3 ms·
No they are not. Airliners fly in the lower stratosphere, the troposphere is what is primarily warming. The effects on ozone are another story. [edit] for anyo
by ch4s3 5y ago
No they are not. Airliners fly in the lower stratosphere, the troposphere is what is primarily warming. The effects on ozone are another story.
[edit] for anyone downvoting, I'm referencing this paper[1] in the Encyclopedia of Global Environmental Change from 2002, which says:
> Increases of the concentration of
small particles emitted from aircraft with similar residence
times have also been measured near dense flight routes. CO2
on the other hand, has a lifetime of the order of 100 years
and gets distributed essentially over the whole atmosphere.
Therefore, the effects of CO2 emissions from aircraft are
indistinguishable from the same quantity of CO2 emitted at
the same time by any other source.
It's consistent with older research as well, and I can't find anything newer that refutes the claim.
[1] https://www.dlr.de/pa/en/Portaldata/33/Resources/dokumente/mitarbeiter/Schumann_Encyclopedia_Aircraft_Emissions_c415-_o.pdf https://www.dlr.de/pa/en/Portaldata/33/Resources/dokumente/m...
- nkurz 5y agoI think your reasoning is correct for CO2, but the OP asked about "emissions" in general. For some of these, the dispersion is less, and thus the high altitude does make a difference. I've only skimmed it, but this seems to be a good paper describing the different effects: http://www.anjakollmuss.com/wp-content/uploads/2017/04/SEI_Air_Travel_Emissions_Paper2_June_09.pdf http://www.anjakollmuss.com/wp-content/uploads/2017/04/SEI_A... While agreeing that a multiplier is not strictly correct, they recommend applying multiplier "greater than 2" to properly account for the non-CO2 effects of air traffic on global warming: Though science-based reasoning discourages the use of a simple multiplier to account for non-CO2 effects, such a multiplier is desirable from a policy and climate protection point of view. We elaborate on a number of scientific and value-related issues and conclude that a multiplier of 2 or greater should be used for air travel emissions calculators to account for non-CO2 warming effects.
- ch4s3 5y agoYeah I understood the OP to mean c02 and added the caveat about other emissions. It seems pretty uncertain, especially as lower level stratospheric mixing seems poorly understood. But, my understanding extends only as far as having read 3 papers on the topic.