Urban construction often ignores the carbon cost of excavated soils. A South Korean study found that exposed soils release significant amounts of CO2 and methane, especially after heavy rain. This overlooked source of emissions could be a key target for city level climate mitigation. Researchers found that combining deep soil burial with a 2% biochar amendment can cut CO2 emissions by 42.5% and methane by nearly 96%. Integrating these practices into construction workflows offers a practical way to sequester carbon and reduce the overall footprint of urban development.
