110 results for group: climate-change

The potential for carbon dioxide removal by enhanced rock weathering in the tropics: An evaluation of Costa Rica

Abstract 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 ...

The impact of geochemical and life-cycle variables on carbon dioxide removal by enhanced rock weathering: Development and application of the Stella ERW model

ABSTRACT The carbon dioxide removal (CDR) potential of enhanced rock weathering (ERW) depends on dynamic interactions between several biogeochemical and life-cycle variables. This paper reports results from a systems model developed to account for key variable interactions and provide a computational tool for optimizing ERW applications. We discuss the model development, comparisons with laboratory and field test data, and results from a series of sensitivity analyses for several hypothetical ERW applications. The simulations were performed using a model developed in Stella Architect, an object-oriented systems dynamics modeling code. The model ...

Organic carbon source controlled microbial olivine dissolution in small-scale flow-through bioreactors, for CO2 removal

ABSTRACT The development of carbon dioxide removal methods, coupled with decreased CO2 emissions, is fundamental to achieving the targets outlined in the Paris Agreement limiting global warming to 1.5 °C. Here we are investigating the importance of the organic carbon feedstock to support silicate mineral weathering in small-scale flow through bioreactors and subsequent CO2 sequestration. Here, we combine two bacteria and two fungi, widely reported for their weathering potential, in simple flow through bioreactors (columns) consisting of forsterite and widely available, cheap organic carbon sources (wheat straw, bio-waste digestate of pig ...

Soil cation storage as a key control on the timescales of carbon dioxide removal through enhanced weathering

ABSTRACT Significant interest and capital are currently being channeled into techniques for durable carbon dioxide removal (CDR) from Earth’s atmosphere. A particular class of these approaches (referred to as enhanced weathering (EW)) seeks to modify the surface alkalinity budget to durably store CO2 as dissolved inorganic carbon species. Here, we use SCEPTER (a reaction- transport code designed to simulate EW in managed lands) to evaluate the throughput and storage timescales of anthropogenic alkalinity in agricultural soils. Through a series of alkalinity flux simulations, we explore the main controls on cation storage and export from ...

Impact of Climate on the Global Capacity for Enhanced Rock Weathering on Croplands

Seung H. Baek, Yoshiki Kanzaki, Juan M. Lora, Noah Planavsky, Christopher T. Reinhard, Shuang Zhang Abstract Enhanced rock weathering (ERW) on croplands has emerged as an economically and ecologically promising negative emissions technology. However, estimated total carbon sequestration potential from ERW on croplands and its potential sensitivity to climate conditions requires further understanding. Here we combine 1-D reactive transport modeling with climate model experiments to simulate ERW on ∼1,000 agricultural sites globally. Applying a fixed rate of 10 tons of basalt dust per hectare on these sites sequesters 64 gigatons of CO2 over a ...

Improved net carbon budgets in the US Midwest through direct measured impacts of enhanced weathering

Ilsa B. Kantola, Elena Blanc-Betes, Michael D. Masters, Elliot Chang, Alison Marklein, Caitlin E. Moore, Adam von Haden, Carl J. Bernacchi, Adam Wolf, Dimitar Z. Epihov, David J. Beerling, Evan H. DeLucia Abstract Terrestrial enhanced weathering (EW) through the application of Mg- or Ca- rich rock dust to soil is a negative emission technology with the potential to address impacts of climate change. The effectiveness of EW was tested over 4 years by spreading ground basalt (50 t ha−1 year−1) on maize/soybean and miscanthus cropping systems in the Midwest US. The major elements of the carbon budget were quantified through ...

Constraining the Potential of Land-Based Negative Emissions Technologies (NETs) From a Data-Driven Perspective

Rafael M. Santos, Francisco Araujo, Hiral Jariwala, Reza Khalidy, Fatima Haque and Yi Wai Chiang Introduction Enhanced rock weathering (ERW), as a negative emissions technology for climate change mitigation, has received far more public, governmental, and academic attention (according to the authors’ account of engagement with such actors) in the past year than in the many years since its first mention in the literature. The term ERW was conceived by Beerling (2017), but the field of research referred to as “enhanced weathering” (EW) can see its origins, by this name, at least as far back as the works of Power and Southam (2005) and ...

The Mining Industry’s Role in Enhanced Weathering and Mineralization for CO2 Removal

Ian M. Power, Carlos Paulo, Kwon Rausis Abstract Enhanced weathering and mineralization (EWM) aim to remove carbon dioxide (CO2) from the atmosphere by accelerating the reaction of this greenhouse gas with alkaline minerals. This suite of geochemical negative emissions technologies has the potential to achieve CO2 removal rates of >1 gigatonne per year, yet will require gigatonnes of suitable rock. As a supplier of rock powder, the mining industry will be at the epicenter of the global implementation of EWM. Certain alkaline mine wastes sequester CO2 under conventional mining conditions, which should be quantified across the industry. Furtherm...

Pathways, roundabouts, roadblocks, and shortcuts to safe and sustainable deployment of enhanced rock weathering in agriculture

Rafael M. Santos, Francisco Araujo, Hiral Jariwala, Reza Khalidy, Fatima Haque and Yi Wai Chiang Introduction Enhanced rock weathering (ERW), as a negative emissions technology for climate change mitigation, has received far more public, governmental, and academic attention (according to the authors’ account of engagement with such actors) in the past year than in the many years since its first mention in the literature. The term ERW was conceived by Beerling (2017), but the field of research referred to as “enhanced weathering” (EW) can see its origins, by this name, at least as far back as the works of Power and Southam (2005) and Lenton ...

Improving food security and farmland carbon sequestration in China through enhanced rock weathering: Field evidence and potential assessment in different humid regions

Fuxing Guo, Haowei Sun, Jing Yang, Linsen Zhang, Yan Mu, Yanping Wang, Fuyong Wu Abstract\ Enhanced rock weathering (ERW) in farmland is an emerging carbon dioxide removal technology with crushed silicate rocks for soil improvement. However, due to climatic variability and field data limitations, uncertainties remain regarding the influence of ERW on food security and soil carbon pools in temperate regions. This study focused to evaluate the crop productivity and carbon sequestration potential of farmland ERW in China by conducting field monitoring in different humid regions and ERW performance model. Additionally, the contribution of climate, ...