Hello,
This is a quick collection of links on what I hope are reasonably
neutral sources for the effects of air transport relative to other
things.
First up a pdf from the Intergovernmental Panel on Climate Change's
(IPCC) fourth assessment
(
http://www.ipcc.ch/pdf/assessment-report/ar4/wg3/ar4-wg3-ts.pdf).
Page 29 gives a nice breakdown of the contributing sectors, in which
all of Transport comes to 13.1%, compared to all of power to say
25.9%. Later on page 49 we have a sub-split of transport and in the
year 2000 Air accounts for about 1/2 Gt CO2 out of 5 Gt of CO2, making
it very roughly 10% of 13.1%, so ~2% if we're being harsh of global
emissions. Road transport was more than 80% of the transport sector.
There is the added point that these emissions are being added to the
atmosphere at high altitude which is probably not helpful, but...at
the same time that's not damaging air quality on the ground either.
Depends what you consider to be the worse type of pollution, global
temperatures, air quality, noise etc or some weighted combo of these?
This link is something that I've seen before as a pretty up to date
estimate on how to work out the impact of aircraft. Please note the
size of the error bars on the contributing parts of the Radiative
Forcing on Page 7 and the comment on the level of understanding of
each one. (
http://www.jpmorganclimatecare.com/media/documents/pdf/aviation_emissions__offsets.pdf).
We need a lot more atmospheric chemists, but there appears to be
little money in it and it's a hard subject.
As to the question is it a good trade, well the Royal Aero Society
thinks so (bias warning) which claims that it contributes
significantly to global GDP
(
http://www.raes.org.au/assets/Uploa...n-Paper-Aviation-Emissions-Climate-Change.pdf)
We'd probably find ways round it if we couldn't fly, so I don't
really see that as a big argument.
My big complaint really is that aviation has made itself a dumb
target. Almost everyone can agree that flying less is good, because in
reality people fly only a few times a year and before low cost
carriers even less. So what's one less long weekend in Prague?
But if it came to building a massive new and efficient power station
down your road (*cough*nuclear*cough*) you'd not be pleased. Because
of this aviation is an easy target for politicians and doesn't offend
any voters. Please see the confusion on wind farms (as useless as they
might be). If we could improve energy generation but just a small
amount (5%) we'd completely obliterate the impact made by aircraft.
Not that they aircraft industry isn't trying, it's made massive
improvements, more than any other, since the 70s. But even if we made
aircraft 50% more efficient than now, an impressive feat if possible,
then it'd only take a bit more power generation to completely
eradicate that.
I'm not saying flying is all good, it's not, but compared to some
other things it's a really stupid small and ineffective target.
Actually that's turned out to be quite long, hope you enjoyed it.
H