Schlagwort: enhanced weathering

Working Paper: Monitoring CO2 Concentrations in Soil Gas: A Novel MRV Approach for Cropland-Based ERW?

by Dirk Paessler, Ralf Steffens, Jens Hammes, Ingrid Smet, Carbon Drawdown Initiative, May 17, 2023

This paper discusses the challenges the authors have faced in the past 2.5 years of field-experiments trying to measure the speed of Enhanced Rock Weathering (ERW) in agricultural settings for removing CO2 from the atmosphere. They propose using CO2 sensors placed inside the soil in combination with automated CO2 flux meters on top of the soil as a new method to assess the Carbon Dioxide Removal (CDR) effects resulting from ERW treatments in agricultural settings.

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Webinar: Scrubbing the Skies – Enhanced Rock Weathering in the Global South

Tuesday, April 18, 7 – 8 pm CEST hosted by Institute for Carbon Removal and Policy 

Given the current focus of ERW development in Global North geographies, in the absence of a concerted parallel effort in the Global South, it is likely that any future economic benefits accruing to farmers from ERW in the form of carbon offset payments will disproportionately benefit farmers in rich countries. The panelists in this webinar, Garrett Boudinot and Yifan Powers will present their report, which aims to shift some of these actions and benefits to include poor smallholder farmers in low- and middle-income countries along with discussing further implications of ERW in the carbon removal space.

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Coyne (2023): Crushing It: Can Ground-Up Rock Help Save the Earth?

Kristen Coyne IN: CSA News 68, https://doi.org/10.1002/csan.20986

The promising idea of enhanced weathering has attracted not only a growing number of scientists, but also environmental entrepreneurs who are turning the research into action, albeit at a pace not everyone is comfortable with. While the scientific and business approaches operate under different rules, there’s room for cooperation, data sharing, and innovation as they target the common enemy of climate change.

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Kanzaki et al. (2023): New estimates of the storage permanence and ocean co-benefits of enhanced rock weathering

Yoshiki Kanzaki, Noah J Planavsky, Christopher T Reinhard IN: PNAS Nexus, Vol 2 (4), https://doi.org/10.1093/pnasnexus/pgad059

The authors use an ensemble of Earth system models to provide new insights into the efficiency of CDR through enhanced rock weathering (ERW) by explicitly quantifying long-term storage of carbon in the ocean during ERW relative to an equivalent modulated emissions scenario. They find that although the backflux of CO2 to the atmosphere in the face of CDR is in all cases significant and time-varying, even for direct removal and underground storage, the leakage of initially captured carbon associated with ERW is well below that currently assumed.

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Harrington et al. (2023): Implications of the Riverine Response to Enhanced Weathering for CO2 removal in the UK

K.J. Harrington, R.G. Hilton, G.M. Henderson IN: Applied Geochemistry 152, 105643, https://doi.org/10.1016/j.apgeochem.2023.105643

Previous estimates have suggested that enhanced silicate weathering (EW) has the potential to remove significant quantities of CO2, as much as 6–30 Mt CO2 yr−1 for the UK. However, if secondary carbonates are precipitated during the riverine transport of the products of EW, a portion of this CO2 will be re-released, lowering the net carbon dioxide removal (CDR) potential of the mitigation strategy. Here, the authors assess the fluvial response to EW in the UK by calculating the expected riverine carbonate precipitation due to the dissolution of 10–50 t ha−1 yr−1 of silicate rock on available arable cropland in major UK catchments.

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Lammers et al. (2023): Electrolytic Sulfuric Acid Production with Carbon Mineralization for Permanent Carbon Dioxide Removal

Laura N. Lammers, Yanghua Duan, Luis Anaya, Ayumi Koishi, Romario Lopez, Roxanna Delima, David Jassby, David L. Sedlak IN: ACS Sustainable Chem. Eng.; doi.org/10.1021/acssuschemeng.2c07441

Here, a scalable CDR and mineralization process is reported in which water electrolysis is used to produce sulfuric acid for accelerated weathering, while a base is used to permanently sequester CO2 from air into carbonate minerals. The process can be integrated into existing extractive processes by reacting produced sulfuric acid with critical element feedstocks that neutralize acidity (e.g., rock phosphorus or ultramafic rock mine tailings), with calcium- and magnesium-bearing sulfate wastes electrolytically upcycled.

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Gao et al. (2023): Enhanced Silicate Rock Weathering—A New Path of “Carbon Neutrality”

Weibin Gao, Yang Chen, Haoxian Wang IN: Advances in Earth Science 38 (2), pp. 137-150; doi: 10.11867/j.issn.1001-8166.2022.093

The calculation results show that China can remove 0.13~0.80 Gt CO2 through ERW annually, which is conducive to the realization of the “carbon neutrality” goal. Combining the progress of domestic and international research, the main application effects and influencing factors of ERW are summarized, the potential of ERW application in China is analyzed, and the main issues facing ERW application in China are discussed from five aspects: technology, economy, safety, society, and policy. In view of the focus and shortcomings of the current research, the calculation of ERW carbon sequestration, potential hazards of application, and other key concerns and challenges are presented.

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West et al. (2023): Making mistakes in estimating the CO2 sequestration potential of UK croplands with enhanced weathering

Landis Jared West, Steven A. Banwart, Maria Val Martin, Euripides Kantzas, David J. Beerling IN: Applied Geochemistry 151, 105591, https://doi.org/10.1016/j.apgeochem.2023.105591

Buckingham et al. (2022) report results from an alkaline soil ‘tubes on a roof’ ERW experiment with coarse basalt dust. The authors of this article highlight unfortunate fundamental errors in the execution of the experiment, reporting and interpretation of the results. These ERW results for a chalk soil, under dry conditions, are then extrapolated erroneously across millions of hectares of UK croplands to misrepresent UK cropland CO2 removal potential by ERW.

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