Frequently asked questions

For now, no. We are currently working with larger organisations to pilot the carbon.txt specification. This will help us uncover use cases and implementation details that will be applicable to smaller providers and website operators.

Expanding the carbon.txt specification to cater for self-hosted sites is on our roadmap. You can follow this Github issue to keep updated with progress.

For now, no. We are currently working with larger organisations to pilot the carbon.txt specification. This will help us uncover use cases and implementation details that will be applicable to smaller providers and website operators.

Expanding the carbon.txt specification to cater for self-hosted sites is on our roadmap. You can follow this Github issue to keep updated with progress.

Currently, we accept the doctypes below:

• annual-report: An organisations annual sustainability reporting.
• webpage: A web page outlining steps taken to avoid, reduce, or offset greenhouse gas emissions from service operations.
• certificate: Certificates showing the steps taken to purchase green energy, or offset greenhouse gas emissions from service operations.
• other: A catch-all for everything else.

There are a few reasons for taking the approach we’ve described on this site.

Primarily, we are adopting an approach which leans heavily on existing web standards, and technologies. This allows for familiarity, and we hope will lead to these ideas being easier to adopt/implement.

We believe that providing a way for hosting providers/managed services to implement the carbon.txt specification for their product/s is key to broader adoption. It allows us, as a small not-for-profit driving this idea, to have a much larger reach & impact when compared to the alternative of relying on individuals to upload carbon.txt files to their own domains.

In the long run, we think that demonstrating how we can use existing internet and web standards to make sustainability claims easily discoverable, as well as human and machine readable, will result in a web where it's easier to trust green claims. Not only that, conventions like carbon.txt allows us follow green claims to the supporting evidence used to back them up.

Domains must be associated to an organisation that is a verified green hosting provider with the Green Web Foundation before they show up as being green. This is to mitigate against bad actors taking credit for the green claims made in another organisation's carbon.txt file.

There are two ways to associate a domain with a verified green hosting provider:

1. Using domain hashes - New domains are only automatically recognised as green, and associated to a verified green provider, if there is a matching domain hash available when they are first submitted/checked through the Greencheck API.
2. Manually - Green Web Foundation staff can manually create a record for a new domain, and associate with an existing verified green hosting provider.

The internet is a distributed network by its very nature. And, many hosting providers - especially CDNs and edge compute services - will serve content from locations around the world. Some of these locations could be in regions that run entirely (or almost entirely) on green energy.

At present, carbon.txt is designed to work at an organisational level, for organisations aiming to demonstrate that 100% of the carbon emissions associated with operating digital infrastructure have been accounted for.

We're looking into ways and funding to surface greater geographic resolution for location-based carbon intensity, to reflect the physical reality. If you're interested in collaborating or funding our work, please get in touch.