Uncertainty in Greenhouse Gases, Nitrogen Oxides, and Sulfur Oxides Emission Estimates: Technical Considerations and Statistical Calculation Methods

摘要

The global Oil & Natural Gas industry has been active in promoting consistency and harmonization for industry emission inventories. With the emergence of greenhouse gas (GHG) emissions reporting schemes and mitigation efforts, including emission trading systems, data robustness is receiving increased attention. Similarly, there has been considerable activity for estimating and/or measuring emissions of criteria pollutants, including nitrogen oxides (NO_x) and sulfur oxides (SO_x. The uncertainty of an emissions inventory, or of quantified emission reductions, is determined largely by the uncertainties of the estimates of the largest contributing sources. In turn, each of these uncertainties depends on the quality and availability of sufficient data to estimate emissions, or on the ability to measure these emissions and properly account for their variability. This paper will provide an overview of API-sponsored work to develop technical considerations and statistical calculation methods for addressing uncertainty in emissions estimation. Addressing uncertainty for GHG emission estimates complements the APIGHG Methodology Compendium (API Compendium). It augments existing industry guidance with technically valid approaches that enhance emissions estimation robustness and data quality. The topics to be discussed include: clarification of the sources of uncertainty in entity emission inventories; information on measurement practices; and explanation of statistical procedures that can be used to quantify uncertainties.