What Does Eating Plants Do For the Environment?

Many of the activities of human beings on Earth have a devastating effect on our environment.  The pollution of air by manufacturing activities and our dependence on vehicles of all kinds; the clear-cutting of forests in the quest for more animal grazing land; the degradation of soils through over-cropping and over-grazing; the contamination of oceans by plastics and heavy metals; all these events are shocking in the damage they are doing to the Earth.  It can be disheartening to contemplate these harms to our fragile environment, especially when it seems that there is nothing that one person can do to make any difference.   Nevertheless there is an action that each and every one of us performs several times a day that can have a significant impact on the health of our “little green planet”.

The food we choose to eat is not just the biggest decision we can make for our own health but it can also have a significant effect on the environment we live in.  This is markedly true when it comes to the amount of animal-sourced foods that we consume.  In fact it can be said that the human appetite for animal flesh is a driving force behind virtually every type of environmental damage now threatening our future – climate change, deforestation, fresh water scarcity, air and water pollution, erosion and biodiversity loss (1).  If the choices of one person can have a positive effect, you can imagine the value of ecologically sound food choices coming from more and more of the 7.6 billion people that make up the population of the world today.

It is now very evident that the Earth cannot continue into the future feeding a population that partakes freely in animal-sourced food (15,16).  In 2010 the United Nations reported that diets rich in meat and dairy products are unsustainable and that it is vital for feeding future populations that a worldwide change in diet away from animal products occurs. (2) The UN points out that land-based animal agriculture causes at least 14.5% of human-induced greenhouse gas emissions making it the second largest contributor to greenhouse gas and climate change next to fossil fuels (2,3). Results of a study released on July 18, 2018 revealed that the world’s top five meat and dairy producers combined (Brazil’s JBS, New Zealand’s Fonterra, Dairy Farmers of America, Tyson Foods and Cargill) are on par with the greenhouse gas emissions of Exxon-Mobil and significantly higher than those of Shell or BP (4).   These three fossil-fuel companies are reported to be among the highest emitting companies in the world (5).   However, it is predicted that by 2050 the five food-producing companies mentioned above will be responsible for 81% of global greenhouse gas emissions.  (4)

Organizations are finally waking up to this truth.  One country trying to lead by example is Germany, who, in February 2017, banned meat from the menus of their official environment ministry functions.  Their impetus was a study published by the Oxford Martin School in the UK that showed that limiting meat consumption could cut food-related greenhouse gas emissions by a third while saving 5 million lives.  Moreover, a change to vegetarian diets could reduce emissions by 63% and save 7 million lives, and going completely vegan could reduce emissions by 70% and save 8 million lives. (6)

One greenhouse gas in particular, nitrous oxide, is the most potent of the greenhouse gases that contribute to climate change. Nitrous oxide has 265 times the Global Warming Potential (GWP) of carbon dioxide. Because nitrogen is essential in food production, over 80% of nitrous oxide emissions originate from activities of agriculture.  The gas is released from tilled soil, fertilizers and animal manure.  Growing crops to feed animals being raised for food introduces more nitrogen release.  Only a small fraction of the nitrogen ingested by livestock is consumed by humans due to the phenomenal waste that occurs between the farm field and the dinner table (7).  As we look into the future it is apparent that the world is on course to experience severe climate change.  The world population is expected to reach 8.9 billion by 2050 and meat consumption is on an accelerating rising trajectory (7).  At the same time the global standard of living is expected to increase, bringing with it a predicted 70% rise in demand for agricultural products (8).  Just reaching the minimum goal of STABILIZING atmospheric nitrous oxide by 2050 would require a 50% reduction in the consumption of all meats in the developed world.   In reality, the target should be REDUCING the level of nitrous oxide in the atmosphere.  For this greenhouse gas alone, a massive worldwide effort will be required to diminish its potent warming effect on the Earth.  Substantial reductions in the amount of meat produced are essential.  Additional approaches include switching from eating beef and pork to chicken and fish with their lower carbon footprints, cutting fertilizer use at least in half and growing winter ground cover crops that would absorb nitrogen and prevent its release into the atmosphere (7).

The livestock sector impacts the production of other greenhouse gases as well.  It accounts for 9% of the carbon dioxide emissions stemming from human-related activity.  Livestock production also results in 64% of the ammonia in the atmosphere, a big contributor to acid rain, and about 37% of all human-produced methane (8).  Methane has 28 times the GWP of carbon dioxide (9).

