To limit the increase in global average temperature to 1.5˚C as stated in the Paris Agreement, deep decarbonization of the global economy together with large scale Carbon Dioxide Removal (CDR) from the atmosphere is required. CO2 removal combined with permanent solid storage via enhanced rock weathering and mineral carbonation in mafic to ultramafic rocks has the potential to remove substantial amounts of CO2 on a decadal timescale. My talk will focus on two different CDR approaches: In-situ mineral carbonation of mafic and ultramafic rocks, and enhanced weathering of alkaline mine waste. Using some of my past and ongoing work, I will discuss rapid mineral carbonation in mafic and ultramafic rocks for permanent CO2 storage, as demonstrated by the CarbFix project in Iceland (Matter et al. 2016, Snæbjörnsdóttir et al., 2017) and more recently in the peridotites of the Oman ophiolite. Using a mix of environmental and deliberately injected tracers has enabled us to quantitatively verify mineral carbonation in subsurface reservoirs. In addition, I will highlight the gigaton scale CO2 capture potential of alkaline mine waste from the global mining industry via enhanced weathering as a second, promising CDR approach for climate change mitigation (Bullock et al., 2021).
Bullock, L.A., James, R.H., Matter, J., Renforth, P., & Teagle, D.A.H. (2021) Global carbon dioxide removal potential of waste materials from metal and diamond mining. Front. Clim. 3:694175. (doi:10.3389/fclim.2021.694175)
Matter, JM., et al. (2016) Rapid carbon mineralization for permanent disposal of anthropogenic carbon dioxide emissions. Science 352 (6291), 1312-1314, (doi:10.1126/science.aad8132)
Snæbjörnsdóttir et al. (2017) The chemistry and saturation states of subsurface fluids during the in situ mineralization of CO2 and H2S at the CarbFix site in SW-Iceland. Int. J. Greenh Gas Cont 58, 87-102 (doi:10.1016/ijggc.2017.01.007).