Water
Cutting out meat and animal products is the greatest water use reduction any household can make
Animals have to eat and drink too. About 80% of our agriculture is animal feed, and farm animals require vast amounts of water. Cows can drink over 40 gallons of water a day — separate from the water it takes to grow the 100+ pounds of plant food they can eat in a day. About 70% of the world’s freshwater withdrawals already go to agriculture, most of it into that feed loop. Per calorie or gram of protein, meat and dairy use far more water than beans, grains, and most vegetables. It is infinitely more efficient to eat plants directly. Moving toward plant foods is the single biggest water savings a household can make. We would use magnitudes less water if we didn’t harm or kill animals.
What the evidence says
The main points first. Every claim is tied to a source below.
Our World in Data · Environmental impacts of food production
70% of the world’s freshwater withdrawals go to agriculture
Our World in Data: 70% of global freshwater withdrawals go to agriculture. Animals have to eat and drink too. About 80% of our agriculture is animal feed, so most of that farm water is not growing food for people — it is growing corn, soy, and grass for farm animals. Cows can drink over 40 gallons of water a day, separate from the water it takes to grow the 100+ pounds of plant food they can eat in a day. Most of a steak’s water footprint never reached a trough. Eat the plants directly and you skip that extra loop. We would use magnitudes less water if we didn’t harm or kill animals.
Our World in Data · Poore & Nemecek (2018)
Farm animals drink water — and their feed uses even more
Mekonnen and Hoekstra measured the full water cost of animal products. Per calorie or gram of protein, meat and dairy use far more water than beans, grains, and most vegetables. Most of that water goes into growing the feed, not into the animal’s trough. Cows can drink over 40 gallons a day on top of the water already used to grow their feed. It is infinitely more efficient to eat plants directly.
Our World in Data · water pollution · Poore & Nemecek (2018)
Dropping animal products is the single biggest water savings on a plate
Poore and Nemecek found that meat and dairy dominate agriculture’s water pollution and a large share of water withdrawals. In EU diet models, a vegetarian pattern had the lowest water footprint. Moving toward plant foods is the single biggest water savings a household can make. We would use magnitudes less water if we didn’t harm or kill animals.
Sources
Papers and datasets. Caveats stay on the card — small samples and single animals included on purpose.
Ecosystems, 2012 · Meta-analysis
The green, blue and grey water footprint of farm animals
Mekonnen & Hoekstra: animal products have far larger water footprints per calorie or gram of protein than starchy crops, pulses, and most vegetables — driven mainly by feed.
Science · Meta-analysis
Poore & Nemecek — freshwater withdrawals
Meat and dairy dominate agriculture’s water pollution and a large share of withdrawals. Cutting them is one of the largest dietary water savings.
Clean Water Action · Review
Plant-based diets and water footprint
Plant-based diets cut household water footprints while improving health markers.
Ecological Indicators, 2013 · Observational
The water footprint of the EU for different diets
Vanham, Mekonnen & Hoekstra: a vegetarian diet produced the lowest water footprint of the EU diet scenarios modeled. Animal products drove the gap.
Our World in Data · Review
Water use of food products
Our World in Data (Poore data): freshwater withdrawals per kilogram, per 1,000 kcal, and per 100 g protein are far higher for most animal products than for starchy crops and pulses. Agriculture takes ~70% of global freshwater withdrawals.