In a current joint position paper, the Federation of German Industries (BDI), the German Trade Union Confederation (DGB) and the environmental organisations Nature And Biodiversity Conservation Union (NABU) and World Wide Fund For Nature (WWF) advocate for the integration of underground CO2 storage (carbon capture and storage, CCS) into the comprehensive climate strategy. This technical measure, which serves as a natural carbon sink in addition to supporting intact ecosystems, is also being recommended for application in Germany.
“As a geologist, I welcome the associations’ joint position on CCS technologies. I consider their implementation to be reasonable and feasible”, says Professor Christoph Hilgers of the Institute of Applied Geosciences at KIT University. “In many industrial processes, generating CO2 can’t be prevented, for example in cement production. Using technical processes, the CO2 can be separated and transported underground via transport infrastructure, where it can be stored long-term.”
As early as the 1970s, the technical feasibility of CCS was successfully proven in the USA. CCS is already in practical use in Norway, where around a million tonnes of CO2 are stored underground every year. By contrast, Germany still has a de facto ban on this technology. “There is no sound scientific justification for this moratorium”, is Hilgers’ argument. “Generally speaking, we have large volumes of rock in Germany where the long-term storage of CO2 is possible. In the process, the CO2 is liquefied by means of pressure and is stored starting at depths of about a kilometre, where it behaves like a liquid and tends to stay underground. The Federal Institute for Geosciences and Natural Resources (BGR) conducted an extensive investigation to find out which places were safe for CCS back at the beginning of the millennium.”
Hilgers emphasises that there are potential risks that need to be considered. These include the possibility of CO2 coming to the surface through old bore holes or the risk of CO2 escaping naturally given specific geological conditions due to excess pressure underground. “Of course, we have to fully investigate this possibility before approving a repository. In this case, I consider the risk to be manageable and limited. After weighing the opportunities and risks, I believe that, on the whole, CCS is indispensable for achieving our climate goals.”