Durability: The capacity to store carbon over time without releasing it back to the atmosphere.
In the State of the CDR - 2nd Edition - carbon pools with characteristic storage timescales on the order of decades or more are classed as sufficiently durable for CDR. These include trees, wetlands, soils, biochar, durable wood products (e.g. timber for construction), mineral products (e.g. aggregates), marine sediments, ocean bicarbonate, depleted fossil fuel reservoirs, saline aquifers and mineral rock formations.
Source: The State of CDR, 2nd Edition