106 results for group: climate-change


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 ...

Enhanced weathering potentials—the role of in situ CO2 and grain size distribution

Thorben Amann, Jens Hartmann, Roland Hellmann, Elisabete Trindade Pedrosa, Aman Malik Abstract The application of rock powder on agricultural land to ameliorate soils and remove carbon dioxide (CO2) from the air by chemical weathering is still subject to many uncertainties. To elucidate the effects of grain size distribution and soil partial pressure of carbon dioxide (pCO2) levels on CO2 uptake rates, two simple column experiments were designed and filled nearly daily with an amount of water that simulates humid tropical conditions, which prevail in areas known for being hotspots of weathering. Multiple materials (dunite, basanite, agricultural ...

Possibilities of using silicate rock powder: An overview

Claudete GindriRamos, James C.Hower, Erika Blanco, Marcos Leandro Silva Oliveira, Suzi Huff Theodoro Abstract This study evaluates the on use of crushed rocks (remineralizers) to increase soil fertility levels and which contributed to increase agricultural productivity, recovery of degraded areas, decontamination of water, and carbon sequestration. The use of these geological materials is part of the assumptions of rock technology and, indirectly, facilitates the achievement of sustainable development goals related to soil management, climate change, and the preservation of water resources. Research over the past 50 years on silicate rocks ...

Land-based measures to mitigate climate change: Potential and feasibility by country

Stephanie Roe, Charlotte Streck, Robert Beach, Jonah Busch, Melissa Chapman, Vassilis Daioglou, Andre Deppermann, Jonathan Doelman, Jeremy Emmet-Booth, Jens Engelmann, Oliver Fricko, Chad Frischmann, Jason Funk, Giacomo Grassi, Bronson Griscom, Petr Havlik, Steef Hanssen, Florian Humpenöder, David Landholm, Guy Lomax, Johannes Lehmann, Leah Mesnildrey, Gert-Jan Nabuurs, Alexander Popp, Charlotte Rivard, Jonathan Sanderman, Brent Sohngen, Pete Smith, Elke Stehfest, Dominic Woolf, Deborah Lawrence Abstract Land- based climate mitigation measures have gained significant attention and im-portance in public and private sector climate policies. ...

The global potential for increased storage of carbon on land

Wayne S. Walker, Seth R. Gorelik , Susan C. Cook-Patton, Alessandro Baccini, Mary K. Farina, Kylen K. Solvik, Peter W. Ellis, Jon Sanderman, Richard A. Houghton, Sara M. Leavitt, Christopher R. Schwalm, Bronson W. Griscom Abstract Constraining the climate crisis requires urgent action to reduce anthropogenic emissions while simultaneously removing carbon dioxide from the atmosphere. Improved information about the maximum magnitude and spatial distribution of opportunities for additional land-based removals of CO2is needed to guide on-the-ground decision-making about where to implement climate change mitigation strategies. Here, we pre-sent a ...

What is the maximum potential for CO2 sequestration by “stimulated” weathering on the global scale?

Jens Hartmann, Stephan Kempe Abstract Natural chemical weathering of silicate rocks is a significant sink for soil and atmospheric CO2. Previous work suggested that natural chemical weathering may be stimulated by applying finely ground silicate rocks to agricultural areas or forests [stimulated weathering (SW)]. However, it remained unknown if this technique is practical to sequester globally significant amounts of CO2 under realistic conditions. Applying first estimates of “normal treatment” amounts from a literature review, we report here a theoretical global maximum potential of 65 106 t sequestered C a−1 if SW would be applied ...

Increased carbon capture by a silicate-treated forested watershed affected by acid deposition

Lyla L. Taylor, Charles T. Driscoll, Peter M. Groffman, Greg H. Rau, Joel D. Blum, David J. Beerling Abstract Meeting internationally agreed-upon climate targets requires carbon dioxide removal (CDR) strategies coupled with an urgent phase-down of fossil fuel emissions. However, the efficacy and wider impacts of CDR are poorly understood. Enhanced rock weathering (ERW) is a land-based CDR strategy requiring large-scale field trials. Here we show that a low 3.44 t ha−1 wollastonite treatment in an 11.8 ha acid-rain-impacted forested watershed in New Hampshire, USA, led to cumulative carbon capture by carbonic acid weathering of 0.025–0.13 t ...

Nutrients release from powder phonolite mediated by bioweathering actions

Laene de Fátima Tavares, André Mundstock Xavier de Carvalho, Luis Gustavo Brogliato Camargo, Samarina Gabriele de Fátima Pereira, Irene Maria Cardoso Abstract Silicate rock powders have been appointed as possible nutrient alternative sources which might enhance the agricultural sector sustainability. However, the application of those materials directly in soil presents as main limitations the low content and solubility of the mineral nutrient sources. In this perspective, the aim of the present study was to evaluate, in a bioweathering perspective, the conjunct application potential of phonolite with organic composts over the nutrients ...