GHG Footprint

Definition:

The GHG Footprint is the amount of greenhouse gas emissions that ReFED estimates would result from a given food surplus management scenario.

GHG Footprint Equation:

GHG Footprint = Sum of Tons Surplus Sent to Each Destination * ( Upstream MTCO2e per ton + Downstream MTCO2e per ton for Each Destination )

Equation for Net Benefit of Alternative Scenario:

Net Benefit = GHG Footprint of Current Scenario - GHG Footprint of Alternative Scenario

The following table includes an example calculation to illustrate this methodology as implemented in the Impact Calculator.

Table 1. Example Calculations Performed to Estimate the GHG Footprint of Two Food Surplus Management Scenarios

DATA ITEM	DATA SOURCE OR CALCULATION	EXAMPLE
Sector	User provided	Retail
Weight of Food by Destination (Current Scenario)	User provided	A grocery retail sustainability manager wants to understand the potential GHG impact that could be expected from a new technology solution to prevent surplus of fruit and vegetable produce in their stores. They also want to start donating perfectly-good-to-eat produce that is currently being landfilled just because it’s past the ‘sell by’ date. Currently, they estimate the following annual breakdown of their produce surplus by destination: 20 tons donations 30 tons composting 50 tons landfill ——————————— 100 tons total annual produce surplus
Weight of Food by Destination (Alternative Scenario)	User provided	Based on a recent analysis from a hired consultant, they estimate that 50% of the food they’re currently sending to compost and landfill could be prevented by the new prevention technology. They also think that an additional 5 tons of the food that they’re currently landfilling because it’s past the ‘sell by’ date is perfectly-good-to-eat produce that could be donations instead. This would be the new destination breakdown after implementing the prevention solution and increased donations: 40 tons prevented 25 tons donations 15 tons composting 20 tons landfill _____________________ 100 tons total
Upstream GHG Factors	Developed from data provided by Quantis (See Appendix A for more detail on GHG Factors)	As listed in Appendix A, these are the following Upstream GHG Factors for surplus produce at Retail: Prevention: 0 MTCO2e per Ton (this assumes that each unit of food surplus prevention results in 1 less unit of food production required to meet demand so the production emissions cancel each other out) Donations: 0.680592 MTCO2e per Ton (this assumes that each unit of food donations results in 0.5 units less of food production required to meet demand) Composting: 1.361184 MTCO2e per Ton (includes production, storage, and transport through the Retail stage) Landfill: 1.361184 MTCO2e per Ton (includes production, storage, and transport through the Retail stage)
Downstream GHG Factors	Developed from data provided by Quantis (See Appendix A for more detail on GHG Factors)	As listed in Appendix A, these are the following Downstream GHG Factors for surplus produce at Retail: Prevention: 0 MTCO2e per Ton Donations: 0.013715 MTCO2e per Ton (assumes 4.18% of donations food ends up being landfill instead of donations) Composting: 0.034810 MTCO2e per Ton (includes transport to compost facility, energy use to turn compost piles, fugitive emissions, and assumes compost will be used as a fertilizer and soil amendment offset) Landfill: 0.328308 MTCO2e per Ton (includes transport to landfill, fugitive methane emissions, energy recovery offset, and landfill carbon storage)
Current Scenario GHG Footprint	= Current Tons donations * (Upstream + Downstream GHG Factors for Donations) + Current Tons composting * (Upstream + Downstream GHG Factors for Composting) + Current Tons landfill * (Upstream + Downstream GHG Factors for Landfill)	= 20 tons donations * ( 0.680592 MTCO2e per ton + 0.013715 MTCO2e per ton ) + 30 tons composting * ( 1.361184 MTCO2e per ton + 0.034810 MTCO2e per ton ) + 50 tons landfill * ( 1.361184 MTCO2e per ton + 0.328308 MTCO2e per ton ) = 140 MTCO2e
Alternative Scenario GHG Footprint	= Alternative Tons prevention * (Upstream + Downstream GHG Factors for Prevention) + Alternative Tons donations * (Upstream + Downstream GHG Factors for Donations) + Alternative Tons composting * (Upstream + Downstream GHG Factors for Composting) + Alternative Tons landfill * (Upstream + Downstream GHG Factors for Landfill)	= 40 tons prevention * ( 0 MTCO2e per ton + 0 MTCO2e per ton ) + 25 tons donations * ( 0.680592 MTCO2e per ton + 0.013715 MTCO2e per ton ) + 15 tons composting * ( 1.361184 MTCO2e per ton + 0.034810 MTCO2e per ton ) 20 tons landfill * ( 1.361184 MTCO2e per ton + 0.328308 MTCO2e per ton ) = 72 MTCO2e
Net Benefit of Alternative Scenario	= Current Scenario GHG Footprint - Alternative Scenario GHG Footprint	= 140 MTCO2e - 72 MTCO2e = 68 MTCO2e avoided under the alternative scenario Click here to see this example in the ReFED Impact Calculator.