Schlagwort: Carbon Dioxide Removal

Peer-reviewed Publications

Suhrhoff et al. (2026): An Ecosystem of Carbon Dioxide Removal Reviews – Part 3: Enhanced Weathering

Tim Jesper Suhrhoff, Christiana Dietzen, Tyler Kukla, Abby Lunstrum, Tom Reershemius et al., IN: CDR.Xiv (Preprint), https://doi.org/10.70212/cdrxiv.2026417.v1

Enhanced Weathering (EW) is an emerging Carbon Dioxide Removal (CDR) approach within a growing portfolio of mitigation strategies, offering the potential for durable CDR alongside agronomic co-benefits. As interest in CDR increases, EW is transitioning from a primarily scientific concept toward early-stage implementation, requiring a comprehensive synthesis of the current evidence base. This systematic review focuses primarily on soil-based EW using silicate rock feedstocks. Across empirical and modelling studies, area-normalized CDR fluxes have a median value of 0.84 tonnes of carbon dioxide per hectare per year (tCO₂ ha⁻¹ yr⁻¹) and span several orders of magnitude. The variance in reported fluxes reflects not only context-dependent differences in EW performance, but also the diversity of quantification approaches, which differ by use case and vary in terms of their system boundaries and treatment of loss processes. When scaled globally, evidence from empirical constraints and/or modelling approaches converges on a maximum technical CDR potential of ~0.2–2 GtCO₂ yr⁻¹, though some estimates are higher. Significant uncertainty remains regarding the magnitude, persistence, and timing of loss processes after initial CDR has occurred, including secondary phase formation and cation exchange, and in how these losses depend on local soil and climate conditions and deployment strategies. Interactions with soil organic carbon introduce additional uncertainty but also the potential for increasing total CDR. Beyond CDR, EW is consistently associated with improvements in soil properties and crop productivity. Its deployment within managed land systems creates opportunities for synergies with other land-based CDR approaches, enabling combined inorganic and biological carbon sequestration. At the same time, EW raises important socio-economic and governance considerations, including distributional impacts, environmental risks, and conditional public support.

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Peer-reviewed Publications

Vienne et al. (2026): River alkalinity enhancement for scalable and energy-efficient geochemical carbon dioxide removal: potential, costs and risks?

Arthur Vienne, Tom Cox, Harun Niron, Tim Jesper Suhrhoff and Sara Vicca, IN: CDR.Xiv (Preprint), https://doi.org/10.70212/cdrxiv.2026539.v1

Gigaton-scale carbon dioxide removal (CDR) from the atmosphere will be necessary to limit global warming to below 2 C. Current approaches, such as afforestation or biochar, are constrained by land and biomass availability, whereas direct-air carbon capture technologies are energy-intensive and costly. Here, the authors discuss river alkalinity enhancement (RAE), a geochemical carbon dioxide removal strategy that uses readily available limestone (CaCO₃) and derived slaked lime (Ca(OH)₂) to increase alkalinity in rivers. Unlike the direct addition of these minerals to the ocean, which is currently restricted by the London protocol, addition of alkalinity to rivers is already commercially applied in some regions and alkalinity dosing can be monitored in controlled systems. Controlled rock dissolution in ponds allows for direct measurement of CO₂ removal prior to water release back into rivers, enhancing traceability and verification.They simulate CO₂ uptake in 149 major rivers, considering river flows and chemistry and life-cycle emissions from mining, grinding and transporting rock and pumping water in reactor ponds.

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Peer-reviewed Publications

Aliabadi et al. (2026): Carbon Dioxide Removal Options for Energy Transitions: BECCS versus DACCS in Germany

Danial Esmaeili Aliabadi, Sandra Gutjahr, Mohammad Sadr, Matthias Jordan and Daniela Thrän, IN: IEEE, https://doi.org/10.1109/EEM68581.2026.11589592

There is an ongoing debate about whether the authors should heavily invest in variable renewable energy to reduce anthropogenic emissions and utilize surplus electricity for direct air carbon capture and storage (DACCS), or instead prioritize bioenergy with carbon capture and storage (BECCS) to provide system flexibility while simultaneously removing atmospheric emissions. Although DACCS is more costly, achieving ambitious climate targets may ultimately require such extreme mitigation options. In this study, the authors integrate DACCS technology into the stochastic BENOPTex model, which features various BECCS concepts and CO₂ utilization pathways, to investigate the optimal contribution of carbon removal technologies for net-zero energy systems under different conditions in Germany. The risk sensitivity is formulated using the Value-at-Risk measure.

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Peer-reviewed Publications

Belotti et al. (2026): Reimagining ownership and governance for carbon dioxide removal (CDR): exploring existing alternative models to advance equity and justice

Giulia Belotti, David Branigan, Holly Caggiano and Sara Nawaz, IN: Carbon Management, https://doi.org/10.1080/17583004.2026.2694126

Carbon dioxide removal (CDR) technologies are rapidly transitioning from research to real-world application. At present, private-sector oriented logics for CDR deployment dominate—a primacy that poses several risks for just and equitable outcomes. To date, however, there has been little consideration of how non-private sector ownership arrangements could facilitate just and equitable scaling of CDR. This paper explores several examples of alternative ownership and governance models, asking what other arrangements might be possible and desirable. Drawing on methods informed by qualitative evidence synthesis, the authors examine a diverse range of examples across sectors with structural similarities to select CDR approaches: agriculture, energy systems, mining, aquatic resources, and water infrastructure.

