an illustrated field guide, drawn badly on purpose

The road to a chat reply

You type eight words and press send. Somewhere between your thumb and the answer, a building in another country gets slightly warmer and evaporates a mouthful of water. Here is the whole journey, one stop at a time.

start by sending a message, like you always do
0.3watt-hours
1.1millilitres of water
0.1grams of CO2

…for one ordinary message. Now multiply by a billion a day.

scroll
01

Go on then. Send one.

Type anything. We will follow it the whole way and keep the receipts.

AI
Some Modelonline, allegedly
Ask me anything. I promise not to mention the water.
02

The nine stops

Click any stop to poke at it. Or hit play and watch your message travel.

pick a stop up there, or press play

03

The bill, so far

Everything you have sent on this page, added up. Keep sending, watch the glass fill.

500 mL 375 250 125

0 mL evaporated on your behalf

0 messages sent

0.0 mL water, evaporated and gone

— on site · — at the power plant

0.0 Whelectricity, drawn from a grid

0.0 gCO2e, released somewhere

0tokens pushed through a model

04

Fiddle with it

Same message, different choices. Watch the same question cost twenty times as much — or a fortieth.

which model answers

how long the answer is

300 output tokens (~225 words)

how long the conversation already is

1,200 tokens of history re-read every single turn

where the building is

— L/kWh on site — L/kWh at the plant — g CO₂/kWh — PUE

how they get rid of the heat

one message, with these settings

—water
—energy
—carbon

05

Now multiply by everyone

A mouthful is nothing. That is exactly why the argument is never about one message.

1 billion messages a day

—

    06

    So what does that actually do to a place?

    Six things that come up every time a data centre shows up in a town. Tap a card to open it.

    07

    The bits that actually move the needle

    Not "turn off your camera on calls". Things with real leverage.

      None of this is an argument for not using the thing. It is an argument for knowing what you are spending, the same way you know roughly what a flight costs or what a steak costs.

      A mouthful of water. Then you close the tab.

      08

      Where these numbers came from

      And, more importantly, how wrong they might be.

      Read this before you quote me

      Nobody outside the big labs knows the real per-message figures, and the honest published range spans more than a factor of ten. These are back-of-an-envelope estimates anchored to the few measurements that exist.

      The shape of the thing is solid — decode dominates, water follows the grid, location matters more than almost anything. The exact digits are not.

        the whole calculation, such as it is

        IT energy   = (context + input) × 0.12 mWh + output × 0.95 mWh   × model factor
facility    = IT energy × PUE
water       = facility kWh × (on-site WUE × cooling factor + off-site EWIF)
carbon      = facility kWh × grid intensity