The best results reflect cost-effective, safer, more sustainable operations. If these premises are applied to decisions on which techniques and technologies should be combined on a particular undertaking in order to maximize its environmental benefits, then the results of research from the University of Sheffield involving CO2 capture from the atmosphere need to be followed, especially when the matter becomes the best way to manage croplands.
Carbon Capture and Long-Term Storage Strategies Mitigate Global Warming
In recent years we all have been hearing about “CO2 capture” as a promising technique for carbon removal from the atmosphere, which would help reduce significantly the impacts of global warming and climate change. At a large scale, research on the subject has revolved around CO2 capture (at point source) and the posterior injection in geologic reservoirs, such as depleted oil and gas reservoirs and deep saline aquifers in sedimentary basins at depths typically >800 m. To complete the cycle of CO2 removal, a storage phase follows capture and injection, whereby a process known as mineralization of CO2 occurs by the combination of the gas with silicate minerals. However, this technology still has challenges to address, such as possible CO2 dissolution into groundwater, and heavy metal formation and release.
At a smaller scale but still very effective would be supplementing soils with crushed silicate rocks such as basalt left over from ancient volcanic eruptions. This could reduce the amount of CO2 entering the atmosphere and improve food security, found a new study from The University of Sheffield and the University of Illinois Champaign-Urbana. As the rock grains dissolve chemically in soils, they take up CO2 and release plant-essential nutrients.
Enhanced Rock Weathering in Cropland Soils – a New Study Sheds Light
Professor David Beerling, Director of the Leverhulme Centre for Climate Change Mitigation at the University of Sheffield and lead author of the research, said: “This study has transformed how we think about managing our croplands for climate, food and soil security. It helps move the debate forward for an under-researched strategy of CO2 removal from the atmosphere – enhanced rock weathering – and highlights supplementary benefits for food and soils”.
The research, published on 19 February 2018 in Nature Plants, examined the approach which involves amending soils with abundant crushed silicate rocks, like basalt, left over from ancient volcanic eruptions. As these minute rock grains dissolve chemically in soils, they take up carbon dioxide and release plant-essential nutrients.
Compared to other carbon removal strategies, applying enhanced rock weathering together with traditionally managed croplands have the following benefits: 1) it does not require separate land used to grow food or increase the demand for freshwater, 2) it entails reducing the use of agricultural fertilizers and pesticides, 3) it lowers the cost of food production, 4) it increases the profitability of farms and reduces the barriers to uptake by the agricultural sector.
Crushed silicate rocks could be applied to any soils, but arable land is the most obvious since it is worked and planted annually. It covers some 14 million square kilometers or 10 percent of the global land area.
Professor Stephen Long at the University of Illinois Champaign-Urbana and co-author of the study concluded: “Global warming is a problem that affects everyone on the planet. Scientists generally have done a poor job of getting across the point that the world must reduce emissions of greenhouse gases from fossil fuels and combine this with strategies for extracting carbon dioxide from the atmosphere to avoid a climate catastrophe.”