The duration for which CO2 can be sequestered in a stable and safe manner. Storage duration can differ significantly, depending on the type of reservoir. For example, concentrated CO2 stored in geologic formations deep underground is effectively permanent (thousands of years), whereas forest carbon stocks can release carbon back into the atmosphere due to wildfire or tree harvesting.
source: J Wilcox, B Kolosz, & J Freeman (2021) CDR Primer; Concepts