SUPPLEMENTARY INFORMATION:

The Draft Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2013 is being made available for a thirty day public review and comment period. Annual U.S. emissions for the period of time from 1990 through 2013 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), sulfur hexafluoride (SF₆), and nitrogen trifluoride (NF₃) 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: 1990-2013 is the latest in a series of annual U.S. submissions to the Secretariat of the UNFCCC. EPA requests recommendations for improving the overall quality of the inventory report to be finalized in April 2015, as well as subsequent inventory reports.

As in previous years and as encouraged by stakeholders in public comments received on the inventory, this inventory report incorporates data reported to the EPA's Greenhouse Gas Reporting Program (GHGRP). For certain sectors, the inventory uses values calculated by aggregating GHGRP data that are confidential business information (CBI). Once aggregated, these values no longer disclose facility-level data. In order to determine that an aggregation protects underlying CBI, the EPA uses criteria established through a recent Federal Register notice (79 FR 32948, June 9, 2014) and posted on the GHGRP Web site, http://www.epa.gov/​ghgreporting/​. The EPA intends to continue to use GHGRP data, including aggregated CBI values, to develop the annual inventory. Some aggregations are calculated from data reported by many separate companies that the aggregations far exceed the criteria established by the EPA. For aggregations that do not far exceed the aggregation criteria, the EPA plans to notify facilities prior to publishing the aggregated data as noted in the FR notice.