How much of an event's carbon footprint does attendee transport account for?

At most events it's the largest category, often exceeding energy, catering and waste combined. It depends on the audience's average travel distance and the venue, but it's rarely a minor share.

What is scope 3 and why does it matter so much for an event?

Scope 3 (GHG Protocol) covers indirect emissions from the value chain: suppliers, catering, and above all attendee transport to the venue. For events, it's almost always the scope that weighs most in the total.

Do I need a consultancy to calculate my event's carbon footprint?

For a full, certified calculation, yes, you usually need a specialised consultancy. But the attendee transport category can be measured with real data (kilometres, occupancy, CO₂ avoided) without waiting on that process, and that data then feeds the full calculation.

Which emissions-reduction measure has the biggest impact at an event?

Almost always, acting on attendee transport: it's the largest category, so a small improvement there (say, raising average vehicle occupancy) cuts more total CO₂ than optimising catering or waste.

How is the CO₂ avoided by carpooling calculated?

By comparing the distance travelled per vehicle and its real occupancy against the scenario where every person would have travelled alone: the more people share the same trip, the more CO₂ that trip avoids.

Guide for organizers

Event carbon footprint

An event's carbon footprint is the sum of every emission it generates, from the first supplier building the stage to the last attendee getting home.

It's not an abstract number: more and more city councils, sponsors and ticketing platforms ask for it as a condition to collaborate, and getting it wrong (or not calculating it at all) leaves organisers with no argument when it's time to defend it.

A packed crowd of attendees at a concert, illustrating the scale of an event's audience

What an event's carbon footprint is and why it matters to measure it

An event's carbon footprint groups emissions across several categories: venue energy, catering, waste, production materials (staging, merchandise), and transport — of attendees, artists, staff and suppliers alike.

Measuring it does three very concrete things: meets what a sponsor or council asks for, prioritises which reduction measures have the most real impact (instead of investing in whichever sounds best), and lets you compare editions to prove real improvement, not just intent.

How to calculate your event's carbon footprint

The standard methodology (the GHG Protocol) splits emissions into three scopes: direct emissions from the event itself (scope 1), emissions from the energy it consumes (scope 2), and all the indirect emissions from the value chain — suppliers, catering, and above all attendee transport (scope 3).

At most events, scope 3 is by far the largest — and within it, attendee transport usually outweighs every other supplier combined. That's why calculating an event's carbon footprint without real transport data seriously underestimates its actual impact.

Data sources differ by category: electricity and fuel use at the venue (bills), waste generated (reports from the waste management provider), and transport — the category that needs origin, transport mode and vehicle occupancy data, usually the hardest to get without a dedicated tool.

Black and white aerial view of a highway with a traffic jam

How to reduce your event's emissions

Reduction measures pay off far more when prioritised by impact category, instead of spreading effort evenly across all of them:

Attendee transport: raising average vehicle occupancy (carpooling) and reinforcing public transport or shuttles at peak-demand time slots — usually the highest-impact lever, since it's the largest category.
Venue energy: contracting certified renewable energy and using more efficient generators where there's no grid connection.
Catering and waste: a lower-footprint menu, waste sorted by type, and reduced single-use packaging.
Production and logistics: staging reused across dates or editions, and consolidated transport of materials.

How VIB3S reports the CO₂ avoided through shared mobility

VIB3S measures CO₂ avoided from real trips — shared kilometres and actual vehicle occupancy — not a generic per-attendee estimate. That figure feeds directly into the transport portion of your carbon footprint calculation, broken down by date, ready for your sustainability report or to justify to a sponsor.

Event types