CO2-removal News

Peer-reviewed Publications

Bauer et al. (2026): In-situ deep ocean monitoring reveals rapid kelp degradation limits marine biomass-based carbon sequestration potential and alters benthic ecosystems

Kohen W. Bauer, Paulo V. F. Correa, Alex Lupin, Stefanie Mellon, Mojtaba Fakhraee, Anna C. Savage, Alison K. Tune, Alexander L. Slonimer, Bradley Rochlin & Fabio C. De Leo, IN: Communications Earth & Environment, https://doi.org/10.1038/s43247-026-03342-0

Sinking macroalgal biomass carbon to the deep seafloor has been proposed as a means of removing atmospheric carbon dioxide, but the persistence of this carbon and its ecological impacts remain poorly constrained. Here, the authors present results from a year-long in-situ experiment in the Northeast Pacific oxygen minimum zone, where kelp was deployed and monitored with high-resolution time-lapse imaging.

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Peer-reviewed Publications

Arraga et al. (2026): Demonstration of direct air capture of CO₂ using microalgae raceway reactors

R. Arraga, M. Barceló-Villalobos, R. Esteitie, M. Ahaddouch, C. Sánchez-Salinas, F.G. Acién, IN: Journal of CO₂ Utilization, https://doi.org/10.1016/j.jcou.2026.103376

The continuous increase in atmospheric CO₂ concentration underscores the urgent need for scalable and energy-efficient carbon removal technologies. This study demonstrates, for the first time, the implementation of a tailored Direct Air Capture (DAC) concept integrated within large-scale microalgae raceway reactors, enabling direct CO₂ uptake from ambient air without external gas supply. A 600 m² reactor operated continuously with Scenedesmus sp. maintained stable productivity (12 g m⁻² day⁻¹) under extreme carbon limitation (TIC ≈ 20 mg L⁻¹, pH ≈ 10).

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Peer-reviewed Publications

Searchinger et al. (2026): Decades of Increased Emissions from Forest-Fueled BECCS – Preprint

Timothy Searchinger, Liqing Peng, Daniella Russi, Charles Canham, IN: ResearchSquare, https://doi.org/10.21203/rs.3.rs-9038129/v1

Should climate policies encourage bioenergy with carbon capture and storage (BECCS) using wood from existing forests? Although mitigation pathways in integrated assessment models often rely on BECCS fueled by energy crops, European governments are moving to financially support BECCS sourced instead from existing forests. To estimate its emissions and financial costs, they develop a model that transparently tracks carbon flows from forest to end use and allows policymakers to easily alter assumptions.

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Peer-reviewed Publications

Kozian et al. (2026): A global analysis of expected revenues from carbon dioxide removal

Alyssa Kozian, Jakob Ellensohn, Tobias S Schmidt and Bjarne Steffen, IN: Environmental Research Letters, https://doi.org/10.1088/1748-9326/ae499d

Carbon dioxide removal (CDR) must scale rapidly to achieve net-zero emissions by mid-century. This scale-up requires substantial investment in the CDR industry, underpinned by stable revenues. While various different revenue streams are conceivable, and academic literature proposes diverse interventions to support CDR, they lack an empirical understanding of revenue expectations from the actors that develop and deploy CDR solutions. Drawing on 50 structured interviews with senior leaders from companies headquartered in 17 countries who develop CDR projects in 52 countries, here they assess expected revenue streams across different permanent CDR solutions. While voluntary carbon markets dominate in 2024, compliance markets are expected to become the main revenue source by 2030 already, particularly through the opening of cap-and-trade systems for removals. Direct subsidies are mainly important for immature technologies. By considering differences in expected revenues across CDR solutions and geographies, policy mixes can be designed to effectively support investment and scale-up in the heterogeneous CDR industry.

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Peer-reviewed Publications

Ihasusta et al. (2026): Choosing the appropriate methodology to monitor soil organic carbon (SOC) in croplands: aligning methods with evolving monitoring reporting verification (MRV) frameworks

Ainhoa Ihasusta, Ahmad Al Bitar, Niels H. Batjes, Fenny van Egmond et al., IN: Taylor & Francis, https://doi.org/10.1080/17583004.2026.2638317

Monitoring soil organic carbon (SOC) has gained significant recognition, not only for national greenhouse gas inventories but also for voluntary carbon markets and agri-environmental policies. This has amplified the need for accurate, continuous, and cost-effective SOC stock monitoring from field to national scales. Consequently, methodological frameworks have emerged to address these diverse needs. They rely on measurement and/or modeling of the SOC, considering several complexities (Tiers 1, 2 and 3), combined or not with remote sensing. However, practical implementation guidelines for choosing the most suitable monitoring approach for specific contexts and purposes remain incomplete. Therefore, this study analyses current SOC monitoring methodologies for croplands and proposes a decision tree to help MRV stakeholders select the monitoring strategy considered most appropriate for their context.

