A calculation tool based on scientific data
To find out how much greenhouse gas (GHG) is emitted by our actions, we use **emissions databases **combined with calculation models. This process is rigorous and based on a standardized methodology.
Each action (traveling, eating, heating your home, etc.) is analyzed in detail to estimate its total climate impact.
"Emission factors": reliable reference units
An **emission factor **represents the **amount of CO₂e emitted **for a given unit of activity. For example:
| Action | Emission factor |
|---|---|
| 1 km by gasoline car | ~200 g CO₂e/km |
| 1 kWh of electricity (Swiss mix) | ~20 to 150 g CO₂e/kWh |
| 1 kg of beef | ~27 kg CO₂e/kg |
| 1 email with attachment | ~10 g CO₂e |
| These figures come from reliable sources such as OFEV (Switzerland), ADEME (France), or industry references. |
Life cycle assessment (LCA)
**Life cycle assessment **(LCA) is a method for measuring the total environmental impact of a product or service, from its manufacture to the end of its life. This includes:
- Extraction of raw materials
- Manufacturing
- Transport
- Use
- End of life (recycling, incineration, etc.)
This method provides a **comprehensive and accurate overview **of the carbon footprint of each action.
A calculation tailored to the Geneva context
The Nos Gestes Climat – Genève calculator uses databases specific to the region:
- Electricity mix calculated to include local production in Geneva, including hydroelectric and solar photovoltaic power
- Current energy prices and heating methods
- Local mobility and consumption data
This provides a **more realistic and representative **result for the canton's residents.
The role of the calculator
The calculator gathers the most relevant data and applies it to your answers:
- Quantity x emission factor = CO₂e impact
- The answers are translated into emissions
- The total is then calculated to give your annual footprint
This allows you to quickly and easily identify which items have the greatest impact on your carbon footprint.
What if the data is not available?
For certain specific actions or objects, there is not always a local or recent emission factor available. In this case, the calculation tool:
- Uses averages based on similar cases
- Makes a conservative but consistent estimate
- Continuously improves its databases based on user feedback and recent studies
Objective: better understanding for better choices
Measuring your carbon footprint makes the invisible visible. By translating each action into CO₂ equivalents, we can better understand **where the most useful efforts **for the planet lie.
To go further:
https://www.ge.ch/document/geneve-lance-premier-calculateur-empreinte-carbone-cantonal
https://www.geneve.ch/themes/durabilite/climat/comprendre/empreinte-carbone
https://www.geneve.ch/actualites/alors-fais-tonnes-calculateur-carbone-estimer-empreinte