Research to Develop New Policies for Carbon Sequestration Technology

Carbon capture and sequestration (CCS) is regarded as a key possible solution for reducing rising CO2 emissions and combating climate change. It consists of capturing CO2 emissions from fossil-fuel burning sources and injecting them into deep geologic formations. Nevertheless, there is still concern regarding the potential risks associated with injecting large quantities of CO2, the long storage times that will be required for any climate benefit, and the fact that CO2 will be floating on the surface. Future climate policies will have to address these risks in order to protect public and environmental health and to ensure that geologic sequestration (GS) is safe and effective.

In a recent study, American researchers identified a list of technical and research issues that will have to be addressed in order to establish an adequate regulatory and legal framework for GS. They also analysed case studies that reduced the uncertainties in two areas of research: surface leakage of CO2 and groundwater quality. Finally, the authors discussed policy implications of the analysed case studies and suggested targeted research to support development of scientifically-based regulatory and legal frameworks.

The study identifies five research areas driven by regulatory and legal demands for CCS:

- Surface leakage. Injected CO2 could migrate to the surface through abandoned well bores, faults, and fractures. Understanding the mechanisms, magnitude of leakage, and the steps and technology to remediate leakage are important factors for risk assessment and risk management. 

- Groundwater quality. The potential risks in this case come from the floatation of CO2, its potential to mobilise organic and inorganic compounds in aquifers, and its potential to displace subsurface liquid on a regional scale. Research in this area will increase understanding of this risk. 

- Regional impacts. Potential risks due to the injection of large quantities of CO2 include induced seismicity, basin-scale displacement of subsurface fluids and increased risk of surface leakage due to alterations in the subsurface pressures. Research to understand and model regional impacts requires large-scale pilot projects to assess these risks. 

- Permanence. The effectiveness of CCS will depend on CO2 remaining stored for a long period of time. The prediction of changes in the risk profile of the stored CO2 over time and the identification of adequate monitoring and validation methods to manage risk are important issues that emerge in this research area. 

- Definition of liability and responsibility. The potential liability of an operator for damage due to CO2 leakage has to be well delineated and uncertain areas highlighted. In this regard, research will be needed on the technologies required for mitigating the damage caused and for repairing the site. 

The two case studies that are analysed illustrate how research can inform decision makers on policy issues, regulatory needs and legal considerations. They show that some wells might represent a risk of surface leakage that should be addressed. Also, it seems that the mobilisation of metals does not present a large risk, nevertheless, little is known about the potential liberalisation of metals upon injection of CO2 in certain areas and the concentrations and fluxes that could generate such a risk.

Overall, the study highlights the need to orientate research in order to understand key risks and limit uncertainties observed in different geological conditions and locations that might play an important role for the wider deployment of CCS. It concludes that it is necessary to further strengthen the link between science and regulatory and legal decision-making if CCS is to be developed successfully.