Which methods are used for estimating emissions?

The selected answer encompasses a comprehensive range of methods used for estimating emissions. Emission factors and mass balance methods provide foundational approaches for estimating emissions based on known data or averages for specific processes and substances.

Emission factors are average values that represent the amount of pollutants emitted per unit of activity or fuel consumed, allowing for straightforward calculations when the activity level is known. Mass balance, on the other hand, involves accounting for all inputs and outputs of materials in a system, balancing the quantities to estimate emissions based on what is not accounted for.

Stack tests and Continuous Emissions Monitoring Systems (CEMS) represent more direct measurement techniques. Stack tests involve collecting air samples directly from the exhaust of a facility to measure emissions at specific points in time. CEMS continuously monitor emissions and can provide real-time data on the concentration of pollutants.

Including all these methods highlights the various approaches available for estimating emissions across different scenarios, whether through estimation based on established factors and balances or through direct measurement and monitoring. This comprehensive view reinforces the understanding that there is no one-size-fits-all technique; rather, a combination is often necessary to achieve accurate and reliable emission estimates.