1. Estimating CO2 emissions
How to simply calculate the participants' transport CO2 emissions?
🧮 Maths are simplified for conveniance.
Est. CO2 emission = participants’ traveled kilometers (km) * X kg
X depends on the mode of transportation:
Mode of Transport CO2 emission / 1 km (per passenger)2 ✈️ Airplane 0.16 kg 🚗 Car (avg: 1.6 passengers) 0.14 kg 🚌 Bus 0.08 kg ⛴️ Ferry 0.06 kg 🔋 Electric Vehicle (avg: 1.6 passengers) 0.05 kg 🚄 Train 0.03 kg 🚴 Bicycle 0 kg Example:
- 20 participants will attend the event, and 10 of them will arrive in private cars (diesel engine) (round trip – 200km). The rest will fly (average flight distance – 1000km)
- The combined CO2 footprint of car travel: 2000 km (total distance traveled by participants) * 0.14 = ~280 kg CO2
- The combined CO2 footprint of flying: 20 trips * 1000 km * 0.16 = ~3200 kg CO2
- Total est. emission: ~3480 kg CO2
- 20 participants will attend the event, and 10 of them will arrive in private cars (diesel engine) (round trip – 200km). The rest will fly (average flight distance – 1000km)
What's the most convenient way to calculate the event participants' travel CO2?
Visitor Registration at the Entrance
For instance, the Climate Museum had asked every arriving visitor two questions: (1) what mode of transportation they used to arrive; and (2) how far they traveled. The responses were recorded digitally and, after the event concluded, allowed for a simple calculation of the approximate amount of CO2 “produced” during each visitor’s arrival.
Capturing Visitors’ CO2 at the Start of the Event
Another method used by some organisers, like “AY Institute,” involves asking participants at the beginning of the event to open (for example, by scanning a QR code) a very simple digital form for calculating CO2 (see example below). In the form, participants answer several questions (how they arrived, how far they traveled, how they plan to return) and receive an approximate amount of CO2 “produced” during their arrival. This process takes just a few seconds, and the participants’ responses are recorded in the overall event statistics.
How to simply calculate the CO2 emissions from energy usage?
🧮 Maths are simplified for conveniance.
Approx. CO2 emissions = event duration (in hours) * number of participants * X CO2 kg
X depends on:
During the event: X 💡 No heating / no air conditioning (AC) 0.52 kg 🌡️ Heating and/or air conditioning (AC) will be used 0.6 kg Example:
The event will last 8 hours and will have 20 participants (the event will take place in Lithuania, during the heating season). Thus, the approx. CO2 footprint of the event is 8 * 20 * 0.6 = ~96 kg CO2
💡 Tip: to calculate energy usage CO2 emission more exact, check your electricity / heating bills after the event. Average CO2 emissions per KWh of electricity was 253 grams10 in Europe’s 6 largest economies – Germany, France, United Kingdom, Italy, Spain and The Netherlands – in the last quarter of 2023.
How to calculate the approx. CO2 emissions of participants' accommodation?
🧮 Maths are simplified for conveniance.
Approx. CO2 emissions = number of participant nights (in hotels or other paid accommodation) * ~20 CO2 kg
Example:
- 20 event participants will spend 1 night in a hotel
- Total amount of CO2 “produced”: 20 nights * 20 = ~400 kg CO2
What to do with the estimated CO2 emissions?
- Save this data for offsetting & reporting later.
- Plan your (event) budget accordingly. For example, offsetting one ton of CO2 will cost from 2 to 6 euros when planting trees or when investing in certified CO2-reduction projects3.
⚠️ Important: CO2 compensation alone is not enough to slow down climate change processes. Thus, the primary focus should be on reducing the amount of CO2 emitted in your activities as much as possible and offsetting only the remainder.
Do you have more tips / suggestions?
On average, this is how much CO2 each of us “produces” annually (living, working, traveling) in the EU1
2. Reducing CO2 During an Event
How to reduce (participants') transport CO2 emissions?
- Provide opportunities for everyone interested to participate online
- Encourage event participants (from other cities) to use trains and other public transportation (the event location should be near bus/train stations)
- Align the start and end times of the event with the public transport schedule
- Offer free public transport tickets to participants
- Encourage (e.g., as the event approaches) local participants to use bicycles or electric scooters (ensure there is a secure bike parking area at the event location)
- (If possible) organize car sharing and/or ridesharing
- Reduce the distance(s) between event locations (if it takes place in multiple locations)
How to reduce CO2 emissions when accommodating participants and choosing event locations?
- Choose environmentally friendly hotels4
- Encourage overnight guests to bring and use their own personal care items
- Organize transportation to and from lodging facilities, thereby reducing the number of cars used
- Select event spaces and rooms of appropriate size (see below for recommendations)
- Opt for locations with plenty of natural light to reduce electricity use
- Choose locations close to railway and/or bus stations
Recommended room size
Standing space 0.6 m2 per person 60 m2 for 100 people Mixed standing and seating space 0.9 m2 per person 90 m2 for 100 people Seating space 1.2 m2 per person 120 m2 for 100 people
How to reduce CO2 emissions in catering?
