Fig. 2: Different scenarios after mining pristine land, expressing the loss and recovery of carbon stocks and soil-related ecosystem services.

“Pristine” represents a scenario where the ecosystem is in equilibrium and conserves full functionality, with the maximum potential for the provision of essential soil-related ecosystem services (e.g., provision of food, fiber, and energy; regulation of the hydrological cycle; nutrient cycling; biodiversity conservation; and climate regulation). In this scenario, the total organic carbon (TOC) stock, i.e., the sum of above-ground biomass carbon (AGBC) and soil organic carbon (SOC), within legally active mine sites in Brazil is estimated to be 2.55 Gt CO₂eq. The “degraded” scenario represents the postmine condition after the complete removal of vegetation and soil. In the absence of soil, the system loses its capacity to provide ecosystem services and becomes a source of CO₂, with the eventual loss of the previous TOC stocks. CO₂ emissions occur through the decomposition of biomass carbon from vegetation and the degradation of organic matter from the stripped soil. In the “reclaimed” scenario, the construction of Technosols from mine waste and possibly other types of waste and residues (e.g., domestic and/or industrial) would favor rapid environmental reclamation, where the reclaimed land could be used for multiple purposes (e.g., agriculture, agroforestry, forestry, and reforestation). Our results indicate that the use of Technosols could lead to an offset of 0.52–1.00 Gt CO₂eq, owing to soil carbon sequestration only. Considering the re-establishment of vegetation (data unknown), the recovery of AGBC stocks could lead to TOC stocks greater than 1.00 Gt CO₂eq. Importantly, mine reclamation with Technosols would lead to the recovery of soil-related ecosystem services.