Carbon dioxide (CO₂) emissions from industrial plants can be strongly reduced by CO₂ capture and storage in deep geological formations. A large share of the storage capacity for CO₂ in Europe is located in sandstone formations below the North Sea. Even though potential storage formations in the German Exclusive Economic Zone (EEZ) are only partly explored, the available estimations suggest that remaining anthropogenic emissions of German industries can be substantially reduced by capturing and storing CO₂ below the seabed within the German North Sea sector. Against this background, the GEOSTOR consortium of the research mission CDRmare aims to find prospective areas for CO₂ storage and design a roadmap for the implementation of CO₂ storage within the German North Sea.

Because former oil and gas fields or sandstone formations are estimated to only reach half the required volume for marine storage of carbon dioxide, also basalt deposits are increasingly being tested for their potential suitability. PERBAS (Permanent sequestration of gigatons of CO₂ in continental margin basalt deposits) aims to further investigate the technology of CO₂ storage in marine basalt complexes and to provide the necessary framework parameters for industrial planning. To this end, ten companies and public research institutions from Germany, Norway, the United States of America and India are working together under the leadership of Dr. Jörg Bialas, marine geophysicist at GEOMAR Helmholz Centre for Ocean Research Kiel. The participating countries contribute a total funding of 3.6 million euros for three years. GEOMAR receives about 800,000 euros from the Federal Ministry for Economic Affairs and Climate Action for its contributions. In July 2023, all participants met at GEOMAR for the joint project launch.

► PERBAS-Factsheet: "Storing CO₂ in flood basalts under the sea: options on a billion-ton scale"

In the long-term research project ECO2 (2011-2015), scientists at GEOMAR dealt with the risks and possible consequences of CO₂ storage in the seafloor. The Norwegian company Statoil (now Equinor) has been storing CO₂ above the Sleipner gas field in the Norwegian North Sea since 1996. Carbon dioxide, which is produced during natural gas extraction, is injected there into the so-called Utsira sandstone formation. Using this practical example, the researchers were able to verify very well the safety of submarine storage facilities. Large-scale investigations there and at old wells in the North Sea showed that for every million tons of gas injected into the subsurface, only about ten tons escape from the seafloor again, so the benefit of CO₂ storage under the sea is significantly greater than the damage. In a follow-up project, STEMM-CCS, initiated by the UK National Oceanography Centre, one of the aims was to develop new tools and techniques for environmental monitoring and for monitoring, quantifying and assessing CO₂ emissions.