Sociotechnical implications for a carbon reliant world. Renewable and Sustainable Energy Reviews (2023).
2. Advances in subsea carbon dioxide utilization and storage. Energy Reviews (2023).
3. The feasibility of reaching gigatonne scale CO2 storage by mid-century. Nature Communications (2024).
4. A review of CO2 storage in geological formations emphasizing modeling, monitoring and capacity estimation approaches. Petroleum Science (2019).
5. Estimating geological CO2 storage security to deliver on climate mitigation. Nature Communications (2018).
6. Recent advances in carbon dioxide geological storage, experimental procedures, influencing parameters, and future outlook. Earth-Science Reviews (2022).