Agriculture does not only affect greenhouse gas emissions.  Global agriculture is the world’s largest consumer of water, using 70% of freshwater resources. Livestock production demands water for raising animals, growing feed crops and processing products and is directly affected by the availability of water (10).  Water consumption by livestock is predicted to increase two- or three-fold as the Earth’s temperature rises due to global warming (11).

Livestock production impacts the environment in still more areas.  The livestock industry uses about 30% of the Earth’s entire land surface for pasture and 33% of global arable land for producing its feed.  Consequently, it is a major driver of deforestation.  Latin America is an example of a region that is suffering from the loss of its wooded areas with 70 to 80% of the former forests of the Amazon now cleared for grazing animals (12,13).  Livestock herds also cause wide-scale damage to land through overgrazing; compaction and erosion of soil; and pollution of water through animal wastes, antibiotics and hormones used in producing food animals, and the fertilizers and pesticides used in growing feed crops.  Livestock are considered to be the main source of phosphorous and nitrogen contamination of the South China Sea (12). Additionally, meat and dairy animals contribute to loss of species diversity because of their devastation of ecosystems.  In fact, 15 out of 24 important ecosystems are now in decline due to destruction caused by livestock (12).

Beef production in particular is a major culprit in environment damage.  Research shows that beef requires 28 times more land, 11 times more water and produces 5 times more greenhouse gases than the production of pork or chicken.  Compared to potatoes, wheat and rice, the impact is even greater, with beef production requiring 160 times more land and resulting in 11 times more greenhouse gases.  Interestingly, one of the major reasons for this is that cattle are ruminants which make far less efficient use of their feed.  Feeding cattle with grain increases the inefficiency.  However, even grass-fed cattle have greater environmental impact than other food animals (3).

In 2014 University of Minnesota’s Institute on the Environment investigated methods of feeding more people using only the world’s existing cropland. First of all, it is possible for more food to be produced on existing land.  In Africa and some parts of Asia and Eastern Europe there is a wide difference between potential crop yield and the actual yield.  Closing this gap by even 50% in these areas could provide enough calories to feed 850 million people.  Secondly, between a third and a half of the food produced from crops is wasted due to lack of infrastructure in the developing world and to wasteful habits in more affluent countries.  The study points out that preventing the waste of meat is extremely important since the misuse of even a single kilogram of beef equals the waste of 24 kilograms of wheat when considering the water, fertilizer, and cropland needed and greenhouse gases produced.  Thirdly, water used for irrigation could be used more efficiently by applying it only where it is needed.  It is estimated that between 8 and 15% of water sprayed on crops currently is not necessary or is lost through run-off and evaporation. Fourthly, much fertilizer is also wasted.  About 60% of the nitrogen applied to crops worldwide is excessive.  Phosphorus is also used indiscriminately even though its sources are dwindling.  And lastly, research shows that at least 4 billion people could be fed with the crops currently used to feed livestock.  The main perpetrators in these losses are the U.S., China and Western Europe through diversion of large amounts of corn to animal feed (14).

In 2016 researchers modelled the world as it is expected to be in the future in order to predict how human beings could feed themselves without converting any more forests into agricultural land. They concluded that “deforestation is not a biophysical necessity”.  Human diets turned out to be the strongest determinant of the use of available space for food production, stronger than crop yields or cropland availability.  The models used realistic assumptions of future yields, area needed for farming, livestock feed requirements and human diets and observed these parameters under 500 different sets of conditions.  Plant-based diets were found to be particularly impressive for protecting forests. In fact, the only diet that would work with all future possible scenarios of yield and cropland area, including 100% organic agriculture, was a plant-based diet. Meat-heavy diets require at least double the resources of a vegan or vegetarian diet and, by the year 2050, diets containing meat would likely require an additional 50% increase in global cropland area.  Calculations reveal that, if everyone was vegan in 2050, the world would require less cropland than it did in the year 2000 and an area the size of the entire Amazon rainforest could be put back into forest.  Vegetarian diets follow close behind, being compatible with 94% of future scenarios and potentially allowing an area the size of India to return to nature.  (13)

I’ll leave the last word to a report released in June 2018 which suggests that cutting meat and dairy from the diet may be the single most beneficial step you can take for our planet.  Data from about 38,000 farms found that producing animal-based foods takes up more than 80% of the world’s farmland but provides only 18% of our calories and 37% of our protein.  On top of that, production of meat and dairy account for 60% of the greenhouse gas emissions stemming from agricultural activities.   For example, beef production uses 36 times more land and produces six times more emissions than does a green crop such as peas.  Even grass-fed beef has much higher impact on the environment than plant-based food.  Author, J. Poore, points out that adopting a plant-based diet has far more environmental benefit than cutting down on air travel or driving an electric car (17).

