CO2-removal News

Peer-reviewed Publications

Gonzalez-Coffin et al. (2026): Naturalness catalyzes public support for carbon dioxide removal and low-carbon energy technologies

Sarah Gonzalez-Coffin, Shahzeen Z. Attari, Holly Buck, Amanda R. Carrico, Yoel Inbar, Ezra Markowitz, Kaitlin T. Raimi, Jonathon P. Schuldt, Trisha Shrum and Leaf Van Boven, IN: Communications Earth & Environment, https://doi.org/10.1038/s43247-026-03829-w

Carbon dioxide removal and low-carbon energy technologies offer promising methods to reduce greenhouse gas emissions, yet widespread deployment depends on public support. Two studies in the United States examined how naturalness shapes public support for six carbon dioxide removal and four low-carbon energy technologies. To the degree that participants in Study 1 perceived technologies as more natural, they supported them more, judging them as less risky and frightening, and more beneficial.

LINK

#
Peer-reviewed Publications

Keroglou & Ciez (2026): Process-based lifecycle climate, energy, water and material constraints of solid adsorbent production for gigaton-scale direct air capture

Ioannis Keroglou and Rebecca Ciez, IN: Energy & Environmental Science, https://doi.org/10.1039/D6EE03173K

Negative emissions technologies like direct air capture are critical for achieving global decarbonization targets. Sorbent materials are central to direct air capture systems, with solid adsorbents requiring lower regeneration temperatures and avoiding the evaporative losses of liquid sorbents. As use-phase emissions decline due to technological advances and the use of low-carbon power sources, sorbent manufacturing impacts become increasingly important. Prior studies of sorbent manufacturing rely on oversimplified life cycle inventories and proxy data, resulting in substantial uncertainty. Here, the authors apply a process-based model to develop sorbent-specific inventories for scaling the production of polyethyleneimine-based solid adsorbents and evaluate their cradle-to-gate climate change, fossil resource scarcity, and water use impacts in the United States.

LINK

#
Peer-reviewed Publications

Çakanel (2026): Integrity-first control of direct air capture systems under carbon certifiability constraints

Ahmet Çakanel, IN: Applied Energy, https://doi.org/10.1016/j.apenergy.2026.128430

Direct air capture (DAC) systems are increasingly deployed with the goal of delivering net-negative carbon emissions through permanent CO₂ storage or utilization. However, capturing CO₂ from the atmosphere does not guarantee that the removal remains certifiable under conservative measurement–reporting–verification (MRV) frameworks. Grid electricity with variable carbon intensity, auxiliary power demand, and MRV uncertainty margins interact during cyclic operation to create transient periods of net-positive emissions that accumulate as a liability over time. This cumulative liability, referred to as carbon debt, must remain bounded relative to physical capture if reported removals are to be defensible under third-party verification standards. This study introduces Carbon-Integrity-Constrained Control (CICC), a supervisory framework that treats carbon certifiability as an operational constraint enforced in real time, rather than as a retrospective accounting adjustment. Admissible operation is characterized by a bounded debt-to-capture ratio (δ≤δmax).

LINK

#
Peer-reviewed Publications

Ward et al. (2026): Blue Carbon in an Era of Carbon Accounting

M. Ward, M.T. Costa, A.M. Ricart, S. Crooks, L.M. Wedding and P.I. Macreadie, IN: Annual Review of Environment and Resources, https://doi.org/10.1146/annurev-environ-121522-043142

Blue carbon ecosystems—mangroves, tidal marshes, seagrass meadows, and, increasingly, seaweeds—are being rapidly integrated into climate mitigation frameworks. Yet, despite their prominence in global carbon offset discourse, blue carbon projects remain dominated by mangroves (∼89% of projects). Here, the authors synthesize recent developments in blue carbon science, carbon accounting, and market integrity. Global restoration potential could deliver annual removals of ∼109 (98–119; 95% CI) million tonnes of organic carbon, while habitat loss causes annual emissions of up to ∼63 (55–71) million tonnes. Realizing carbon benefits is constrained by monitoring, reporting, and verification costs, data gaps, and methodological challenges.

