Join Professor John Barrett OBE (University of Leeds), Toby Green (Co-Founder, MyCarbon) and Emilien Hoet (Co-Founder, Carbon Accounting Alliance) on Thursday 26th November for a webinar on all things emission factors. We'll look at how factors are built, how to choose between them, and a new practitioner course launching in 2027.
Emission factors were the focus of two roundtables at our annual conference in October, moderated by Mike Berners-Lee and Timothy Baynes. Both tackled the same question: how might we harmonise and improve emission factor selection, and could this be solved pre-competitively?
What we heard in the room
Emission factors sit behind almost every number in a carbon footprint, yet they can often feel like a black box. Participants described that black box from several angles:
Inconsistency. Datasets can differ widely for the same activity, shaped by different methodologies, boundaries and assumptions. Clients who switch provider can see all their numbers change.
Access. Many factors sit behind paywalls, which raises an awkward question: how do you verify an inventory if you cannot see what is behind it? Open sources help, but coverage has gaps. Electricity factors are not even published for some countries.
Age. Factors can be years old by the time they are used, a particular problem in fast-moving areas like AI. Annual releases can also land at awkward moments, leaving teams to decide whether to wait for the update.
Authority. Clients and auditors may insist on factors from established databases, even when those databases update slowly. Authority and accuracy are easily confused.
The underlying barriers run deeper. Accounting protocols go into detail on how to calculate emissions but leave much of the choice of factor to interpretation. Spend-based factors come from input-output models originally built for other purposes. Good datasets take real resources to create, and without legislation there is limited pressure to publish.
The stakes are rising too. As carbon taxes come into play, differences between emission factors will have direct commercial consequences.
What could change
The ideas on the table were ambitious. They included an independent ratings organisation for datasets, a central source of industry feedback on factors, and common release dates and formats across jurisdictions.
These are big, collective pieces of work. But the groups also kept returning to something more immediate: capability. One called for training on how to use emission factors. The other called for carbon literacy on both sides of the market, and for better ways to explain to boards why an inventory changes.
Some of the guidance already exists. The GHG Protocol Scope 3 Standard covers how to assess data for completeness, reliability and representativeness, but it is easy to miss.
In practice, emission factors are often applied without a clear understanding of how they were developed or whether they suit the intended use of the results. How often do we stop to ask what assumptions sit behind a factor, and whether it is the right choice for the purpose?
A new course, and a chance to find out more
That is the gap a new practitioner course sets out to close. In 2027, the University of Leeds and MyCarbon are launching a two-day course designed to build a deeper understanding of emission factors. It will help carbon accounting professionals make more informed choices and produce more robust, consistent outputs.
The webinar is your chance to find out more about the course, meet the people behind it and explore the challenges facing the profession.
Few people are closer to the subject than John Barrett. His Leeds team developed the model behind the UK's official carbon footprint statistics and the Defra spend-based emission factors. He has advised UK government departments and the Climate Change Committee, and was a lead author for IPCC Working Group III.
What we'll cover
The current emission factor landscape, and why it matters more than we might think
The main types of emission factor database, from multi-regional input-output (MRIO) models like the one behind the Defra spend-based factors to process LCA databases and hybrid approaches, and what each is built from
Spend, activity and LCA: the three main quantification pathways and the trade-offs between them
A first look at the new two-day practitioner course
Q&A
Who should join
The webinar is for carbon accountants and sustainability practitioners who select or apply emission factors in their work, and anyone considering the course. The course itself is for people who qualify at registered practitioner grade and above on the ISEP Register of Carbon Accountants and Auditors.
Unsure where you sit? Complete our free competency self-assessment.