The rate of mineralization depends on both the abundance (determined by the reservoir rock mineralogy) and the rate at which cations are released from silicate
Phosphatase and Chloroflexi were the main factors influencing SOC mineralization under drought stress, while TN and Ascomycota were the primary factors under
Further, mineralization rates tend to be higher in soils where inorganic phosphates are actively taken up and sequestered in plants and where microbial grazers
Other operation conditions including reaction temperature, initial CO2 concentration, residence time corresponding to the flow rate of CO2 gas stream, and water
The dominant capital factor involves the reactor vessels that house the chemical conversion of CO2 into stable mineral form, while the dominant operating cost
### **1) What is Carbon Mineralization?**. Carbon mineralization is a process that naturally occurs over hundreds or thousands of years in which certain minerals inside rocks react with atmospheric CO2 to create carbonates, solid minerals that securely remove and sequester CO2. Alkaline minerals within the rock powder react with ambient CO2, trapping it in solid carbonates. A key concern with scaling up carbon mineralization above ground is the need to increase mining to access large amounts of alkaline material, as well as grinding and transport — all of which require energy. Carbon removed through surficial mineralization, for example, is challenging to account for and monitor because oceans, coasts and soils, where mine tailings and crushed rocks are spread, are open systems (as compared to a closed-system DAC plant). Carbon mineralization presents significant potential as a carbon removal approach, within a larger suite of carbon removal and climate actions, to help reach global climate goals.
Engineered carbon mineralization emulates and accelerates natural rock weathering, whereby calcium (Ca) and magnesium (Mg) silicate minerals react with carbon dioxide dissolved in water to form calcium and magnesium carbonate minerals that are stable on geologic timescales. *Ex situ* carbon mineralization can be done with silicate rocks and even alkaline industrial byproducts.4 Calcium and magnesium are found in many other materials that are often considered the 'wastes' of industrial processes: mining wastes, steel slag, air pollution control residue, fly ash, and many other industrial wastes are abundant in magnesium and/or calcium and can be used as feedstocks for *ex situ* mineralization processes. At the Clean Energy Conversions Lab, we research carbon mineralization as a method of carbon storage in two projects: the first project loops Mg and Ca oxides that are highly reactive with CO2 to conduct direct air capture;5 the second leaches calcium and magnesium from mining wastes from carbonates.6 Our research into carbon mineralization extends beyond the lab as we consider how economics, mapping, life cycle assessments, and US policy can help deploy carbon mineralization on a broad scale.
Their unique dynamics—driven by freeze–thaw cycles, moisture constraints, and slow microbial turnover—may necessitate tailored temperature response formulations not currently embedded in most ESMs. Taken together, our results highlight that: (1) no single temperature response function captures Q10_obs variability across all ecosystems and temperature ranges; (2) simple and hybrid exponential functions show relatively robust performance, particularly in cropland, grassland, and forest soils; (3) high-latitude, subsoil, and high-temperature responses remain poorly 225 constrained due to data limitations; (4) expanding observational datasets across diverse ecosystems—especially in extreme environments—is essential for improving the realism and generalizability of temperature response functions in ESMs. Ultimately, our comparison provides a benchmark for refining temperature sensitivity formulations in soil carbon models, emphasizing the need for ecosystem-specific calibration and incorporation of nonlinear temperature effects to reduce uncertainty in future carbon-climate feedback projections.