Understanding emission factors for carbon footprint calculations

Emission factors form the core of carbon footprint calculations. Multiplying these by the activity variable – any emission-generating activity – results in a carbon footprint. But where can you find suitable emission factors? And why are there so many choices for the same products? Let's dive deeper into it.

What is an emission factor?

The emission factor is the amount of selected emissions in proportion to the determined amount. The chosen emission is often the unit of measurement for all greenhouse gases, the equivalent of carbon dioxide, where the quantity represents the amount of product or service used. The emission factor thus indicates the amount of emissions released into the atmosphere during a specific activity. Its unit can be e.g.

• Food: kg CO2e/kg
• Electricity: g CO2e/kWh
• Financial transactions: kg CO2e/eur
• Fuels: t CO2e/TJ

(Emma Valliová, more at biocode.io)