CO2-removal News

Peer-reviewed Publications

Clarkson et al. (2025): Prestressed solar updraft towers for use in greenhouse gas removal

J.A. Clarkson, A.B.A. French, S.D. Guest and C.J. Burgoyne, IN: Solar Energy, https://doi.org/10.1016/j.solener.2025.114044

Greenhouse gas removal technologies will require huge throughputs of air in order to effectively remove diffuse greenhouse gases: solar updraft towers, which utilise a greenhouse induced stack effect, could provide this airflow. For such a system to be economically feasible, the tower structure must be efficient and, ideally, lightweight; however, existing designs mainly consider slip-formed concrete tubes, which must be relatively stocky to resist buckling. The authors therefore propose the alternative, lightweight, structural form of a prestressed hyperboloid cable-net, suspended from a central compression mast via a “bicycle wheel” at the top, and covered in fabric to form a chimney. Their objective is to show the feasibility of such a structure: they investigate the structural mechanics via a simplified analytical model and scale physical model, finding good agreement between the models in predicting the lateral stiffness of the tower. These models, combined with estimates of the wind load, are then used to estimate the sizing of a 1000 m tall, 100 m diameter tower.

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Peer-reviewed Publications

Science – Wu et al. (2025): Distributed direct air capture by carbon nanofiber air filters

Ronghui Wu, Hernan E. Delgado, Yi Xie, Yuanke Chen et al., IN: Science Advances, https://doi.org/10.1126/sciadv.adv6846

The rising atmospheric CO₂ concentration is one of the biggest challenges human civilization faces. Direct air capture (DAC) that removes CO₂ from the atmosphere provides great potential in carbon neutralization. However, the massive land use and capital investment of centralized DAC plants and the energy-intensive process of adsorbent regeneration limit its wide employment. The authors develop a distributed carbon nanofiber (CNF)–based DAC air filter capable of adsorbing CO₂ downstream in ventilation systems. The DAC air filter not only has the potential to remove 596 Mt CO₂ year⁻¹ globally but can also decrease energy consumption in existing building systems. The CNF-based adsorbent has a capacity of 4 mmol/g and can be regenerated via solar thermal or electrothermal methods with low carbon footprints.

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Peer-reviewed Publications

Fetanat & Tayebi (2025): Evaluation of climate intervention technologies for sustaining cities close to oil and gas operations: A sustainability and feasibility-based decision support system under molecular fuzzy set

Abdolvahhab Fetanat and Mohsen Tayebi, IN: Process Safety and Environmental Protection, https://doi.org/10.1016/j.psep.2025.108031

As cities universally grapple with exacerbating challenges from environmental extremes such as wildfires, heat waves, air pollution, climate change, and carbon dioxide (CO₂) emissions, there is an urgent need for a decision support system (DSS) to provide actionable insights for policymakers and plan the mitigation of the adverse impacts of these extremes on communities. In this regard, climate intervention technologies are important and valuable technologies for sustaining cities under environmental extremes. Assessing these technologies for use as an optimal alternative is urgently needed in most of Iran’s southern regions due to the proximity of cities in these regions to oil, gas, and petrochemical systems. According to, in order to optimize the use of these technologies for the studied regions, an intelligent DSS based on a systematic model, namely the Delphi-fuzzy molecular ranking (DFMORAN) model is conducted by considering the sustainability and feasibility principles of different climate intervention technologies. For implementing the DEFMORAN model, ten climate intervention technologies consisting of 1) stratospheric aerosol injection (SAI), 2) space-based geo-engineering (SBG), 3) marine cloud brightening (MCB), 4) direct air capture with carbon storage (DACCS), 5) enhanced weathering, 6) biochar, 7) afforestation and reforestation (AR), 8) bioenergy with carbon capture and storage (BECCS), 9) soil carbon sequestration (SCS), 10) marine biomass and blue carbon (MBBC) are considered as decision-making alternatives. Also, an evaluation system containing 17 criteria-based sustainability and feasibility principles (economic, environmental, social, and feasibility aspects) is used.

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Peer-reviewed Publications

Apeaning et al. (2025): Bridging the divide: How unequal carbon dioxide removal deployment threatens climate equity and global mitigation feasibility

Raphael Apeaning, Puneet Kamboj and Mohamad Issa Hejazi, IN: Smart and Sustainable Planet Change, https://doi.org/10.1016/j.spc.2025.09.012

The Paris Agreement’s goal of limiting global warming to well below 2 °C, ideally 1.5 °C, places significant emphasis on Carbon Dioxide Removal (CDR) technologies. However, the global landscape for CDR deployment remains uneven, with significant disparities in technological capacity, economic readiness, and regional ambition. This study investigates how limited access to CDR technologies could exacerbate global economic inequality under a 1.5 °C pathway. Using the Global Change Analysis Model (GCAM v6.0), six scenarios ranging from unrestricted CDR availability to constrained deployment are evaluated.

