CO2-removal News

Peer-reviewed Publications

Evanset al. (2025): The Known Unknowns of Petrogenic Organic Carbon in Soils

Daniel L. Evans, Sebastian Doetterl, Nora Gallarotti, Eleanor Georgiadis, Sami Nabhan, Stephan H. Wartenweiler, Timo M. Y. Rhyner, Benedict V. A. Mittelbach, Timothy I. Eglinton, Jordon D. Hemingway and Thomas M. Blattmann IN: AGU Advances, https://doi.org/10.1029/2024AV001625

Intensifying effects of global climate change have spurred efforts to enhance carbon sequestration and the long-term storage of soil organic carbon (OC). Current soil carbon models predominantly assume that inputs of OC are biospheric, that is, primarily derived from plant decomposition. However, these overlook the contribution of OC from soil parent material, including petrogenic organic carbon (OCpetro) from OC-bearing (meta-)sedimentary bedrock. To the authors knowledge, no soil carbon model accounts for the inputs of OCpetro to soils, resulting in significant gaps in their understanding about the roles OCpetro plays in soils. Here, they call for cross-disciplinary research to investigate the transport and stability of OCpetro across the bedrock–soil continuum. They pose four key questions as motivation for this effort.

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Cajada et al. (2025): Regionally-Dependent Arctic Sea Ice Recovery to CO₂ Removal

M. Inês Cajada, Seok-Woo Son, Jaeyoung Hwang, Hyo-Seok Park and Soon-Il An, IN: Earth’s Future, https://doi.org/10.1029/2024EF005597

The decline of Arctic sea ice area (SIA) has accelerated in recent decades and is projected to continue in a warming climate. This trend can be reversed by reducing atmospheric CO₂ concentrations. A large-ensemble model experiment, in which atmospheric CO₂ concentrations are quadrupled and then reduced to the initial state, shows an overall recovery of Arctic SIA by CO₂ removal, but at a slower rate than its decline to CO₂ increase.

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Peer-reviewed Publications

Yun & Rossi (2025): Exploring the Use of Treated Water in Water Reclamation Facilities for Carbon Dioxide Capture and Sequestration

Nakyeong Yun and Ruggero Rossi, IN: ACS ES&T Engineering, https://doi.org/10.1021/acsestengg.5c00276

Water reclamation facilities contribute to the emission of greenhouse gases during the treatment of wet waste and following the release of the treated water effluent in receiving water bodies due to the high concentration of greenhouse gas precursors dissolved in the effluent. Here, an electrochemical cell was used to capture inorganic carbon dissolved in the treated liquid effluent discharged from four wastewater treatment plants.

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Peer-reviewed Publications

Nature – Falvo & Robertson (2025): Nature-based climate solutions can help mitigate the radiative forcing that follows deforestation

Grant Falvo and G. Philip Robertson, IN: Communications Earth & Environment, https://doi.org/10.1038/s43247-025-02291-4

Here the authors quantify the radiative forcing caused by the historical deforestation of an ecoregion in the U.S. Upper Midwest and the adoption of eight nature-based climate solutions. They combined regional forest inventory data with over three decades of remote sensing and in situ data from a replicated land use change experiment.

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Peer-reviewed Publications

Schaffer et al. (2025): Enhanced weathering of kimberlite residues in a field experiment: Implications for carbon removal quantification and mine waste valorization

Zivi R Schaffer, Kwon RausisIan, Ian M Power and Carlos Paulo, IN: Frontiers in Climate, https://doi.org/10.3389/fclim.2025.1592626

Scaling up enhanced rock weathering (ERW) will require gigatonnes of suitable rock, which could include mine wastes such as the estimated 3.9 Gt of kimberlite residues from historic diamond mining. Here, the authors conducted metre-scale field experiments (2021)(2022)(2023) in Ontario, Canada, to assess fine processed kimberlite residues for ERW and test carbon-based methods for CO₂ removal (CDR) quantification, including CO₂ fluxes, and measurements of soil and porewater inorganic carbon.

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Science-Policy Documents

Marx et al. (2025): Development of the ecological activity index as an integrative ecosystem assessment and monitoring asset for ocean alkalinity enhancement

Lukas Marx, Jennie Rheuban, Daniel McCorkle, Christopher Murray, and 6 more, IN: ResearchSquare, https://doi.org/10.21203/rs.3.rs-6371725/v1

Ocean alkalinity enhancement (OAE) is an mCDR approach that sequesters carbon dioxide by adding alkaline materials into the marine environment. Currently, no environmental impact assessment framework exists for OAE. Here, the authors describe an assessment approach using public datasets of multiple trophic levels and fishing activity. They develop the ecological activity index (EAI), a quantitative tool to identify locations and times of year that minimize impacts on critical ecosystem metrics.

