CO2-removal News

Peer-reviewed Publications

Sovacool et al. (2026): Plentitude of Pathways: Expert Views on the Benefits and Risks of Carbon Dioxide Removal in Six Countries

Benjamin K. Sovacool, Nick Fitzpatrick, Livia Fritz and Lucilla Losi, IN: Environmental Science & Technology, https://doi.org/10.1021/acs.est.6c02066

A consensus is emerging that carbon dioxide removal (CDR) is indispensable for achieving net-zero targets and managing hard-to-abate greenhouse gas emissions. However, many modeling and quantitative studies fail to represent the complex sociotechnical landscape of CDR, often limiting their scope to a few technological options and providing an incomplete analysis of the trade-offs between deployment benefits and risks. This study addresses this gap through a qualitative, expert-driven assessment of the most significant benefits and risks facing CDR deployment across three Global North (Italy, Norway, and the United Kingdom) and three Global South (Brazil, Malaysia, and Saudi Arabia) contexts. Methodologically, the study derives its insights from an original data set of N = 98 semistructured interviews with a diverse range of CDR experts from academia, government, civil society, and the private sector.

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Peer-reviewed Publications

Ayisi et al. (2026): Biological carbon sinks in aquaculture: evaluating sequestration potential and integration into carbon markets

Christian Larbi Ayisi, Samuel Ayeh Osei, Adelaide Henewaa and Rosemary Anderson Akolaa, IN: Hydrobiologia, https://doi.org/10.1007/s10499-026-02551-w

Interests in carbon markets worldwide have increased significantly due to the growing urgency of climate change mitigation, prompting a reassessment of nature-based solutions for reducing greenhouse gas (GHG) emissions. Wetland environments and forests have long been recognized as carbon sinks, but little is known about how aquaculture helps sequester carbon and how it may be included into carbon credit markets. With a focus on shellfish, seaweed, and integrated multi-trophic aquaculture (IMTA), this study examines the potential of aquaculture systems to sequester carbon. This study also examines how prepared various aquaculture systems are to take part in compliance and voluntary carbon markets. Through biological processes including carbonate shell formation, photosynthetic CO₂ uptake, and sedimentary carbon burial, aquaculture can function as a blue carbon sink.

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Peer-reviewed Publications

Deeksha (2026): Agroforestry as a Corporate Carbon Sink: Institutionalizing Farmer-Generated Carbon Credits

S. Deeksha, IN: International Journal of Research and Scientific Innovation, https://doi.org/10.51244/IJRSI.2026.1303000221

The accelerating climate crisis and rising corporate net-zero commitments have intensified demand for credible carbon offset mechanisms. Agroforestry, which integrates trees with crops and livestock systems, presents a scalable nature-based solution capable of sequestering significant atmospheric carbon while enhancing rural livelihoods. This paper proposes an institutional framework for transforming farmer-managed agroforestry systems into structured corporate carbon sinks through verified carbon credit generation. Drawing upon global climate governance frameworks such as the Paris Agreement and mitigation pathways outlined by the Intergovernmental Panel on Climate Change, the study conceptualizes a Farmer–Corporate Carbon Institutional Model (FCCIM). The model integrates carbon measurement, reporting and verification (MRV), aggregation through Farmer Producer Organizations (FPOs), and corporate procurement mechanisms. A financial simulation framework is developed to estimate revenue potential per hectare under different agroforestry densities.

