UK could cut carbon emissions by adding rock dust to agricultural soil, study finds
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Adding rock dust to UK agricultural soils could absorb up to 45 per cent of the atmospheric carbon dioxide needed for net-zero, researchers from the University of Sheffield have said.
In a new study, they demonstrated that the practice could remove between 6 and 30 million tonnes of carbon dioxide (CO2) from the atmosphere annually by 2050.
The cost of carbon dioxide removal is currently estimated to be around £200 per tonne with expectations that this will fall to half that by 2050. This makes the rock dust solution highly competitive relative to other removal options.
The research also finds other benefits including the mitigation of nitrous oxide, the third most important greenhouse gas, and widespread reversal of soil acidification caused by intensification of agriculture. It can also be used as a substitute for expensive imported fertilisers in many cases. By reducing demand for imported fertilisers, using rock dust avoids carbon emissions and offsets costs of deployment.
Deployment would be straightforward, the study finds, because the approach uses existing infrastructure without the need for expensive facilities such as direct air capture with carbon capture storage, and bioenergy crops.
The plan would require mining operations to produce the basalt rock dust, which would need to be carried out in a way that does not raise the concerns of local communities.
Professor David Beerling, senior author of the study, said: “Our analysis highlights the potential of UK agriculture to deliver substantial carbon drawdown by transitioning to managing arable farms with rock dust, with added benefits for soil health and food security.”
Dr Euripides Kantzas, another lead author, said: “By quantifying the carbon removal potential and co-benefits of amending crops with crushed rock in the UK, we provide a blueprint for deploying enhanced rock weathering on a national level, adding to the toolbox of solutions for carbon-neutral economies.”
Professor Nick Pidgeon, from Cardiff University, said: “Meeting our net zero targets will need widespread changes to the way UK agriculture and land is managed. For this transformation to succeed we will need to fully engage rural communities and farmers in this important journey.”
In 2020, the UK government introduced its Agriculture Bill which governs farming in England after Brexit, marking a shift away from the EU subsidy system of paying farmers mostly for the amount of land they farm.
It included provisions to pay UK farmers for ‘public goods’ such as protecting water and air quality, boosting wildlife and tackling climate change.
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