As part of the annual process to develop the U.S. Inventory of Greenhouse Gas Emissions and Sinks (GHG Inventory), the EPA assessed new data for updates to its estimates for natural gas and petroleum systems. The EPA updated its estimates for petroleum and natural gas systems in the exploration, production, processing, transmission and storage, and distribution segments.
Please see the memos below for information on these updates. The Natural Gas and Petroleum Systems methodology annexes for the 1990-2016 GHG Inventory are available below as well.
For previously posted information from the stakeholder process, view the archives of memos and presentation slides regarding updates considered for the 1990-2016 GHG Inventory.
View information about revisions to estimates for natural gas and petroleum systems in the GHG Inventory for earlier Inventory release years.
Methodology Annexes
- Annex 3.5: Methodology for Estimating CH4 and CO2 Emissions from Petroleum Systems (XLSX)(1 pg, 151 K)
- Annex 3.6: Methodology for Estimating CH4 and CO2 Emissions from Natural Gas Systems (XLSX)(1 pg, 309 K)
Memos on updates to estimates for petroleum and natural gas systems
You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.- Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2016: Revisions to CO2 Emissions Estimation Methodologies (PDF)(20 pp, 596 K)
- Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2016: Revisions to Create Year-Specific Emissions and Activity Factors (PDF)(7 pp, 296 K)
- Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2016: Additional Revisions Considered (PDF)(25 pp, 533 K)
- Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2016: Abandoned Oil and Gas Wells (PDF)(16 pp, 475 K)
- Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2016: Revisions to Natural Gas and Petroleum Systems Uncertainty Estimates (PDF)(27 pp, 665 K)