Global Warming

Carbon Dioxide Emissions from Passenger Flight

March 11th, 2008 Subscribe To Our Feed

Calculating Carbon Dioxide Emissions from Passenger Flight.

The Internet provides us a wondrous array of information; unfortunately the level of this information can vary greatly. Similarly there are many different flight calculators available on the Internet, returning you the reader with different results for the same information this can be rather confusing. This conflicting information is down to differences in the calculation, as there are several factors that need to be taken into account. Some of the online calculators will not take any of these factors into account while other will not count all the factors.

OK, What are these Factors then?

Length of flight
Size of plane
The calculation of flight distance
Other Pollutants other than CO2
Class of seating

Length of Flight.

There are Different factors that need to be applied for short, medium and long haul flights. Each one has a different emissions per passenger per km for each one of these due to the increased emissions required for take off, taxiing and idling (the shorter the flight the higher the proportion of flight fuel used for takeoff, taxiing and idling).

Size of Plane

This is a obvious one, but the bigger the plane the mores fuel it needs.

The calculation of flight distance

The Earth is not flat, so distances cannot be calculated on a straight-line formula as planes will ultimately have to mirror the Earths curvature, resulting in an Arch flying pattern. This distance can be calculated using an approximation formula (the Great Circle Distance Formula) Please refer to How to calculate the distance between two points on the Earth for a more mathematical explanation.

Other Pollutants other than CO2

When calculating carbon dioxide for air travel a consideration is needed to calculate the other effects of aviation other than CO2. Other greenhouse gasses emitted into the atmosphere are:

NOx compounds
Ozone
Methane
Water
Contrails
Particles

These are all emitted from aircraft exhausts at the same time as CO2. These elements are released directly into the Stratosphere. Because of the height they are exhausting they have a higher potential to effect the anthropogenic radiative forcing that naturally takes place in the Stratosphere. The effects are much greater than the fossil fuel production on land due to the longer residence times required. Such an effect is taken into account by the development of the radiative forcing index (RFI) which compares the total radiative forcing effect caused by aviation to that caused by CO2 alone.

Class of seating Economy vs Business and First Class:

Because it requires more aircraft space and resources to cater for business class passengers, and even more for first class passengers, you really need to take this into account when calculating your emissions. Business class passengers are responsible for twice the emissions of economy class, and first class are responsible for three times.