Insights into land- and ocean-based CO₂ removal
© CDRterra/CDRmare, Frank Wölffing
At a joint evening event in the German capital, researchers from CDRmare and CDRterra discussed with stakeholders from policy and practice how long-term CO₂ removal and storage on land and in the ocean can contribute to climate neutrality.
To achieve its climate targets, Germany must not only reduce emissions but also remove and permanently store large amounts of carbon dioxide (CO₂) from the atmosphere. But how can this process be designed responsibly and effectively? After three years of interdisciplinary research, scientists from the two research programmes CDRmare and CDRterra shared their combined expertise on Carbon Dioxide Removal (CDR) and Carbon Capture and Storage (CCS) on land and in the ocean with policymakers and practitioners. To foster this exchange, they invited participants to an “After Work Insight” event in Berlin on 2 July. Around 50 representatives from ministries, NGOs and associations gathered at the Magnus House to discuss key findings and policy options with the researchers.
Shaping the path towards climate neutrality together
The German government is currently developing several strategies and programmes that directly or indirectly support the achievement of climate targets — including the Carbon Management Strategy, the Long-Term Strategy for Negative Emissions, the Action Programme for Natural Climate Protection, and the Biomass and Ocean Strategies. Research from CDRmare and CDRterra provides important evidence-based knowledge to inform these processes. Through events like this, the scientists actively engage in dialogue with political decision-makers and other relevant stakeholders to share insights and help shape the path towards climate neutrality together.
© CDRmare/CDRterra, Frank Wölffing
After a welcome address by Stefan Müller, Head of Division 7 “Future Planning – Research for Fundamentals and Sustainable Development” at the German Federal Ministry of Education and Research, the spokespersons of CDRterra (Prof. Dr. Julia Pongratz from Ludwig-Maximilians-Universität München) and CDRmare (Prof. Dr. Andreas Oschlies from GEOMAR and Prof. Dr. Gregor Rehder from the Leibniz Institute for Baltic Sea Research) presented highlights from the first phase of the two research programmes on land- and ocean-based CDR methods. They also provided an outlook on research questions and projects they plan to address in the second phase.
“For a comprehensive and realistic assessment of CO₂ removal methods, it is essential to understand side effects and risks associated with established approaches. Current research therefore brings together a wide range of disciplines,” said Julia Pongratz. “However, we will also need new technologies for a meaningful CDR portfolio, which must be further explored. These technologies are not yet well understood in society. To enable people to form a realistic understanding of the possibilities and limitations of CO₂ removal and to make evidence-based decisions, dialogue between science, politics, business, and society is essential.”
Dialogue is essential for carbon dioxide removal
In addition to numerous land-based carbon dioxide removal approaches, the ocean also offers a wide range of options for extracting additional CO₂ from the atmosphere. “The physical and biogeochemical processes underlying these options have played a significant role in stabilising the Earth’s climate throughout its history. However, their potential as well as their side effects in the context of deliberate CO₂ removal are still not well understood,” said Andreas Oschlies. “The most important task of marine research is therefore to investigate the possible impacts of such interventions on the marine environment and society, and to provide the corresponding actionable knowledge for political and societal decision-making,” added Gregor Rehder.
Impressionen des Afterworkinsights-Events in Berlin
Key messages from CDRmare and CDRterra
The scientists summarised the current state of research on carbon dioxide removal and storage in the following key statements:
- Carbon dioxide removal (CDR) is necessary as a complement to emissions reductions.
To limit global warming, humanity must achieve carbon neutrality by mid-century at the latest. This requires a massive reduction in emissions. However, there will remain unavoidable residual emissions. Clearly defining these is central to the responsible application of CO₂ removal and storage methods in order to reach net zero. - Potentials and uncertainties need further research.
There are still uncertainties regarding the scalability and efficiency of CDR methods. Reliable estimates of removal potential and implementation scenarios are essential for assessing feasibility and effectiveness. Therefore, further research, technology development, and pilot projects are needed. - A broad CDR portfolio can help minimise risks.
To spread risks, multiple CDR approaches will be required. Different CO₂ removal methods come with different advantages and disadvantages, for example regarding the permanence of storage and potential side effects.
A portfolio approach could help foster synergies between methods, reduce trade-offs (such as limited land availability, biomass use, or biodiversity protection), and thereby increase societal acceptance. The extent to which portfolio approaches create synergies or additional trade-offs still needs further investigation. - Developing markets, regulation, MRV, and infrastructure is key for scaling CDR.
Establishing a regulated and independently monitored market for CO₂ removal and storage, along with clear regulatory frameworks, is essential to ensure climate effectiveness as well as environmental and social integrity, while also enabling investment and the implementation of CDR and CCS projects (Carbon Capture and Storage). Building transport and storage infrastructure is a key prerequisite for many methods. Ensuring integrity and transparency requires effective monitoring, reporting, and verification (MRV). - Biodiversity and Sustainable Development Goals (SDGs) must not be compromised by CDR.
CO₂ removal and storage methods must contribute to effectively limiting climate change. At the same time, they must not undermine sustainable development in other areas in line with the Paris Agreement and the Sustainable Development Goals (SDGs).