CO₂-removal News

Peer-reviewed Publications

Abegg et al. (2024): Expert Insights into Future Trajectories: Assessing Cost Reductions and Scalability of Carbon Dioxide Removal Technologies

Manon Abegg, Zeynep Clulow, Lucrezia Nava, David M. Reiner IN: Frontiers in Climate, doi:10.3389/fclim.2024.1331901

This study explores the future costs and scalability of DACCS and BECCS to advance net-zero goals. The authors analyze expert opinions on these technologies‘ potential costs and deployment scales for 2030, 2040, and 2050. Data was collected from 34 experts, comprising 21 DACCS and 13 BECCS specialists. They provided 90% confidence interval estimates and ‚best estimates‘ for future costs and deployment under two International Energy Agency (IEA) policy scenarios -Stated Policies (STEPS) and Net Zero Emissions by 2050 (NZE).

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Peer-reviewed Publications

Robertson et al. (2024): Polymer Sorbent Design for the Direct Air Capture of CO2

Mark Robertson, Jin Qian, Zhe Qiang IN: ACS Applied Polymer Materials, https://doi.org/10.1021/acsapm.3c03199

Here, direct air capture (DAC) represents an essential need for reducing CO2 concentration in the atmosphere to mitigate the negative consequences of greenhouse effects, involving systems that can reversibly adsorb and release CO2, in which polymers have played an integral role. This work provides insights into the development of polymer sorbents for DAC of CO2, specifically from the perspective of material design principles. The authors discuss how physical properties and chemical identities of amine-containing polymers can impact their ability to uptake CO2, as well as be efficiently regenerated. 

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Peer-reviewed Publications

Ünal et al. (2024): The nexus between direct air capture technology and CO2 emissions in the transport sector

Emre Ünal, Alexander Ryota Keeley, Nezir Köse, Andrew Chapman, Shunsuke Managi IN: Applied Energy, 363, 123112, https://doi.org/10.1016/j.apenergy.2024.123112

British Columbia provides a substantial chance to examine emissions that were produced after the DAC actions were put into place in 2015. In this study, the difference-in-differences methodology is employed for the very first time to compare the emissions that are produced by the transport sectors in British Columbia with those emitted by other provinces in Canada. The role that GDP and population play in the release of emissions is also taken into consideration in this paper. Based on the research results, it can be observed that the implementation of DAC initiatives has yielded notable effects. 

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Peer-reviewed Publications

Nature – Yu et al. (2024): Maximizing carbon sequestration potential in Chinese forests through optimal management

Zhen Yu, Shirong Liu, Haikui Li, Jingjing Liang, Weiguo Liu, Shilong Piao, Hanqin Tian, Guoyi Zhou, Chaoqun Lu, Weibin You, Pengsen Sun, Yanli Dong, Stephen Sitch, Evgenios Agathokleous IN: Nature Communications, 15, https://doi.org/10.1038/s41467-024-47143-5

Forest carbon sequestration capacity in China remains uncertain due to underrepresented tree demographic dynamics and overlooked of harvest impacts. In this study, the authors employ a process-based biogeochemical model to make projections by using national forest inventories, covering approximately 415,000 permanent plots, revealing an expansion in biomass carbon stock by 13.6 ± 1.5 Pg C from 2020 to 2100, with additional sink through augmentation of wood product pool (0.6-2.0 Pg C) and spatiotemporal optimization of forest management (2.3 ± 0.03 Pg C). 

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Peer-reviewed Publications

Iff et al. (2024): The Dissolution of Olivine Added to Soil at 32°C: The Fate of Weathering Products and its Implications for Enhanced Weathering at Different Temperatures

Nicholas Iff, Phil Renfort, Philip Pogge von Strandmann IN: Frontiers in Climate, doi: 10.3389/fclim.2024.1252210

This study uses an experimental setup that aims to encapsulate natural field conditions in a controlled setting using soil cores retrieved from UK cropland amended with crushed olivine at 32°C. Results are compared to previously run identical enhanced weathering experiments at 4°C and 19°C. The experiments reveal temperature-dependent variations in the behaviour of different elements, most importantly Mg and Si, with silicon being retained at moderate temperatures and magnesium being retained at higher temperatures, most likely due to different retention mechanisms such as Si reprecipitation (e.g. as cation-depleted encapsulating Si layers) and cation exchange (affecting Mg, but to a lesser degree Si).

