Permanence is the durability of a carbon storage outcome. It asks how long the carbon is expected to remain out of the atmosphere and what happens if that storage is reversed.
Reversal risk
Forests and soils can lose carbon through fire, drought, pests, harvesting or a change in management. Engineered stores can also fail, but the probability and monitoring approach differ by technology and reservoir.
A reversal weakens the original climate claim unless the programme replaces or compensates for the loss.
How standards manage permanence
Land-based projects often use long-term monitoring commitments, risk assessments and pooled buffers. Some contracts add replacement obligations or insurance.
Biochar methodologies apply durability factors based on material properties and approved use. Geological storage relies on site characterisation, injection monitoring and long-term containment rules.
Permanence is a spectrum
A one-hundred-year benchmark is common in carbon markets, but buyers increasingly compare storage across a broader spectrum. Temporary biological storage, century-scale biochar and geological storage do not provide identical durability.
That does not make one category universally superior. Nature-based projects can deliver urgent ecosystem and livelihood benefits, while durable removals are important for neutralising residual fossil emissions.
Buyer due diligence
Review the storage mechanism, reversal scenarios, monitoring duration, buffer or insurance design and contractual liability. Price should reflect these characteristics rather than treating every tonne as interchangeable.
Compare our biochar removal project with soil carbon and agroforestry insetting to see how permanence controls vary by activity.
