Assessing the potential and cost of enhanced rock weathering in China

Large-scale carbon dioxide removal is essential for carbon neutrality, but current options face constraints. Enhanced rock weathering is a promising alternative, yet its viability at a national scale in China remains unquantified. Here we show, using a spatially explicit analysis across China’s croplands, that a single-year basalt application could remove 0.44–0.79 billion tonnes of CO2 by 2100, at a net life-cycle-adjusted cost of 127–226 US dollars per tonne of CO2 removed. Particles finer than those typically used commercially provide the most favorable balance between removal potential and cost. Multi-year application has the potential to contribute 5–30% of China’s negative emissions needs by 2060, with priority areas in Northeast, Central-South, and East China. As an initial spatially resolved assessment, this study supports considering enhanced rock weathering in China’s carbon-management portfolio and motivates field trials and coupled soil–river geochemical modeling to constrain weathering, downstream carbon retention, and losses. Enhanced rock weathering contributes 5 to 30 percent of China’s negative emissions needs by 2060 at a net cost of 127 to 226 dollars per tonne of carbon dioxide removed, according to a spatially explicit grid-level analysis of croplands using basalt application scenarios