If you’ve ever been tasked with measuring the carbon footprint of your events, the first question is usually the most obvious one: where do you actually start? Most people know they need to be capturing something, but the gap between that and knowing what to collect, from whom, and how confidently, is where things tend to stall.
The good news is that event carbon measurement doesn’t require perfection from day one. It requires a starting point. Your first year is about setting a baseline, understanding roughly where your emissions are coming from, which areas you have good data for, and where the gaps are. That baseline is what everything else builds on.
The main categories of an event carbon footprint
The starting point for most events is understanding the main categories that contribute to your carbon footprint. These tend to fall across a few consistent areas: energy use at the venue, catering, transport (both for attendees and for production), materials and build, waste, and staff travel and accommodation.
Not every event will have the same profile across these categories. An exhibition with a large build will look very different to a conference dinner, but the categories themselves are a reliable framework to work from.
What the data tells us is that the areas with the highest emissions are not always the areas where data is easiest to get. Energy, for example, is one of the more significant contributors to an event’s footprint, yet venue-level consumption figures are often hard to access, meaning many organisers end up relying on estimates.
Waste data is similarly patchy. That doesn’t mean you skip these areas, it means you record what you have, note where estimates have been used, and work to improve data quality over time.
Working with your suppliers
One thing that catches many organisers off guard is how much of the data you need sits outside your direct control. Venue energy consumption, waste volumes, catering figures, production materials: a significant portion of what makes up your event’s carbon footprint lives with your suppliers.
Getting that data requires engagement, and in some cases, it requires building new processes and conversations into how you work with them. That takes time, particularly in the first year. Industry data shows that energy data was captured in only around 57% of measured events, and waste data even less consistently, and supplier data gaps are a large part of why.
However, working within a carbon measurement platform, like TRACE, which allows you to invite your suppliers to import data on your behalf makes this process more streamlined for both parties.
The 2025 Temperature Check Europe report, which analyses data from approximately 1,000 events across Europe, is worth reading alongside this if you’re new to event carbon measurement. It gives useful context on where the industry currently sits, what the main emissions hotspots are, and where measurement practice is still developing. For someone building their first baseline, that industry context matters.
Where to focus first
Given that data quality varies so much across categories, it helps to be deliberate about where you put your energy early on. Staff travel and accommodation tends to be one of the more consistently reported areas, with industry data showing it was captured in around 88% of measured events.
Production transport follows at approximately 75%. These are reasonable places to build confidence before tackling harder areas.
Audience travel is worth noting separately. It’s often flagged as a priority, yet only around 43% of events recorded any audience travel data at all, and where it was captured, it frequently represented only a proportion of total journeys. Partial data here is still useful, but it needs to be clearly labelled as such.
The honest reality is that in your first year, you will have gaps. What matters is that you know where those gaps are, you’re transparent about them, and you have a plan to address them over time. Focus on the areas of your event where you have the most control, or highest predicted impact, as good data here will be most valuable and lead you to different, lower-impact decisions quicker.
Spreadsheets versus a measurement platform
Many organisations start measuring in spreadsheets, and there’s nothing wrong with that as a first step. The limitations tend to show up over time, particularly when you’re trying to apply consistent methods across multiple events, or when you need to explain your figures to a client or stakeholder.
Inconsistent assumptions, version control issues, and the time required to maintain them manually are common pain points. Meanwhile, working within a carbon measurement platform (like TRACE by isla) can make your first steps easier, as the technical elements of carbon measurement are already in place for you. So, all you need to do is focus on data collection.
Whether you’re working in a spreadsheet or a dedicated platform, the underlying principle is the same: capture activity data where you can, be clear about where you’ve estimated, and apply consistent methods each time.
Consistency is what makes your data comparable year on year, and comparability is what turns a one-off report into genuine insight.
What good looks like over time
Organisations that are further along in their measurement journey tend to share a few common traits. They prioritise data confidence over data completeness, meaning they’d rather have reliable figures for six categories than shaky figures for ten.
They embed data capture into event delivery workflows rather than scrambling for information after the event, they apply consistent boundaries and assumptions across all their events, even where gaps remain and they also reassess their boundaries year-on-year, to make sure they’re capturing the highest quality data possible at that time.
That’s the direction of travel: repeatable, defensible practice that improves year on year.
Getting started
If you’re at the beginning of this process, the Event Carbon Measurement Bundle is a free practical resource that covers the foundations of event carbon measurement, from what to capture to how to build consistency into your approach. It’s a useful reference whether you’re setting up measurement for the first time or trying to bring more rigour to what you’re already doing.
