By using the ICAO Carbon Emissions Calculator Methodology to calculate your share of the flight’s emissions on a per passenger km basis. Historic data from our own aircraft like fuel consumption and passenger loadings are all considered in the calculator and we also apply a different factor for long and short haul flights.

We also calculate distance between airports using the ‘great circle distance’ which is the shortest distance between two points on the globe.

**What is Radiative Forcing Index (RFI) and do you apply it to your calculations?**

Radiative Forcing Index (RFI) is a multiplier that takes account of the extra gases emitted to the atmosphere when you fly at altitude – which are greater than burning fossil fuels at ground level. Scientists estimate the impact is between 1 and 4 times greater but because of the uncertainty on what that additional impact is, the aviation industry do not include RFI in their emission calculations, so our calculation doesn’t include RFI.

For further details on our calculation methodology visit ICAO’s site .