[Sequestration of Inorganic Carbon in Soil： A Promising Measure to Address Climate Change]

The continuous increase of CO₂ levels in the global atmosphere has drawn global attention to CO₂ sequestration technologies. As the largest terrestrial carbon reservoir， the soil carbon pool plays a crucial role in global climate change. Despite the comparable storage of inorganic and organic carbon in soils， research on soil inorganic carbon remains insufficient. With the intensification of soil acidification， it is speculated that inorganic carbon reserves in global soil will be reduced by 23.0 billion tons （30 cm thickness） over the next 30 years. Therefore， enhancing the fixation of inorganic carbon in soil is one of the key measures to mitigate climate change. This paper summarizes the effectiveness and main influencing factors of three different methods for inorganic carbon sequestration： silicate weathering enhancement， microbial agents， and biochar. Enhanced silicate weathering involves the collection， crushing， and spreading of silicate minerals to accelerate their natural weathering process and promote reaction with dissolved CO₂ to form soil carbonate， with an estimated annual sequestration of 0.5-2 Pg CO₂. Microbial agents utilize microorganisms that promote calcium carbonate precipitation to improve soil pH and increase inorganic carbon content. Biochar， by adjusting soil pH and enhancing microbial growth， enhances the fixation of inorganic carbon in soil， with an estimated maximum annual sequestration of 1.8 Pg CO₂. This review summarizes the mechanisms， applications， carbon sequestration effects， and main factors influencing the effectiveness of inorganic carbon sequestration methods. In the future， additional research needs to be performed to optimize soil inorganic carbon sequestration measures further and conduct long-term field trials in different climate zones to reveal the application effects in various climates， thus providing support for the promotion of inorganic carbon sequestration.