SOIL CARBON SEQUESTRATION AND CLIMATE CHANGE MITIGATION

Abstract

Soils constitute the largest terrestrial pool of organic carbon, holding nearly three times as much carbon as the atmosphere, and are therefore central to strategies for mitigating anthropogenic climate change. This review synthesises current understanding of soil carbon sequestration (SCS) as a nature-based climate mitigation option, covering the size and dynamics of the soil organic carbon (SOC) and soil inorganic carbon (SIC) pools, the biophysical and microbial mechanisms that stabilise carbon in soil, and the management practices — conservation agriculture, residue retention, cover cropping, agroforestry, integrated nutrient management, and improved grazing — shown to enhance SOC stocks. It also examines emerging tools for quantifying and verifying sequestration, including remote sensing, proximal sensing, and process-based biogeochemical models, and discusses the policy architecture (carbon markets, national inventories, and international commitments) that translates soil-based sequestration into climate accounting. Sequestration potential is shown to be strongly conditioned by soil texture, climate, land-use history, and management duration, with saturation limits and reversibility risk constraining long-term storage. The review concludes that SCS is a credible, cost-effective complement to direct emission reductions — not a substitute for them — and identifies priority research needs in long term monitoring networks, standardised measurement–reporting–verification (MRV) protocols, and region-specific management guidance, with particular relevance to intensively cultivated, semi-arid agroecosystems such as those of north-west India.