178 results for group: journal-article
Global agricultural N2O emission reduction strategies deliver climate benefits with minimal impact on stratospheric O3 recovery
ABSTRACT
Agricultural nitrous oxide (N2O) emission reduction strategies are required given the potency of N2O as a greenhouse gas. However, the growing influence of N2O on stratospheric ozone (O3) with declining stratospheric chlorine means the wider atmospheric impact of N2O reductions requires investigation. We calculate a N2O emission reduction of 1.35 TgN2O yr-1 (~5% of 2020 emissions) using spatially separate deployment of nitrification inhibitors ($70–113 tCO2e−1) and crushed basalt (no-cost co- benefit) which also sequesters CO2. In Earth System model simulations for 2025–2075 under high (SSP3-7.0) and low (SSP1-2.6) surface ...
The efficacy of enhancing carbonate weathering for carbon dioxide sequestration
ABSTRACT:
Enhanced weathering is a geoengineering strategy aiming to increase continental weathering rates, thereby increasing the delivery of atmospheric carbon (as HCO−3) to the oceans. Most enhanced weathering studies focus on the capacity of silicate rocks (e.g., basalt) and minerals (e.g., olivine, Mg2SiO4, or wollastonite CaSiO3) to remove atmospheric CO2. However, carbonate minerals (e.g., calcite, CaCO3) could provide an additional, rapid way to increase HCO−3 export to the oceans. Recent studies suggest that 0.84 Gt C yr−1could be removed from the atmosphere through the enhanced dissolution of calcite in soils, provided carbonic acid ...
Additive effects of basalt enhanced weathering and biochar co-application on carbon sequestration, soil nutrient status and plant performance in a mesocosm experiment
ABSTRACT
Co-deployment of a portfolio of carbon removal technologies is anticipated in order to remove several gigatons of carbon dioxide from the atmosphere and meet climate targets. However, co-application effects between carbon removal technologies have rarely been examined, despite multiple recent perspectives suggesting potential synergies between basalt enhanced weathering and biochar application. To study the co-application effects of basalt for enhanced weathering and biochar on carbon sequestration, along with related co-benefits and risks, we conducted a fully replicated factorial mesocosm experiment with wheat. Basalt applied alone (74 t ...
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 ...
Initial agronomic benefits of enhanced weathering using basalt: A study of spring oat in a temperate climate
ABSTRACT
Addressing soil nutrient degradation and global warming requires novel solutions. Enhanced weathering using crushed basalt rock is a promising dual-action strategy that can enhance soil health and sequester carbon dioxide. This study examines the short-term effects of basalt amendment on spring oat (Avena sativa L.) during the 2022 growing season in NE England. The experimental design consisted of four blocks with control and basalt- amended plots, and two cultivation types within each treatment, laid out in a split plot design. Basalt (18.86 tonnes ha−1) was incorporated into the soil during seeding. Tissue, grain and soil samples ...
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 ...
India’s biogeochemical capacity to attain food security and remediate climate
Ishfaq Ahmad Mir, Thomas J F Goreau, Joanna Campe, James Jerden
Abstract
In order to supply wholesome food and slow down climate change, this paper covers India's agrogeological resources. The soils are the result of the weathering of rocks with ages ranging from more than a billion years to the most recent Holocene. Because they are severely deficient in vital minerals, many soils have low agricultural production. In addition to helping to fertilise soils, reduce atmospheric carbon dioxide levels, and stop the acidification of the Indian Ocean, rock powder weathering and biochar have significant positive effects on the productivity of Indian ...
Environmental impacts and resource use of urban agriculture: a systematic review and meta-analysis
Erica Dorr, Benjamin Goldstein, Arpad Horvath, Christine Aubry, and Benoit Gabrielle
Abstract
Environmental merits are a common motivation for many urban agriculture (UA) projects. One powerful way of quantifying environmental impacts is with life cycle assessment (LCA): a method that estimates the environmental impacts of producing, using, and disposing of a good. LCAs of UA have proliferated in recent years, evaluating a diverse range of UA systems and generating mixed conclusions about their environmental performance. To clarify the varied literature, we performed a systematic review of LCAs of UA to answer the following questions: What is ...