Q800. What factors could have influenced greenhouse gas trends?

A800. In general, observed trends in greenhouse gas totals presented in GHGRP data are due to changes in data reported by facilities. However, for fluorinated gas producers (subpart L), chemical pulp and paper mills (subpart AA) and suppliers of natural gas and natural gas liquids (subpart NN), changes to methods facilities use to determine their greenhouse gas data has had an impact on observed trends (click links to learn more about changes in each industry).

With the exception of fluorinated gas producers (subpart L), EPA has corrected for a change in the GWPs used by reporters to determine their GHG quantities, which provides a consistent time series for all years of data reported to the GHGRP. Click here to learn more.