We measured it — and we're publishing the method, the sources, and the parts we're not sure about.
Every few months someone tells us AI is destroying the planet, one chatbot reply at a time. It's a fair question to ask of a site built almost entirely on AI-generated readings. So instead of guessing, we measured — our own servers, our own model usage, real numbers from our own logs — and then went looking for honest, sourced comparisons instead of picking whichever one flattered us.
Here's what we found, with the confidence level attached to each number, because a claim without its confidence level isn't really a claim.
One Magical Chart reading — the AI generation, the page it's served on, its share of the always-on database — costs less than 0.4 grams of CO₂. That's measured from our own request logs and hosting, converted using published energy-to-carbon factors, not a marketing estimate.
The strongest comparison we found comes from Arcom and Arcep, France's audiovisual and telecoms regulators, working with ADEME (the French environment agency). Their October 2024 study — a full life-cycle analysis, externally reviewed to ISO 14040/14044 standards, not a marketing blog — measured the carbon cost of an hour of different audiovisual uses in France:
At ~51 g/hour, that's under a gram every minute. One Magical Chart reading, at under 0.4 g, costs about the same as 28 seconds of scrolling video on your phone.
The official study groups platforms together rather than naming them. For a platform-by-platform figure, the most-cited source is Greenspector, a private French research firm — a 2021 test, one phone (a Galaxy S7), one minute of feed-scrolling per app, not externally reviewed (via Carbon Literacy Project and L'Info Durable, since the original Greenspector page is no longer online). It found TikTok the heaviest of ten platforms tested, at 2.63 g CO₂ per minute — about 158 g/hour, the same order of magnitude as the official figure above, which is reassuring even though the two studies don't agree on method.
At that rate, the average TikTok session (45.5 minutes a day, per Global Web Index) costs roughly 300 readings' worth of carbon — in one day, from one habit most people never think twice about.
We looked for an equivalent official figure for video games and didn't find one — the Arcom/Arcep/ADEME study explicitly excludes gaming from its scope. Two private estimates (Greenly, and an unreviewed 2022 market-data study) put an hour of PC or cloud gaming somewhere around 100 to 440 grams of CO₂. We're publishing it because it's the best we could find, not because we're confident in it — treat it as a rough order of magnitude, not a citable number.
"A number without its confidence level isn't a fact — it's a guess wearing a fact's clothes." 🐑
We're not going to tell you that using Magical Chart "saves the planet." Nobody opens a tarot app instead of watching a video — there's no substitution happening, so there's no emissions avoided. Claiming otherwise would be exactly the kind of dishonest math we're trying not to do here.
What the numbers do show is narrower and, we think, more useful: the public worry about AI's footprint is real but badly aimed. A five-second AI-generated reading gets scrutinised in a way that forty-five minutes of ordinary video scrolling, every single day, never does — even though the scrolling costs more, minute for minute, by every source we could find.
Running Magical Chart is not where most of its footprint lives. We tracked our own git history: 800+ hours of development went into building this site — a laptop running, screen on, for that long, and still counting. Converted the same way as everything above, that's roughly 2 to 6 times more energy than a full month of the product actually running for real visitors. Add the laptop's own manufacturing footprint, amortised fairly, and it alone outweighs a year of the site's operation. This number only grows while we keep building, which is why we don't quote it to the hour.
An audit that only shows the "clean" number — the AI, the servers — while leaving out the months of work it took to build the thing, isn't really an audit. It's a highlight reel.
The full working — every source, every formula, every range — is public. We'd rather be checkable than impressive.
A Magical Chart reading costs under half a gram of CO₂ — about what 28 seconds of scrolling video costs, by the most solid published source we could find. We're not claiming that makes us green. We're claiming we measured it, and we're telling you exactly how.
✦ Read our full approach →For reflection & transparency ✦ not a certification, not a green claim 🌙