Corporate events account for a significant portion of a company’s emissions—a figure that is often overlooked in overall carbon footprint assessments because it is spread across dozens of stakeholders: service providers, caterers, venues, and the participants themselves. A trade show with 5,000 attendees, a two-day seminar, an annual conference: each format generates emissions that are difficult to isolate and quantify. Yet, measurement always comes before reduction. This article offers a practical method for calculating the carbon footprint of your events, benchmarks by format, and the most effective levers for action.
Measuring after the fact allows us to assess the results. Measuring beforehand allows us to take action. This is the difference between a post-event audit—useful but merely descriptive—and eco-design, which incorporates carbon impact as a decision-making criterion from the very start, when choosing the venue, format, and caterer. At this stage, key decisions are still open to change. Once they’re made, they’re set in stone.
The example of transportation illustrates this clearly: choosing a venue accessible by train rather than by plane can reduce travel emissions by a factor of five to ten, depending on where participants are coming from (source: ADEME Carbon Database). This decision must be made early on, when selecting the venue. Once the venue has been booked, the opportunity is lost.
The regulatory landscape reinforces this necessity. The Corporate Sustainability Reporting Directive (CSRD) requires companies of a certain size to provide non-financial reporting that includes their direct and indirect emissions. Events falling under an organization’s Scope 3 emissions are included in this scope. Those who have already established a calculation method at the event level will be much better prepared to meet these requirements.
The standard method in France is Bilan Carbone®, originally developed by ADEME in collaboration with Jean-Marc Jancovici and now managed by the Association Bilan Carbone (ABC). Its principle is based on collecting activity data (kilometers traveled, kilograms of waste produced, kWh consumed, etc.) and multiplying it by emission factors to obtain tons of CO₂ equivalent (tCO₂e). It is applied to the events sector with specific adaptations.
Defining the scope: Scope 1, 2, and 3 in the context of events
The distinction between the three scopes takes on particular significance in the events industry. Scope 1 includes the organizer’s direct emissions: on-site diesel generators, vehicles owned by the organization. Scope 2 covers purchased energy: electricity for the venue, air conditioning, lighting. These are important, but rarely decisive.
Scope 3 is the most critical factor. It encompasses all indirect emissions: participant transportation (including service providers and speakers), lodging, catering, production of printed materials, booths and signage, and waste. This scope typically accounts for between 70 and 90% of an event’s total carbon footprint. This is where the real work happens—and this is also where the most powerful levers for reduction lie.
A best practice is to establish clear boundaries before performing the calculation: geographic scope (which participants’ locations are included?), number of people included (participants, speakers, vendors, staff?), and duration covered (including setup and teardown?). These decisions must be documented so that the calculation can be replicated from one event to the next.
Key broadcast stations to watch
A systematic analysis of available event carbon footprints reveals a relatively stable hierarchy, regardless of the event format. Transportation accounts for the vast majority of emissions, followed by food and beverage services, and then energy.
These proportions vary depending on the type of event and where the participants are coming from. A regional event where all participants arrive by train will have a very different profile from an international conference where half the participants arrive by plane.
Corporate conferences and seminars
Corporate seminars are often underestimated because they seem “small.” However, a two-day residential seminar for 100 people, including travel, can generate between 20 and 60 tCO₂e depending on the modes of transportation used and where the participants are coming from. On an individual basis, the carbon footprint can amount to several hundred kilograms of CO₂e per person—the equivalent of a round-trip flight from Paris to Barcelona.
The key is the venue’s location and accessibility. A seminar held at a venue with good public transportation access, catering primarily to attendees from the Île-de-France region, will have a radically different transportation footprint than a seminar held at a remote luxury hotel accessible only by car.
Festivals, trade shows, and large gatherings
The effect of scale radically changes the scope of the problem. A marginal contribution per participant becomes massive when there are 10,000 people. Data collected by the Business Climate Convention (CEC) during one of its sessions in Marseille (approximately 200 participants) identified transportation as accounting for nearly 45% of emissions, and purchases (catering and lodging) for 36% (source: CEC report, published on LinkedIn). Items often perceived as significant—such as printed materials and decorations—often turn out to be secondary. Transportation, on the other hand, consistently dominates.
Major events have also begun to measure and report their results. This approach is gradually becoming the standard for CSR credibility, particularly in sectors where brand image is critical.
Hybrid events: an underrated tool
The hybrid format (in-person + remote) is often touted as a miracle solution. The figures confirm this to some extent: a study by WSP covering seven events showed that a virtual conference with 560 participants generated 10 tCO₂, whereas its in-person equivalent would have produced 274 (source: WSP report, cited by Evenement.com). For a convention with 18,000 attendees, the figures were 176 and 10,348 tCO₂ respectively.
