Fig. 3: Source-specific CH4 emissions comparison between this study and the 2020 Greenhouse Gas Inventory.
From: Closing the methane gap in US oil and natural gas production emissions inventories
Bar chart compares CH4 emissions estimates (mean of Monte Carlo uncertainty realizations) across source categories for the United States 2015 oil and natural gas production-segment between this study and the 2020 Greenhouse Gas Inventory (GHGI)25. Error bars reflect the 95% confidence interval based on the 2.5 and 97.5 percentile values extracted from the empirical distributions. Inset pie charts illustrate individual contributions of our inventory to equipment leaks (right pie chart) and tanks (left pie chart). Discrepancies with the GHGI are dominated by liquid hydrocarbon tank leaks, unintentional emissions from thief hatches and pressure-relief valves (PRVs), and flashing emissions (~2.3 Tg yr−1 CH4) and equipment leaks (~1.4 Tg yr−1 CH4). Details regarding the modelling of tank emission sources is given in Supplementary Methods 4. Results in tabular form are given in Supplementary Table 3 and Supplementary Table 4.
