Q721. For certain sectors, why is the GHG data not necessarily comparable between 2010 and subsequent reporting years?

A721. Beginning with Reporting Year 2011,  12 additional source categories began reporting GHG data for the first time. Some new facilities became subject to the GHGRP that were not required to report in 2010. Additionally, some facilities had already been subject to the GHGRP, and added reporting for the new source categories starting in 2011. Therefore emissions reported by the facilities, and aggregated emissions at the geographic or sector level, do not necessarily represent the same scope of emissions.