In preparation for UMD Food Day we calculated the carbon and water footprint of some of the meal options available through dining services.
What factors into the carbon and water footprints? Carbon Footprint can include many different factors from production emissions – pollution from fertilizers and machines used to harvest and process foods, to the C02 emitted in transporting the foods from the farm to market to your plate. If you wanted to be really accurate you could even include C02 emitted while cooking, however that is difficult data to gather.
For our calculations we simply used the carbon footprint of the production of each major food ingredient, and the amounts of each ingredient the recipe called for. For example in Beef and Mushroom Ragout there is 1 lb of garlic. The carbon footprint for the production of 1 lb of garlic is 0.43 kg. So the in the recipe garlic contributes 0.43 kg of CO2. For each element of the recipe (excluding oil and spices) we calculated the carbon footprint per amount and then added them together to get a total estimated footprint.
For some recipe ingredients such as marinara sauce or flour tortillas there is no footprint data available. If one was so inclined they could figure out the recipes for those ingredients and calculate their footprints and add them to the meal’s footprint. However at the end of the day it would still be an estimate, as even food production footprints vary from region to region with different climates and common practices changing water usage. So we found our estimates substituting similar items with known footprint values for the unknown – the value of tomatoes for marinara sauce, and flour for flour tortillas.
The water footprint was calculated in same way but using data on how much water it takes to grow and produce the various recipe elements.