Dr. Thorben Amann

is a geologist and postdoctoral researcher at the Institute for Geology, University of Hamburg. One of his main topics of research is accelerated rock weathering. He investigates its potential, technical feasibility and possible risks for deployment on land (CDRterra research mission) and at sea (CDRmare research mission), with a particular focus on various ocean alkalinity enhancement methods. > web

Prof. Dr. Christian Baatz

is engaged in research and teaching on climate ethics, sustainability and global justice in the Department of Philosophy at Kiel University, where he is a Junior Professor. In this capacity, the environmental ethicist leads the research group “Financing Adaptation to Climate Change in the Global South: Investigating a Fair and Practical Distribution of Scarce Resources”, which is funded by the German Federal Ministry of Education and Research (BMBF). His studies on political and ethical principles for targeted carbon dioxide removal provide input for three research projects: one of which is developing review guidelines for ocean-based CDR methods as part of the German CDRmare research mission, and two projects on the ethics of land-based CDR. > web

Dr. Miranda Böttcher

is a political scientist and research associate in the Climate Policy and Politics Research Cluster at the German Institute for International and Security Affairs (SWP) in Berlin. She monitors environmental and climate policy processes at national and international level and looks at which strategies and rules would facilitate environmentally sound and socially equitable use of ocean-based CDR methods in future. She is one of the world’s leading experts on the political and institutional feasibility of carbon dioxide removal and is a member of the GESAMP Working Group on Ocean Interventions for Climate Change Mitigation, which among other things provides advice to the London Protocol’s bodies. Together with colleagues in the German CDRmare research mission, she is currently developing review guidelines for ocean-based CDR methods, which are intended to aid policy-makers, business and civil society stakeholders in conducting transparent and accessible assessments of proposed CDR projects and facilitate fact-based decision-making thereafter. > web

Dr. Oliver Geden

is a social scientist and Head of the Climate Policy and Politics Research Cluster at the German Institute for International and Security Affairs (SWP) in Berlin. His main areas of research are European and international policy on energy, climate and environmental topics, with a current focus on social and political developments in relation to atmospheric carbon dioxide removal (CDR). His expertise and research findings provide input for the German research missions on land-based CDR (CDRterra) and ocean-based CDR (CDRmare). As a Lead Author for the IPCC’s Working Group III, Oliver Geden and fellow authors summarized the international body of knowledge on carbon dioxide removal for the IPCC’s Sixth Assessment Report (AR6). He also made a significant contribution to the AR6 Synthesis Report as a Chapter Coordinator. In July 2023, Oliver Geden was elected Vice-Chair of Working Group III (Mitigation of Climate Change) and became a member of the IPCC Bureau. In this role, he will facilitate and support the compilation of the report in the seventh assessment cycle. > web

Dr. David P. Keller

is a senior scientist in the Marine Biogeochemical Modelling Department at the GEOMAR Helmholtz Centre for Ocean Research in Kiel. His main areas of research include assessments of carbon dioxide removal (CDR) approaches for climate change mitigation; and feedbacks between biogeochemical cycles and the climate. He also studies the interactions between marine ecosystems and biogeochemistry. David Keller uses Earth System modelling for many of his scientific studies. On complex research topics, he appreciates the benefits of close cooperation with academics from many other disciplines. David Keller currently leads the OceanNETs project (Ocean-based Negative Emission Technologies), which is funded by the European Union’s Horizon 2020 Programme and investigates ocean-based CDR approaches. As one of four lead scientists, he currently coordinates the international Carbon Dioxide Removal Model Intercomparison Project and has a lead role in five other research projects on carbon dioxide removal (CDR). He provided expert input on CDR for the IPCC’s Sixth Assessment Report and was a Contributing Author for the Working Group I and Working Group III reports. > web

