The Effect of Dietary & Transportation Choices on Climate Change

Abstract

Goals: Many health organizations encourage people to use human-powered transportation “because it is better for your health and the environment”. However, the greenhouse gas (GHG) emissions produced to iso-calorically replace the energy expended in human transportation could make this potential environmental benefit untrue; our study tests this truism. Methods: Holding other (e.g., electricity consumption, consumer goods, household size) sources of GHGs constant, we varied transportation mode (walking, biking, or driving) and diet type (to reflect differing % of calories from meat, as calories from meat require higher GHG production). Principle Results: The pounds of carbon dioxide emitted per mile by vegan vs carnivorous bicyclists, walkers, and car drivers are: vegan bicyclist 0.1 lbs/mile, vegan walker 0.3 lbs/mile, carnivorous bicyclist 0.4 lbs/mile, car driver 1.1 lbs/mile, carnivorous walker 1.3 lbs/mile. Major Conclusions: Our data suggest that if you eat a very high meat diet, walking may be worse for the environment than driving. Since eating less meat is healthier, and walking and biking are also clearly typically better for an indi-vidual’s health than is driving, we encourage people to make it more likely that walking and bicycling are also better for plane- tary health, by eating less meat and then using human-powered transportation.