Event sustainability leads are being held to higher scrutiny than ever before when it comes to their organisation’s emissions data. They’re expected to know what the numbers are and how confident the organisation is in them.
It’s part of the territory that events are internally and publicly scrutinised, which is why it’s extra important within this industry that an organisation’s sustainability data is as strong as possible.
For event sustainability leads who are finding this mission challenging, it is not a failure of intent or capability, but a reflection of the structural reality of how events are delivered and where current measurement practices still fall short.
As scrutiny increases, it’s important that we’re honest about where event data typically breaks down, and what credible progress really looks like in practice.
Events sit where data confidence is lowest
Insights from the Temperature Check Reports show a clear pattern: the areas with the highest emissions are often not the areas with the strongest data confidence.
Across industry datasets captured through TRACE:
- Staff travel and accommodation data was completed in around 88% of measured events, making it one of the most consistently reported data areas.
- Production transport data was recorded in approximately 75% of events, again with relatively low reliance on estimates.
- In contrast, energy data was captured in only around 57% of events, and waste data even less consistently, despite both being known contributors to event emissions.
For sustainability leads, this creates a familiar challenge. An organisation may be measuring their events, but confidence varies sharply depending on the data type, particularly where primary data depends on venues or suppliers outside direct control.
Measurement effort does not equal measurement quality
Another key insight from industry data is that more measurement does not automatically mean better measurement.
Many organisations are already investing time in capturing event emissions, yet analysis shows:
- Some of the most frequently reported emissions rely heavily on estimated data
- Data is often captured inconsistently across events, even within the same organisation
- Different teams apply different assumptions, limiting comparability over time
Audience travel is a good example. While often discussed as a priority, early industry reporting indicates only around 43% of events recorded any audience travel data at all, and the low rate of audience travel data capture is still accurate as of 2025. Where it was captured, it frequently represented only a proportion of total journeys.
For sustainability leads, partial data can still be valuable, but only when its limitations are clearly understood and communicated.
What leading organisations are doing differently
Organisational insights highlighted in the Temperature Check Reports point to a noticeable shift among more mature organisations.
These organisations tend to:
- Prioritise data confidence over data completeness
Focusing first on areas where reliable activity data already exists. - Embed measurement into event delivery processes
Making data capture part of standard workflows, not a post-event clean-up exercise. - Standardise methods internally
Applying consistent boundaries and assumptions across all events, even where gaps remain.
This approach reduces rework, improves internal trust in the data, and makes it easier for sustainability leads to explain results, including uncertainty, with confidence.
Learning from where the gaps are
One of the most valuable outcomes of industry measurement has been visibility of where data is missing or unreliable.
For example:
- Waste volumes are often underreported, suggesting systemic reporting gaps rather than genuinely low waste generation.
- Energy data is frequently estimated, highlighting ongoing challenges in accessing venue-level consumption figures.
- Materials data, despite being heavily influenced by event design decisions, is inconsistently captured across event types.
For sustainability leads these gaps are signals, pointing to where internal processes, supplier engagement, or contractual data requirements need to evolve.
Reframing success for sustainability leads
As regulatory, assurance and stakeholder expectations grow, success is not defined by having a complete dataset.
It is increasingly defined by being able to say, with confidence:
- Which data is robust
- Where estimates have been used
- How consistently methods are applied
- And what is being done to improve quality over time
Industry reporting consistently shows that clarity builds trust, even when the picture is incomplete. Overstated certainty, by contrast, often creates more risk than transparency ever does.
Building progress without overclaiming
With time and due process, event data can become more consistent, more explainable and more useful.
For sustainability leads, progress often looks like:
- Fewer assumptions year on year
- Stronger internal alignment on boundaries
- Improved data quality in priority areas
- And a shared understanding of what ‘good enough for now’ actually means, at both an organisational and industry level
That is how event measurement matures, through repeatable, defensible practice.
For teams looking to strengthen how they approach event carbon measurement, the Event Carbon Measurement Starter Pack offers practical guidance on improving data quality, consistency and confidence.