Diet and Climate Change: Does It Matter?

Abstract

ISEE-0878 Background: Substantial evidence exists linking food production and environmental degradation. Climate change may alter agricultural productivity across wide areas, decreasing food security. Often overlooked is the interconnection between food consumption patterns and climate change. We compared the carbon emissions of agricultural inputs required to produce vegetarian and nonvegetarian diets. Methods: Food consumption patterns of vegetarians were compared with nonvegetarians, by using data from the Adventist Health Study, a cohort of 34,000 California Adventists, of which 45% were vegetarians. Consumption of 10 foods, of a 50 food-item questionnaire, was significantly different by vegetarians (beef, chicken, eggs, beans, and six fruits). California agricultural practices and commodity production data were collected for three carbon-intensive operations: fertilizer and pesticide application, and primary energy. The three inputs were converted into carbon equivalent (CE) emissions per amount of commodity produced using published emission factors, and subsequently multiplied by the differential consumption of the 10 food items. Results: Consumption of a vegetarian diet resulted in 2.4 times less CE emissions compared to a nonvegetarian diet in this population. Producing the commodities for the vegetarian diet required fertilizer, pesticide, and primary energy inputs, which resulted in 4.0, 2.5, and 1.05 less CE emissions, respectively. The emissions associated with the production of a vegetarian diet are annually 7.1 kg CE per capita less than those of a nonvegetarian diet. Conclusion: Producing a vegetarian diet results in substantially less GHG emissions than a nonvegetarian diet. These findings support the hypothesis that plant-based diets have a lower global warming potential than meat-based diets, although exceptions may occur in relation to some agricultural practices, transportation and processing. Daily food choices of large segments of the population may ultimately result in major impacts on the environment and have public health consequences. Diet matters for mitigating climate change.