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Peer-reviewed Publications

Ryan et al. (2024): The potential for carbon dioxide removal by enhanced rock weathering in the tropics: An evaluation of Costa Rica

P.C. Ryan, A. Santis, E. Vanderkloot, M. Bhatti, S. Caddle, M. Ellis, A. Grimes, S. Silverman, E. Soderstrom, C. Stone, A. Takoudes, P. Tulay, S. Wright IN: Science of The Total Environment, 927, 172053, https://doi.org/10.1016/j.scitotenv.2024.172053

Tropical environments show great potential to sequester CO2 by enhanced rock weathering (ERW) of powdered mafic rocks applied to agricultural fields. This study seeks to assess carbon dioxide reduction (CDR) potential in the humid tropics (1) by experimental weathering of mafic rock powders in conditions simulating humid tropical soils, and (2) from weathering rates determined from a Holocene tropical soil chronosequence where parent material is andesitic sediments. Experimentally determined weathering rates by leaching of basaltic andesites from Costa Rica (Arenal and Barva) for 50 t ha−1 applications indicate potential sequestration of 2.4 to 4.5 t CO2 ha−1 yr−1, whereas the USGS basalt standard BHVO-1 yields a rate of 11.9 t ha−1 yr−1.

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Peer-reviewed Publications

Eisaman et al. (2024): Pathways for marine carbon dioxide removal using electrochemical acid-base generation

Matthew D. Eisaman IN: Frontiers in Climate, https://doi.org/10.3389/fclim.2024.1349604

Research over the past decade has resulted in various methods for removing CO2 from the atmosphere using seawater and electrochemically generated acids and bases. This Perspective aims to present a unified framework for comparing these approaches. Specifically, these methods can all be seen as falling into one of two categories: those that result in a net increase in ocean alkalinity and use the “ocean as a sponge” for atmospheric CO2 (ocean alkalinity enhancement, or OAE) and those that cycle ocean alkalinity and use the “ocean as a pump” for atmospheric CO2 (ocean alkalinity cycling, or OAC). In this Perspective, approaches for marine carbon dioxide removal (mCDR) using electrochemistry are compared using this framework, and the similarities and differences of these two categories are explored.

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Peer-reviewed Publications

Skov et al. (2024): Initial agronomic benefits of enhanced weathering using basalt: A study of spring oat in a temperate climate

Kirstine Skov, Jez Wardman, Matthew Healey, Amy McBride, Tzara Bierowiec, Julia Cooper, Ifeoma Edeh, Dave George, Mike E. Kelland, Jim Mann, David Manning, Melissa J. Murphy, Ryan Pape, Yit A. Teh, Will Turner, Peter Wade, Xinran Liu IN: PLoS ONE, https://doi.org/10.1371/journal.pone.0295031

This study examines the short-term effects of basalt amendment on spring oat (Avena sativa L.) during the 2022 growing season in NE England. The experimental design consisted of four blocks with control and basalt-amended plots, and two cultivation types within each treatment, laid out in a split plot design. Basalt (18.86 tonnes ha−1) was incorporated into the soil during seeding. Tissue, grain and soil samples were collected for yield, nutrient, and pH analysis.

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Peer-reviewed Publications

Smetacek et al. (2024): Rectifying misinformation on the climate intervention potential of ocean afforestation

Victor Smetacek, Mar Fernández-Méndez, Franziska Pausch, Jiajun Wu IN: Nature Communications, 15, https://doi.org/10.1038/s41467-024-47134-6

The authors show that the green and golden tides of Ulva prolifera and Sargassum horneri, respectively, that build up dense mats of free-floating biomass in the millions-of-tonnes range in the eutrophic, central Yellow Sea are more appropriate “natural analogues” for future OAFF than the diffuse Great Atlantic Sargassum Belt (GASB). The dense Yellow Sea algal rafts demonstrate that disparate macroalgal species are capable of building up prodigious, free-floating, harvestable biomass at rates depending on the supplies of seeding stocks (from macroalgal thalli fragments) and nutrients (by eutrophication) that can serve as potential crops for seaweed farms based on artificial upwelling of nutrient-rich water in the vast spaces of the open ocean.

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Peer-reviewed Publications

Nature – Prütz et al. (2024): A taxonomy to map evidence on the co-benefits, challenges, and limits of carbon dioxide removal

Ruben Prütz, Sabine Fuss, Sarah Lück, Leon Stephan, Joeri Rogelj IN: Communications Earth & Environment, 5, https://doi.org/10.1038/s43247-024-01365-z

Recent exponential growth in literature is rapidly filling this gap but makes the synthesis of the evidence on carbon dioxide removal side effects increasingly challenging. Here the authors address this issue by mapping this literature and proposing a taxonomy to synthesize and compare evidence on carbon dioxide removal side effects. The expansive evidence warrants the use of machine learning to systematically select relevant research and provide an inventory of nearly 400 co-benefits, challenges, and limits.

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