Perhaps this menacing news will paradoxically bring a small measure of comfort with the knowledge that there is something practical for each human being to do that will lessen the human burden on our planet.  It’s not necessary to jump right in with both feet.  Just decreasing the amount of meat and dairy that you consume is a good start.  And if you find you can eventually stop eating meat altogether, your own body and the planet Earth itself will thank you.



1 Worldwatch Institute. Is Meat Sustainable? World Watch Magazine, July/August 2004; Volume 17, No. 4.

2 http://www.unep.fr/shared/publications/pdf/dtix1262xpa-priorityproductsandmaterials_report.pdf

3 Eshel, G., Shepon, A., Makov, T., Milo, R. Land, irrigation water, greenhouse gas, and reactive nitrogen burdens of meat, eggs, and dairy production in the United States. PNAS August 19, 2014; 111 (33): 11996-12001.

4 Emissions impossible: How big meat and dairy are heating up the planet . GRAIN and the Institute for Agriculture and Trade Policy (IATP) | 18 July 2018 |

5 Griffen, P. CDP Carbon Majors Report 2017. The Carbon Majors Database

6 Springmann, M., Godfray, C.J., Rayner, M., Scarborough, P. Analysis and valuation of the health and climate change cobenefits of dietary change. PNAS 2016; 113(15): 4146-4151.

7 Davidson, E.A. Representative concentration pathways and mitigation scenarios for nitrous oxide. Environmental Research Letters, 12 April 2012; 7(2): 2012 IOP Publishing Ltd.

8 FAO (Food and Agriculture Organization of the United Nations), 2009a. Global agriculture towards 2050. High Level Expert Forum Issues Paper. FAO, Rome.

9 Greenhouse Gas Protocol, Global Warming Potential Values; https://www.ghgprotocol.org/sites/default/files/ghgp/Global-Warming-Potential-Values%20%28Feb%2016%202016%29_1.pdf

10 Thornton, P.K., Van de Steeg, J., Notenbaert, A., Herrrero, M. The impacts of climate change on livestock and livestock systems in developing countries: A review of what we know and what we need to know. Agric. Syst. 2009; 101 : 113-127

11 Nardone, A., Ronchi, B., Lacetera, N., Ranieri, M.S., Bernabucci, U. Effects of climate change on animal production and sustainability of livestock systems. Livest. Sci.; 130 (2010) :57-69.

12 http://www.europarl.europa.eu/climatechange/doc/FAO%20report%20executive%20summary.pdf

13 Erb, K.-H., Lauk, D., Kastner, T., Mayer, A.,Theurl, M.C., Haber, H. Exploring the biophysical option space for feeding the world without deforestation. Nature Communications 2016; Volume 7, Article number: 11382 (2016)

14 West, P.C., Gerber, J.S., Engstrom, P.M., Mueller, N.D., Brauman, K.A., Carlson, K.M., Cassidy, E.S., Johnston, M., MacDonald, G.K., Ray, D.K., Siebert, S. Leverage points for improving global food security and the environment. Science, 2014; 345 (6194): 325.

15 Pimentel, D., Pimentel, M. Food, energy and society. Niwot, CO: Colorado University Press, 1996.

16 Pimentel, D., Pimentel, M. Sustainability of meat-based and plant-based diets and the environment.
The American Journal of Clinical Nutrition Sept. 2003; 78(3): 660S–663S.

17  Poore, J., Nemecek, T.  Reducing food’s environmental impacts through producers and consumers.  Science 01 Jun 2018; 360 (6392): 987-992.

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Promoting a healthy adventurous lifestyle powered by plants and the strength of scientific evidence.

My name is Debra Harley (BScPhm) and I welcome you to my retirement project, this website. Over the course of a life many lessons are learned, altering deeply-rooted ideas and creating new passions.

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