B003-0002
Carbon Dioxide Removal via Enhanced Rock Weathering With Agriculture in Large-Scale Field Trials

Monday, 7 December 2020
Poster
Rachael Helen James1, Grace Andrews1, Christopher R Pearce2, Gabriella Jardine1, Heather Goring-Harford1, Dimitar Epihov3, Michael D Masters4, Kok Loong Yeong5, Ilsa B Kantola6, Evan H DeLucia7 and David John Beerling8, (1)University of Southampton, Ocean and Earth Science, Southampton, United Kingdom, (2)National Oceanography Centre, Southampton, United Kingdom, (3)University of Sheffield, Animal and Plant Sciences, Sheffield, United Kingdom, (4)University of Illinois, Urbana, IL, United States, (5)University of Sheffield, Sheffield, United Kingdom, (6)University of Illinois at Urbana-Champaign, Institute for Sustainability, Energy, and Environment; Carl R. Woese Institute for Genomic Biology, Urbana, IL, United States, (7)University of Illinois at Urbana-Champaign, Center for Bioenergy and Bioproducts Innovation; Institute for Sustainability, Energy, and Environment; Department of Plant Biology; Carl R. Woese Institute for Genomic Biology, Urbana, IL, United States, (8)University of Sheffield, Leverhulme Centre for Climate Change Mitigation; Department of Animal and Plant Sciences, Sheffield, S10, United Kingdom
Abstract:
Integral to any strategy for achieving enhanced removal of carbon dioxide from the atmosphere is the need to establish robust, repeatable approaches for quantifying CO2 removal and verifying its long-term storage. These are not only required for any emissions trading schemes, but also for the development of IPCC Tier 1 protocols.

Application of crushed silicate rock to agricultural lands enhances CO2 removal via weathering, converting CO2 to (i) alkalinity, principally in the form of dissolved hydrogen carbonate ions in soil and discharge waters, and (ii) pedogenic carbonate that may precipitate from carbonate-saturated soil waters. CO2 sequestered via pathway (i) is stored on timescales of >105 years, and on timescales of ~104 years via pathway (ii) [e.g. 1]. Carbon dioxide may also be converted into (iii) biomass and (iv) soil organic carbon, but the stability of these storage reservoirs is likely to be considerably shorter [e.g. 2].

We are conducting large-scale long-term field trials of enhanced rock weathering applied to contrasting agroecosystems in the USA (mid-west corn belt), Malaysia (oil palm) and UK (arable croplands). In this presentation, we report preliminary estimates of CO2 removal with an approach that accounts for the effects of application of fertilisers and the differential effects of alkalinity generation vs carbonate formation for the efficacy of CO2 removal. We show that the application of crushed basalt can increase alkalinity in soil and discharge waters and pedogenic carbonate content. Rates of CO2 removal are an order of magnitude higher in the tropics compared to temperate agroecosystems. Establishing the long-term trends in CO2 removal via continued basalt application is a vital next step that will be addressed in the next stage of our field trials.

[1] Beerling D.J. et al. (2020) Nature 583,242-248.

[2] Andrews M.G. & Taylor L.L. (2019) Elements 15, 253-258.

<< Previous Abstract | Next Abstract >>