CO2-removal News

Peer-reviewed Publications

Olasehinde et al. (2026): Socio-economic implications of deploying COP28 pledged negative emission technologies

Daniel O. Olasehinde, Olusola Bamisile, Caroline Acen, Chukwuebuka Ejiyi and Qi Huang, IN: Carbon Capture Science & Technology, https://doi.org/10.1016/j.ccst.2026.100590

Achieving the Paris Agreement’s targets will inevitably impose financial burdens, but choosing the most economically viable path is critical. At COP28, countries pledged to triple renewable energy capacity to 11,000 GW and double energy efficiency gains to 4 % annually by 2030. The agriculture, forestry, and land use (AFOLU) sector also committed to reducing emissions and enhancing carbon dioxide removal (CDR). Using the En-ROADS modeling tool, this study evaluates five global scenarios combining varying degrees of fossil fuel reduction and CDR deployment: Ref (based on current COP28-aligned pledges), Ref++ (Ref with added fossil fuel taxes and carbon pricing), limCDR (Ref++ plus limited deployment of technological CDR up to 50 % of its potential), modCDR (Ref with moderate CDR deployment up to 65 % of potential, but no fossil fuel taxation), and allCDR (Ref with full utilization of technological CDR potential and no fossil fuel taxation). While population growth is held constant across all scenarios, economic outcomes diverge.

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Peer-reviewed Publications

Pavia & Lambert (2026): Carbon dioxide removal by enhanced weathering on American green clay tennis courts

Frank J. Pavia and Jonathan E. Lambert, IN: Applied Geochemistry, https://doi.org/10.1016/j.apgeochem.2026.106737

40,000 tennis courts in the United States are constructed and maintained by spreading basalt feedstock similar to that used for carbon dioxide removal via enhanced rock weathering. Silicate weathering therefore readily occurs on these courts, yet the carbon sequestration associated with this weathering has never been quantified. The authors have built a model that quantifies net CO₂ sequestration during the lifetime of green clay tennis courts. They calculate gross CO₂ sequestration rates associated with silicate weathering and conduct a lifecycle analysis for emissions during court construction. This allows them to determine net sequestration rates at each court as well as assess the factors that lead to maximal CO₂ sequestration at different sites.

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Peer-reviewed Publications

Bicer et al. (2026): Integrated DAC-HVAC systems for CO₂ capture and sustainable hydrogen production from condensed water

Y Bicer, I Ghiat, Y M Abdullatif, A Banu, T Al-Ansari and A I Amhamed, IN: IOP Conference Series: Earth and Environmental Science, https://doi.org/10.1088/1755-1315/1587/1/012019

Carbon dioxide removal is essential to meet net-zero targets and stay within the 1.5 °C climate goal, with Direct Air Capture (DAC) technologies playing a critical role in removing both current and historical emissions. In parallel, low/zero-carbon fuels such as green hydrogen play a crucial role in decarbonizing hard-to-abate sectors and enabling a clean energy transition. This study introduces a novel integration of DAC technology within building Heating, Ventilation, and Air Conditioning (HVAC) systems, designed to recover water from the DAC cycle for sustainable hydrogen production. In the Temperature-Vacuum Swing Adsorption (TVSA) process, water condenses as a byproduct during the desorption phase. This condensed water can be repurposed as a feedstock for green hydrogen production via electrolysis, offering a sustainable water input for proton exchange membrane (PEM). By coupling DAC with hydrogen generation, the system supports both negative emissions and clean fuel production. The HVAC-integrated DAC system reduces energy demand by leveraging the building’s exhaust air stream, which exhibits relatively stable temperature and humidity levels. This integration not only lowers the thermal requirements of the DAC process but also reduces HVAC energy consumption through increased air recirculation. In addition to energy benefits, the system contributes to improved indoor air quality by removing carbon dioxide from indoor environments, where concentrations often exceed 1000 ppm. The system uses a solid sorbent of SBA-15 functionalized with tetraethylenepentamine (TEPA) in a TVSA cycle. A thermodynamic analysis was conducted, which was used in the economic analysis to size equipment, estimate their base costs, and quantify operational costs.

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Peer-reviewed Publications

Sarmah et al. (2026): Systematic review on proliferation of microalgae and carbon sequestration potential for sustainability

Mitrakhi Sarmah et al., IN: PubMed, https://pubmed.ncbi.nlm.nih.gov/41731188/

Rising atmospheric CO₂ underscores the need for carbon mitigation strategies. Microalgae have emerged as a promising nature-based solution due to their exceptional photosynthetic efficiency, rapid biomass production, and adaptability to diverse environmental conditions. It satisfies the mandate of different sustainable development goals viz. SDG-02, 06, 07, 09, 12 and 13. This study investigates the carbon sequestration potential of various microalgae along with different microalgal cultivation systems, factors affecting cultivation, genetic interventions and solution-based applications. It was investigated that carbon sequestration potential of various microalgal strains varied in between 0.06 and 2.57 g L⁻¹ d⁻¹, where Haematococcus pluvialis exhibited the highest rate (2.57 g L⁻¹ d⁻¹). Among the different types of microalgae cultivation systems, the biofilm reactors and hybrid reactor designs were evaluated for higher efficiency. Environmental and operational factors influencing carbon fixation capacity are critically compared. The study explores genetic interventions for enhanced microalgal productivity both quantitatively and qualitatively.

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Peer-reviewed Publications

Danzer & Kirchengast (2026): Bringing fairness also into carbon removal shares of countries is essential for a just transition

Julia Danzer and Gottfried Kirchengast, IN: Global Environmental Change, https://doi.org/10.1016/j.gloenvcha.2026.103114

Towards achieving the Paris goal of limiting global warming to well below 2°C with an effort to reach 1.5°C, countries not only need to drastically reduce their emissions but also to partially deploy carbon dioxide removal (CDR). CDR from the atmosphere can be achieved by various methods, ranging from nature-based solutions to technical options. The authors started with a survey of recent studies and found mounting evidence that CDR use needs great caution, since there exist strong biophysical and socio-economic constraints on scaling it up; and emission and removal fluxes are not equivalent in terms of climate outcomes.

