How to calculate the carbon footprint of an event?

On the eve of the Paris 2024 Olympic Games, the events industry is aiming high, but so are pollution and criticism. Given its significant economic impact (32 billion euros in 2019 according to EY), the events industry, from seminars to festivals and trade shows, must undertake a responsible transformation and accelerate its decarbonization trajectory, or risk moving in the wrong direction.

The first step in this decarbonization trajectory is measuring the emissions of your event.

But how to perform this calculation? What are the standards and references? What emission sources should be considered? Follow the guide!

Standards and references for carbon footprint calculation

The calculation of an event's carbon footprint is governed by various evolving standards and references to better address climate challenges. Initially defined by the British Standards Institute (BSI) in the context of the carbon neutrality standard, new references have emerged. Here are the main ones:

Main references

• Greenhouse Gas Protocol: An international protocol aimed at establishing a regulatory framework to better define GHG emissions.
• Bilan Carbone®: A set of methods that allow the measurement and monitoring of the amount of greenhouse gases an organization emits due to its activities.
• PAS 2060: A standard dedicated to carbon neutrality applicable to all types of organizations. It covers all activities occurring before the event (related to preparation), during the event, and after (during disassembly or planned as a legacy of the event).

Main standards and guidelines

• Sustainability Report: The CSRD (Corporate Sustainability Reporting Directive), effective from January 1, 2024, aims to progressively extend, strengthen, and harmonize non-financial reporting related to sustainable development across Europe. The CSRD framework includes 12 standards distributed according to an ESG (Environmental, Social, and Governance) approach. The objective for companies is to work on and communicate about these issues by following a principle of double materiality, considering both the impact of the company's activities on its economic, social, and natural environment, and vice versa, the impact of its environment on its activities.
• Low-Carbon Strategy and Greenhouse Gas Emissions Inventory: The National Low-Carbon Strategy is France's roadmap for reducing greenhouse gas emissions. It defines the decarbonization strategy scenario for 2050, along with objectives, guidelines, and intermediate milestones to achieve it. These take the form of carbon budgets, i.e., emission caps set for five-year periods, combining long-term and short-term goals.

Climate communication in France

In France, the Climate and Resilience Law, effective January 1, 2023, provides a regulatory framework for climate communication. To prevent "greenwashing" risks, companies can no longer claim "carbon neutrality" (or any equivalent expression) of a product or service in France without providing access on their website and via a QR code or link on the product or advertisement to a summary report detailing:

• The product or service's carbon footprint, established beforehand in a complete and scientific manner;
• The approach and proven evidence demonstrating that all greenhouse gas emissions are primarily avoided, then reduced, and finally compensated.

Additionally, following ADEME's recommendation, it is advised not to use the term “carbon neutral” for your products or services, as this expression is imprecise or misleading if it does not meet the requirements of the Climate and Resilience Law mentioned above. Prefer mentioning a contribution to carbon neutrality (a dynamic and collective commitment) when highlighting your decarbonization trajectory.

Since you can't decarbonize what you don't measure, how do you proceed with the calculation? What data should be considered when organizing events? Let's get to the heart of the matter.

Specific emission sources for events

The principle of carbon calculation relies on the collection of activity data, which is then multiplied by emission factors (EF) that convert this activity data into CO2e emissions (e.g., 2.7 kgCO2e per liter of gasoline) to obtain the carbon footprint of the activity or event. For those who haven’t read our responsible event glossary, an EF is a ratio between a unit of good or service and the amount of greenhouse gas emitted in consuming that unit of product or service. The EFs are multiplied by the quantity of goods or services to obtain a result in tons or kg of CO2e.

Here are the main specific emission sources for events to consider:

• Transport of People (Participants/Staff): Emissions related to the transport of participants and staff to and from the event, whether by car, plane, train, or other means.
• Freight (Transport of Goods): Emissions associated with transporting goods needed for the event, such as technical equipment, decorations, audiovisual equipment, etc.
• Man-hours: The time spent by staff organizing and coordinating the event. This includes planning, managing suppliers, trips to and from clients or sponsors, and all other tasks related to the successful execution of the event. This emission source notably considers all pre-event and setup/teardown work, which is rarely accounted for.
• Materials and Space Setup: Emissions from the manufacturing, purchasing, and use of materials for setting up the event space, including stands, decorations, temporary installations, etc.
• Energy: Greenhouse gas emissions from the consumption of electricity, gas, or other energy sources necessary for the event's operation, including lighting, heating, air conditioning, etc.
• Catering: Emissions from the production, preparation, and distribution of food and beverages for participants and staff.
• Accommodation: Greenhouse gas emissions related to accommodating participants and staff in hotels, hostels, or other types of lodging.
• Goodies: Emissions generated by the production, packaging, and distribution of promotional gifts or souvenirs given to event participants.
• Waste: Emissions from the management of waste generated during the event, including collection, transport, treatment, and disposal.
• Digital (Websites, Livestreams, etc.): Greenhouse gas emissions associated with the use of digital resources such as servers for hosting websites, streaming platforms for live events, email campaigns, etc.

