The two key sectors of energy and food must change dramatically in order to avoid the worst environmental impacts of climate change. With a growing population, this necessitates a shift away from an animal product-based diet. (UNEP, Assessing the Environmental Impacts of Consumption and Production, 2010)
A projected doubling of meat and dairy consumption by 2050 would imperil the planet due to increased emissions related to livestock, increased consumption of the Earth’s biomass (plant matter grown to feed livestock), and reactive nitrogen (manure and fertilizer chemicals causing multiple harms to the environment). A diet of 100% protein from soy sources would have only 1% of the impact in 2050 of a diet in which 100% of protein was from meat. (Pelletier. Dalhousie University in Canada, 2010)
A person adopting a vegetarian diet for a year would reduce more emissions than someone swapping their car for a Toyota Prius. (University of Chicago in the US report, 2006)
The emissions from consuming a diet of 100% locally grown food was compared to one of 100% plant-based foods. A vegan diet led to a reduction of 7 times the emissions of a locally-grown diet. (Carnegie Mellon University, 2008)
In 2008, Germany’s Foodwatch Institute estimated shifting from a conventional diet including meat and dairy, to a conventionally-raised vegan diet would reduce emissions 87%, while shifting to an organic diet including meat and dairy would only reduce emissions 8%. By contrast, a 100 % organic vegan diet would reduce emissions 94%.
Switching to a diet that replaces all meat with soy by 2050 would reduce the protein-associated carbon footprint 96%. (Pelletier. Dalhousie University in Canada, 2010)
Eating more of certain animal products such as chicken (instead of beef) will NOT help mitigate environmental impacts. Researchers have found that protein from chicken has an energy efficiency rating of just 5% compared to plant-based foods such as tomatoes, with 60%; oranges and potatoes at 170%, and 500% for oats. (p. 7 report by Eshel, Martin. University of Chicago, 2005)
Eating fish will not help either. Fish was found to be similarly inefficient, in part because of the energy required for long-distance voyages to hunt large fishes such as tuna. Also, even the so-called “best managed” fish farms generate widespread environmental damage. (Dr. John Volpe. University of Victoria in British Columbia, Canada)
Pelletier, N. and Tyedmers, P. (2010, October). Forecasting potential global environmental costs of livestock production 2000–2050. PNAS. Retrieved January 11, 2011 from PNAS website http://www.pnas.org/content/107/43/18371.full.pdf
Weber, C. L. and Matthew, H. S. ( 2008, April 16). Food-Miles and the Relative Climate Impacts of Food Choices in the United States. Environ. Sci. Technol. [Electronic version] 2008, 42(10), 3508–3513. ACS Publications. Retrieved January 11, 2011 from http://pubs.acs.org/doi/abs/10.1021/es702969f