OpenAI CEO Sam Altman reveals how much water a single ChatGPT question really uses and it’s not what you think

Sam Altman

OpenAI CEO Sam Altman has just revealed a surprising detail about ChatGPT’s environmental impact — and it might not be what most people expected. In a blog post published Tuesday, Altman said that a single ChatGPT query uses just one fifteenth of a teaspoon of water.

That’s about 0.000085 gallons per query, or just a few drops.

With growing concern over how much energy and water AI systems consume, Altman’s claim adds an interesting twist to the conversation. “People are often curious about how much energy a ChatGPT query uses,” he wrote, adding that the average query uses around 0.34 watt-hours — roughly what an oven would consume in just over a second or what a high-efficiency light bulb uses in a couple of minutes.

Altman believes the cost of intelligence will eventually drop to “near the cost of electricity,” suggesting that AI could become more accessible and sustainable in the long run.

But it’s not all that simple.

AI models, especially large ones like GPT-4, rely on massive data centers that need to be cooled constantly — and that’s where water comes in. Last year, The Washington Post reported that generating a 100-word email using GPT-4 could use more than a bottle of water. The exact amount of water used can vary depending on the location and climate where data centers are based.

This latest update from Altman comes amid increasing scrutiny around the environmental footprint of AI. Some researchers have even warned that AI could consume more energy than Bitcoin mining by the end of 2025.

OpenAI hasn’t explained how Altman calculated this new water usage figure, and some experts are likely to want more transparency. Still, the claim seems aimed at easing public concerns about the growing resource demands of AI.

So the next time you ask ChatGPT a question, just know — it’s using only a tiny sip of water. But the bigger question remains: can AI grow sustainably at scale?