Scopes of a Bilan Carbone®

The Bilan Carbone®, initially developed by ADEME and now managed by the Association for Low Carbon Transition, is the most well-known and widely used method in France. The term has since become part of everyday language. The method includes five key steps within a given scope (product, service, organization…) such as stakeholder engagement, carbon footprint measurement within the defined scope, identification of reduction measures and implementation of a decarbonization trajectory for continuous improvement, communication, and transparency.

To categorize greenhouse gas emissions by source or type of activity of a company, and to frame the scope of the Bilan Carbone®, different scopes must be considered. Generally, three main scopes can be distinguished:

Organizational scope

The organizational scope includes all stakeholders necessary for organizing and executing the event. This scope helps identify all suppliers and stakeholders that you will need to contact during the data collection phase, as they hold, through their service or involvement in the event, part of the carbon footprint of your event and therefore the necessary data for its calculation.

Operational scope

The operational scope of an event's carbon footprint applies to the emitting activities inherent to organizing the event. It includes:

• The preparatory phase (e.g., creating stands);
• The event itself;
• The post-event phase (e.g., post-event communication).

The emissions of an event are mainly related to its scope 3 (indirect emissions not related to energy production or purchase). The energy produced (scope 1) and purchased (scope 2) by the venue is rarely under the event organizer's control. Other categories of activities or emission sources concerning other service providers are also included in scope 3.

Temporal scope

Unlike a company's activities, which are relatively continuous, an event takes place over a short period, so you need to anticipate data collection as much as possible to ensure an accurate estimate of the event's carbon footprint.

Moreover, your service providers offer time-limited services (this also applies to you concerning participants and the advertiser if applicable), so you must anticipate the data collection need for each stakeholder (including participants) and transmit the appropriate request as early as possible (via the specifications and project exchanges, notably), ideally from the event's conception phase.

Selection of scopes

To robustly evaluate and assess the carbon footprint of your event over its entire scope, we recommend evaluating them based on two criteria:

• Responsibility: The flows/sources for which you are directly responsible within the framework of your event (e.g., your purchases).
• Dependence: The flows/sources essential for the successful execution of your event, but for which you are dependent/not directly responsible (e.g., participant transport).

For each source, you can answer the following question: Can my event take place as planned if I remove this flow/source? If the answer is no, I must keep the flow/source and calculate its impact. If the answer is yes, I can remove the flow/source from my calculation scope. It will be easier to reduce the footprint on the sources you are responsible for rather than those you are dependent on, although it is important to try to reduce the latter as much as possible.

How to perform the calculation? Different approaches

There are different approaches to evaluating GHG emissions, depending on your level of maturity in carbon accounting and the quality of the data available to you. Each approach associates activity data with emission factors to calculate the GHG emissions associated with an activity. To obtain the most accurate carbon footprint possible, and especially to analyze the footprint and identify emission reduction areas, it is important to have the most representative data of the physical reality of your activity. Since it is sometimes difficult to obtain precise data on all your emission sources, you should prioritize your time investment on the most emissive sources.

Physical Approach (Specific EF)

This approach involves calculating a greenhouse gas emission by considering the consumption of a good or service (activity data) and a specific emission factor representative of the good or service consumed. This approach offers better accuracy if the activity data is known and the emission factor representative.

Monetary Approach (Average EF)

This approach involves calculating a greenhouse gas emission by considering the cost of a good or service and an average emission factor for the cost of goods or services. The accuracy is lower due to the variations in the price of a good or service.

A concrete example

Imagine we are organizing a two-day seminar for 100 people with a gala dinner. Here is an example of an event's carbon footprint:

• 80% from participant and staff transport;
• 15% from materials and infrastructure;
• 5% from catering.

By focusing efforts on the main emission sources (scope 3), such as participant transport, we can reduce the carbon footprint. For instance, encouraging carpooling or train travel can significantly lower emissions. Additionally, sourcing local and seasonal food for catering and using sustainable materials for the setup can further reduce the event's overall carbon footprint.

Conclusion

By following these guidelines and leveraging available standards and references, you can accurately measure and subsequently reduce the carbon footprint of your events, contributing to a more sustainable events industryc