AI

One beef burger uses the water of about 1.4 million AI prompts

By WhyStopHarmingAnimals.com

You would need about 1.4 million AI prompts to use as much water as one quarter-pound beef burger[1][2]. The calculation takes two published figures. OpenAI’s Sam Altman put the water used by an average ChatGPT query at about 0.32 millilitres[1]. A University of Michigan life-cycle assessment by Heller and Keoleian put a quarter-pound U.S. beef patty at 437.7 litres of consumptive water[2]. Divide one by the other and you get about 1.4 million[1][2].

The range

Different sources give different answers, and the full range runs from about 8,800 to about 5.5 million prompts per burger[1][3].

The low end comes from Li and colleagues, whose 2023 paper Making AI Less Thirsty estimated that GPT-3 used about a 500 millilitre bottle of water for roughly 10 to 50 medium-length replies, depending on when and where it ran[3]. That works out to about 10 to 50 millilitres per reply[3]. Against the Michigan patty, that is about 8,800 to 44,000 prompts[2][3].

The high end comes from counting more of the beef’s water. The 437.7 litre figure counts only blue water, the water drawn from rivers, lakes and wells. It leaves out green water, the rain that falls on pasture and feed crops, so the full amount is higher. Mekonnen and Hoekstra’s global water footprint study, published in Ecosystems in 2012 and summarized by the Water Footprint Network[5], counts green, blue and grey water together and puts beef at about 15,400 litres per kilogram[4]. That makes a quarter-pound patty about 1,750 litres, around 460 gallons[4]. Against OpenAI’s 0.32 millilitres, that is about 5.5 million prompts[1][4]. Many people assume the burger figures are inflated by green water, but the central 1.4 million figure leaves it out.

The bottle-per-email figure

A 2024 Washington Post article said ChatGPT used about 519 millilitres of water, a little more than a bottle, to write a 100-word email[6]. The number spread widely. It modeled GPT-4 writing a full email, which is neither an average prompt nor the figure OpenAI later published[1]. The research underneath the headlines, Li and colleagues’ 2023 paper, put a medium-length GPT-3 reply at about 10 to 50 millilitres[3], and headlines turned that into a bottle per email. The 1.4 million figure uses OpenAI’s published average and the Michigan study[1][2], with the other studies giving the range[1][3].

A burger that skips the cow

The same Michigan study compared a quarter-pound Beyond Burger with a quarter-pound U.S. beef burger[2]. The plant patty used 99% less water, 93% less land, 90% fewer greenhouse gases and 46% less energy[2][7]. In absolute terms, the Beyond Burger used 3.27 litres of consumptive water against 437.7 litres for beef[2]. Weighted for water scarcity, the figures were 1.1 litre-equivalents against 218.4[2]. Beyond Meat publicizes the study[7][9], so the product comparison is one company’s burger against average U.S. beef[2], and the gap is in line with the other water figures for beef above.

Someone would have to use a chatbot for years to match the water in a single burger. The feed and water for tens of billions of farm animals are used every day whether or not anyone opens a chat window, and a vegan burger that does the same job is already on the shelf.