83 results for group: climate-change

Assessment of the enhanced weathering potential of different silicate minerals to improve soil quality and sequester CO2

Emily Pas, Mathilde Hagens, Rob Comans Abstract Enhanced weathering is a negative emission technology that involves the spread of crushed silicate minerals and rocks on land and water. When applied to agricultural soils, the resulting increase in soil pH and release of nutrients may co-benefit plant productivity. Silicate minerals and rocks differ in their enhanced weathering potential, i.e., their potential for both carbon dioxide (CO2) sequestration and soil quality improvements. However, studies comparing silicate minerals and rocks for this dual potential are lacking. Therefore, we compared the enhanced weathering potential of olivine ...

Removal of atmospheric CO2 by engineered soils in infrastructure projects

M. Ehsan Jorat, Karl E.Kraavi, David A.C.Manning Abstract The use of crushed basic igneous rock and crushed concrete for enhanced rock weathering and to facilitate pedogenic carbonate precipitation provides a promising method of carbon sequestration. However, many of the controls on precipitation and subsequent effects on soil properties remain poorly understood. In this study, engineered soil plots, with different ratios of concrete or dolerite combined with sand, have been used to investigate relationships between sequestered inorganic carbon and geotechnical properties, over a two-year period. Cone penetration tests with porewater pressure ...

Impacts of dissolved phosphorus and soil-mineral-fluid interactions on CO2 removal through enhanced weathering of wollastonite in soils

Cameron Wood, Anna L.Harrison, Ian M.Power The weathering of silicate minerals removes carbon dioxide (CO2) from the atmosphere over geologic timescales and is also investigated as an engineered strategy to mitigate climate change on decadal timescales. “Enhanced rock weathering” (ERW) is a carbon dioxide removal strategy that involves spreading of pulverized, highly reactive silicate rock at the Earth's surface such as within agricultural and natural soils. The rate and efficacy of ERW in agricultural soils to remove CO2 is difficult to quantify owing to the complex geochemical environment including biological-mineral-fluid-atmosphere intera...

Assessing a bio-energy system with carbon capture and storage (BECCS) through dynamic life cycle assessment and land-water-energy nexus

Andrei Briones-Hidrovo, José Ramón Copa Rey, Ana Cláudia Dias, Luís A.C. Tarelho, Sandra Beauchet Abstract Nowadays, much attention is being paid to so-called Negative Emissions Technologies (NETs), designed to remove carbon dioxide from the atmosphere and keep global temperature rise below 1.5 ◦C. The deployment of NETs can trigger environmental impacts, which can be addressed through the lens of Life Cycle Assessment (LCA). According to the literature, there are several drawbacks when NETs are assessed under the life cycle framework. In this sense, this study aims at contributing to the literature by assessing a NET in a manner that the ...

Evaluating feedstocks for carbon dioxide removal by enhanced rock weathering and CO2 mineralization

Carlos Paulo, Ian M.Power, Amanda R.Stubbs, Baolin Wang, Nina Zeyen, Siobhan A.Wilson Abstract Mineralogically complex feedstocks, including kimberlite, serpentinite, and wollastonite skarns, have vast capacities to sequester carbon dioxide (CO2) through enhanced rock weathering and CO2 mineralization. However, only a small reactive fraction of these feedstocks will be accessible for carbon dioxide removal at Earth’s surface conditions. We have developed a new method to evaluate the reactivity of mineral feedstocks that consists of a batch leach test using CO2 coupled with total inorganic carbon (TIC) analysis to quantify easily extractable Mg ...

CO2 sequestration by wollastonite-amended agricultural soils – An Ontario field study

Fatima Haque, Rafael M.Santos, Yi Wai Chiang Abstract Terrestrial enhanced weathering is the spreading of silicate powder on land, and can sequester atmospheric CO2 through carbonation of calcium- and magnesium-rich minerals. When applied to soils, at suitable geochemical conditions, alkaline minerals lead to accumulation of soil inorganic carbon as pedogenic carbonates. Agricultural land covers 37 % of the Earth’s land surface, thus offering a natural sink for atmospheric CO2. Wollastonite (CaSiO3) has been commercialized in Ontario as an agricultural soil amendment for several years, but it is not known if or how much CO2 is sequestered ...

Carbonate precipitation in artificial soils produced from basaltic quarry fines and composts: An opportunity for passive carbon sequestration

D.A.C. Manning, P. Renforth, E. Lopez-Capel S.Robertson, N. Ghazireh Abstract The proportions of different carbon pools within artificial soils prepared by blending composts with dolerite and basalt quarry fines has changed over a period of 7 years, accumulating inorganic carbon as carbonate minerals newly formed within the soils. With no artificial energy inputs following construction, this is regarded as a passive mineral carbonation process. Carbon isotope data show that up to 40% of the carbon within the soil carbonate is derived from photosynthesis, mixed with carbon from geological sources (limestone present in the quarry fines). Organic ...

Organic acids and high soil CO2 drive intense chemical weathering of Hawaiian basalts: Insights from reactive transport models

Alida Perez-Fodich, Louis A. Derry Abstract We have investigated how biota contributes to rapid chemical weathering of Hawaiian basalts using a reactive transport model and chemical data from a soil chronosequence. These Hawaiian soils have developed under a tropical forest with rainfall >200 cm/yr and exhibit extensive weathering on timescales of 104 years. We developed a series of multicomponent reactive transport models to examine the role of soil respiration and low molecular weight organic acids in generating these intense weathering patterns. The base model starts with a 1-m basaltic porous media reacting with a fluid of rainwater ...

Climate change mitigation: potential benefits and pitfalls of enhanced rock weathering in tropical agriculture

Abstract David P. Edwards, Felix Lim, Rachael H. James, Christopher R. Pearce, Julie Scholes, Robert P. Freckleton and David J. Beerling Restricting future global temperature increase to 2°C or less requires the adoption of negative emissions technologies for carbon capture and storage. We review the potential for deployment of enhanced weathering (EW), via the application of crushed reactive silicate rocks (such as basalt), on over 680 million hectares of tropical agricultural and tree plantations to offset fossil fuel CO2 emissions. Warm tropical climates and productive crops will substantially enhance weathering rates, with potential ...

Carbon Accounting for Enhanced Weathering

Thorben Amann, Jens Hartmann Abstract The inevitable deployment of negative emission technologies requires carbon accounting to incentivise the investment and to foster an active CO2 certificate trading schema. Enhanced Weathering as one of the negative emission technologies is being tested in the field now, but lacks a verifiable and cost-effective carbon accounting approach. Based on results from a lab scale column experiment and field observations, it is hypothesized that the observed stable positive correlation between total alkalinity and electrical conductivity may present a way to easily predict the initial CO2 sequestration at the ...