For the buildup (sequestration) of carbon in soil, CO2 certificates can be issued, which could play a central role in climate policy. CO2 certificates were developed for the industrial and energy sectors in order to compensate for a country's emissions between the individual sectors or to be able to trade emission rights between countries. In the context of the United Nations Framework Convention on Climate Change (UN 1992), this was also made possible for the forestry sector. There are already certificates for soil carbon on the voluntary CO2 market, which supports private reduction efforts. What requirements should compensation projects based on soil carbon buildup meet?
Verification: The storage of the additional carbon must be quantifiable and therefore verifiable because it is intended to compensate for other real emissions.
Permanence: The accumulated carbon must be stored permanently. Temporary increases in the soil carbon stock do not contribute to the achievement of the goal, but a newly built up stock must be maintained permanently.
Additionality: A sink project should meet the condition of additionality. This means that a sink is only created by the incentive of the CO2 certificate, so that an expensive measure, for example, only becomes economical through the additional income from the sale of the certificate.
Leakage: A measure should avoid the risk of leakage. This refers to the shift of the avoided emissions in a project to other countries or the occurrence of additional emissions outside the system boundaries of the project. For the soil system, such a shift occurs when a sink is realized at the expense of another sink or even by creating a source elsewhere.
A special activity is the rewetting of drained organic soils. This is less about creating a sink, but about preventing a strong and constant source of CO2. Peatland rewetting is one of the most effective mitigation measures in the land use sector (e.g., see here)
