CO2-removal News

Peer-reviewed Publications

Gulde et al. (2025): Frameworks to assess climate change responses – A systematic analysis to enhance frameworks for Carbon Dioxide Removal

Felix Gulde, Maximilian Witting, Frederike Neuber, Christian Baatz and Matthias Garschagen IN: Environmental Research Letters, https://doi.org/10.1088/1748-9326/adcad3

This study conducts a systematic literature review of assessment frameworks used for climate change responses, analyzing how they address what the authors identified as key requirements. By expanding the scope beyond CDR-specific assessment frameworks, they identify and derive valuable insights and approaches that can inform their refinement. Following a three-step approach, they first conducted a preceding scoping review to determine key requirements for holistic assessments. Second, a systematic literature review was conducted to identify a broad range of assessment frameworks for climate responses. Third, based on a qualitative content analysis we examined how these frameworks address the key requirements identified earlier.

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Peer-reviewed Publications

Dörpmund (2025): Motivations and challenges for carbon dioxide removal development: empirical evidence from market practitioners

Felix Dörpmund IN: Environmental Research Letters, https://doi.org/10.1088/1748-9326/adcad4

This study explores the role of private companies in shaping the early CDR innovation ecosystem by conducting interviews with senior practitioners (suppliers, purchasers / marketplaces, investors) actively involved in CDR markets. The author examines their motivations and challenges.

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Peer-reviewed Publications

Yao et al. (2025): Exploring Site-Specific Carbon Dioxide Removal Options With Storage or Sequestration in the Marine Environment – The 10 Mt CO2 yr−1 Removal Challenge for Germany

W. Yao, T. M. Morganti, J. Wu, M. Borchers, A. Anschütz, L.-K. Bednarz, K. A. Bhaumik, M. Böttcher, K. Burkhard, T. Cabus, A. S. Chua, I. Diercks, M. Esposito, M. Fink, M. Fouqueray, F. Gasanzade, S. Geilert, J. Hauck, F. Havermann, I. Hellige, S. Hoog, M. Jürchott, H. T. Kalapurakkal, J. Kemper, I. Kremin, I. Lange, J. M. Lencina-Avila, M. Liadova, F. Liu, S. Mathesius, N. Mehendale, T. Nagwekar, M. Philippi, G. L. N. Luz, M. Ramasamy, F. Stahl, L. Tank, M.-E. Vorrath, L. Westmark, H.-W. Wey, R. Wollnik, M. Wölfelschneider, W. Bach, K. Bischof, M. Boersma, U. Daewel, M. Fernández-Méndez, J. K. Geuer, D. P. Keller, A. Kopf, C. Merk, N. Moosdorf, N. Oppelt, A. Oschlies, J. Pongratz, A. Proelss, G. J. Rehder, L. Rüpke, N. Szarka, D. Thraen, K. Wallmann, N. Mengis IN: Earth’s Future, DOI: 10.1029/2024EF004902

Marine carbon dioxide removal (mCDR) and geological carbon storage in the marine environment (mCS) promise to help mitigate global climate change alongside drastic emission reductions. However, the implementable potential of mCDR and mCS depends, apart from technology readiness, also on site-specific conditions. In this work, we explore different options for mCDR and mCS, using the German context as a case study. The authors challenge each option to remove 10 Mt CO2 yr−1, accounting for 8%–22% of projected hard-to-abate and residual emissions of Germany in 2045. They focus on the environmental, resource, and infrastructure requirements of individual mCDR and mCS options at specific sites, within the German jurisdiction when possible. This serves as an entry point to discuss main uncertainty factors and research needs beyond technology readiness, and, where possible, cost estimates, expected environmental effects, and monitoring approaches. In total, they describe 10 mCDR and mCS options; four aim at enhancing the chemical carbon uptake of the ocean through alkalinity enhancement, four aim at enhancing blue carbon ecosystems‘ sink capacity, and two employ geological off-shore storage.

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Peer-reviewed Publications

Baatz et al. (2025): A holistic assessment framework for marine carbon dioxide removal options

Christian Baatz, Lukas Tank, Lena-Katharina Bednarz, Miranda Boettcher, Teresa Maria Morganti, Lieske Voget- Kleschin, Tony Cabus, Erik van Doorn, Tabea Dorndorf, Felix Havermann, Wanda Holzhüter, David Peter Keller, Matthias Kreuzburg, Nele Matz-Lück, Nadine Mengis, Christine Merk, Yiannis Moustakis, Julia Pongratz, Hendrikje Wehnert, Wanxuan Yao and Gregor Rehder IN: Environmental Research Letters, https://doi.org/10.1088/1748-9326/adc93f

The authors present a novel assessment framework designed for mCDR options. The framework provides important conceptual advancements to existing frameworks currently used to assess climate options: It clearly distinguishes between and allows for the assessment of both the feasibility and desirability of mCDR options, it makes explicit the evaluative standards upon which the assessment is based and it separates the descriptive listing of information from the evaluation of said information. The assessment framework aims to advance the debate on what role mCDR can and should play in responding to the climate crisis by providing a tool for both policymakers and stakeholders to assess mCDR options in a transparent and comprehensive way.

