NATURE EDITORIAL on atmospheric carbon dioxide (CO2) removal (CDR) via enhanced silicate rock weathering (ERW), deployable with croplands; remove between 0.5 billion and 2 billion tonnes of CO2 from the air each year; cost between $80 and $180 per tonne of CO2"

Nature editorial on atmospheric carbon dioxide (CO₂) removal (CDR) via enhanced silicate rock weathering (ERW), deployable with croplands (2020): “Could spreading basalt dust on farmers’ fields help to remove atmospheric carbon? A large multidisciplinary team of scientists is confident it could, and that doing so could boost crop yields and soil health at the same time. In this issue, David Beerling, a biogeochemist at the University of Sheffield, UK, and his colleagues explore a strategy to enhance rock weathering (D. J. Beerling et al. Nature 583, 242–248; 2020). This is a continuously occurring natural phenomenon in which carbon dioxide and water react with silicate rocks on Earth’s surface. In the process, atmospheric CO₂ is converted into stable bicarbonates that dissolve and then flow into rivers and oceans. The idea of scaling up this process to remove carbon has been considered for some three decades. The team’s results provide the most detailed analysis yet of the technical and economic potential of this approach — and some of the probable challenges, including gaining public acceptance… The researchers modelled what would happen to atmospheric carbon if basalt dust was added to agricultural lands in the world’s biggest economies, including Brazil, China, the European Union, India, Indonesia and the United States. According to their calculations, doing so would remove between 0.5 billion and 2 billion tonnes of CO₂ from the air each year. The upper limit is more than 5 times the annual emissions of the United Kingdom, and akin to offsetting emissions from around 500 coal-fired power plants. … Moreover, mining rock on industrial scales, pulverizing it and spreading the dust on crop fields will not be cheap. The current price of carbon on the European Union’s emissions trading system is less than €28 (US$31) per tonne. By contrast, Beerling and his colleagues estimate that enhanced rock weathering will cost between $80 and $180 per tonne of CO₂” (Nature editorial, “Pulling carbon from the sky is necessary but not sufficient”, Nature 583, 167-168, 2020: https://www.nature.com/articles/d41586-020-02001-4?utm_source=Nature+Briefing&utm_campaign=d8ecc52b76-briefing-dy-20200709&utm_medium=email&utm_term=0_c9dfd39373-d8ecc52b76-44714333 ).