Scientists at the Lawrence Livermore National Laboratory in California have demonstrated a new technique to remove and store atmospheric carbon dioxide while generating carbon-negative hydrogen and producing alkalinity, which could be used to offset ocean acidification.

The team has demonstrated that, when saline water is electrolysed to produce hydrogen fuel and other gases, the acidity produced will accelerate silicate mineral dissolution. The resulting electrolyte solution has a significantly elevated hydroxide concentration that strongly absorbs and retains atmospheric CO2.

The process produces alkaline carbonates and bicarbonates which the researchers suggest could be used to mitigate ongoing ocean acidification.

Lead author of a paper, Greg Rau, said that  "We not only found a way to remove and store carbon dioxide from the atmosphere while producing valuable H2, we also suggest that we can help save marine ecosystems with this new technique".