An important point to note: hybrid models generate their own digital emissions—from streaming, data centers, and equipment used by remote participants. While these emissions remain low in absolute terms compared to the transportation avoided, they must be included in the calculation to ensure accuracy. Partial hybridization is a powerful tool when planned in advance, not added as a last resort.
Measuring your carbon footprint is the first step toward taking a responsible approach. But raw data isn’t enough: you have to analyze it, interpret it within its context, and turn it into a concrete action plan. That’s where the process really comes into its own.
The Event Mural: A Tool for Raising Public Awareness
Before diving into the numbers, it is often necessary to create the cultural conditions for a carbon footprint initiative to be accepted and supported by the community. This is the purpose of the Event Sector Fresque, developed by the REEVE (Eco-Event Network) association: a half-day collaborative workshop, inspired by the Climate Fresque, designed specifically for professionals in the event sector.
Who is this workshop intended for, and how can it be incorporated into a CSR initiative?
The Event Industry Mural is designed for event teams, agencies looking to train their staff, and executive committees developing a CSR plan. Unlike a traditional lecture, it fosters a systemic understanding of the industry’s impacts through collective intelligence: each participant actively builds their own understanding of the connections between the events industry, climate change, and social issues.
In a structured CSR approach, the Fresque plays a unique role: it raises awareness and inspires action, whereas the carbon footprint assessment quantifies and prioritizes. The ideal sequence is: Fresque (collective awareness) → Carbon footprint assessment (measurement and quantification) → Action plan (prioritization and decision-making). The workshop can also be used to relaunch an ISO 20121 initiative or inject momentum into an internal working group.
Reading and Interpreting Your Event's Carbon Footprint
An event carbon footprint cannot be interpreted in isolation. It must be considered in the context of the event type, size, location, and previous editions, if any. The initial review should identify the “hot spots”: the two or three categories that account for more than 80% of emissions. It is on these that reduction efforts should focus, not on symbolic actions affecting 2% of the footprint.
To track progress over time, it is recommended to precisely document the assumptions and activity data used in each edition. Without this, it is impossible to know whether a year-over-year variation reflects a true reduction or a change in scope. A tCO₂e ratio per participant is more useful than an absolute figure for comparing events of different sizes.
What organizations have learned: feedback
The most consistent finding across all published event carbon footprint assessments is the pervasive role of transportation. Organizers who have never conducted such an assessment often assume that printed materials, decorations, or energy consumption are their primary sources of emissions. Calculations consistently show that transportation—particularly air travel and private cars—accounts for 50 to 75 percent of the total carbon footprint.
Another common lesson: the difficulty of collecting data. Obtaining reliable information on participants’ modes of transportation—or on emissions associated with service providers—is often the main operational hurdle. This finding underscores the need to integrate data collection (registration forms with questions about mode of transportation, contractual clauses for service providers) into standard processes—rather than as an afterthought.
Focus on high-impact levers
The guiding principle to follow is: prevent first, reduce next, and offset only as a last resort. Carbon offsetting—the purchase of carbon credits linked to reforestation or carbon capture projects—should not be presented as the primary solution. ADEME explicitly warns against claims of “carbon neutrality” and recommends prioritizing actual reduction.
High-impact measures, in order of effectiveness:
Choose a location accessible by public transit or train—this is the most effective measure. Reduce or even eliminate air travel by prioritizing a central location. Go plant-based: switching from a meal with red meat to a vegetarian meal reduces the catering footprint by 50 to 70% (source: ADEME Carbon Database). Limit printed materials and giveaways: low absolute impact, but a strong signal that’s easy to implement. Pool accommodations and guide participants to hotels within walking distance. Use reusable modular booths instead of disposable structures.
How can you select suppliers that align with your CSR approach?
A service provider that cannot provide its own emissions data cannot be seriously included in an event carbon footprint assessment. The ability to provide this data is therefore a selection criterion in its own right. Beyond that, certifications provide benchmarks: ISO 20121 is the international standard for responsible event management, while the European Ecolabel and the Lucie certification attest to a comprehensive CSR approach.
Including environmental clauses in requests for proposals is still a rare practice, but one that is gaining traction: requirements to provide a carbon footprint assessment of the service, commitments regarding the share of renewable energy, and waste management policies. These clauses are changing the conversation with service providers and accelerating the sector’s transformation.
Calculating an event’s carbon footprint is now within reach for any organizer, provided they have the right tools and a clear method. The main hurdle isn’t technical: it’s deciding to get started—ideally as early as the planning phase of the next event. Waiting until you have a perfect assessment before taking action is the surest way to never get started.
Calculating a carbon footprint is a natural part of a broader CSR approach: impact reporting, transparent communication with participants and clients, and continuous improvement from one event to the next. It also opens the door to other related topics that we will continue to explore: waste management at events, accessibility and inclusion as components of a responsible event, and the growing role of digital tools in the automated collection of event activity data.
