Usable CO2 storage capacity ten times lower than previously thought

The planet’s capacity to store carbon dioxide underground safely is significantly lower than previously estimated, according to a study published in Nature.

Researchers at the International Institute for Applied Systems Analysis in Austria calculated a theoretical global reserve of around 11,800 gigatonnes of CO2. When geological risks such as earthquakes, groundwater contamination, proximity to population centres, and political constraints were applied, the figure dropped to about 1,460 gigatonnes. That equates to roughly 35 to 40 years of global emissions at current levels of around 37 gigatonnes annually, according to the International Energy Agency.

In climate terms, the researchers said this would reduce warming by about 0.7C, compared with earlier projections suggesting that wide-scale storage could help cut warming by 5 to 6C, the reduction needed to align with the 2015 Paris Agreement.