; (D) standards for data collection and dissemination; (E) farmer data management and privacy; (F) greenhouse gas emissions and soil health inventories and databases, as described in subsection (h); and (G) criteria for soil health and greenhouse gas emissions reductions payments and environmental markets, as described in subsection (i). (g) Measurement system (1) Purpose The Secretary shall evaluate existing outcomes-based measurement systems for recordkeeping, modeling, and measurement of farm-level greenhouse gas emissions and soil carbon sequestration, including measures of soil disturbance, plant diversity, continual living cover, residue management, advanced grazing management, and crop-livestock integration, to determine which such systems can be implemented quickly, improve in accuracy and ease over time, use the best available science and technology, and are cost-effective. (2) Guidance Not later than 18 months after the date of enactment of this subsection, the Secretary shall issue guidance on the outcomes-based measurement system evaluated under paragraph (1), based on recommendations from the advisory committee under subsection (f), and information from agroecosystem models (including COMET Farm and COMET Farm Planner), remote sensing data and analysis (including the Operational Tillage Information System), soil health demonstration trials carried out under section 1240H(c)(7), existing and emerging public and private environmental services protocols, measurement systems, and benchmarks, and field-level measurement. (3) Review The Secretary, based on recommendations from the advisory committee established under subsection (f), shall— (A) establish and maintain such an outcomes-based measurement system when feasible; (B) conduct periodic review of such system, and any necessary updates