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Peer-reviewed Publications

Nature – Liu et al. (2025): Degradable film mulching increases soil carbon sequestration in major Chinese dryland agroecosystems

Zihan Liu, Chenxu Zhao, Nanhai Zhang, Jing Wang, Zhaoyang Li, Yves Uwiragiye, Nyumah Fallah, Thomas W. Crowther, Yuanyuan Huang, Yi Xu, Sheng Zhang, Yakov Kuzyakov, Kadambot H. M. Siddique, Zhikuan Jia, Zucong Cai, Scott X. Chang, Minggang Xu, Christoph Müller and Yi Cheng, IN: Nature Communications, https://doi.org/10.1038/s41467-025-60036-5

Plastic film mulching (PM), which contributes to nearly half of the increased crop yields in dryland agroecosystems, exacerbates environmental burdens due to its non-degradable nature. Globally, there is a growing demand to replace non-degradable PM with degradable film mulching (DM), yet its impacts on soil organic carbon (SOC) in dryland agroecosystems remains unknown. Here, using multi-field studies and mesocosm experiments, the authors found that DM strongly increased but PM reduced SOC storage (0–1 m).

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Peer-reviewed Publications

Babonneau et al. (2025): A robust asymptotic control model to analyze climate policy with CDR options

Frédéric Babonneau, Alain Haurie, Marc Vielle, IN: EPFL Infoscience, https://doi.org/10.1016/j.jedc.2025.105114

A three-region optimal economic growth model is proposed to represent the global energy transition to net-zero emissions when carbon dioxide removal (CDR) technologies are available. The main features of the model are (i) the representation of the economy and energy use with nested CES production functions; (ii) the representation of climate policy through the use of a safety cumulative emissions budget concept; and (iii) the introduction of an international emissions trading scheme for the implementation of climate policy. Using an infinite horizon optimal control paradigm, several contrasting scenarios are analyzed both in an asymptotic steady state or “turnpike” point, and in an optimal transition to sustainability. This very compact model produces dynamic path simulations that are consistent with the main recommendations from IPCC for long term climate policies. The potential use of this simple model in future developments in climate and economic modeling is discussed.

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Peer-reviewed Publications

Moshi et al. (2025): The Influence of Sediment Properties on CO₂ Hydrate Sequestration in Sub-Seafloor Saline Sediments: A Review of Formation and Stability

Jennifer S. Moshi, Chaohua Guo, Fravian M. Marobo, Orgenes S. Moshi, IN: Energy & Fuels ,https://doi.org/10.1021/acs.energyfuels.5c01292

CO₂ hydrate storage in subseafloor saline sediments has shown promise through sediment-specific and sediment modification approaches aimed at maximizing hydrate formation, stability, and storage potential. However, the long-term storage efficiency is compromised due to the harsh conditions of the subseafloor saline sediments, such as overly high pressure and temperature conditions, fluctuation in salinity, sediment interactions, and sediment heterogeneity. Techniques, such as the use of inorganic emulsifiers, amino acids, and coatings with nanoparticles (NPs) or functionalized compounds, have revealed benefits in enhancing CO₂ hydrate formation, stability, dispersion, and nucleation, leading to improved storage capacity and long-term storage efficiency. In this work, the performance of sediment surface modification techniques in enhancing CO₂ hydrate formation efficiency, storage capacity, and long-term storage efficiency, such as surface roughening, nanotechnology-based modifications, chemical functionalization, electrokinetic methods, thermal treatment methods, and the factors that impair their effectiveness, was highlighted. Additionally, the roles of chemical additives, such as sodium chloride, surfactants, and polymers, in sediment modification for improved CO₂ hydrate storage were examined. Synergistic interactions among sediment surface roughening, NPs, and chemical additives to the interfacial tension reduction, induction time reduction, increased adsorption tendencies, and wettability change were presented. In addition, the review addresses challenges and potential remedies, synthesizing experimental data, simulations, and theoretical studies to advance the understanding of sediment-specific and sediment modification CO₂ hydrate storage. By consolidating existing knowledge, this work aims to guide CO₂ storage researchers, engineers, and policymakers in optimizing subseafloor saline sediments as viable CO₂ reservoirs, contributing to global carbon mitigation efforts.

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Peer-reviewed Publications

Woods et al. (2025): Techno-Economic Assessment of Atmospheric Carbon Removal via Industrial Composting of Biomass Waste with CO₂ Capture

Ethan Woods, Nicolas Clauser, Jesse Daystar and William Joe Sagues, IN: ACS Omega, https://doi.org/10.1021/acsomega.4c10158

The techno-economic feasibility of removing atmospheric CO₂ via industrial composting of high-moisture, heterogeneous biomass waste with CO₂ capture is assessed. The novel composting process generates a relatively high concentration of biogenic CO₂ for capture, while avoiding the emission of methane and generating a nutrient-rich soil amendment. Empirical data generated from compost bioreactors at 0.5 L and 25 L scales inform the techno-economic assessment.

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