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Peer-reviewed Publications

Natividad et al. (2026): Organic–inorganic carbon coupling shapes carbon dioxide fluxes in seagrass ecosystems

Mariche B. Natividad, Wei-Jun Cai, Nina Bednaršek, Jian-Jhih Chen and Wen-Chen Chou, IN: Communications Earth & Environment, https://doi.org/10.1038/s43247-026-03805-4

Seagrass meadows can remove atmospheric carbon dioxide through organic carbon production and storage, but they also alter seawater chemistry through calcium carbonate formation and dissolution. Most blue carbon assessments focus on organic carbon burial and overlook how inorganic carbon cycling regulates carbon dioxide exchange. This Perspective presents a framework linking organic carbon metabolism, carbonate cycling, and sedimentary processes to explain when seagrass ecosystems function as net carbon dioxide sinks or sources. The authors introduce a compensation ratio that defines the balance between organic carbon uptake and calcification-driven carbon dioxide release and show how this balance changes with environmental conditions and sediment carbon sources. Using the Dongsha Island lagoon as a case study, the authors show how seagrass metabolism coupled to dissolution of geologically derived carbonate sediments can sustain alkalinity generation and long-term carbon dioxide uptake. Together, this framework provides a more complete basis for evaluating blue carbon and the climate mitigation potential of carbonate-rich coastal ecosystems.

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Peer-reviewed Publications

Delval et al. (2026): Guidance on integrating marine environmental impacts of ocean alkalinity enhancement into life cycle assessment

Mona H. Delval, Patrik J. G. Henriksson, Paul Behrens, Laura Scherer, Pablo Trucco-Pignata, Patricia Grasse, Phil Renforth and Nils Thonemann, IN: The International Journal of Life Cycle Assessment, https://doi.org/10.1007/s11367-026-02707-z

Ocean alkalinity enhancement (OAE) is considered a promising marine carbon dioxide removal (mCDR) option and may contribute to climate change mitigation. Life cycle assessment (LCA) is used to assess OAE environmentally but faces limitations in capturing marine impacts. Improving the assessment of OAE in LCA requires a detailed understanding of its marine environment impact pathways to develop sub-compartmentalised and regionalised characterisation factors (CFs). The authors demonstrate how such pathways can be identified.
The authors build on Woods et al. (2021), who propose a qualitative framework to identify key components of impact pathways, and Richter et al. (2024), who provide guidance on framework development in a multidisciplinary context. The authors develop a methodological approach that allows to qualitatively identify the marine environmental impact pathways of OAE and determine which components are integrated in LCIA models or missing, as an initial phase toward developing CFs for life cycle impact assessment (LCIA).

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Peer-reviewed Publications

Jessen et al. (2026): Subsoil acidity causes long delays in inorganic carbon sequestration by Enhanced Weathering

Søren Jessen, Rasmus Jakobsen, Majken Looms, Per Ambus and Dieke Postma, IN: arXiv, https://doi.org/10.48550/arXiv.2607.01835

While a looming atmospheric CO₂ overshoot calls for immediate carbon sequestration, delays associated to Enhanced Weathering (EW) carbon dioxide removal are being investigated. Topsoil acidity is already known to delay EW carbon sequestration, but subsoil acidity remains underexplored. Using century-long agricultural liming of formerly acidic heathland as a proxy for EW, this study provides empirical evidence of subsoil-imposed delays.

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Peer-reviewed Publications

Adewole et al. (2026): Design and Implementation of Direct Air Capture Systems Based on Moisture Swing Adsorption for Efficient Carbon Dioxide Removal

Oluwatosin O. Adewole, Taopheeck Yusuf, Victor Hammed and Abdulrahman M. Hassan, IN: International Journal of Innovative Science and Research Technology, https://doi.org/10.38124/ijisrt/26apr580

Direct air capture (DAC) is necessary for achieving negative emissions and meeting the temperature targets outlined in the Paris Agreement. However, challenges of scalability and energy demands persist. This paper presents a comprehensive design framework for large-scale DAC systems utilizing moisture swing adsorption (MSA), an innovative method that leverages humidity cycles to regenerate sorbents with near-isothermal energy, thereby reducing energy penalties by 50-70% compared to thermal swing alternatives. The study proposes an architecture combining modular air contractors, structured sorbent monoliths using anion exchange resins, CO₂ compression trains, and controlled humidification chambers, enabling continuous cyclic operation in various climatic conditions. Governing equations for momentum balance, mass transfer, and adsorption kinetics inform finite element simulations and computational fluid dynamics, which are validated against laboratory-scale experimental data.

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Peer-reviewed Publications

Nagaraj et al. (2026): Thrombolites as a potential nature-based solution for carbon dioxide removal

Veena Nagaraj, Daniel Gorman, M. James McLaughlin, Santonu K. Sanyal, Thomas Jones, et al., IN: Carbon Capture Science & Technology, https://doi.org/10.1016/j.ccst.2026.100651

Achieving net-zero targets requires emerging carbon dioxide removal (CDR) pathways capable of contributing to long-term carbon storage. Microbialite communities, including stromatolites and thrombolites, are promising but under-explored biological platforms with potential for scalable CDR. Their deployment has been limited by uncertainties surrounding survivability in seawater, biomineralisation rates, net CO₂ drawdown, and compatibility with engineered substrates. Here, the authors address four conceptual barriers using thrombolites from hypersaline Lake Clifton (Western Australia).

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Scientific Theses

Haavisto (2026): Why does policy design matter when integrating permanent carbon removals into the EU ETS? Assessing the outcomes through dynamic modelling

Jami Haavisto, IN: University of Helsinki, https://helda.helsinki.fi/items/5b2dad84-add8-4f61-9ed4-b1a44360b7ce

Integrating permanent carbon removals into the European Union Emissions Trading System (EU ETS) is under an active debate, and such integration may occur as early as the upcoming reform of the EU ETS. This thesis examines how policy design affects the environmental and economic outcomes, using a dynamic ETS model extended to include permanent removals produced through bioenergy with carbon capture and storage (BECCS).

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