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Peer-reviewed Publications

Sheng et al. (2026): The forest carbon paradox: novel insights into China’s forest-economy-emissions relationships

Zhelin Sheng, Kaimei Zhang, Chen Ling, Wenjuan Shen, Zihan Zhang, Chuanxin Ma, Changlei Xia, Keyi Chen, Yu Shen, Yu Hao and Jiangang Han, IN: npj Climate Action, https://doi.org/10.1038/s44168-026-00350-w

Forest-climate-economy relationships present critical challenges for climate mitigation in rapidly developing economies. While forests are traditionally viewed as carbon sinks, their effectiveness as tradable carbon products remains difficult to quantify in the near term due to time lags and scale mismatch with energy-driven emissions dynamics. This study examines these relationships in China using data from 30 provinces (from 2000 to 2019). Using LSTM-MLP hybrid models and multispatial Convergent Cross Mapping, the authors reveal what they term the “forest carbon paradox”: despite China’s extensive afforestation efforts increasing forest coverage significantly, these initiatives demonstrate limited immediate impact on CO₂ emissions and GDP trajectories.

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Peer-reviewed Publications

Zhang et al. (2026): Durability and CO₂ sequestration capacity of carbon sequestration foamed concrete under magnesium and sodium sulfate attacks

Xiang Zhang, Songyu Liu, Kai Wu, Zhenyang Yuan, Zengfeng and Guojun Cai, IN: Construction and Building Materials, https://doi.org/10.1016/j.conbuildmat.2026.145506

Carbon sequestration foamed concrete (CFC) is primarily composed of MgO, serpentine, silty clay, water and carbon dioxide (CO₂) foam. CFC has been extensively studied in previous literature for its exceptional performance in CO₂ sequestration. However, the lack of studies on the durability of CFC under sulfate attack remains a significant challenge for its large-scale application as a building material. This study investigated the durability and CO₂ sequestration of CFC under chemical sulfate attack by evaluating the changes in specimen volume, mass, phase identification and CO₂ sequestration capacity. The CFC specimens were exposed to magnesium sulfate (MgSO₄) and sodium sulfate (Na₂SO₄) solutions for 10, 20 and 30 days, respectively, after which a series of tests were conducted.

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Peer-reviewed Publications

Li et al. (2026): Carbon dioxide sequestration into biomineral armor by ants

Hongjie Li, Yihang Fang, Weiqiang Li, Jing Liu, Chang-Yu Sun, Xue Kang, Gaspar Bruner-Montero, Joseph Sardina, Xiaochang Mo, Jia-Long Hao, Jianchu Mo, Lei Cheng, Zhaoming Liu, Ted R. Schultz, Richard E. Johnston and Cameron R. Currie, IN: bioRxiv, https://doi.org/10.64898/2026.01.21.700952

Over geologic time, Earth’s climate has been shaped by the capture and conversion of atmospheric carbon dioxide (CO₂) into stable carbonate minerals, including dolomite [CaMg(CO₃)₂]. Accelerating natural carbon mineralization offers significant potential for mitigating anthropogenic climate change. Using stable carbon isotope tracking, nano-scale secondary ion mass spectroscopy, and 13C SSNMR, the authors show that, paralleling global biosphere-level processes, Sericomyrmex amabilis fungus-farming ants rapidly convert CO₂ in their nest chambers into a biomineral layer covering their exoskeletons.

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Peer-reviewed Publications

MacIsaac et al. (2026): Imbalances in climate outcomes in net-zero pathways with fossil fuel CO₂ emissions and reforestation-based CO₂ removals

Alexander J. MacIsaac, Kirsten Zickfeld, Pierre Etienne Banville and H. Damon Matthews, IN: Communications Earth & Environment, https://doi.org/10.1038/s43247-026-03329-x

Reforestation is considered an important nature-based climate solution to help achieve net-zero CO₂ emissions. However, strategies using reforestation-based CO₂ removal to offset fossil fuel emissions may not lead to the same climate outcome as avoiding the fossil fuel emissions. Here, the authors use an Earth System model of intermediate complexity to compare the climate outcome of different pathways: a reference pathway, and net-zero pathways where additional fossil fuel CO₂ emissions relative to the reference pathway are balanced by reforestation-based CO₂ removals (“Reforestation Net-zero pathways”).

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Peer-reviewed Publications

Roston (2026): The Carbon Market Can’t Trade: Designing Contracts and Institutions for Carbon Removal Assets

Marc Roston, IN: Oxford Open Climate Change, https://doi.org/10.1093/oxfclm/kgag003

Carbon removal markets have failed to deliver liquidity, price discovery, or scale. This failure is institutional rather than technological. Current markets trade registry certificates that record past attestations, not claims on carbon or obligations governing its continued absence from the atmosphere. As a result, no object of custody exists; buyers acquire neither enforceable control nor ongoing remedies tied to stored carbon. Even if such claims were properly constituted, carbon storage would remain difficult to govern through markets because it is inherently location- and time-bound, resisting delivery, substitution, and exit in ways unlike standard commodities or property interests. This article identifies these problems in sequence. First, current certificate-based practice fails to create a carbon asset at all. Second, conditional on remedying that absence, genuine carbon claims would face binding constraints of custody and alienability: performance must be governed over time, and claims must be transferable without extinguishing accountability. Existing practices-particularly retirement as an end-state-foreclose these mechanisms by design.

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