Will Being a Vegetarian Save the Planet? - Part 1: Why am I asking this Question?

Nothing will benefit human health and increase chances for survival of life on Earth as much as the evolution to a vegetarian diet
— Albert Einstein

I first heard this quote in a lecture at university about the environmental impacts of agriculture. I took it for granted at the time, after all it was common knowledge that meat-eating was environmentally devastating. The trouble is, there’s no reliable evidence Einstein ever said this[1]. He wrote variously about his feelings on the subject[2], and it certainly seems he had some vegetarian leanings[1-3], but there’s no evidence he said those words.

Whilst it has been ‘common knowledge’ that eating meat is damaging to the environment since the 90’s[4-6], like Einstein quotes, things aren’t quite as straightforward as they initially appear. Moreover, ‘facts’, are something I am inherently deeply suspicious of: there is nothing we know with absolute certainty.

That’s why I’m asking, what will seem to some of you, a silly question. Why of course being a vegetarian is good for the planet. What else would it be? I think this is too unsophisticated an answer, it oversimplifies the large and complex system of our blue planet. Meat is an enormous industry, and the planet is a gigantic ecosystem, their interactions will be anything but straightforward. Moreover, it’s hard to know who to believe...

Meat is, as I discovered when I was a vegetarian, a very emotive subject. It’s difficult to find unbiased views on the subject. Estimations of meat’s damage to the planet can range from PETA’s(1) >51% of all greenhouse gas emissions are caused by animal agriculture[7], all the way to the Cattleman’s beef board claiming that “Beef is environmentally and nutritionally efficient[8]. Clearly, both organisations have agendas and biases, but even in the scientific literature there’s not agreement.

Take water use for example. In the literature, estimates of water usage for rearing cattle can range from as much as 200,000 litres of water per kilogram of beef produced, all the way down to <4,000 litres[9]. Even the United Nations (UN) has trouble, in 2006 the Food and Agricultural Organisation of the UN (FAO) released a document called ‘Livestock’s Long Shadow’ that gave an overview of the impact of meat production[10], which was greeted with much criticism(2), and in 2010 they admitted some of their calculations were flawed[12].

A selection of newspaper headings from December 2015 claiming that being vegetarian is worse for the environment than eating meat.

Even as recently as December 2015 news headlines were filled with the idea that being vegetarian was worse for the environment than eating meat[13-17]. In actual fact the study these articles quoted, by Michelle S. Tom and colleagues[18], said no such thing. On a per calorie basis they found that some vegetables, like lettuce, caused more greenhouse gas emissions than some meats, like pork. The thing is you’d have to eat a whole lot of lettuce to make up the calories in bacon, so this conclusion is unsurprisingly and doesn’t really represent reality.

Nevertheless, it does seem that things aren’t quite as intuitive as you might think. Could I eat high calorie foods, like meat, and therefore eat less food and then end up having a lesser impact on the environment? To quote one of the authors of the 'lettuce is bad paper', Paul Fischbeck: “You can’t lump all vegetables together and say they’re good. You can’t lump all meat together and say it’s bad”. In other words, things aren’t as simple as they first appear.

All this is why I’m bothering to answer this question. I don’t think we have a good answer all the time. In the next few weeks I’ll attempt to cut through the various opinions, and critically assess the scientific literature to answer the question: Will being a vegetarian save the planet?

Join me for the next 8 weeks as I attempt to tackle this question. If you don't want to miss out on anything then sign up with your email below. New sign-ups will be entered into a competition and the winners will receive a photoshop of whatever they like. I've made friends into action heroes, giants, and sat them atop piles of Donald Trump. Whatever you want, just enter your email below!


(1) People for the Ethical Treatment of Animals

(2) Some claimed that they overestimated use of inorganic fertilisers, but they likely actually underestimated. Others argued that CO2 emissions should be higher if they included respiration, but if you follow this line of reasoning to its conclusion then livestock actually become a carbon sink. The best criticism (and the one they admit) is accounting, or not, for deforestation. Inclusion or exclusion radically changes the estimates of CO2 emissions. For more detail see Smil[11].


1.         International Vegetarian Union. Albert Einstein (1879-1955)  [Available from: http://www.ivu.org/history/northam20a/einstein.html

2.         Albert Einstein, Carl Seelig, Carl Seelig, Carl Seelig. Mein weltbild: Querido Amsterdam; 1934.

3.         Alice Calaprice. The New Quotable Einstein: translation of letter to Hermann Huth, 27th December 1930; Einstein Archive 46-756: Princeton University Press; 2005.

4.         JD Gussow. Ecology and vegetarian considerations: does environmental responsibility demand the elimination of livestock? American Journal of Clinical Nutrition. 1994;59:1110S-6S.

5.         Micheal Allen Fox. The Contribution of Vegetarianism to Ecosystem Health. Ecosystem Health. 1999;5:70-4.

6.         G. Tansey, J. D'Silva. The Meat Business: Devouring a Hungry Planet: St. Martin's Press; 1999.

7.         PETA. Meat and the Environment[Available from: http://www.peta.org/issues/animals-used-for-food/meat-environment/.05/02/2017

8.         Cattleman's Beef Board and National Cattleman's Beef Association. Beef's Shrinking Environmental Footprint: Fact Sheet 2010 [Available from: http://www.explorebeef.org/cmdocs/explorebeef/beefs shrinking environmental footprint_fact sheet.pdf

9.         Bradley G. Ridoutt, Peerasak Sanguansri, Michelle Nolan, Nicki Marks. Meat consumption and water scarcity: beware of generalizations. Journal of Cleaner Production. 2012;28:127-33, 0959-6526.

10.       Henning Steinfeld, Pierre Gerber, T. D. Wassenaar, Vincent Castel, Cees de Haan. Livestock's long shadow: environmental issues and options: Food & Agriculture Org.; 2006.

11.       Vaclav Smil. Should We Eat Meat? Evolution and Consequences of Modern Carnivory: Wiley-Blackwell; 2013.

12.       Alastair Jamieson. UN admits flaw in report on meat and climate change. The Telegraph. 2010.

13.       Peter Dockrill. Vegetarian and 'healthy' diets may actually be worse for the environment, study finds. Science Alert. 2015.

14.       Adam Withnall. Lettuce is ‘three times worse than bacon' for emissions and vegetarian diets could be bad for environment. The Independent. 2015.

15.       Peter Whoriskey. Is a vegetarian diet really better for the environment? Science takes aim at the conventional wisdom. The Washington Post. 2015.

16.       Rob Waugh. Bad news, vegetarians – eating salad is worse for the environment than meat. Metro. 2015.

17.       Shilo Rea. Vegetarian and “Healthy” Diets Could Be More Harmful to the Environment. Carnegie Mellon University News. 2015.

18.       Michelle S. Tom, Paul S. Fischbeck, Chris T. Hendrickson. Energy use, blue water footprint, and greenhouse gas emissions for current food consumption patterns and dietary recommendations in the US. Environment Systems and Decisions. 2016;36(1):92-103.