Klimaschutz durch Meeresnatur: Potentiale und Handlungsoptionen

Marine ecosystems like mangroves forests, seagrass meadows, salt marshes and macroalgae can store carbon in their biomass and sediments. Rehabilitation, restoration and conservation of these ecosystems can increase the potential for atmospheric carbon uptake by the ocean. This concept was first introduced as ‘blue carbon’ during the preparation for the 15th UN Climate Change Conference in Copenhagen in 2009 and since then it has seen continuous incorporation into politics and research. The long-term sequestration of atmospheric CO2 via blue carbon ecosystems supports the 1.5°C goal of the Paris Agreement. The CO2 that is sequestered by blue carbon ecosystems is part of the global carbon sink and therefore it can be counted as ‘negative emissions’ in the global carbon stocktake. However, such negative emissions should not be implemented as a substitute for necessary political and economic measures towards a carbon neutral future. Rehabilitation and restoration of blue carbon ecosystems as a natural carbon sink is one of many measures but cannot replace the significant reduction of global emissions needed for the realisation of the global climate targets. This study discusses the scientific, economic and political realm of blue carbon. Furthermore, possible courses for political action “in”, “by”, and “through” Germany that could strengthen the potential of blue carbon ecosystems to sequester carbon are explored. The study investigates a variety of blue carbon ecosystems to determine to what extent the expansion and conservation of blue carbon ecosystems can support additional climate adaptation targets and Sustainable Development Goals. The evaluation of a multitude of implemented and ongoing blue carbon projects across the globe gives insight to best practices and possible financing mechanisms. A political guideline for Germany regarding blue carbon was developed together with the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety.