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carbon.txt

carbon.txt makes sustainability data easier to discover and use on the web.

What is carbon.txt?

Carbon.txt is a single place to look on any domain – /carbon.txt – for public, machine-readable, sustainability data relating to that company.

It’s a web-first, connect not collect style approach, of most benefit to those interested in scraping the structured data companies have to publish according to national laws. Designed to be extended by default, we see carbon.txt becoming essential infrastructure for sustainability data services crunching available numbers and sharing the stories it can tell.

We envisage a carbon.txt data ecosystem supporting meaningful action on the defining challenge of our time – the climate crisis.

Using carbon.txt

The carbon.txt project is still in its infancy, and as such a robust public version is still under development.

In Q1 2025, we anticipate publishing a first version, with associated documentation and user guides.

We’re committed to working in the open throughout development and updating this page regularly as we progress.


Project updates

May 2023 – ran a closed pilot to prototype a first version of the carbon.txt standard with funding from Internet Society Foundation. We proposed a convention for website owners and digital service providers to demonstrate their digital infrastructure runs on green electricity, which proved successful. Our carbon.txt github repo has more details.

Sept 2023 – Collaborated with Wikirate to understand how much of the internet is covered by credible Net Zero targets. We discovered significant hurdles to collecting sustainability data that we realised extending carbon.txt could overcome.

April 2024 – awarded funding in NGI Search’s 4th open call to expand the initial prototype to surface more comprehensive sustainability data. We’re making it possible for the standardised reports mandated in Europe by the Corporate Sustainability Reporting Directive (CSRD), and the data required by the Energy Efficiency Directive (EED) to be findable on any domain at /carbon.txt.

Sept 2024 – concluded in-depth research and scoping of the technical work required to fetch CSRD and EED data presented in a carbon.txt file. We plan to create an open-source, standalone carbon.txt package that we and others can use. We’re calling this the carbon.txt validator.

Currently – building a carbon.txt validator service for CSRD reports running Oct – Jan 2025.

Future – Between Feb and April 2025, put the validator into use directly in our own Green Web verification process. We’ll leverage our influence to create a critical mass of companies implementing carbon.txt files on their own sites, linking to sustainability data about themselves.


Licenses

The code for carbon.txt is licensed Apache 2.0 (What does this mean?).


Ways to stay updated

Our monthly newsletter is the best way to receive email updates about Green Web Foundation’s work, including carbon.txt. Subscribe to our newsletter.

You can also catch-up on progress via our blog’s dedicated carbon.txt category – https://www.thegreenwebfoundation.org/categories/carbon-txt.