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Martocello et al. (2026): The state of macroalgae carbon dioxide removal: insights from a methodology development team

Donald E. Martocello, Thomas Storwick and Carolyn Buchwald, IN: Frontiers in Climate, https://doi.org/10.3389/fclim.2026.1761760

In the face of anthropogenic climate change, there is strong impetus to develop and implement durable carbon dioxide removal (CDR) technologies, alongside emissions reductions. CDR is an emerging private sector industry seeking to provide scientifically rigorous carbon offsets for entities unable to reduce carbon emissions below regulatory compliance or to support voluntary claims of carbon neutrality and reduction. Among nature-based CDR strategies, macroalgae (seaweed) cultivation is frequently cited as a promising and emerging pathway for ocean carbon storage in a variety of contexts. Despite widespread discussion in the literature and numerous papers that have modeled successful long-term storage by macroalgae cultivation, few field-scale studies exist and no accepted carbon crediting framework exists. Recently, a joint industry-academic partnership attempted to develop a rigorous ecologically-sound carbon credit methodology that aligned the goals of private sector and academic interests in macroalgae CDR. This perspective piece discusses the story of this endeavor, outlining the fundamental science necessary for developing a methodology, challenges that ultimately prevented the team’s completion, and insights into the necessary steps for advancing macroalgae CDR further.

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Peer-reviewed Publications

Jerden et al. (2026): Soil Remineralization in Agroecological Systems: A Critical Review

James Jerden, Thomas Vanacore and Joanna Campe, IN: EarthArXiv, https://doi.org/10.31223/X5F196

Soil degradation threatens global food security, human nutrition, biodiversity, water resources, and climate stability by depleting soil organic matter, exhausting nutrient reserves, and disrupting carbon and nitrogen cycles. Conventional input-intensive agriculture has delivered yield gains but has also contributed to widespread micronutrient deficiencies, nutrient loading of waterways, soil erosion, and greater vulnerability to climate extremes. Soil remineralization, using finely ground, often locally sourced silicate and related rock powders co-applied with organic and biological amendments, offers a nature-based strategy to rebuild soil health and resilience while reducing dependence on synthetic fertilizers. Historical and contemporary evidence indicate that soil remineralization can enhance crop yields, nutrient uptake, soil structure, and carbon storage, especially on highly weathered or degraded soils. However, the use of inappropriate rock types, excessive application rates, and narrow carbon-offset framings poses agroecological risks. Here the authors review soil remineralization in agroecological systems by integrating biogeochemical theory, a historical survey, and a new synthesis of 191 experimental and field observations.

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Peer-reviewed Publications

Guo et al. (2026): Metal bioaccumulation from diatoms to Antarctic krill under ocean alkalinity enhancement with steel slag

Jiaying A Guo, Kerrie M Swadling, Robert F Strzepek, Lavenia Ratnarajah, Scott Meyerink, Rob King, Ashley T Townsend and Lennart T Bach, IN: ICES Journal of Marine Science, https://doi.org/10.1093/icesjms/fsag066

Ocean alkalinity enhancement (OAE) is an emerging carbon dioxide removal (CDR) strategy that utilizes alkaline materials to increase alkalinity in seawater and associated CO₂ storage as bicarbonate. Steel slag is a potential alkaline source material for OAE due to its widespread availability and comparatively high efficiency to enable CDR. However, steel slag also contains trace metals. To assess the risks of metals related to slag-based OAE on marine food chains, the authors conducted a 14-day experiment culturing the diatom Chaetoceros neogracilis and Antarctic krill Euphausia superba under an OAE scenario (+ 30 µmol kg⁻¹ alkalinity). They used a two-factorial design, where slag-treated and control diatoms were fed to krill cultured in slag-treated and control seawater, respectively.

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Peer-reviewed Publications

Pernet et al. (2026): A system-based analysis of carbon fluxes shows that bivalve aquaculture cannot be considered a marine carbon dioxide removal strategy

Fabrice Pernet, Phillip Williamson and Frédéric Gazeau, IN: ICES Journal of Marine Science, https://doi.org/10.1093/icesjms/fsag073

Marine carbon dioxide removal (mCDR) is gaining momentum as part of the global climate mitigation portfolio. Yet as enthusiasm grows, so does the risk of overstating the carbon removal potential of marine activities that were never designed as climate interventions. Among these, bivalve aquaculture is increasingly framed as a nature-based carbon sink. The authors critically examine whether bivalve farming meets the scientific and policy criteria to qualify as a valid method of mCDR, emphasizing additionality, permanence, accountability, and the obligation for robust monitoring, reporting, and verification (MRV), including life-cycle assessment and certification frameworks. They demonstrate why bivalve farming does not currently qualify as an mCDR pathway.

