No abstract

Meat and dairy products in the food industry represent a significant portion of anthropogenic green house gas emissions. To meet the Intergovernemental Panel on Climate Change recommendations to limit global warming, these emissions should go down. Meat and dairy products are also responsible for the majority of our daily, vital, protein intake. Yet, meat and dairy products contain very different amounts of proteins, making it difficult in general to rationalize which protein source has the lowest carbon footprint. Here we offer a practical and pedagogical review, comparing the carbon footprint of a variety of meat and dairy products with respect to their protein content. We report further on a number of consumer oriented questions (local or imported? organic or not? cow or goat milk? hard or soft cheese?). We investigate finally the carbon footprint of different dietary choices for several countries, by keeping the total number of meat and dairy proteins constant. Dairy-only diets are in general a little less carbon intensive than current diets; while up to 60% lower carbon footprint diets can be achieved by eating for only part poultry, small animals and yogurt. Our assembled data is readily available through an open source app allowing to investigate personalized dietary scenarios. We expect our results to help consumers perform enlightened carbon footprint dietary choices. Our methodology may be applied to broader questions, such as the carbon footprint of proteins in general (including fish and plant proteins). We hope our work will drive more studies focusing on consumer-oriented questions.