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Peer-reviewed Publications

Campbell et al. (2026): Harnessing naturally occurring sodium carbonate and bicarbonate for gigatonne-scale carbon dioxide removal

James Campbell, Spyros Foteinis, Reinaldo Juan Lee Pereira, Mohamad Katish, Phil Renforth, IN: EarthArXiv, https://doi.org/10.31223/X5276Q

Ocean alkalinity enhancement is a promising carbon dioxide removal (CDR) approach, but scaling up to gigatonnes (Gt) of CO₂ per year will require safe, sustainable, and abundant alkaline feedstocks. Here, the authors propose the use of a relatively unexplored resource for OAE, namely naturally occurring sodium (bi)carbonates. They identified and mapped 109 such deposits globally, although quantitative resource information is available for only 16. Quantified deposits collectively contain >200 Gt of sodium (bi)carbonate-rich minerals and brines, dominated by trona (Na₂CO₃·NaHCO₃·2H₂O) and nahcolite (NaHCO₃) mainly concentrated in the USA, China, Turkey, and Kenya. They then assessed three OAE pathways using trona as a feedstock, i.e., 1) Mining, crushing, and ocean dispersal of trona (gross CDR capacity 0.16 tCO₂ t⁻¹); 2) Calcine trona with carbon capture and storage to produce soda ash (Na₂CO₃) (0.31 tCO₂ t⁻¹) prior to dispersal; and 3) Purification of soda ash via dissolution, crystallisation, and drying prior to dispersal. Using Green River, Wyoming, USA (~116 Gt of bedded trona) as a case study, life cycle assessment informed on the net-negativity of each pathway.

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Peer-reviewed Publications

Park et al. (2026): Scale-Bridging Solid Adsorbents for Direct Air Capture: Integrating Material Chemistry, Structured Contactors, and Advanced Regeneration Processes

Injun Park, Sieun Kim, Karoline L. Hebisch, Inhwan Park, Minhyung Lee and Dong-Yeun Koh, IN: ChemRxiv, https://doi.org/10.26434/chemrxiv.15000500/v1

Direct air capture (DAC) has emerged as an essential, emissions source independent pathway toward global net-zero targets. Compared to solvent-based systems, solid adsorbent-based DAC holds distinct advantages due to its broader material versatility, modular scalability, and streamlined equipment architecture. However, transitioning from laboratory-scale material discovery to commercial deployment requires a holistic, system-level engineering approach. Because intrinsic adsorbent properties dictate the design of scalable structured contactors, the selection of energy-efficient regeneration methods, and the ultimate techno-economic and environmental viability of the process, these interdependent components must be synergistically co-optimized. To address this co-optimization challenge, the authors provide a critical, integrated evaluation of solid adsorbent DAC.

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Peer-reviewed Publications

Campbell et al. (2026): Harnessing naturally occurring sodium carbonate and bicarbonate for gigatonne-scale carbon dioxide removal

James Campbell, Spyros Foteinis, Reinaldo Juan Lee Pereira, Mohamad Katish and Phil Renforth, IN: EarthArXiv, https://doi.org/10.31223/X5276Q

Ocean alkalinity enhancement is a promising carbon dioxide removal (CDR) approach, but scaling up to gigatonnes (Gt) of CO₂ per year will require safe, sustainable, and abundant alkaline feedstocks. Here, the authors propose the use of a relatively unexplored resource for OAE, namely naturally occurring sodium (bi)carbonates. The authors identified and mapped 109 such deposits globally, although quantitative resource information is available for only 16. Quantified deposits collectively contain >200 Gt of sodium (bi)carbonate-rich minerals and brines, dominated by trona (Na₂CO₃·NaHCO₃·2H₂O) and nahcolite (NaHCO₃) mainly concentrated in the USA, China, Turkey, and Kenya.

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Peer-reviewed Publications

Ihasusta et al. (2026): Choosing the appropriate methodology to monitor soil organic carbon (SOC) in croplands: aligning methods with evolving monitoring reporting verification (MRV) frameworks

Ainhoa Ihasusta, Ahmad Al Bitar, Niels H. Batjes, Fenny van Egmond et al., IN: Carbon Management, https://doi.org/10.1080/17583004.2026.2638317

Monitoring soil organic carbon (SOC) has gained significant recognition, not only for national greenhouse gas inventories but also for voluntary carbon markets and agri-environmental policies. This has amplified the need for accurate, continuous, and cost-effective SOC stock monitoring from field to national scales. Consequently, methodological frameworks have emerged to address these diverse needs. They rely on measurement and/or modeling of the SOC, considering several complexities (Tiers 1, 2 and 3), combined or not with remote sensing. However, practical implementation guidelines for choosing the most suitable monitoring approach for specific contexts and purposes remain incomplete. Therefore, this study analyses current SOC monitoring methodologies for croplands and proposes a decision tree to help MRV stakeholders select the monitoring strategy considered most appropriate for their context.

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Peer-reviewed Publications

Kozian et al. (2026): A global analysis of expected revenues from carbon dioxide removal

Alyssa Kozian, Jakob Ellensohn, Tobias S. Schmidt and Bjarne Steffen, IN: Environmental Research Letters, https://doi.org/10.1088/1748-9326/ae499d

Carbon dioxide removal (CDR) must scale rapidly to achieve net-zero emissions by mid-century. This scale-up requires substantial investment in the CDR industry, underpinned by stable revenues. While various different revenue streams are conceivable, and academic literature proposes diverse interventions to support CDR, the authors lack an empirical understanding of revenue expectations from the actors that develop and deploy CDR solutions. Drawing on 50 structured interviews with senior leaders from companies headquartered in 17 countries who develop CDR projects in 52 countries, the authors assess expected revenue streams across different permanent CDR solutions.

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