"Crushed basalt applied to agricultural land could soak up billions of tons of carbon dioxide and boost crops. Let's put it to the test, says Olive Heffernan"

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Beerling, David J.; Leake, Jonathan R.; Long, Stephen P.; Scholes, Julie D.; Ton, Jurriaan; Nelson, Paul N. et al. (2018): Farming with crops and rocks to address global climate, food and soil security. In Nature Plants 327, p. 810. DOI: 10.1038/s41477-018-0108-y.

"Managed croplands worldwide are already equipped for frequent rock dust additions to soils, making rapid adoption at scale feasible, and the potential benefits could generate financial incentives for widespread adoption in the agricultural sector. However, there are still obstacles to be surmounted. Audited field-scale assessments of the efficacy of CO₂ capture are urgently required together with detailed environmental monitoring. A cost-effective way to meet the rock requirements for CO₂ removal must be found, possibly involving the recycling of silicate waste materials. Finally, issues of public perception, trust and acceptance must also be addressed."

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Griffioen, Jasper (2017): Enhanced weathering of olivine in seawater. The efficiency as revealed by thermodynamic scenario analysis. In The Science of the Total Environment 575, pp. 536–544. DOI: 10.1016/j.scitotenv.2016.09.008.

"This study aimed to characterise how olivine can weather in seawater, to elucidate the role of secondary precipitation and to ascertain the efficiency in terms of molar CO₂ removal per mole of olivine dissolution. Geochemical thermodynamic equilibrium modelling was used, which considered both the variable mineralogical composition of olivine and the kinds of secondary precipitates that may be formed. The advantage is that such an approach is independent from local or regional factors as temperature, related kinetics, mineralogy, etc. The results show that the efficiency falls when secondary precipitates are formed."

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Kantola, Ilsa B.; Masters, Michael D.; Beerling, David J.; Long, Stephen P.; DeLucia, Evan H. (2017): Potential of global croplands and bioenergy crops for climate change mitigation through deployment for enhanced weathering. In Biology letters 13 (4). DOI: 10.1098/rsbl.2016.0714 

"Enhanced weathering (EW) in agricultural soils—applying crushed silicate rock as a soil amendment—is a method for combating global climate change while increasing nutrient availability to plants. EW uses land that is already producing food and fuel to sequester carbon (C), and reduces N₂O loss through pH buffering. As biofuel use increases, EW in bioenergy crops offers the opportunity to sequester CO₂ while reducing fossil fuel combustion. Uncertainties remain in the long-term effects and global implications of large-scale efforts to directly manipulate Earth's atmospheric CO₂ composition, but EW in agricultural lands is an opportunity to employ these soils to sequester atmospheric C while benefitting crop production and the global climate."

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