• 9.18 g CO₂e / g protein

• 2.90 kg CO₂e / kg hemp hearts

• 1.32 kg CO₂e / lb hemp hearts

• 31.56% protein for hemp hearts (Based on average of values reported by the Washington State Department of Agriculture, 2017)

Carbon Footprint of Gasoline: 8.89 kg CO₂e / gallon

• Based on EIA (2016)

Carbon Footprint of Hemp at Farm Gate: 0.52 kg CO₂e / kg

• Average of 5 farm gate values reported in 4 peer reviewed studies is 2.00 kg CO₂e / ha.

• Based on a yield of 38,741 hg / ha (See Land Use Calculations), the farm gate emissions are 0.52 kg CO₂e / kg.

• Note: Hemp is grown for seed, fiber, or both seed and fiber. The carbon footprint is 100% allocated to seed, despite some hemp seed crops also being grown for fiber.

• Value uses the carbon footprint of hemp fiber as a proxy for hemp seed, for which there are fewer LCA studies. Fiber emissions are generally higher for fiber than for seed, reflecting the larger biomass of fiber plants.

Carbon Footprint After Processing: 1.16 kg CO₂e / kg

• Assuming an average loss of 3.5% from processing hemp seed to hemp hearts, based on Shelling Machine (2020), which states a “Non-Sorted” rate of 2-5%.

• 41.84% of the total hempseed weight removed in the dehulling process (Based on average of values reported by the Washington State Department of Agriculture, 2017), which results in a total primary loss of 43.88%.

• Primary energy use of the shelling machine is 14.59 kWh / 650 kg, or 0.08 MJ / kg, which is 0.01 kg CO₂e / kg (See Carbon Footprint of Cooking for MJ to CO₂e Conversion). This does not include transport to the processing facility or building energy use.

• Based on the low energy use of the shelling machine, Consumer Ecology assumes a higher value based on the full shelling process of peanuts. The University of Arkansas Center for Agricultural Research and Sustainability Technical Report (2012), report a carbon footprint for peanut shelling of 0.046 kg CO₂e per kg peanut butter, which is mostly allocated to the shelling machine. Consumer Ecology assumes a shelling carbon footprint of 0.05 CO₂e / kg, based on this study. This value is in relative agreement with the processing carbon footprint of vegetables reported by Clune et al. (2017) of 0.06 CO₂e / kg.

• Added the median value of 0.05 kg CO₂e / kg value of packaging reported in Clune et al. (2017).

• Added the median value of 0.09 kg CO₂e / kg value of transport to the Regional Distribution Center reported in Clune et al. (2017).

Carbon Footprint of Transport to & Storage at Retail: 0.13 g CO₂e / kg

• Fresh

• Source: Carbon Footprint From the Regional Distribution Center to Retail

Carbon Footprint of Transport Home: 0.84 kg CO₂e / kg

• Assumed one 8-ounce package purchased.

• Source: Carbon Footprint of Shipping and Transport Home

Carbon Footprint of Food Loss: 0.87 kg CO₂e / kg

• Processing Loss: 43.88%

  • Processing Loss From Food Waste: 0.29 kg CO2e / kg

• Retail Loss: 6%

  • Retail Loss From Food Waste: 0.08 kg CO2e / kg

  • Carbon Footprint at Retail With Food Waste: 1.37 kg CO2e / kg

• Consumer Loss: 18.62%

  • Loss From Consumer Waste: 0.50 kg CO₂e / kg

• Carbon Footprint with Food Loss: 2.71 kg CO₂e / kg

• Source: Carbon Footprint of Food Waste Generated

Carbon Footprint of Disposal: 0.20 kg CO₂e / kg

• 26.2% wasted by consumer after 43.88% processing loss.

• Assuming that all hulls are wasted, which may not happen in practice.

• Source: Carbon Footprint of Food Disposal

Cradle to Grave Carbon Footprint: 2.91 kg CO₂e / kg

Additional Assumptions:

• Energy use from refrigeration at home is not considered. The electricity load of a refrigerator is considered separate from the foods placed inside of it, because it is assumed that every household has a refrigerator, regardless of how much food is in it. The individual load of opening the refrigerator for one item has been estimated to be around 2 g CO₂e / opening (0.02 MJ / opening; Terrell, 2006), and thus does not meet the cutoff for sensitivity of carbon footprints set at 2 significant digits for kg CO₂e.