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Peer-reviewed Publications

Li et al. (2026): Preparing low-calcium carbonatable clinker using waste concrete powder and its negative CO₂ emission feasibility

Jiaxin Li, Wei Chen, Bo Li, Bo Yuan and Kuo Yang, IN: Journal of Building Engineering, https://doi.org/10.1016/j.jobe.2026.116197

Innovative building materials represent an essential pathway for addressing the stockpiling of construction waste as well as achieving carbon emission reduction in the building materials industry. This study presents an experimental investigation on converting high-silica waste concrete powder (WCP) into a low-calcium carbonatable clinker. Based on the CaO-SiO₂-Al₂O₃ ternary phase diagram, through compositional design, WCP was mixed with a supplementary calcium source (waste hydrated cement paste, HCP) to form a clinker comprising C₂S and C₃S₂ at 1150°C. The synthesized clinker was subsequently carbonation-cured, achieving a compressive strength of 83.8 MPa at 7 days with CaCO₃ as the main binding phase.

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Peer-reviewed Publications

Hoffmann et al. (2026): Monitoring, reporting, and verification of marine carbon dioxide removal: Exploring scientific consensus and divergences across continents

Linn J. Hoffmann, Lennart T. Bach, Kohen W. Bauer, Jessica Cross, Anwesha Ghosh, Jose Martín Hernández-Ayón, Karin Kvale, et al., IN: Elementa: Science of the Anthropocene, https://doi.org/10.1525/elementa.2025.00113

Marine Carbon Dioxide Removal (mCDR) approaches are increasingly considered for climate change mitigation as a supplement to rapid emissions reduction. However, it is still unclear if mCDR approaches could be effective, safe, and accountable. A critical requirement for mCDR to work, potentially, is robust monitoring, reporting, and verification (MRV) of greenhouse gas(es) removed through mCDR activities. MRV frameworks and protocols are currently developed in a scattered manner by individual stakeholders, so that the principles they are built upon may or may not appeal to the broader international community that is interested in the ocean commons. International agreement and consolidation on MRV for mCDR seem crucial to legitimize and validate mCDR, considering that the ocean is a globally interconnected fluid and that activities by some may affect many others. Here, the authors undertake a step toward consolidation of MRV by consulting the international scientific community. They established a global network of scientists organized into 6 “continental” nodes, each of which addressed the same set of MRV-related questions and whose thoughts were equally weighted in the synthesis.

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Peer-reviewed Publications

Elaouzy et al. (2026): Integration of direct air capture with solar tower and chimney power plants: energy, economic and carbon assessments

Youssef Elaouzy, Mustapha Soukri, Kumar Patchigolla, Abdulkarem I. Amhamed and Abdelghafour Zaabout, IN: Solar Energy, https://doi.org/10.1016/j.solener.2026.114656

The integration of concentrating solar power and direct air capture (DAC) systems remains limited by the high energy penalty, intermittency, and the lack of efficient system-level designs for waste heat utilization and cost reduction. This study evaluates the energy, economic, and carbon performance of an integrated system in which a DAC unit is installed between the towers of a solar tower power plant (STPP) and a solar chimney power plant (SCPP). This system aims to leverage the STPP waste heat to reduce DAC energy penalty, enhance SCPP electricity generation, and capture substantial amounts of CO₂. The feasibility of the system is analyzed under nine scenarios involving different waste heat recovery and supply configurations for CO₂ desorption and power generation. Furthermore, sensitivity analyses are performed, exploring the impact of key technical and economic parameters on overall performance.

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