Guide to PAS 2050 How to assess the carbon ... - Aggie Horticulture

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Appendix III: Product carbon footprint – worked example
Input Amount Source
kg CO 2
e per tonne wheat 60 Calculation: emissions per tonne waste × tonnes
waste per tonne wheat
tonnes wheat per tonne croissants 0.9 Supplier interview
kg CO 2
e per tonne croissants 54 Calculation: emissions per tonne wheat × tonnes
wheat per tonne croissants
Other raw materials calculated as above
Other raw materials include butter, which due to its high emissions factor represents a higher proportion of
the total footprint than that suggested by its mass (and thus a higher proportion of the overall product
footprint than is suggested by these results).
Manufacturing
(3a) Baking
kWh gas used per tonne croissants 1000 Supplier interview
kg CO 2
e per kWh gas 0.2 Emission factor database; based on gas source
kg CO 2
e per tonne croissants 200 Calculation: kWh gas used per tonne croissants ×
emissions per kWh gas
kWh electricity used per tonne 200 Supplier interview
croissants
kg CO 2
e per kWh electricity 0.5 Emission factor database; based on national grid
kg CO 2
e per tonne croissants 100 Calculation: kWh electricity used per tonne
croissants × emissions per kWh electricity
total baking kg CO 2
e per tonne 300 Calculation: kWh gas emissions per tonne
croissants
croissants + kWh electricity emissions per tonne
croissants
(3b) Packaging
kg CO 2
e per kg plastic film 2 Emission factor database
kg plastic film per 1,000 bags 20 Supplier interview
kg CO 2
e per 1,000 bags 40 Calculation: emissions per kg plastic film × kg
plastic film per 1,000 bags
tonnes croissants per 1,000 bags 1 Internal data
kg CO 2
e per tonne croissants 40 Calculation: emissions per 1,000 bags/tonnes
croissants per 1,000 bags
(3c)
Waste
Transport
average distance (km) 50 Supplier interview