Carbon Storage in Tropical Laterites: Insights into Mineralogical Controls and Sequestration Potential

Abstract

Lateritic soils are widespread in the tropics but their role in carbon storage has not been well studied. This study reports petrographic, grain-size distribution, XRD, XRF, and total organic carbon (TOC) analyses of selected laterite samples from four representative profiles in Kerala, India, to assess their carbon sequestration potential. Our results show that carbon stocks in these laterites are between 10.4 and 457.6 t ha−1, which is equivalent to 38.17 and 1679.39 t CO2 equivalent ha−1, with the highest values occurring in the Vilangara profile.The data reveal that iron- and aluminium-rich minerals such as goethite, gibbsite, and kaolinite play a central role in stabilising organic carbon through mineral-organic associations, enabling long-term carbon retention even under intense tropical weathering. Given their extensive distribution and demonstrated capacity for carbon storage, lateritic soils should be recognised as significant components of the global carbon cycle and integrated into future carbon accounting and climate mitigation strategies.