APPENDIX C$_{ }$ The CO$_{2}$, CH$_{4}$, and N$_{2}$O emissions are again adjusted to account for GWP with a result of  CO$_{2e }$ (in metric tons).  Equation C-13  ( CO$_{2e }$ Emission Calculation for Pacific Northwest Electrical  Consumption ) provides an example for electrical consumption in the Pacific Northwest.  Most airports have implemented waste management activities designed to recycle various forms  of waste. These activities produce GHG emission reductions when contrasted with activities that  do not recycle (i.e., divert waste from landfills).  GHG emissions related to the  waste management practices should be estimated using EPA’s  Waste Reduction Model (WARM) 68 . WARM is available both as a Web-based calculator and as  a Microsoft Excel spreadsheet. WARM calculates and totals GHG emissions of baseline alternative waste management practices—source reduction, recycling, combustion, composting,  and landfilling. The model calculates emissions in metric tons of  CO$_{2e }$ for 26 materials and 8  mixed material categories  (e.g., construction and demolition waste,  aluminum cans, glass,  plastic, paper, wood, and metals , etc.) commonly found in municipal solid waste (MSW). The  emission factors represent the GHG emissions associated with managing one short ton of MSW  in a specified manner.  WARM also provides several options for landfill emissions modeling, including whether or not  landfill gases are recovered. Emissions from the transportation of the waste to the landfill are  also incorporated into WARM. Default transportation distances of 20 miles  can be used if site- specific data is unavailable.  For each material type, the amount of material recycled, landfilled, composted, and/or combusted  is input into WARM. GHG savings are then be calculated by comparing the emissions associated  with the alternative scenario with the emissions associated with the baseline scenario.  The following section discusses the methodologies for computing GHG emissions refrigerant usage at airports. At airports, refrigeration usage can be composed of air conditioning  and heat pumps, chillers, fire extinguishers, and storage refrigeration.  72$_{ }$ 68 EPA,  Waste Reduction Model (WARM) , Version 13, June 2013,  http://epa.gov/epawaste/conserve/tools/warm/index.html.  C.2.8 Refrigerant Usage  C.2.7 Waste Management  Equation C-13. CO$_{2e }$Emission Calculation for Pacific Northwest Electrical Consumption  CO$_{2 }$(metric tons)  =  Electrical Consumption (kWh) x 819.21 pounds CO$_{2 }$per MWh x short ton per  2,000 pound x 0.907185 metric ton per short ton x 0.001 MWh per kWh  CH$_{4 }$(metric tons)  =  Electrical Consumption (kWh) x 15.29 pounds CH$_{4 }$per GWh x short ton per 2,000  pound x 0.907185 metric ton per short ton x 0.000001 GWh per kWh  N$_{2}$O (metric tons)  =  Electrical Consumption (kWh) x 12.50 pounds N$_{2}$O per GWh x short ton per 2,000  pound x 0.907185 metric ton per short ton x 0.000001 GWh per kWh  CO$_{2e }$(in metric tons) = Electrical CO$_{2 }$+ Electrical CH$_{4 }$x 34 + Electrical N$_{2}$O x 298 