A Comprehensive Assessment of Carbon Dioxide Removal Options for Germany

Abstract

To reach their net‐zero targets, countries will have to compensate hard‐to‐abate CO ₂ emissions through carbon dioxide removal (CDR). Yet, current assessments rarely include socio‐cultural or institutional aspects or fail to contextualize CDR options for implementation. Here we present a context‐specific feasibility assessment of CDR options for the example of Germany. We assess 14 CDR options, including three chemical carbon capture options, six options for bioenergy combined with carbon capture and storage (BECCS), and five options that aim to increase ecosystem carbon uptake. The assessment addresses technological, economic, environmental, institutional, social‐cultural and systemic considerations using a traffic‐light system to evaluate implementation opportunities and hurdles. We find that in Germany CDR options like cover crops or seagrass restoration currently face comparably low implementation hurdles in terms of technological, economic, or environmental feasibility and low institutional or social opposition but show comparably small CO ₂ removal potentials. In contrast, some BECCS options that show high CDR potentials face significant techno‐economic, societal and institutional hurdles when it comes to the geological storage of CO ₂. While a combination of CDR options is likely required to meet the net‐zero target in Germany, the current climate protection law includes a limited set of options. Our analysis aims to provide comprehensive information on CDR hurdles and possibilities for Germany for use in further research on CDR options, climate, and energy scenario development, as well as an effective decision support basis for various actors.

Plain Language Summary

Countries aiming to achieve net‐zero emissions will have to remove the remaining carbon dioxide from the atmosphere through carbon dioxide removal (CDR). However, current assessments of CDR options rarely consider socio‐cultural or institutional aspects or set the CDR options in the specific context of their implementation. In this study, researchers conducted the first context‐specific feasibility assessment of CDR options in Germany, considering six dimensions, including technological, economic, environmental, institutional, and social‐cultural aspects. The study assessed 14 CDR options, including chemical carbon capture options, bioenergy combined with carbon capture and storage, and options to increase ecosystem carbon uptake. The study found that CDR options like cover crops or seagrass restoration face low implementation hurdles but have small CO ₂ removal potentials, while options like woody‐biomass combustion or mixed‐feedstock biogas production have high CDR potentials but face large economic and institutional hurdles. The analysis aims to provide comprehensive information on CDR options for use in further research and as an effective decision support basis for a range of actors.

Key Points

• More context‐specific assessments of carbon dioxide removal (CDR) options are needed to guide national net‐zero decision making

• Ecosystem‐based CDR options with comparably low implementation hurdles in Germany show relatively small CO ₂ removal potentials

• High CDR potential options in Germany face high institutional, technological and societal hurdles linked in many ways to geological storage