What is CO2e (Carbon Dioxide Equivalent)?

CO2e, or carbon dioxide equivalent, is a standard unit for measuring carbon footprints. It expresses the impact of different greenhouse gases in terms of the amount of CO2 that would create the same amount of warming.

Why do we use CO2e?

Different greenhouse gases have different effects on global warming. For example:

• Methane (CH4) is about 25 times more potent than CO2
• Nitrous oxide (N2O) is about 298 times more potent than CO2
• Some refrigerants can be thousands of times more potent

By converting all these gases to CO2e, we can compare their impacts using a single number.

Example

If a product produces:

• 1 kg of CO2
• 1 kg of methane (equal to 25 kg CO2e)

Its total carbon footprint would be 26 kg CO2e.