CO2 emissions calculators for airfreight: a methodological bias that can lead to bad choices

The alert was given by our local forwarders.

During the COVID period, some major forwarders based on CDG airport drew our attention on the fact that the CO2 calculators that they use for the evaluation of the CO2 emissions of their shipments gave counter intuitive results.

Thus, for a shipment sent from Paris to Shanghai, for example, the CO2 calculators that are currently used by the air cargo industry estimate that it is better in terms of CO2 emissions to use a full freighter flight departing from a remote european airport rather than using a passenger flight departing directly from Paris-CDG!

Totally counter intuitive indeed, when it seems so logical that the freight carried in the belly of passenger aircrafts, using residual capacity in the plane, could be granted a marginal part of the emissions of the flight.

Counter intuitive again when you consider that carrying the freight to another European airport requires trucks, contributing to road congestion and to additional CO2 emissions...

We decided to focus on this issue, since we couldn't understand the reasons of such a situation that not only seemed illogical but also could lead to bad choices and to a breach of competition btw airports.

The answers to our questions came with the report of @TNO (a research institute in Netherlands): "Carbon Footprinting of Combined Passenger Freight Operations in Aviation Networks", issued in november 2020.

In a very clear demonstration, the report explains how the results of the CO2 calculators lead to such counter intuitive results: the CO2 calculators are based indeed on the IATA recommendations Practice 1678 or on the EU standard EN 16258 "Methodology for calculation and declaration of energy consumption and greenhouse gas emissions of transport services".

Those recommendations or standards propose to allocate the CO2 emissions of the passengers flights to the freight and to the passengers based on their respective contribution to the payload of the planes, taking into account a virtual weight per pax of 100 kg and 50 kg for empty seats.

The searchers from TNO highlight that the consequence of such a methodology is that, theoretically speaking, on a similar flight from Amsterdam to Shanghai, the same weight of cargo carried on a passenger flight would be granted 50% more CO2 emissions than the same weight of cargo carried on a full freighter flight!

When using advanced tools taking into account the performances of each aircraft, the searchers conclude that the real gap is +21% of emissions for the cargo carried in the passenger flights.

There is no objective reason to this situation! How can a similar weight of cargo generate more emissions when carried in a passenger flight than in a full freighter flight? How can this same weight of cargo increase its emissions when the configuration of the flight will give more places to the business class, hence reducing the number of passengers in the flight but using the same space? I personally don't understand...

By drawing the reasoning to its limits and to the absurd, searchers consider that such results could lead to developing new full freighter flights from remote airports when space could be filled locally with cargo in passenger flights...Everyone can imagine the consequences in terms of environment when we are all working hard to find ways to reduce the footprint of the air industry.

Hence the researchers from TNO propose alternative methodologies that would take into account:

• the use of capacity: 1 ton of freight carried on passenger flight should be granted the same proportion of emissions of the flight as one ton on a full freighter flight

or

• the revenue: CO2 emissions on a passenger flight could be allocated proportionally to the revenues of the flight generated by passengers on one side and cargo on the other side.

Maybe other methodologies could be imagined. One could be a mix of the two proposed methodologies from TNO.

Anyway, whatever the methodology, I strongly believe that the current ones that are used in the industry should be changed quickly to grant the cargo activity the real part of the CO2 emissions that it generates when carried in a passenger flight.

As a citizen of the world, before being a cargo manager, it is for me a question of attributing to one economical activity the reality of its emissions and not trying to minimize the emissions of one economical activity by overestimating another.

Link to TNO: TNO - innovation for life - Envision it | TNO