A new study by the Hong Kong University of Science and Technology (HKUST) has found that CO2 in the deep Earth may be more active than previously believed and could have played a bigger role in climate change than previously thought. The research, led by Professor Pan Ding, analyzed the dissolution of CO2 in water and its potential effects on reducing the return of carbon from underground to the atmosphere.
The vast majority of the Earth’s carbon is buried in its interior and it is important to understand how much carbon lies in deep reservoirs hundreds of kilometers underground. Using first-principles simulations in physics, Professor Ding’s team found that CO2 may be more active than previously thought in Earth’s deep carbon cycle, which largely influences the carbon transport between Earth’s deep and near-surface reservoirs.
The study suggests that confining CO2 and water in suitable nanoporous minerals may enhance the efficiency of underground carbon storage and that turning CO2 together with water into rocks under nanoconfinement offers a secure method to permanently store carbon underground with a low risk of return to the atmosphere.
Previous studies focused on properties of dissolved carbon in bulk solutions, but in deep Earth or underground carbon storage, aqueous solutions are often confined to the nanoscale in pores, grain boundaries, and fractures of Earth’s materials, where spatial confinement and interface chemistry may make the solutions fundamentally different.
The findings of the study have been published in the international academic journal Nature Communications and pave the way for studies into more complicated carbon reactions in water in deep Earth, such as the formation of diamonds, abiogenetic petroleum origin, and even deep life.