Q799. What are the global warming potentials (GWPs) used in publication of GHGRP data?

A799. Beginning in reporting year 2013, the GWPs used by reporters to determine their GHG quantities were generally changed from those displayed in internationally-accepted data from the Intergovernmental Panel on Climate Change’s (IPCC) Second Assessment Report (SAR) to the Fourth Assessment Report (AR-4). See Table A-1 for a complete list of gases and their associated GWP’s. To present a consistent time-series, EPA re-calculated prior year emissions totals using the revised GWP values. Raw data submitted by facilities for prior years remains as submitted using SAR GWP’s.