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Peer-reviewed Publications

Cormos (2025): Techno-economic and environmental life cycle analysis of renewable-based combined potassium – calcium looping cycle for direct air CO₂ capture

Calin-Cristian Cormos IN: Journal of Environmental Chemical Engineering, DOI: 10.1016/j.jece.2025.116601

The author evaluates an innovative energy- and cost-efficient potassium – calcium looping cycle as a promising Direct Air CO₂ Capture (DAC) technology. The potassium – calcium looping cycle is a reactive system which captures CO₂ by a combination of liquid solvent and solid sorbent. The high temperature energy recovery capability of this system makes it very promising for an energy- and cost-efficient CO₂ capture. To reduce the environmental impact, various renewable energy sources can be used to cover the required thermal duty, especially, the heat demand of the calcination reactor. The two investigated DAC concepts (fuelled by solar or biomass) are set to capture 1 Mt/y CO₂ from air with about 75 % capture rate. The conceptual design, detailed process modelling and validation, followed by overall energy optimization, done by thermal integration analysis, were used to assess the key techno-economic and environmental performance indicators.

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Peer-reviewed Publications

Guo et al. (2025): Effects of ocean alkalinity enhancement on plankton in the Equatorial Pacific

Jiaying A. Guo, Robert F. Strzepek, Zhongwei Yuan, Kerrie M. Swadling, Ashley T. Townsend, Eric P. Achterberg, Thomas J. Browning and Lennart T. Bach IN: Communications Earth & Environment, https://doi.org/10.1038/s43247-025-02248-7

A critical knowledge gap is how ocean alkalinity enhancement could influence marine plankton communities. Here the authors conducted 19 shipbased experiments in the Equatorial Pacific, examining three prevalent alkaline substances (sodium hydroxide, olivine, and steel slag) and their effects on natural phytoplankton populations under realistic and moderate alkalinity enhancements.

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Peer-reviewed Publications

Felix Dörpmund (2025): Motivations and challenges for carbon dioxide removal development: empirical evidence from market practitioners

Felix Dörpmund IN: Environmental Research Letters, DOI: 10.1088/1748-9326/adcad4

The study explores the role of private companies in shaping the early CDR innovation ecosystem by conducting 79 interviews with senior practitioners (suppliers, purchasers / marketplaces, investors) actively involved in CDR markets. Examining their motivations, the author finds themes that range from personal upbringing and caring for the following generations, to being catalytic in the creation of a new industry. All motivations are grounded in the recognition of CDR as an important component of global climate change mitigation. Identified challenges stretch across the categories of technology, organizations, policy and regulation, ecosystem, finances, and the public eye. This presents a complex picture, as all actors seek to solve a multi-faceted, concurrent coordination and scaling problem while dealing with a challenging set of uncertainties.

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Peer-reviewed Publications

Liu et al. (2025): Mineral‑fungal interactions in response to biochar amendment: implications for carbon storage in saline-alkali soil

Lu Liu, Mengmeng Chen, Jeroen Meersmans, Yuyi Li, Shirong Zhang & Xiaodong Ding IN: Plant and Soil, DOI: 10.1007/s11104-025-07360-3

Biochar application has been widely acknowledged as an environment-friendly practice to promote soil organic carbon (SOC) stabilization and sequestration in agroecosystems. However, the interaction between fungal and minerals on organic carbon storage and stabilization with biochar application still remains unclear in saline-alkaline soil. In the present research, this interaction has been studied by following 6 years treatments at an experimental farm: i) CK, without any fertilization; ii) NPK, only mineral fertilizer; iii) BC, 8.0 Mg ha−1 biochar-based NPK and iv) FeBC, 8.0 Mg ha−1 Fe modified biochar-based NPK, respectively.

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Peer-reviewed Publications

Science – Liang et al. (2025): Climate mitigation potential for targeted forestation after considering climate change, fires, and albedo

Shijing Liang, Alan D. Ziegler, Peter B. Reich, Kai Zhu, Dashan Wang, Xin Jiang, Deliang Chen, Philippe Ciais and Zhenzhong Zeng IN: Science Advances, doi.org/10.1126/sciadv.adn7915

The carbon sequestration potential of afforestation and reforestation remains uncertain in satellite-based assessments, particularly when accounting for dynamic climate conditions, vegetation-climate feedback, fire-dominated disturbance, and the trade-offs associated with surface albedo changes. Leveraging a coupled Earth system model, the authors estimated the global forestation mitigation during 2021–2100 under a sustainable shared socioeconomic pathway.

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Peer-reviewed Publications

Ren et al. (2025): Study on Carbon Removal from Coal Gangue to Purify Kaolin by Flotation with Different Collectors

Xiaoling Ren, Xinqian Shu, Yue Wu and Andong Yu IN: ACS Omega, https: //doi.org/10.1021/acsomega.5c00123

In order to explore the effects of carbon chain length of nonpolar saturated hydrocarbons and the type of polar groups on coal gangue flotation, five saturated hydrocarbons with different carbon chain lengths and seven hydrocarbons and hydrocarbon derivatives with different groups were selected for flotation.

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