Similar to the better known robots.txt file, the carbon.txt file is also a txt file located on your webserver.

This text file is meant to keep information about the resources used to serve your website and information related to your own carbon footprint.

In other words, it is a convention for website owners and digital service providers to demonstrate that their digital infrastructure runs on green electricity.

The Green Web Foundation

This is an initiative spear-headed by The Green Web Foundation, and to be fair, the initiative is still in its very early stages. However, I think the idea is so great that I think everyone should implement it!

Even if the pilot is currently only for service providers, the general idea makes sense for any website owner.

If you already have a Sustainability Policy, and maybe you’re even offsetting carbon too, the carbon.txt is a great place to be public about it!

• carbon.txt is a canonical location where your carbon footprint is documented. Easy to find.
• carbon.txt is readable by humans, and crawlable by machines!

Make your own carbon.txt

I’ve been implementing carbon.txt for ImageEngine as a part of the pilot. 

An example for sites using ImageEngine as a CDN, and Netlify as hosting:

[upstream]
providers = [
    { domain = "netlify.com", service = "shared-hosting" },
    { domain = "imageengine.io", service = "cdn" }
]

[org]
credentials = [
     # Optional, but if you have a sustainability policy, you can reference it here.
    { domain = "yoursite.com", doctype = "webpage", url = "https://yoursite.com/sustainability/"}
]

(The contents is represented using TOML syntax.)

Because imageengine.io is registered with The Green Web Foundation as a Green Host (a public data set), this will also count positively against anyone following the trances provided by the file.

Moreover, if you, or a data program, want to dig further, ImageEngine’s carbon.txt file is located here: https://imgeng.in/carbon.txt.

Ideally, carbon.txt will provide a chain of references – a “graph” if you will – where the entire footprint of the involved providers are documented. 

Read more about the initiative here.