1 — The receipt
The photo is read on this device. Nothing is uploaded, and no account is involved.
2 — What we found
Every quantity is editable. Anything marked assumed is a typical pack size, because the receipt line never said how much.
3 — The carbon price
The same range the front page uses. The higher the price, the stronger the behavioural push — and the more redistribution it demands.
How rough is this? Rough. OCR misreads receipts, shop wording is ambiguous, and a product name rarely tells you the weight. The figure is an order-of-magnitude answer to “what would this basket cost if the damage were in the price”, not a tax assessment. Correct the quantities and it gets a good deal closer.
Sources: Poore & Nemecek (2018), Science 360:987 (food) · UK DEFRA 2023 (fuel) · Apple/Levi’s Product Environmental Reports (electronics/clothing). Text recognition by Tesseract.js, running in this browser.