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Peer-reviewed Publications

Nature – Wang et al. (2025): Terraced fields increased soil organic carbon content in croplands of the Loess Plateau

Qinqin Wang, Yuanxiao Xu, Guofeng Zhu, Yinying Jiao, Dongdong Qiu, Siyu Lu, Jiangwei Yang, Longhu Chen, Gaojia Meng, Rui Li, Ling Zhao, Enwei Huang and Yuhao Wang, IN: Scientific Reports, https://doi.org/10.1038/s41598-025-19872-0

Terracing is widely distributed in mountainous and hilly areas worldwide to increase grain production, control soil erosion, increase soil moisture, and improve soil quality, potentially impacting soil carbon pools. This study investigates how agricultural activities and ecological restoration measures affect soil carbon pools in terraced areas of the Chinese Loess Plateau. The authors established an observation system in typical terraces and collected soil samples from 0 to 100 cm depth in terraces with different crops and ecological restoration vegetation.

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Peer-reviewed Publications

Hickey et al. (2025): Carbon storage portfolios for the transition to net zero

Conor Hickey, Stuart Jenkins and Myles Allen, IN: Joule, https://doi.org/10.1016/j.joule.2025.10.011

Net-zero targets are widely adopted by companies and countries worldwide. To achieve these goals, more companies are investing in diverse carbon removal portfolios. This study develops a new risk management framework that combines forestry, biochar, and geological storage offsets into portfolios that could stabilize global temperatures over multi-century time periods.

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Peer-reviewed Publications

Nisbet & van der Made (2025): Direct air capture of CO₂: an industrial perspective

Tim M Nisbet and Alexander W van der Made, IN: Current Opinion in Chemical Engineering, https://doi.org/10.1016/j.coche.2025.101190

Direct air capture (DAC) is a crucial carbon dioxide removal (CDR) technology for achieving net-zero emissions by balancing atmospheric CO₂ release with removal. It serves two key roles: (a) when integrated with Carbon Capture and Storage (DAC-CCS), it enables permanent CO₂ removal to offset emissions from hard-to-abate sources like aviation; and (b) when combined with Carbon Capture and Utilization (DAC-CCU), it provides non-fossil CO₂ for producing defossilized fuels and zero-carbon chemicals. To fulfill these roles, DAC systems must be scalable and economically viable. While academic studies often focus on assessing sorbent performance under a limited range of weather conditions and for limited periods, the authors advocate that industrial scale deployment demands DAC systems with additional key features.

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Peer-reviewed Publications

Bach et al. (2025): Lethal by design? Guiding environmental assessments of ocean alkalinity enhancement toward realistic contextualization of the alkalinity perturbation

Lennart Thomas Bach, Michael Dominik Tyka, Bin Wang and Katja Fennel, IN: CDRXIV, https://doi.org/10.70212/cdrxiv.2025457.v1

Ocean Alkalinity Enhancement (OAE) aims to mitigate climate change by increasing the chemical capacity of seawater to store anthropogenic CO₂. OAE can be implemented through multiple pathways, each of which intentionally modifies marine carbonate chemistry through increases in total alkalinity (TA). Experimental research has only recently begun to assess how such TA perturbations (∆TA) affect ocean geochemical processes and ecosystems. Meaningful assessments need context on how ∆TA induced by different OAE pathways would evolve over time and in magnitude. Here, the authors use a dilution equation, a regional model, and a global model to explore how marine systems and life styles would experience ∆TA under realistic constraints.

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Peer-reviewed Publications

Science – Tang et al. (2025): Tropical forest carbon offsets deliver partial gains amid persistent over-crediting

Yuzhi Tang, Chao Yang, Haishan Wu and Zihao Xu et al., IN: Science, https://doi.org/10.1126/science.adw4094

REDD+ (Reducing Emissions from Deforestation and Degradation Plus) projects generate carbon credits to offset emissions, but recent studies have questioned their effectiveness. The authors evaluated 52 voluntary REDD+ projects across 12 tropical countries using synthetic control methods.

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Peer-reviewed Publications

Cui et al. (2025): Refined big data on carbon sequestration for urban trees: 3D information and spatial carbon stock

Kailong Cui, Yaoping Cui, Xiangzheng Deng, Chaosheng Zhang, Yufei Jia, Tianwei Zhao, Nan Li, Zhifang Shi, Xiang Zhao, Hua Qin, IN: Sustainable Cities and Society, https://doi.org/10.1016/j.scs.2025.106901

Urban trees play a crucial role in regulating the urban environment. Their carbon stock capacity and the importance of 3D information are increasingly recognized by urban managers. However, accurately characterizing urban trees and estimating their carbon stock is hindered by the complexity of urban landscapes and the structural and spatial tree diversity. Here the authors used RGB satellite imagery and locally sampled data to extract 3D information on urban trees in Dublin, Ireland, and to calculate their carbon stock.

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