The foods we eat contribute to our carbon footprint. Here are some common protein sources followed by the kilograms of CO2 energy used per 1000 “food calories” (kcal) produced in order of the most carbon intensive to the least:
Lamb 13.3; Beef 10.8; Turkey 9.2; Pork 7.0; Cheese (shredded) 5.9; Farmed Salmon 5.7; 2% Milk 3.8; Canned Tuna 3.3; Chicken 3.2; Eggs 3.1; Yogurt 2.8; Tofu 2.6; Rice (Cooked) 2.4; Lentils (Cooked) 0.8; Beans (Cooked) 0.6; Peanut Butter 0.4 and Nuts 0.4.
Of course, with best practices the numbers change. Sustainably managed grass fed cows have less impact than feedlot and grain fed cattle. Pastures that are well maintained can become carbon sinks. The United Kingdom’s National Trust found small farms with grass fed cattle can reduce the emission’s impact by up to 94%.
There are also innovative programs in manure to methane conversion for energy. Dairyland Power Cooperative in Wisconsin is a national leader in animal waste to energy conversion from the small farm to the grid. Gundersen Health System and its whole network of hospitals, medical clinics, nursing homes and related facilities based in La Crosse, Wisconsin has become the first health system of its kind to become fully energy independent in part due to methane conversion from dairy farms.
Sources: “Green American”, Fall 2014 and
Environmental Working Group “Meat Eaters Guide”, USDA Additional research: Joe Garmin, Martha Van Gelder
http://www.dairynet.com/energy_resources/animal.php