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marclacoste Jun 17, 2019 01:36 PM
signals 2016: aviation Grams of CO2 per passenger-kilometre
Replies (3)
marclacoste Jun 17, 2019 02:29 PM
Hello, in https://www.eea.europa.eu/publications/signals-2016 the aviation Grams of CO2 per passenger-kilometre is reported as 285gCO2/pkm (p.56). It seems that value is unrealistically high : it would mean airliners burn 285/3.15 (fuel to CO2 conversion)/0.8(kg/l fuel density)= 11.3 L/100km per passenger, a very high value as the Airbus A321 (not even neo) is quoted for 2.2L/100km.<https://www.routesonline.com/[…]/>

The same report cites "a one-way transatlantic flight from Paris to New York in economy class generates around 381.58 kilograms of CO2, according to the ICAO's emissions calculator" and indeed the icao calculator gives now a bit less for CDG-JFK as aircraft are better now, over 5829km: 381.580/5829=65.5 g CO2/km or a more realistic 65.5/0.8/3.15=2.6L/100km in economy.

The source is given as "Estimates are based on the TRACCS database, 2013", and this source states :
"The total pkm for air transport in EU27 countries was an estimated [...] 593'000 Mio. pkm in 2010. (p.161) " and "The total fuel consumption for EU27 countries in TRACCS is 49.43 MTOE in the year 2010 (p.165) "for domestic and international aviation", so the fuel consumption/pkm may be calculated as 49430/593 = 83.36g fuel/pkm

Then "CO2-emissions are calculated by multiplying fuel consumption with the conversion factor of
3.15 t CO2/t fuel" (p.153) to compute a 83.36*3.15=262.6 gCO2/pkm. This seems to be close to the quoted 285g CO2/pkm, but thi is far away from the reality. It could be that the "fuel consumption" is"for domestic and international aviation", thus including intercontinental flying outside EU (at least for departures) while "The total pkm for air transport" is only for the EU27 ! Can you confirm the correct calculation. Thanks.

You can also note Morgan Stanley MSCI calculated the the average airline emissions at 123 g CO2/rpk in 2014, with the lowest being Ryanair at 75 g followed by Easyjet at 82 g. The average include premium passengers while Ryanair and Easyjet are all-economy.
EEA Jun 20, 2019 08:14 AM
Dear M. Marc Lacoste,

Thank you for contacting the European Environment Agency (EEA) and for your interest in the CO2 calculations for air travel.

The data used in the report is by now outdated and cannot be directly compared to newer calculations. Different estimates also often have different definitions and underlying assumptions. We have not done a more recent analysis precisely on this topic but you can find some of our latest analysis on the environment and climate impacts of aviation in our TERM briefing (https://www.eea.europa.eu/[…]/term-briefing-2018) and in the joint European Aviation Environmental Report (https://www.easa.europa.eu/eaer/).

We hope that this will be useful for you.

With kind regards,
EEA Enquiry Service
marclacoste Jun 23, 2019 02:53 PM
Thanks for your reply. This study is quoted by multiple mainstream media while there is no replacement. It's not just outdated (even if the numbers were from 2010, the progress is only ~1%/year, not so different), its computing logic is not explained and may be faulty. A verification and rectification may be needed. There is no comparison for CO2 commissions/pkm in both links: the first only quotes the CO2/km target for cars/vans (not the actual CO2 per passenger/km, with the current fleet and occupancy rate) and the second quotes a 3.4L/100km/pax fuel consumption (so, emissions of 3.4*.8*3.15*10=86 gCO2/pkm) in 2017, much more in line with the industry estimates. I honestly hope for more rigour from the European Environment Agency, given its widespread impact.