Environmental Geoscience

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Negative emission technologies involve removing carbon dioxide (CO2) from the atmosphere and are necessary to limit global warming and prevent the worst impacts of climate change. Of these technologies, enhanced rock weathering and CO2 mineralization aim to accelerate Earth's natural ability to remove CO2 from the atmosphere through chemical weathering by dispersing rock powder over large areas such as mine sites, agricultural fields, and forested lands. Calcium- and magnesium-bearing minerals in the rock powder react with atmospheric CO2, storing the CO2 in waters and solid carbonates. This approach offers an enormous capacity to capture and permanently store CO2 if deployed at large scales. However, there are many uncertainties relating to the rates of CO2 removal, verification of carbon storage, co-benefits, and environmental concerns.This research program comprises four interconnected projects that aim to advance enhanced rock weathering and CO2 mineralization as viable climate change mitigation strategies. Certain mines produce large quantities of mineral wastes suitable for CO2 removal and are accessible for deployment. In collaboration with the mining industry, a field pilot will be initiated at a mine site to measure rates of CO2 removal and verify carbon storage under real-world conditions over several years. A complimentary laboratory study will examine weathered mine wastes to understand weathering processes and how these may stabilize mine wastes and minimize their risk.Enhanced rock weathering field trials will be undertaken in agricultural and forested lands using various rock powders. These trials will be used to evaluate CO2 removal, investigate soil-rock interactions, and assess potential co-benefits such as nutrient release. In addition, complementary laboratory experiments will investigate CO2 removal using highly reactive magnesium and calcium oxide powders.Addressing climate change requires implementing negative emission technologies while also drastically reducing greenhouse gas emissions. This research program advances two of the most promising technologies by developing new methodologies, addressing uncertainties, and demonstrating their effectiveness at large scales. Canada is well suited to capitalize on these approaches, given its abundance of suitable rocks and vast lands for deployment.