LINK

#
Peer-reviewed Publications

Moustafa et al. (2026): Review of Bioenergy with Carbon Capture and Storage (BECCS): Progress, Challenges, and Future Outlook

Nadine Tamer Moustafa, Nishikawa Emily, Koen H. Van Dam, Jennifer F. Holak, Sergey Paltsev, Mai Bui, Sean McCoy and Niall Mac Dowell, IN: SSRN (Preprint), https://dx.doi.org/10.2139/ssrn.7076303

Bioenergy with Carbon Capture and Storage (BECCS) is one of the few carbon dioxide removal (CDR) approaches consistently represented at gigatonne scale in climate mitigation scenarios. However, real-world deployment remains limited, and significant uncertainties persist regarding its feasibility at scale. This review synthesises current evidence on BECCS across technological pathways, biomass supply, lifecycle emissions, infrastructure requirements, and policy and market frameworks.The analysis highlights that BECCS performance is highly pathway-dependent, with substantial variation in carbon efficiency, CO₂ stream characteristics, and technological maturity across thermochemical and biological routes. Beyond technology, biomass availability emerges as a primary constraint. Estimates of global supply are highly sensitive to land-use assumptions, and sustainability-constrained scenarios suggest significantly lower availability. Infrastructure and spatial constraints introduce additional challenges. Biomass resources, geological storage capacity, and demand for negative emissions are not co-located, implying reliance on transport networks, cross-border trade, and coordinated infrastructure expansion.

LINK

#
Peer-reviewed Publications

Thornbush et al. (2026): A Systematic Review of Soil Amendments Using Biochar and Enhanced Rock Weathering (ERW) for Soil Carbon Sequestration

Mary Thornbush, Michael Zhang, Cooper Mandel, Ethan Andrews, Ellen Kempton and Muhammad Muneeb Ur Rehman, IN: Sustainability, https://doi.org/10.3390/su18147011

This review provides a comparative critical synthesis of biochar and enhanced rock weathering (ERW), identifies key trends and gaps in soil carbon research, and outlines pathways for improving carbon sequestration and monitoring in soil systems. From a global perspective, materials and agricultural studies were read to examine the properties of these amendments and their effects in cropland and forest soils. The main research question guiding this literature review was as follows: What are common trends in published biochar and ERW studies? Major themes were derived from the stated question and structure the Discussion. The Web of Science provided access to relevant literature for both biochar and ERW, and a total of 38 articles (biochar: 17; ERW: 21) were read and covered in this paper.

LINK

#
Peer-reviewed Publications

Poetra et al. (2026): Aqueous matrix and limiting factors in steel slag carbonation under elevated CO₂ at ambient conditions

Reinaldy Poetra, Jens Hartmann, Mathilde Hagens, Ina Sophia Nipper, Lukas Rieder and Charly A. Moras, IN: npj Materials Sustainability, https://doi.org/10.1038/s44296-026-00116-9

Alkaline industrial by-products have significant potential for permanent CO₂ sequestration, but their reaction kinetics and controlling factors are often overlooked. This study examined the direct aqueous carbonation of basic oxygen furnace (BOF) slag in a slurry setup with continuous mechanical mixing and CO₂-enriched air bubbling in ultrapure water and natural seawater, at 25% pCO₂ under ambient temperature and 1 atm for 24 h.

LINK

#
Peer-reviewed Publications

Tang et al. (2026): Unequal economic impacts of climate change via idealized carbon dioxide removal: insights from deep learning

Bin Tang, Jianan Wei, Yimin Liu, Bian He, Wen Bao, Yi Yang, Wenguan Wang, Wenting Hu and Anmin Duan, IN: The Innovation, https://doi.org/10.1016/j.xinn.2026.101505

Rapidly reducing carbon dioxide (CO₂) levels is essential to meeting the Paris Agreement’s temperature targets.1,2 Previous assessments of CO₂ removal (CDR) have primarily focused on the hysteresis and invertibility of climate change itself,3–7 overlooking quantitative analysis of potential economic impacts of climate change via CDR. In this study, the authors first develop a powerful neural network model, EconClimNet, trained on decades of economic data from 1,554 sub-national regions worldwide and 111 climate indices derived from the fifth-generation ECMWF atmospheric reanalysis (ERA5). Compared to popular machine learning algorithms used in the Earth Science community, EconClimNet achieves superior performance in capturing the intricate relationship between climate indices and economic outcomes. On this basis, they apply EconClimNet to the outputs from idealized CO₂ ramp up and ramp down experiments from phase 6 of the Coupled Model Intercomparison Project (CMIP6).

LINK

#
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.

LINK

#
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.

LINK

#