How Emissions are Calculated in Measure

For each consumption, Measure multiplies the amount used by the matching emission factor for each gas, then converts each gas to CO2e using its global warming potential (GWP):

Emissions (CO2e) = consumption × emission factor × GWP

For example, 1,000 liters of diesel × 2.68 kg CO2 per liter = 2,680 kg CO2. (Illustrative values.)

For fugitive and process emissions (s1.3 and s1.4), the consumption is already an amount of gas released, so Measure multiplies it by the gas's GWP directly.

When an activity has a custom emission factor, Measure always uses it instead of the automatic factor. The automatic factor is still used for any part of the year that no custom factor covers. For example, if a custom factor covers January to June, Measure uses it for those months and the automatic factor for July to December.

You can choose which IPCC assessment report’s GWP values Measure uses in your preferences. AR4, AR5 and AR6 are supported.

When a consumption period spans more than one emission factor period, Measure prorates the consumption value by the number of days each factor covers, then applies each factor to its share. For example, a bill of 3,100 kWh for December 15 to January 14 (31 days) is split into 1,700 kWh for December 15 to 31 (17 days) and 1,400 kWh for January 1 to 14 (14 days). Each share is then multiplied by the factor that covers those days.