Discover how you can help shape support for certification schemes in the carbon.txt proposed standard. If you’re using or rely on digital sustainability based certifications – like Blau Angel, TCO Certified Cloud or B Corp for example, we’d love to hear from you. Carbon.txt developer Tim Cowlishaw introduces the proposed changes. You can contribute to the discussion on this github issue by the 15th of June!
A little carbon.txt context
Our vision for carbon.txt isn’t just to make sustainability data and disclosures more transparent and discoverable for digital systems and internet infrastructure. We also want to ensure that such data is usable to make impactful decisions. In other words making sustainability reporting accessible is an important goal, but for real impact, we know we need to ensure that it can be used to drive future carbon emissions reduction actions.
One key aspect to this is thinking about voluntary certification schemes – such as Blau Angel, TCO Certified Cloud, or B Corp . We think of these certification schemes as verified, audited standards that make the particular sustainability commitments an organisation subscribes to explicit and comparable, and which are already used to drive responsible procurement and to evaluate environmental impacts.
Up until now, we’ve supported users of carbon.txt who are subscribed to a certification scheme by allowing them to link to a “certificate” as a particular type of document in their carbon.txt. However, we’ve realised there’s scope to do more to make this type of information more useful to downstream users of carbon.txt.
# An example of a certificate disclosure in our current carbon.txt syntax
version="0.5"
last_updated=2026-06-04
[org]
disclosures = [
{ doc_type="certificate", url="https://example.com/certificate.pdf", title="Our certificate of conformance to some voluntary scheme" },
]Bringing certification schemes into carbon.txt
Specifically, we want to explore how to represent structured, human-and-machine readable data about the certification scheme to which a certificate belongs. It’s useful to know, for instance, that a particular document certifies your adherence to the German Blau Angel standard for efficient and sustainable software, and to provide users with access to extra information about those particular concrete standards.
In addition, most certification schemes require a lot of evidence behind the scenes to support the certification. We think carbon.txt could be a useful mechanism to share any or all of that evidence that an organisation works so diligently to produce. If you’re publishing sustainability policies, real time energy usage information, or RECS energy certificates, and these are accepted as evidence by a certifying body, signalling this in the carbon.txt syntax allows downstream users to understand why you’ve received your certification, and what it means in practice. We also hope that in the future it will allow certifying bodies themselves to use carbon.txt to help them conduct their auditing activities.
Key Benefits of Certification Schemes in carbon.txt:
- Clearly signals the particular commitments an organisation has made, as well as documentation of the results
- Indicates the body responsible for auditing the certification for verifiability
- Indicates what evidence the organisation provided for certification, and how the certification affects their emissions in practice.
Help us out: have your say!
For that reason, we’ve begun to flesh out improvements to the carbon.txt syntax with explicit support for certification schemes – but we need your help to get this right and usable! We can already see this idea introduces an extra layer of complexity in the carbon.txt format, and we want to make sure that the result serves the use cases of existing and future users of carbon.txt, and people currently working with certification `schemes and ecolabels.
# Our current proposal for the new certification schemes syntax
version="0.6"
last_updated=2026-04-27
[org]
certification_schemes = [
{ name="our-scheme", url="https://example-certification-scheme.com" },
]
disclosures = [
{ doc_type="annual-report",
url="https://example.com/evidence.pdf",
title="Document provided as evidence for the certification",
certification_scheme="our-scheme"
},
{ doc_type="certificate",
url="https://example.com/certificate.pdf,
title="Certificate of adherence to the scheme" ,
certification_scheme="our-scheme"
},
]Therefore, if you’re accredited by a scheme such as Blau Angel, TCO Certified Cloud or B Corp, you rely on these certifications to make business decisions, or you’re involved in auditing or certifying business under one of these schemes, we’d love it if you could take a look at our proposal and leave us your thoughts on this github issue. The consultation period will run until the 15th of June, and we’ll use your input to directly inform the next version of the carbon.txt syntax, as well as the future direction of the project as a whole.
