Environmental Geoscience

负排放技术涉及从大气中去除二氧化碳(CO2)，对于限制全球变暖和防止气候变化的最严重影响是必要的。在这些技术中，加强岩石风化和二氧化碳矿化旨在通过将岩石粉末分散在矿区、农田和林地等大片地区，通过化学风化来提高地球从大气中去除二氧化碳的自然能力。岩粉中含有钙和镁的矿物与大气中的二氧化碳发生反应，将二氧化碳储存在水和固体碳酸盐中。如果大规模部署，这种方法提供了捕获和永久存储二氧化碳的巨大能力。然而，与二氧化碳去除速度、碳储存的验证、共同效益和环境问题有关的许多不确定性。该研究计划包括四个相互关联的项目，旨在将强化岩石风化和二氧化碳矿化作为可行的气候变化缓解策略。某些矿山产生大量适合去除二氧化碳的矿物废物，并且可以部署。与采矿业合作，将在一个矿场启动一项实地试点，以测量二氧化碳清除率，并在几年的实际条件下验证碳储存。一项免费的实验室研究将检查风化的矿山废物，以了解风化过程以及这些过程如何稳定矿山废物并将其风险降至最低。将在农业和森林土地上使用各种石粉进行增强的岩石风化现场试验。这些试验将被用来评估二氧化碳的去除，调查土壤-岩石的相互作用，并评估潜在的协同效益，如养分释放。此外，补充的实验室实验将研究使用高活性氧化镁和氧化钙粉末去除二氧化碳。应对气候变化需要实施负排放技术，同时大幅减少温室气体排放。这项研究计划通过开发新的方法、解决不确定性并在大范围内展示其有效性来推进两项最有前途的技术。加拿大非常适合利用这些方法，因为它拥有丰富的适合部署的岩石和广阔的土地。

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.