Prof. Dr. Achim Kopf

heads the Marine Geotechnics group at the Center for Marine Environmental Sciences (MARUM), University of Bremen. As a geologist, he mainly researches the structure and physical properties of the sub-seafloor. Within the framework of the CDRmare research mission, he currently leads the research activities on storage of carbon dioxide in the upper oceanic crust. The purpose of these studies is to conduct ocean research drilling in the upper basalt crust in preparation for injecting carbon dioxide, or water containing CO₂, into the reactive rock on an experimental scale. With the aid of a close-meshed network of sensors on the seafloor and in boreholes, the aim is then to observe how carbon dioxide is distributed in the basalt crust and how quickly it mineralizes. > web

Dr. Christine Merk

is the Deputy Director of the Global Commons and Climate Policy Research Center at Kiel Institute for the World Economy. Her main research interests include individual trade-offs between mitigation, carbon dioxide removal (CDR) and stratospheric aerosol injection. She conducts behavioural economics experiments and surveys to explore lay and expert perceptions and reactions. She is currently involved in two research projects that look at acceptance of ocean-based carbon dioxide removal: she leads the work package on public perceptions of marine CDR in the Horizon2020 consortium OceanNETs and contributes to a German research project on seagrass restoration. In parallel, she provides expert input for the GESAMP Working Group on Ocean Interventions for Climate Change Mitigation and is involved in developing review guidelines for ocean-based CDR projects and methods as part of the CDRmare research mission. In addition, together with partners at the Norwegian Research Centre (NORCE), she explores perceptions of the cross-border transportation of CO₂ for storage in Germany and Norway. > web

Dr. Sebastian Milinski

holds a PhD in Earth System Sciences from the University of Hamburg and is now a scientist at the European Centre for Medium-Range Weather Forecasts (ECMWF) in Bonn. As a Chapter Scientist, he supported the team of authors producing the Working Group I contribution (The Physical Science Basis) for the IPCC’s Sixth Assessment Report and assisted in gathering and evaluating the current body of knowledge on climate projections (Chapter 4). Forecasting when global warming will exceed 1.5 degrees Celsius and which development pathways will drive climate change and to what extent were key topics in this context. > web

Dr. Katja Mintenbeck

is a marine biologist. Until summer 2023, she was Director of Science at the IPCC Working Group II Technical Support Unit. In this function, among other duties, she was responsible for the IPCC Special Report on the Ocean and Cryosphere in a Changing Climate, which was published in September 2019, and Volume II (Impacts, Adaptation and Vulnerability) of the IPCC Sixth Assessment Report, published in February 2022. She also supported work on the IPCC Synthesis Report in the sixth assessment cycle. Prior to working for the IPCC, Katja Mintenbeck was a marine biologist in the Integrative Ecophysiology Division at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) in Bremerhaven. Her work focused on the ecology of Antarctic marine biocoenoses and, specifically, the sensitivity of Antarctic fish to disturbances and environmental change, particularly increasing ocean acidification. > web

Prof. Dr. Andreas Oschlies

is an oceanographer and Head of the Biogeochemical Modelling Research Unit at the GEOMAR Helmholtz Centre for Ocean Research in Kiel. His research interests include the physical, biogeochemical and ecological processes of oceanic carbon uptake and possible changes in these processes as a result of climate change. For example, he and his team develop biogeochemical models to investigate changes in the oxygen content of the oceans and their ecological impacts. Since the early 2000s, Andreas Oschlies has been involved in researching and assessing climate engineering techniques and led a German Research Foundation (DFG) interdisciplinary priority programme on this topic from 2013 to 2020. Since 2021, he has served as Co-Chair of the “Marine Carbon Sinks in Decarbonization Pathways” German research mission (CDRmare) in which around 200 scientists from 22 partner institutions conduct cross-disciplinary research on various marine carbon dioxide removal and storage methods. > web

