Models & validation

How estimates are produced and checked

Asset-level emissions come from a combination of bottom-up activity data and top-down satellite-verified fluxes. Both are required; neither is sufficient alone.

Bottom-up plus top-down

Bottom-up: activity-based estimates

For each asset we model production rates, fuel mix, and operating conditions. These translate to emissions via published emission factors (EPA, IPCC, sector-specific methodologies).

Top-down: satellite-verified fluxes

Satellite observations are inverted using atmospheric transport models to estimate emissions over an area. We attribute fluxes to specific assets based on activity timing and prevailing winds.

Reconciliation and uncertainty

Bottom-up and top-down estimates are compared. Persistent disagreement triggers manual review. Each reported number carries an explicit uncertainty range and confidence score.

Validation

Reference assets with disclosed emissions are used to calibrate model parameters
Independent satellite missions cross-check each other (OCO-3 confirming TROPOMI methane plumes, etc.)
Quarterly back-tests compare prior estimates against newly disclosed regulatory data

Detailed methodology

See the emissions methodology page for the full description and downloadable PDF.