With the latest dismal IPCC (Intergovernmental Panel on Climate Change) report hanging over our futures, citizens of the earth are contemplating its revelations. Climate change is well underway. The IPCC states that it is human influence that is warming our atmosphere, oceans and land on a scale that is unprecedented. Sea levels are increasing. Insect populations are being decimated. With the stark reality of abundant wildfires in western Canada and the US, extreme flooding in Europe and China, accelerated melting of glaciers, the increasing appearance of extreme precipitation and severe storms like cyclones, tornados and hurricanes we can no longer deny its existence. Ominously, we may have already passed the point where we can reverse this damaging process (1).
In addition, the United Nations is warning that the outbreak of pandemics, such as the Covid-19 pandemic that we have all lived through during the past two years, are driven by the increasing demand for animal protein in the diet and our increasingly contact with wild animal populations through deforestation and habitat losses (2).
It is disheartening to contemplate these harms to our fragile environment and to our own health, especially when it seems that there is nothing that one person can do to make any difference to such a colossal crisis. 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”. While we may never return to the way we were, we certainly can slow and perhaps even stop the progression of climate change. No matter where we live on this earth, we all have to eat. At least three times a day we choose the foods with which we are going to fuel our bodies. It turns out that these choices have a substantial effect on the health of our environment.
Hopefully, the following gathering together of the existing data regarding the part that food consumption plays in the damage being inflicted on our environment will inspire an urge to reconsider the simple food choices we all make every day. More and more people are becoming aware of the crucial need to take into account the health of both our planet and of ourselves when we choose what we put in our mouths.
A report from June 2018 asserts that adopting a plant-based diet may be the single most beneficial step to take for the health of our planet, resulting in far more environmental benefit than cutting down on air travel or driving an electric car (3). It is simple changes undertaken by millions of people that will have the power to heal.
Agriculture takes up 50% of the inhabitable lands on earth
Of that, nearly 80% of this land is used for livestock
and yet it only provides 18% of the total calories and 37% of the protein that the world eats (3,4)
If this same land was growing food for humans and used exclusively for that purpose
calorie availability for humans would increase by 70%
protein availability would be doubled
and it would supply enough food to feed another 4 billion people (4,5)
At the present time, 33 % of agricultural land worldwide
is used solely for producing feed for livestock (4)
Eating more plant-based could reduce agricultural land use by at least 41% and up to 76% (3,4,6)
Continuing use of meat-heavy diets would demand
an additional 50% increase in global cropland by 2050 (7)
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 (7)
If natural vegetation was re-established on the land no longer needed for food production
it is estimated that 8.1 billion metric tonnes of carbon dioxide
would be removed from the atmosphere each year over 100 years
as natural vegetation re-establishes (3)
Global agriculture is responsible for the use of 70% of all available freshwater (8,9)
Number of gallons of freshwater needed to produce one pound of food (10):
Starchy Roots 46
Beans and lentils 486
Changing typical Western diets to more plant-based diets
would reduce freshwater use by more than 50% (11)
Agriculture is responsible for 78% of eutrophication (4) due to
run-off of nutrients from animal waste
and excessive use of fertilizer
(Eutrophication is the enrichment of water with nutrients such as nitrogen and phosphorus. It affects water quality and lowers oxygen concentration leading to damage to marine ecosystems.)
Agriculture is responsible for up to 30% of total greenhouse gases
and 60% of these greenhouse gases come from the meat and dairy industries (3)
Production of livestock accounts for (4,12)
9% of carbon dioxide emissions originating from human-related activity
64% of the ammonia in the atmosphere
37% of all human-produced methane
More than 80% of nitrous oxide emissions
And it is a large contributor to acid rain
Methane has 28 times the Global Warming Potential of carbon dioxide (13)
Nitrous oxide has 300 times higher Global Warming Potential than carbon dioxide (4)
One gram of protein from beef is associated with
at least 7.5 times more methane emissions than one gram of plant-based protein (4,10)
Kilogram of carbon dioxide emitted per kilogram of produce; (4,14)
Free range beef 58
Beef meadow systems 35
CAFO beef 23
Seafoods (fisheries) 12
Seafood (aquaculture) 5
Vegetable meat substitutes 2
Legumes (Beans, peas, soy) 2
(CAFO stands for Concentrated Animal Feeding Operations aka factory farming. Free range beef cattle use more land and have a longer lifespan than CAFO beef. Because of this they emit more methane and have a larger carbon footprint. Much of this is due to emissions associated with the clearing of more land. (4))
Partial adoption of plant-based diets could reduce food-based greenhouse gas emissions
by at least 30%
Widespread vegetarianism could reduce food-based greenhouse gas emissions by 63%
Widespread veganism could reduce food-based greenhouse gas emissions by 70% (6,15)
If every US citizen substituted beans for beef
the US could reach between 46 and 74% of their greenhouse gas reduction targets
set in the Paris Agreement (4,10)
Beef production requires 160 times more land and produces 11 times more greenhouse gases
than the production of potatoes, wheat or rice (16)
Animal agriculture is responsible for 91% of the destruction of the rain forest since 1970 (4)
Worldwide livestock production is responsible for (3)
57% of water pollution
56% of air pollution
Increased adoption of plant-based diets could reduce loss of wildlife by up to 46% (4,6)
A shift to a healthier diet would result in massive savings in health care costs around the world
A shift to a vegetarian diet would result in an estimated 7.3 million avoided deaths annually
and save 79 million human life years
A shift to a vegan diet would result in an estimated 8.1 million avoided deaths annually
and save 129 million human life years (15)
3 Poore, J., Nemecek, T. Reducing food’s environmental impacts through producers and consumers. Science 01 Jun 2018; 360 (6392): 987-992. Doi: 10.1126/science.aaq0216.
4 Wageningen University and Research, Wageningen, Netherlands. Plant-Based Diets: Food for a Sustainable Future. Course taken October 2021.
7 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).
8 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.
9 Willett, W., Rockström, J., Loken, B., Springmann, M., Lang, T., Vermeulen, S. et al. Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems. The Lancet Commissions. February 2, 2019; 393(10170): 447-492.
11 Aleksandrowicz, L., Green, R., Joy, E.J.M., Smith, P., Haines, A. The Impacts of Dietary Change on Greenhouse Gas Emissions, Land Use, Water Use, and Health: A Systematic Review. PLoSONE. 2016; 11(11): e0165797. Doi:10.1371/journal.pone.0165797.
12 FAO (Food and Agriculture Organization of the United Nations), 2009a. Global agriculture towards 2050. High Level Expert Forum Issues Paper. FAO, Rome.
13 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
15 Springmann, M., Godfray, H.C.J., Rayner, M., Scarborough, P. Analysis and valuation of the health and climate change co-benefits of dietary change. Proc Natl Acad Sci U S A. Apr 2016; 113(15): 4146-4151. Doi: 10.1073/pnas.1523119113.
16 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.