Prof. Dr. Julia Pongratz

holds the Chair of Physical Geography and Land Use Systems at the University of Munich (LMU) and is the Director of the Department of Geography. Her research explores the interactions between humans, vegetation and climate. An expert in vegetation modelling, she is particularly concerned with land use change and its impact on energy, water and carbon cycles in the Earth’s climate system. For example, she studies how, through afforestation/reforestation, humans can potentially increase carbon dioxide uptake in terrestrial vegetation; she also investigates what effects large-scale tree planting would have on the local and supra-regional climate. An expert in land use change and its emissions, she contributed to the IPCC’s Sixth Assessment Report at the invitation of Working Groups I and III. She is also involved with the prestigious Global Carbon Project and is the Speaker and Project Lead for the BMBF-funded CDRterra research programme in which experts from various German research institutions investigate the carbon dioxide removal potential of various land-based CDR methods. One question to which they are seeking answers is to what extent there is potential to apply these methods in Germany to achieve the goal of greenhouse gas neutrality without jeopardizing other sustainable development objectives. > web

Prof. Dr. Alexander Proelß

is a legal scholar and lecturer on international maritime and environmental law, international law and public law in the Law Faculty of the University of Hamburg. In addition to aspects of general international and European law, his areas of research primarily include international environmental law and the law of the sea, foreign constitutional law and selected areas of national environmental law. He is involved in numerous national and international research projects and currently contributes his expertise to the German CDRmare research mission, among others. Here, he and his team investigate which legal frameworks are required to enable the use of ocean-based carbon dioxide removal methods and how the corresponding projects can be regulated at national and international level so as to ensure their compatibility with environmental and marine conservation objectives. > web

Prof. Dr. Gregor Rehder

is a marine biogeochemist. He is Vice Head of the Department of Marine Chemistry at Leibniz Institute for Baltic Sea Research in Warnemünde (IOW) and teaches at the University of Rostock. At IOW, he is also the Work Group Leader of the Trace Gas Biogeochemistry Group in which he and his team study important key processes in the sea and in coastal areas regulating production of trace gases and greenhouse gases that affect climatic processes and biogeochemical cycles. The scientists are developing new techniques for efficient environmental monitoring. Gregor Rehder has been a Co-Chair of the CDRmare research mission since 2021 and coordinates the research activities of the six participating consortia together with Prof. Dr. Andreas Oschlies. > web

Prof. Dr. Wilfried Rickels

is an economist and Director of the Global Commons and Climate Policy Research Center at Kiel Institute for the World Economy. He and his team study the measurement of sustainable marine and maritime development, particularly in the context of the global Sustainable Development Goals, and look at the role and significance of carbon dioxide removal for climate change mitigation. The development of composite indicators and the application of integrated assessment models are particularly important in addressing these research questions. Wilfried Rickels aims to progress both these areas in various research projects. Since January 2023, he has held an endowed professorship to research economic aspects of atmospheric carbon dioxide removal at the University of Kiel. > web

Prof. Dr. Ulf Riebesell

is a marine biologist and expert in biological oceanography at the GEOMAR Helmholtz Centre for Ocean Research in Kiel. A plankton specialist, he was one of the first scientists in the world to study the effects of rising carbon dioxide concentrations on marine organisms. He is familiar to the public primarily for his major mesocosm experiments on ocean acidification in various areas of the sea. Since 2015, Ulf Riebesell has been conducting research studies on artificial upwelling, initially with funding from the European Research Council (Ocean artUp) and, since 2021, as part of the German CDRmare research mission (Test ArtUp). He is also involved in studies on the impacts of targeted ocean alkalinity enhancement (Retake and Ocean Alk-Align) and supervises research within the framework of the EU-funded OceanNETs project. > web

Dr. Michael Sswat

is a postdoctoral scientist in the Biological Oceanography Division at the GEOMAR Helmholtz Centre for Ocean Research in Kiel. In his capacity as project manager, he coordinates research activities in the Test-ArtUp consortium of the German CDRmare research mission and the Helmholtz European Partnering project Ocean-CDR. In both projects, specialists from various research institutes investigate whether artificial upwelling technologies can usefully be deployed for carbon dioxide removal, to what extent they require technical optimization, which environmental risks and ecological impacts are associated with their use, and how possible deployments can be funded and regulated. In parallel, Michael Sswat is a research diver, photographer and freelance marine biologist. > web

