What Are the Greenhouse-Gas-Emission Impacts Associated With Vegan, Vegetarian, and Meat Diets in the United States?

Abstract

The United Nations estimates that the growing human population will reach approximately 9.6 billion by 2050. In order to accommodate the subsequently higher demand for food and related strain on resources, careful consideration of diet choice will be essential. This research evaluates the impact on greenhouse gas emissions from three different diets: vegan, vegetarian, and meat-based. This research is important is because greenhouse gas emissions from food are estimated at around 17% of total emissions. This study measures and evaluates all the steps in the food supply chain related to food production under conditions as they exist in the United States, using the Houston, Texas area as a base for the study. The intent of this research is to increase awareness of the global warming consequences of dietary food choices. My initial expected results—that vegan diets have the least emissions impact and meat-based diets have the highest—were confirmed via life cycle analysis. In this case study, vegan diets had a minimum contribution of 809 kg per person per year, followed closely by the vegetarian diet with 957 kg per person per year. However, a far higher greenhouse gas emission of 2,880 kg per person per year was calculated from the meat-based diet. The data from this study should help guide future food production decisions while also addressing the need for a reduction of greenhouse gas emissions through alternative food choices.