... and sequester it in newly-formed rock mineral, magnesium carbonate. David Keller et al., “Potential climate engineering effectiveness and side effects during a high carbon dioxide-emission scenario,” Nature Communications, Vol. The energy requirements for this technology are substantial. Enhanced weathering on land (terrestrial) Mined olivine (magnesium iron silicate) is ground to a powder and either dumped on beaches where wave action disperses it into water or is spread on land. Rainwater and bicarbonate ions eventually end up in the ocean, where they are formed into carbonate minerals by calcifying organisms (Eq.3), which then sinks out of the surface ocean. Mineral carbonation research has largely focused on the sequestration of CO2 from flue gas. 294, 2001, pp. Since the carbon dioxide is usually first removed from ocean water, these approaches would attack the problem by first reducing ocean acidification. The Nullarbor Plain was also given formal Wilderness Protection Status in 2011 to protect its unique environment, which contains 390 species of plants and many habitats for rare species of animals and birds.14. While field-scale trails adding crushed basalt to cropland are being conducted, other research into enhanced weathering is purely theoretical, and based on modelling exercises. Some research explores the potential of 'In-situ mineral carbonation' in which the CO2 is injected into silicate rock formations to promote carbonate formation underground (see: CarbFix). Therefore, an increase in both carbonate and silicate weathering with respect to carbonate precipitation will result in a buildup of alkalinity in the ocean. 294, 2001, pp. 113–149 Known as enhanced rock weathering, the process involves layering crushed rock onto soil. Pete Smith et al., “Biophysical and economic limits to negative CO2 emissions,” Nature Climate Change, Vol. Ocean methods are being tested by non-profit Project Vesta to see if it is a environmentally and economically viable carbon sequestration strategy.[1][2]. 'Enhanced Weathering' was initially used to refer specifically to the spreading of crushed silicate minerals on the land surface. Marine Cloud Brightening Project: Geoengineering Experiment Briefing, Bio-Energy with Carbon Capture and Storage (BECCS), Geoengineering in the Global South (ETC Podcast), Grounding Teach-In on Geoengineering: A False Solution to the Climate Crisis, Greetings from Ruth Nyambura, HOME Campaign Coordinator. 20228-20233, 11. While this technology will likely be cheap, the maximum annual CO2 sequestration potential is limited. When silicate or carbonate minerals dissolve in rainwater, carbon dioxide is drawn into the solution from the atmosphere through the reactions below (Eq.1&2) to form bicarbonate ions: Eq.1 Forsterite: Mg2SiO4 + 4CO2 + 4H2O → 2Mg2+ + 4HCO3− + H4SiO4, Eq.2 Calcite : CaCO3 + CO2 + H2O → Ca2+ + 2HCO3−. As weathering rate is a function of saturation of the dissolving mineral in solution (decreasing to zero in fully saturated solutions), some have suggested that the quantity of rainfall may limit terrestrial enhanced weathering,[7] although others[8] suggest that secondary mineral formation or biological uptake may suppress saturation and promote weathering. Wikipedia, “Nullarbor Plain,” https://en.wikipedia.org/wiki/Nullarbor_Plain, When energy inputs such as mining, processing and transportation are included, the overall energy requirement for enhanced weathering is huge. Weathering,” University of Bremen, 2001, http://www.iup.uni-bremen.de/PEP_master_thesis/thesis_2012/Thesis_Jesse-Abrams.pdf, 10. Enhanced weathering in the oceans (marine), This technique, similar to treating acidic agricultural lands with lime, proposes adding chemical carbonates to the ocean to theoretically increase alkalinity and therefore carbon uptake. Further, the Nullarbor Plain is home to the aboriginal Wangai people, who were forcibly removed from their ancestral lands once before for nuclear testing in the 1950s and have since received compensation for the injustice and have reoccupied the plain.