- Avoid disposable dishes and other items
- Portion sizes should not be larger than recommended (~700 calories per dish)
- Avoid food waste, give surpluses to staff/participants (if possible)
- Choose a catering company that follows sustainability guidelines5
- If possible, order vegan and/or vegetarian dishes (see table below)
- if possible, the ingredients should be locally sourced
- Encourage participants to drink tap water6 (and to carry reusable water bottles)
Dish type Approximate CO2 footprint 🥦 Vegan 1 kg 🥗 Vegetarian 1 kg 🍝 Fish, chicken, pork 2 kg 🥩 Beef or lamb 5.5 kg
Memorabilia, gifts, and more: how to reduce CO2 emissions?
- Avoid unnecessary printing of documents (use QR codes and other e-alternatives)
- If you do print, choose recycled paper7
- If you reimburse participants for (travel) expenses, request electronic tickets, receipts and/or invoices
- Ask participants to bring their own pens (if used)
- If you enter into contracts with suppliers, provide conditions for the return of unused products
How to reduce events' waste?
- Make it possible for all participants of the event to conveniently sort waste (if not, place sorting & clearly label bins)
- Use reusable temporary event structures (billboards, signage, props, etc.)
- Give virtual awards and prizes
- Review your purchases and reduce the number of possible packages as much as possible
- Avoid combined (composite) packaging that cannot be recycled
- Compress a larger amount of waste, thus reducing the space it will take up during transportation
Do you have more tips / suggestions?
Media about us:
3. Offsetting CO2 emissions
How to offset CO2 emissions by investing in CO2-reducing projects?
How does it work? It’s support for a project that reduces the overall CO2 footprint of the planet by thousands of tons. For example, by replacing light bulbs with more efficient ones in developing countries.
To support such projects, we recommend using one of these platforms:
- United Nations online platform for voluntary cancellation of certified emission reductions (CERs) (climateneutralnow.org)
- CHOOOSE (the most developed private platform)
(👋 we do not receive any benefit from mentioning these platforms)
Good Practice
Ask event participants to contribute a symbolic amount (optionally) towards offsetting the event’s CO2 emissions (with the collected funds allocated for CO2-reducing projects).
How to offset CO2 emissions by planting trees?
🌳 10 kg – that’s a rough average of how much CO2 one tree absorbs per year. Therefore, a tree planted in 2024 will extract about 260 kg of CO2 from the atmosphere by 2050.
European tree planting platform – Adopt trees. Grow Forests. Restore Earth. • Life Terra (1 tree = 6 EUR) (👋 We do not receive any benefit from mentioning this platform).
If you’re planting yourself:
- Read about the best practices9
- Request permission for planting as early as possible (you should contact the local government)
- When it’s time to plant trees, do so in small groups (because the larger the group, the higher the CO2 emission)
Recommendation:
To increase efficiency (and reduce your own carbon footprint) organise one tree planting annually (and plant enough to offset the total CO2 “created” over the year).
What is an offset by pledge to reduce future CO2 emissions?
Pledging to reduce an organization’s CO2 emissions by a percentage (e.g., 10%) annually is also considered a way to offset the CO2 currently being “created”.
How to reduce (real) emissions:
- Read the tips we mentioned earlier
- Plan with your team (at the beginning of the year) how to emit less CO2 and stick to the plan
- Track and report your CO2 footprint (see below)
- Share tips on reducing CO2 emissions with your others
Do you have any tips / suggestions?
“A more sustainable event does not require a lot of time or resources. Moreover, sustainability will appeal to its visitors.”
Gediminas Kondrackis
“A more sustainable event does not require a lot of time or resources. Moreover, sustainability will appeal to its visitors.”
4. Impact Reporting
Why it’s important to report your organization’s CO2 footprint
- Sets a good example for others
- Encourages transparency and accountability in environmental impact
- Provides more insight into the organization’s operations, various processes, and sustainability
- Can assist in the organization’s communication and marketing
- Attracts like-minded partners (and customers) who prioritize sustainability
- Enhances employee engagement and morale by aligning with values of responsibility and sustainability
- Supports compliance with regulations and standards related to environmental protection
Do you have any tips / suggestions?
Checklist for More Sustainable Events
1. (Before the event) estimate the CO2 emissions
2. Reduce emissions during the event
3-4. Offset & report the emissions (after the event)
Share with others:
About us
Name: AY Institute
Address: Naugarduko g. 32/2, Vilnius, Lithuania
Established: 2014
E-mail: hi@akt.lt
Tel: +37064331871
We published the ‘Sustainable Events’ guide to make the culture of events and meetings more sustainable. Why? Because we are all equally responsible for our planet and its future.
Sources
0 Sustainable Travel Guide – How to reduce impact when travelling
1 EU-27: per capita GHG emissions 1990-2021 | Statista
2 European Environment Agency, Fraunhofer ISI and CE Delft, 2020
3 CO2 offset price by planting trees on Life Terra
4 Travel Sustainable | Sustainability at Booking.com
5 Prevention of Food Waste in the Catering Sector (umweltbundesamt.de)