Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2011

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Notice of document availability and request for comments.

SUMMARY:

The Draft Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2011 is available for public review. Annual U.S. emissions for the period of time from 1990 through 2011 are summarized and presented by source category and sector. The inventory contains estimates of carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂ O), hydrofluorocarbons (HFC), perfluorocarbons (PFC), and sulfur hexafluoride (SF₆) emissions. The inventory also includes estimates of carbon fluxes in U.S. agricultural and forest lands. The technical approach used in this report to estimate emissions and sinks for greenhouse gases is consistent with the methodologies recommended by the Intergovernmental Panel on Climate Change (IPCC), and reported in a format consistent with the United Nations Framework Convention on Climate Change (UNFCCC) reporting guidelines. The Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2011 is the latest in a series of annual U.S. submissions to the Secretariat of the UNFCCC.

DATES:

To ensure your comments are considered for the final version of the document, please submit your comments within 30 days of the appearance of this notice. However, comments received after that date will still be welcomed and be considered for the next edition of this report.

ADDRESSES:

Comments should be submitted to Mr. Leif Hockstad at: Environmental Protection Agency, Climate Change Division (6207J), 1200 Pennsylvania Ave., NW., Washington, DC 20460, Fax: (202) 343-2359. You are welcome and encouraged to send an email with your comments to hockstad.leif@epa.gov.

FOR FURTHER INFORMATION CONTACT:

Mr. Leif Hockstad, Environmental Protection Agency, Office of Air and Radiation, Office of Atmospheric Programs, Climate Change Division, (202) 343-9432, hockstad.leif@epa.gov.

SUPPLEMENTARY INFORMATION:

For this year's public review, EPA is calling attention to two specific areas where interested stakeholders could provide feedback to improve the quality of the emission estimates. First, EPA is seeking comments on approaches for using facility-level data reported under EPA's Greenhouse Gas Reporting Program (GHGRP), particularly data from reporters that began reporting in 2011. For selected source categories, EPA could use data elements reported under the GHGRP, such as facility-level data that can be aggregated at the national level, to derive country-specific emission factors for use in estimating industrial process emissions. Categories with GHGRP-related updates under consideration include nitric acid, petrochemical production, phosphoric acid, titanium dioxide, lime production, and several fluorinated gas categories. Interested stakeholders should review detailed methodological approaches in Chapter 4 (Industrial Processes) of the report. Depending on stakeholder feedback, EPA may include revised estimates in the final published inventory report that use these emission factors derived from the specified GHGRP data elements.

The second area is the natural gas sector, which in recent years has experienced significant growth and changes in industry practices. EPA recently solicited and received new information and data related to emissions estimates for the oil and gas industry through a variety of mechanisms, including the formal public notice and comment process of the oil and gas New Source Performance Standards (NSPS) to control VOCs, a stakeholder workshop on the natural gas sector emissions estimates, and data submitted under the GHGRP. In developing the draft inventory report for this public comment period, EPA carefully evaluated relevant information, and has made updates to two key sources: liquids unloading, and completions with hydraulic fracturing and refracturing. EPA also made additional changes to the report to allow for more transparency. EPA seeks feedback on these updates, and on incorporation of GHGRP data, and requests recommendations for improving the overall quality of the inventory report to be finalized in April 2013, as well as subsequent Inventory reports.

The draft report can be obtained by visiting the U.S. EPA's Climate Change Site at: http://www.epa.gov/climatechange/ghgemissions/usinventoryreport.html .