A recent UN briefing published by the IPCC, the International Panel on Climate Change, purports that a plant based diet is key to curbing current climate trends (1). Without a doubt, our consumption of food, and land, across the globe needs to drastically change.
In the United States alone, a third of the land is dedicated to cattle farming, one third of that going to cows and the other two thirds to growing feed. Most deforestation abroad, such as in the Amazon of northern Brazil, has occurred because of the cattle industry. This results in the depletion of a large carbon sink and drives biodiversity into the ground (2). It is evident that livestock dependent industries take a huge toll on the environment, but are plant based diets the solution?
Those that oppose the idea that a plant based diet is more environmentally conscious often cite a study performed at Carnegie Mellon: this study startlingly concluded that lettuce production corresponds to the release of three times more greenhouse gas than bacon (3). While many latched onto this as a reason to eat meat comfortably, the design of the study was quite unsound. The researchers of this experiment compared lettuce and bacon by their calorie to greenhouse gas emissions. Most individuals would not simply be eating lettuce to reach their calorie needs. Taking this into account, a study done later at the University of Michigan, instead compared a well rounded vegetarian diet, vegan diet, and conventional American diet. What differentiates the design of this study from the previous is that the Carnegie Mellon study focused solely on comparing specific foods to one another whereas the University of Michigan study looked at a more well rounded comprehensive diet, integrating all typical foods to make an evaluation. The researchers found that a lacto-ovo vegetarian diet resulted in a 33% decrease in emissions, and a vegan diet 53% less (4).
This past August, the IPCC released statements which directly support a plant based diet as a means of climate control. Debra Roberts, Co-Chair of Working Group 2 in the IPCC stated, “Balanced diets featuring plant based foods...present major opportunities for adaptation and limiting climate change.” In a greater sense the IPCC released this brief to bring the international community’s attention to a centrally focused issue and help push the idea towards designing constructive policy. Becoming more plant-based is one change society can progressively make as a whole to circumvent inevitable environmental problems.
For those at home, the IPCC statements truly do not intend to enforce what everyone should eat, but in general encourage eating meat more sparingly. While opting for a more plant based diet is ideal, it can be a difficult transition for many. For those that find eliminating meat difficult, dropping beef and switching to poultry alone could help sustain up to an additional 160 million Americans. According to Dr. Eshel, a professor at Bard College and a Harvard Radcliffe Institute Fellow, those who fear going meatless usually worry that they will not get in the necessary nutrients comfortably (5). Noticing this, he employed a computer algorithm, which analyzed different foods, to outline a viable means of getting all necessary nutrients (fats, proteins, and vitamins) through a plant based diet to set those with such worries at ease. They found that a diet made up of “soy, green pepper, squash, buckwheat, and asparagus” could easily fulfill nutritional needs while reducing required pastureland by 25% (6). This alone would result in a decrease of nitrogen discharge by 4.5 billion kilograms and circumvent billions of dollars usually needed for damage control (7). His study goes to show how a plant based diet does not require radical change, but rather is about creating habits to be more intentional regarding the foods we eat; this intentional consumption of food is many times over better for our planet.
- UN International Panel on Climate Change. (2019, August 08). Land is a Critical Resource, IPCC report says. Retrieved from https://www.ipcc.ch/2019/08/08/land-is-a-critical-resource_srccl/
- Schiermeier, Q. (2019, August 08). Eat less meat: UN climate-change report calls for change to human diet. Retrieved from https://www.nature.com/articles/d41586-019-02409-7
- Rea, S. (2015, December 14). Vegetarian and “Healthy” Diets Could Be More Harmful to the Environment. Retrieved from https://www.cmu.edu/news/stories/archives/2015/december/diet-and-environment.html
- Heller, M.C., Keoleian, G.A. (2014, September 04). Greenhouse Gas Emission Estimates of U.S. Dietary Choices and Food Loss. Yale Journal of Industrial Ecology. Doi: 10.1111/jiec.12174
- Estrada, I. (2017). Rethinking the American Diet. Retrieved from https://www.radcliffe.harvard.edu/news/radcliffe-magazine/rethinking-american-diet
- Eshel, G., Stainier, P., Shepon, A., Swaminathan, A. (2019, August 08). Environmentally Optimal, Nutritionally Sound, Protein and Energy Conserving Plant Based Alternatives to U.S. Meat. Nature Scientific Reports. Doi: 10.1021
- Hall, S. (2019, August 08). These Plants Can Replace Meat—but Will Doing So Help the Environment? Retrieved from https://www.scientificamerican.com/article/these-plants-can-replace-meat-but-will-doing-so-help-the-environment/