New study on carbon storage: risks and recommendations for action

In view of the urgent need to limit climate change, there is growing interest in technologies that remove carbon dioxide from the atmosphere. A new study carried out by Oeko-Institut on behalf of the German Nature and Biodiversity Conservation Union (NABU) sheds light on the challenges of the geological storage of CO₂ (carbon storage, CS). It focuses in particular on the potential for storage off the coast of countries, known as offshore storage.

This study finds that carbon storage can play a decisive role on the path to climate neutrality. However, in order to minimise risks and ensure the sustainability of this technology, comprehensive improvements in the political approach to and handling of this technology are necessary. This includes strict standards, extended monitoring and an active role for the government.

Minimising risks and ensuring sustainability

The study emphasises that the reduction of greenhouse gas emissions must not be delayed and that the geological storage of CO₂ should be developed in parallel in order to compensate for unavoidable emissions and to achieve negative emissions. Like any technology, carbon storage is associated with risks. These include operational irregularities, potential environmental impacts on marine ecosystems and social acceptance issues. In addition, CS is a new technology that has found little practical application to date. The authors therefore call for an improved regulatory framework, independent monitoring and clear liability regulations to ensure the long-term safety and sustainability of carbon storage.

The study identifies the following risks of carbon storage and political recommendations for action:

1. Regulatory framework and standards: Though the European Union’s CCS Directive provides a regulatory foundation, there is a lack of international standards that would create legal certainty and facilitate cross-border collaboration. It is recommended that harmonised standards are developed and that independent third parties are commissioned with monitoring in order to strengthen confidence in this technology.
2. Technical and operational challenges: Operational disruptions during injection and the use of existing infrastructure originally designed for fossil fuels pose significant risks. Careful site selection and accurate storage practices are crucial to minimise these risks.
3. Monitoring and risk management: Effective monitoring of storage sites, even after injection, is crucial in order to minimise environmental risks. To increase public acceptance and recognise irregularities at an early stage, independent inspections and real-time monitoring systems should be established.
4. Environmental impacts: Although the environmental impacts of CO₂ storage under the sea are low, they should not be neglected. They include, for example, the possibility of CO₂ leakage or noise pollution during storage operations and the construction of infrastructure. Proper site selection and environmental monitoring are crucial in order to avoid possible ecological damage.
5. Human safety: The risk to humans from exposure to CO₂ is low due to the rapid dispersion of the gas in the atmosphere. Nevertheless, storage projects in densely populated areas should be avoided in order to minimise any risks to public safety.
6. Post-closure responsibility: After carbon storage sites close, the responsibilities for them need to be clear. This includes financial security measures to ensure that post-closure remediation is possible. The CCS Directive provides for responsibility to be transferred to state authorities after 20 years (40 years in Germany) at the earliest.
7. Governmental involvement: The EU’s CCS Directive provides a comprehensive governance framework. The greater involvement of governments could help to allay concerns and increase confidence in this technology.

Oeko-Institut's study "Securing the Underground: Managing the Risks of Carbon Storage through Effective Policy Design"