This applicability tool includes a calculator for annual GHG emissions from stationary and portable fuel combustion sources. The calculator uses the Tier 1 calculation methodology in 40 CFR 98, subpart C (Stationary Fuel Combustion Sources). You may use this calculator or any of the other calculation methods in subpart C as specified in 40 CFR 98.233. After using the calculator, you will be returned to this page, where the emissions estimate will be entered into this table.