Dr. Lukas Tank

holds a PhD on the ethics of carbon pricing from Humboldt-Universität zu Berlin and has been a postdoctoral researcher in the Climate Ethics, Sustainability and Global Justice research group in the University of Kiel’s Department of Philosophy since 2021. As well as sharing his expertise as an ethicist with the German CDRmare research mission, Lukas Tank gives public lectures on aspects of climate ethics and contributes to exhibitions and discussion forums. Together with Christian Baatz and his colleague Frederike Neuber, Lukas Tank compiled the propositions on the ethics of CDR presented in Chapter 9. > web

Prof. Dr. Klaus Wallmann

is a geoscientist. He leads the Marine Geosystems Research Unit at the GEOMAR Helmholtz Centre for Ocean Research in Kiel and teaches the foundations of marine biogeochemistry at Kiel University (CAU). His research interests include material turnover at cold seeps and mud volcanoes on the sea floor, the formation of gas hydrates, microbial degradation of organic matter in surface sediments, and the recycling of nutrients from the sediments into the ocean. He is regarded as Germany’s foremost expert in carbon dioxide storage in subsea sandstone formations. From 2011 to 2015, he led an EU research project on the consequences of carbon dioxide storage below the sea floor. As part of the CDRmare research mission, he currently coordinates the GEOSTOR consortium in which researchers aim to identify methods that would allow carbon dioxide storage in geological formations below the seabed in the German sector of the North Sea in compliance with the precautionary principle. > web

Lennart Westmark

studied law in Hamburg and is now a research associate in the working group led by Prof. Dr. Alexander Proelß at the University of Hamburg. His research currently focuses on the legal frameworks for carbon dioxide storage in sandstone formations below the seabed in the German sector of the North Sea. In the CDRmare research mission, Lennart Westmark analyses the international, European and German legislation on subsea carbon dioxide storage and, on this basis, develops recommendations for its practical implementation. For his PhD project, he is investigating the role of climate research in the legislative context. > web

Mirco Wölfelschneider

studied biology and aquatic ecology and, as a scientific staff member, now conducts research in the Mangrove Ecology Working Group at the Leibniz Centre for Tropical Marine Research in Bremen. For his PhD project, he spent several months in Brazil, studying the exchange of organic matter between mangroves and coastal waters. In parallel, as project manager for the CDRmare research consortium on vegetated coastal ecosystems (sea4soCiety), Mirco Wölfelschneider coordinates the many natural and social science studies on seagrass meadows, tidal marshes, kelp forests and mangroves and provides support for the consortium’s Coordinator, Prof. Dr. Martin Zimmer. > web

Prof. Dr. Martin Zimmer

is a biologist. He leads the Mangrove Ecology Working Group at the Leibniz Centre for Tropical Marine Research in Bremen, teaches at the University of Bremen and is a member of the IUCN SSC Mangrove Specialist Group. Every year, he spends several weeks conducting fieldwork in tropical coastal regions populated by mangroves, where he and his team study topics such as the exchange of matter and organisms between neighbouring coastal ecosystems. They analyse sub-surface carbon content and decomposition processes in organic matter and investigate the interactions between organisms in the species-rich mangroves and how these interactions affect ecosystem processes and services. Human-induced environmental changes and their ecological impacts in mangrove forests are a further area of research. Martin Zimmer has coordinated the consortium on vegetated coastal ecosystems (sea4soCiety), part of the German CDRmare research mission, since 2021. In this interdisciplinary consortium, researchers from various institutions investigate the role of seagrass meadows, tidal marshes, mangroves and kelp forests in the ocean’s carbon cycle and look at ways to increase their carbon dioxide uptake in an environmentally sound and socially equitable manner. > web

 

We also wish to thank the team at the German Emissions Trading Authority (DEHSt), who shared their advice and expertise during the preparation of the detailed overview of the EU Emissions Trading System and its forthcoming reform. </a>