Introduction
Carbon sequestration offers a pathway to draw down atmospheric CO₂, but it carries inherent risks. Unchecked, these could undermine public trust and project viability. This article surveys the key challenges— technical, seismic, environmental, and social—and outlines the strategies that turn potential pitfalls into pillars of resilience.
1. Technical & Integrity Risks
Ensuring CO₂ stays underground requires flawless infrastructure:
- Well & Caprock Integrity: Corrosion, cement degradation, or natural fractures can create leakage pathways.
- Pipeline & Compression Systems: Mechanical failures or weld defects may cause surface emissions.
- Injection Rate Control: Overpressure can exceed formation strength, risking unintended migration.
2. Induced Seismicity
Injecting large volumes of fluid raises subsurface pressures—potentially reactivating faults:
- Micro-Seismic Events: Small tremors are common and often harmless, but need continuous monitoring.
- Operational Mitigation: Adaptive injection protocols, pressure bleed-off wells, and real-time seismic feedback loops.
3. Monitoring & Verification Challenges
Robust MRV (Monitoring, Reporting, Verification) is the backbone of trust:
- Detection Sensitivity: Surface and subsurface sensors must spot minute CO₂ fluxes—down to ppm levels.
- Continuous Data Streams: Distributed fiber-optic cables, satellite radar, and soil-gas probes ensure 24/7 vigilance.
4. Environmental & Ecological Impacts
- Brine Displacement: Pushing saline fluid into adjacent formations can affect groundwater tables if not managed.
- Acidification & Mineral Leaching: CO₂-rich fluids may mobilize trace metals, requiring geochemical modeling and water-quality safeguards.
- Surface Ecosystem Effects: Vegetation stress or soil changes at injection sites demand environmental baseline studies.
5. Social & Governance Risks
- Community Acceptance: Early engagement, transparent benefit-sharing, and local stewardship funds build trust.
- Liability & Ownership: Clear legal frameworks for long-term stewardship—spanning decades to centuries—are essential.
- Reputational Risk: A single leak or protest can threaten sector-wide momentum.
Conclusion
No risk can be eliminated, but with proactive management, transparent MRV, and robust governance, carbon sequestration projects can achieve enduring safety and public confidence. Next up: weighing everyday capture vs. permanent burial to choose the right tool for each carbon challenge.