5. Assessment and outlook: levers and constraints for sustainable storage

5.1 Urban development strategy

It has been demonstrated that it is not simply location within an urban unit that limits the COS storage capacity of soils. This capacity is impacted by disturbances linked to changes in land use, the diversity of management practices and, above all, soil sealing.

Protecting existing COS stocks in urban soils means minimizing physical disturbance from civil engineering activities, or massive interventions on existing plant cover. Waterproofing, an extreme case of soil disturbance, is accompanied by excavation of surface horizons, and even deep horizons, resulting in a consequent loss of COS, and CO ₂ emissions. To limit this loss, excavated soil should ideally be used as fill material...