Editorial policy

Sources

Every figure on CO2Stats comes from a named source. We go to the original where we can: the measuring agency’s data file, the company’s own report, the paper itself. Where a figure reached us second-hand, its entry says so.

A figure given only as “at most” or “over” stays a bound. A fact the source does not give is left out, never filled in.

Checking

Before a figure is published, it is checked against its source’s own words. The Kettle ledger keeps each claim’s quote, and each host page sums up the host’s own evidence in our words. Our own calculations, such as the energy to heat a cup of water, are labelled as ours and show their working.

The CO2 pages and the hosting guide’s grid figures come from published datasets, each named on the page.

Corrections and changes

If you think something here is wrong, write to hello@co2stats.com with what and where. We fix errors promptly. When a figure in the Kettle ledger changes, the old figure stays on its page with its date, and the change goes in the ledger’s changelog.

Independence

CO2Stats carries no advertising. Some links to hosting companies may be affiliate links, each marked as such, with a plain explanation above the first one on the page. The hosts we list are our judgement of good hosts: being green is one factor, and price, reliability, support and privacy matter too, which is why we say what each host is good for. Payment never changes our advice.

What we will and will not claim

We follow the UK Competition and Markets Authority’s Green Claims Code. We state specific, measured, dated facts (“this page: 0.12 g CO2e per visit, assessed on 12 October 2026”), never broad claims that a website or a company is “green” or “eco-friendly”. Every carbon figure for a web page is an estimate made with a published method. A host listed by the Green Web Foundation is described in exactly those terms, with the date we checked.