Carbon Sequestration

Carbon sequestration refers to the natural or engineered process of capturing and storing carbon dioxide from the atmosphere or from industrial emission sources, preventing it from contributing to the greenhouse effect and global warming. In the context of mining — including bauxite, iron ore, gold, and diamond operations — carbon sequestration is relevant both as a potential mitigation strategy for residual operational emissions and as a growing area of interaction between mining activities and natural carbon sinks. Natural carbon sequestration occurs through the absorption of CO₂ by forests, wetlands, soils, and ocean ecosystems. Mining companies are increasingly investing in nature-based sequestration solutions — such as afforestation, reforestation, improved forest management, wetland restoration, and soil carbon enhancement — both on mined lands (post-closure revegetation and ecological restoration) and through externally purchased verified carbon offset projects, to balance residual emissions they cannot yet eliminate through operational measures. A particularly relevant mining-specific sequestration opportunity is enhanced weathering and mineral carbonation, where certain mine tailings and waste rock — particularly from mafic and ultramafic geological settings rich in magnesium and calcium silicate minerals — can naturally absorb and permanently store atmospheric CO₂ through geochemical carbonation reactions, forming stable carbonate minerals. Research is advancing on the deliberate acceleration of this natural process as a carbon removal pathway. Geological carbon sequestration — injecting captured CO₂ into deep, porous rock formations — is the primary storage method considered for carbon capture and storage (CCS) projects associated with large mining and smelting complexes. All sequestration and offset claims must meet standards of permanence, additionality, measurability, and verification to be accepted under recognized carbon accounting frameworks such as the Gold Standard, Verified Carbon Standard (Verra VCS), and national registry systems.