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 production, processing, and transmission and storage segments.

Please see the memos below for information on these updates. The Natural Gas and Petroleum Systems methodology annexes for the 1990-2015 GHG Inventory are available below as well.

For previously posted information, view the archives of previously posted memos regarding updates under consideration for the 1990-2015 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(1 pg, 96 K)
• Natural Gas and Petroleum Production(1 pg, 230 K)

Memos on updates to estimates for petroleum and natural gas systems

• Revisions to Natural Gas and Petroleum Systems Production Emissions (PDF)(29 pp, 1 MB)
• Revisions to Natural Gas Systems Processing Segment Emissions (PDF)(21 pp, 690 K)
• Update to Storage Segment Emissions Incorporating an estimate for the Aliso Canyon Leak (PDF)(3 pp, 309 K)