Q800. What factors could have influenced greenhouse gas trends?

A800. Observed trends in greenhouse gas totals presented in GHGRP data are due to changes in GHG emissions reported by facilities. In general, annual variations in reported emissions are caused by the opening of new plants and processes; closing of existing plants and processes; temporary plant and process shutdowns due to equipment failure or construction projects; alterations or enhancements to manufacturing processes; and variations in annual production volume due to changes in customer demand. Facilities and suppliers are allowed to cease reporting if their annual emissions are below 15,000 metric tons CO₂e per year for three consecutive years or below 25,000 metric tons CO₂e per year for five consecutive years. Some industry sectors are also impacted by revisions to emission calculation methods adopted by the EPA to reduce burden on reporters, simplify emission calculations, or improve the quality of the reported data.