For the Animals
An Argument Guide
PT

Home / H. Environment, ecology and agriculture / Part IND

H6

"Avocados and almonds use a lot of water."

The answer in one sentence

it's a selective comparison. Some plant foods, such as almonds and other nuts, do use a lot of water. But the fair comparison is per nutrient and across the whole diet. According to Poore and Nemecek's data, cow's milk uses about 628 liters of water per liter, and soy milk 28. Tofu uses about 93 liters per 100 grams of protein; beef, about 728; cheese, more than 2,500. A well-chosen plant diet uses less water, land and emissions.

Short answer

Some plant crops use a lot of water, and it's good to choose them carefully. But the fair comparison is per nutrient and per diet. According to Poore and Nemecek's data, a liter of cow's milk uses about 628 liters of water, and a liter of soy milk 28. Per 100 grams of protein, tofu uses about 93 liters, peas 178, beef 728 and cheese more than 2,500. No one needs almonds to be vegan.

For children

All foods need water to grow. Some plants, like almonds, need quite a lot. But to make cow's milk or cheese, the cow has to be given water and food for a long time, and that uses even more. Soy milk, for example, uses much less water than cow's milk.

Ask a question back

"If cow's milk uses more water than soy milk, why would plant milk be the problem?"

Como pode aparecer

"Almond milk dries up rivers."
Everyday conversation
"Avocados use a lot of water."
Everyday conversation
"Quinoa took food from people in the Andes."
Everyday conversation
"Vegans are destroying the planet with avocados."
Social media
"Some plant crops have a high water footprint."
Technical version
"Vegans' soy is destroying the Amazon." (which is H1)
Disguised version

The strongest version

How it is said

"Almond milk dries up rivers. Quinoa took food from people in the Andes."

Strongest version (steelman):

  1. P1Some foods popular among vegans, such as almonds and avocados, use a lot of water and are sometimes grown in dry regions.
  2. P2Producing these foods can cause environmental and social harm.
  3. CSo the vegan diet isn't environmentally superior.

P1 and P2 are true in some cases. The problem lies in the conclusion: it compares isolated foods, not diets, and ignores that animal products are among those that use the most water per nutrient.

The argument is valid for the foods cited. It fails as a conclusion about diets.

Full answer

  1. a

    Reconstruction and diagnosis

    The argument picks plant examples and leaves out animal ones:

    FoodWater per 100 g of protein (liters)
    TofuAbout 93
    PeasAbout 178
    Other pulsesAbout 204
    ChickenAbout 381
    Beef (beef herd)About 728
    Cow's milkAbout 1,904
    NutsAbout 2,531
    CheeseAbout 2,539
  2. b

    Where the argument breaks

    1. It's a selective comparison.

    The examples chosen are precisely the plants that use the most water. The main plant protein sources, such as tofu, peas and beans, use far less water than most animal products.

    2. Cow's milk uses much more water than soy milk.

    Per liter, about 628 against 28 liters. Even plant drinks that need more water, such as almond milk, usually compare favorably with cow's milk on land and emissions.

    3. The diet is what matters.

    Plant diets use less land, emit less and, in general, use less water than diets with meat and dairy.

    4. No one needs avocados or almonds.

    They're options, not the basis of a vegan diet. Beans, rice, lentils and vegetables are low-impact plants.

    5. The quinoa story was exaggerated.

    The idea that demand for quinoa harmed Andean producers was disputed by later studies, which found rising household welfare in producing regions while prices were high.

  3. c

    Data and sources

    SourceWhat it saysNote
    Our World in Data, water per 100 g of proteinTofu about 93 L; peas 178; beef 728; milk 1,904; nuts 2,531; cheese 2,539Based on Poore and Nemecek, 2018
    Our World in Data, water per kilogram of productCow's milk about 628 L per liter; soy milk about 28 LBased on Poore and Nemecek, 2018
    Bellemare, Fajardo-Gonzalez and Gitter, 2018, *World Development*As quinoa prices rose in Peru, household welfare increased in producing regions, and negative effects were smallAn 11-year household survey; checked from the abstract
  4. d

    The strongest counter-reply: nuts are an important part of a vegan diet

    The most serious version points out that nuts, which use a lot of water, are an important source of nutrients in vegan diets.

  5. e

    Why the counter-reply doesn't reach the conclusion

    The quantities eaten are small.

    No one eats nuts in the amounts people eat meat or cheese.

    There are alternatives.

    Peanuts, seeds and legumes use far less water.

    The diet as a whole still comes out ahead.

    Even with nuts, a vegan diet uses less land and emits less.

  6. f

    Back to the moral question

    The water footprint of food is an important environmental question, and it deserves attention in every diet. But it doesn't answer the question about the animals: to get meat, milk and eggs, they are raised and killed. If it's possible to live well on plants that use less water, what justifies that cost?

Reasoning errors

Epistemological

Does the evidence support it?

Cherry picking
Picks the plants that use the most water

Logical

Is the form valid?

Unequal comparison
Compares isolated foods, not diets
Tu quoque
Accuses vegans instead of comparing impacts

Biases

Hypocrisy hunting

Finding a flaw in others eases one's own

Linked to L4

Confirmation bias

Accepts the news story that blames vegans

General literature on confirmation bias

Extrapolations

The principle being tested is: "if some food in a diet has a high impact, the whole diet is worse".

If it applied to…Diets with meatTap to see

They'd be worse, because they include cheese and beef

The data confirm it

If it applied to…Diets with coffeeTap to see

They'd be worse, because coffee uses a lot of water

No one concludes this

If it applied to…Vegan dietsTap to see

They'd be worse because of almonds

The whole shows the opposite

Contradictions

Drinks cow's milk.

Which uses much more water than soy milk.

Eats cheese.

One of the foods that uses the most water per unit of protein.

Also eats avocados and nuts.

Which aren't exclusive to vegans.

What the argument gets right

What is true

It's true that some plant foods use a lot of water and that growing them in dry regions can cause problems. Choosing lower-impact foods is part of responsible eating, and vegans aren't exempt from that attention.

But

But the fair comparison shows that the main plant protein sources use far less water than meat and dairy. If the concern is water, a plant diet is the best choice.