Jevon's paradox and air travel

[Dave2002]

I'm not a great fan of air travel, but clearly other people do want to roam around the earth.

Up to now I had thought I preferred [if I have to use planes at all] travelling in the A380 compared to other planes - the A380 being a 4 engined wide body from Airbus.
However there are problems with loading/unloading those planes - as many airports can't really cope with the large number of passengers all arriving at the same time.

Airbus also have a 2 engined plane - the A350, which is slightly smaller, and seemingly almost as good from the passenger point of view as the A380

If we compare the fuel consumption per passenger mile though of different planes, we discover that currently the Boeing 787 Dreamliner has the best fuel consumption according to industry standard measures, and per passenger the fuel efficiency is significantly better than the A380 [the A380 is likely to burn up around 60% more fuel on flights compared to the 787].

However the Airbus A350 has fuel efficiency ratings which are only marginally worse than the 787 Dreamliner [order of 1%], but it may be a better plane from some passenger's points of view.

Unfortunately there is some evidence that enthusiasm for travel [which I don't fully share] is likely to kick in Jevon's paradox - see https://en.wikipedia.org/wiki/Jevons_paradox

So even though there has been considerable improvement in fuel consumption by aircraft over the last decade or two, the overall consumption and corresponding pollution and greenhouse gas emissions will have gone up.

[Serial_Apologist]

Good points to think about, Dave.

[smittims]

I understand airlines use (or used to use) a figure caled 'passenger mile' , that is,the average cost of carrying one passenger for one mile. In the 1970s the aim was to reduce this to one (new) penny. Some aircraft, if filled , could do this, the Boeing 767 for instance.

I love to see an A380 in the air as it seems to be moving slowly, because it is much larger than other aircraft of similar shape. But I should not like to fly in one; the proximity of so many other people crowding round me would be anathema. The only aircraft in which I have ever flown were a Slingsby glider (open cockpit and no parachute!) ) and a De Havilland Chipmunk, in which I wore a parchute and a Mae West: both two-seaters,and both of which I handled in the air. I've never wanted to fly since.

[Dave2002]

This article is interesting: https://en.wikipedia.org/wiki/Fuel_economy_in_aircraft

So is this one - https://www.i6.io/blog/airbus-vs-boe...uel-efficiency

One measure seems to be litres/100 km /PAX. I don't know how much aircraft fuel "really" costs anyway. Unfortunately international "agreements" limit many governments' ability to tax it, and clearly some politicians think it's "good for business" to keep aircraft flying.

[smittims]

Yes, I suppose that's another application of Jevons' paradox. By comparison with, say, rail vehicles, aircraft are intrinsicallty inefficient because of the amount of fuel needed just to keep them in the air. Even light aircaft have have an engine of much greater horsepower than a land vehicle of the same weight.

[Dave2002]

Yes, I suppose that's another application of Jevons' paradox. By comparison with, say, rail vehicles, aircraft are intrinsicallty inefficient because of the amount of fuel needed just to keep them in the air. Even light aircaft have have an engine of much greater horsepower than a land vehicle of the same weight.

Yes - but the infrastructure costs may be lower for air travel over long distances. If the passenger numbers are relatively low - that is the number of people wanting to travel from point A to B is relatively low, and A and B are some distance apart, then ground based transportation between those points is likely to require roads or rail networks to be constructed and/or maintained. The infrastructure costs may not justify the offsetting of fuel. There are often "hidden" emissions issues in building fixed infrastructure - transport for the parts required, and concrete - for example - is known to add to CO2 emissions.

Air travel generally requires infrastructure at the source and destination [airports], plus also administrative infrastructure [air traffic control, emergency provisions etc] - but does not obviously depend on the distances between the start and end points in a linear fashion.

[Serial_Apologist]

The infrastructure costs may not justify the offsetting of fuel. There are often "hidden" emissions issues in building fixed infrastructure - transport for the parts required, and concrete - for example - is known to add to CO2 emissions.

Not to mention the wear and tear on tyres, and the pollution effects therefrom!

[smittims]

The infrastructure angle remkinds me of flying boats, which, before the world was peppered with concrtee runways, were seen as the answer to long-distance travel. Then there was the Fairey Rotodyne, a vertical-take-off airliner which didn't need runways and was cheaper in the air than a helicopter. Sadly, the powers that be simply didn't want it.