Air travel baselines
These baselines are based on data available in NTMCalc 4.0, literature reviews and expert interviews. The settings aim to reflect on general air travel. In general we recommend use of real data if available at sufficient quality. NTM default data are conservatively assessed and should if used thereby not enable low emission calculations. Furthermore they should promote transport suppliers to present their real data in relation to NTM default data, hence being used in the travel service procurement process.
Providing default data for air travelwill by definition entail an element of incorrect emissions and energy use assessment. The main reason is that air emission factors are not linear with distance:
Flying longer distance requires more fuel which adds to gross weight and thereby increases environmental impact itself. In effect this means that every individual flight have its specific emissions.
Another aspect is that the general flying cycle include lift and take-off, cruising and descend. Since the relative impact from cruising is lower than lift and take off means that shorter flights should have a relatively higher impact per shipment.
For this assessment the emissions on high altitude is considered equal to emissions at ground level. This question is controversial as many climate experts claim that high altitude GHG-emissions should be higher than the actual emissions. In order to take this into consideration in a practical way, CO2-emissions are multiplied by a factor (radiative forcing index) linked to altitude and atmospheric conditions. Long distance flights are normally at higher altitude than regional flights. This factor is set differently by different experts at 1-5 depending on flying altitude and underlying physics. At this stage NTM does not include this factor for default aircrafts.
The below data is based on NTMCalc 4.0 and includes range based “proxy” aircrafts on a specified distance. Previously data has been built on range based average aircrafts but in order to better reflect technical development specific aircrafts are used.
For a more specific calculation it should be carried out based on real data from supplier or actual settings of aircraft used in NTMCalc.
* The Swedish domestic average based on actual fuel consumption and cabin factor 70% gives CO2e wtw; 0,132 kg/pkm but some operator claim even lower GHG-emissions (0,088 kg/pkm at the same load factor of 70%). During the pandemic the emissions were significant higher due to low cabin factors.
Clarifications and abbreviations
NTM aircrafts in present default data (See matrix above stated as 2022)
NTM data in previous default data
Describes type of aircraft. Default passenger aircrafts within NTMCalc are generically derived through different specific aircrafts:
Saab 340, Fokker 50, Saab 2000 and B 737 – 600
A 320, ATR 72-100 and Avro RJ-100
B 737 – 800, A 320, A321 – 200 and CRJ – 900
B 757 – 200, A 330 and A 340 – 300
Describes typical ranges for the aircraft type
Refers to actual distance when calculating emissions
Use of energy, including fuel production/ distribution and the combustion (wtw). Only combustion is ttw.
Emissions of carbon dioxide equivalents including fuel production, distribution and the combustion (wtw).
Emissions of fossil carbon dioxide in the combustion phase (ttw).
NTMCalc 4.0; www.transportmeasures.org