Emissions - MokkaMan
Did anyone listen to radio 2 at lunchtime today. They were having a discussion about emissions comparing car and aircraft emissions (I think this was on the back of Tony Blair saying that he would continue flying to his holiday destinations). Apparently a return flight to New York is equivalent to each person on that flight doing 10,000 miles in their car. It is quite useful putting it in perspective like that. It also highlighted that flying really continues to be too cheap an option. It is quite often much cheaper to take a domestic flight than the train. So really the pricing structure is all wrong. Flights should be taxed more, trains subsidised and cars taxed less.

Will it happen? Probably not.
Emissions - Number_Cruncher
>>Flights should be taxed more,

OK

>>trains subsidised

No! The railway system as it stands could not even cope with a modest increase in passenger numbers. On many routes, getting a seat is enough of a challenge already. The rail fares need to be kept high to contain demand.

Obviously, the right thing to do would be to increase capacity, and run some longer trains - unfortunately, the system is going the other way, by replacing decent HST services with 10 or so wonderful, quiet, and comfortable mkIII carriages, with beastly 4 or 5 car sets of tarted up noisy DMUs (Voyagers, Meridians, and others of their vile kind). At least the Turbostars and class 15x trains aren't being used as if they were inter-city expresses.

To me, it seems clear that we should be encouraging people to work from home wherever, and whenever they can. Having people commute in, to sit at a desk with a pc and a phone on it is utter nonsense, which, with the availability of broadband, we don't need to do this any more.

Number_Cruncher
Emissions - cheddar
As I said recently in another thread a longhaul Boeing 747-400 will do around 90 mpg per passenger, short haul 737s etc will be around half of that due to the larger proportion of the total flight that is taxying, take off and climb-to-height.

So take a family of four going on hols, they are combined doing around 22mpg on a long haul flight which perhaps compares well with four up in a large petrol car though the problem is that they will do a 7000 miles plus just going to east coast USA and back for a weekend.

Although a shorthaul 737 does only around 35 to 45mpg per passenger, it makes shorthaul business air travel fairly competitive with single occupancy cars though if the car carries more than one passenger it wins easily.



Emissions - mk124
Good point NC, without the expansion of capacity of the rail network overcrowding on trains will only get worse if we lower the prices.
That is not to say the public transport system should not be given subsidies however, but prehapps the government should look at the incentives for investment that train companies and railtrack (or whatever is is called now) have.

On the pricing system the government is out to tax car owners since they are an easy target. Car taxes are sky high on environmental grounds to stop global warming. However we don't tax domestic heating much else that produces greenhouse gases. Imagine the uproar if we introduced a tax on cows for producing methane, but that just shows car owners are not taxed for the sake of the environment but because they are an easy target.

One of the comments Mr blair told people was that he was not willing to change his travel habits and give up long haul flights. As an economist I think this is quite the right attitude to have, what he is saying is that costs of long haul flights are not high enough to stop him using them. It seems that he is using his freedom of choice.

Taxes apart from providing government revenue also try to change behavour. For example a petrol tax raised on environmental grounds would not make sense if it did not change anyones behavour. In other words the tax does not protect the environment. In my veiw most environmental taxes do work, the high european petrol taxes have made motor manufactures seek greener technolgy and consumers to buy smaller more fuel effecent cars as well as making less journies. If we raise the tax on airline fuel it will have much the same effect on airlines.
What Mr blair may have been trying to point out is that we should not feel guilty about using airplanes, but raise taxes until some people think it costs to much to jet to New Zeland for holiday, and for the airline manufactures to give us greener technology.

-----------------------------------------------

Torque means nothing without RPM
Emissions - Armitage Shanks {p}
Cheddar, you were kind enough to comment on my thread re flying (to Rome) or driving. I read what you say but can't quite get my head round the figures! I think we should be taking gallons per mile per passenger not miles per gallon per passenger! If an aircraft flies 1000 miles with one passenger this is obviously way less efficient than flying the same distance with 100 passengers. The aircraft will be heavier and use a bit more fuel, but the fuller it is the more people are being carried for a given use of fuel. The aircraft will burn say 20000 lbs of fuel to make the trip of 1000 miles which is 20 lbs per mile which is a bit less than 3 gallons per mile. It is obviously way more efficient to fill the aircraft with passengers. It would be doing 3 gallons per mile per passenger with one on board and 0.03 gallons per mile with 100 on board. Be gentle with me if I have got it wrong, please!
Emissions - cheddar
Hi AS,

Take the 747 doing approx 90 mpg per passenger, let's arbitrarily base this on a compliment of 360 passengers, it means it is using about 4 gallons a mile which at 500 miles per hour means it takes about 1.8 secs to use a gallon, or about 20,000 lb/hr or around 160,000 lb per Atlantic crossing.

Very rough, though indicative at least.
Emissions - Armitage Shanks {p}
Thanks Cheddar, I am none the wiser although I am much better informed! What is 90 mpg per passenger - where does that figure come from? Does 90 mpg per passenger imply 1800 mpg with 200 passengers or what? I suggest that the true basis for a comparison of my original fly or drive to Rome scenario is the amount of fuel used, and CO2 emitted, per passenger miletravelled.

I am now going to fly a round trip to Lanzarote for 2 weeks in the sun and I shall spend the whole holiday worrying about this thread!
Emissions - Mad Maxy
MPG; GPM. Same thing. We use mpg as a measure of fuel eficiency. On the continent they use litres/100 km.

HJ strongly illustrates that global warming is multifactorial in origin.

Caning car users is easy because they are a diverse bunch of individuals, and therefore relatively weak.

I would like to see aviation fuels taxed properly. I would also like to see big investment in public transport, so that we DO have a viable (affordable, convenient, pleasant to use) alternative to the car for many journeys. Then people might even switch voluntarily from their cars, not least because the train, tram, bus, etc avoids the congested roads. OK, then the government can start to make motorists pay more for 'unnecessary' journeys.

Cruncher, you seem to know your Class 220s from your 222s. (I used to know all that stuff!)
Emissions - IanJohnson
747 gross around 360 tonnes say 150 tonnes of fuel at 9lb/gallon is 168k litres.

400 Passengers, 6000 mile flight - 2.4 m passenger miles.

(my estimates may be out)

Equates to 14 passenger miles per litre, my Accord does about 40 passenger miles per litre with four up.

So why is there no tax on Avgas to reduce carbon emissions?
Emissions - cheddar
747 gross around 360 tonnes say 150 tonnes of fuel at
9lb/gallon is 168k litres.
400 Passengers, 6000 mile flight - 2.4 m passenger miles.
(my estimates may be out)
Equates to 14 passenger miles per litre, my Accord does about
40 passenger miles per litre with four up.


Lets talk gallons not tonnes, lb or ltrs so as to compare with cars mpg.

I reckon a 747 uses on average 2000 gallons an hour ( that is about 8.5 gals per min per engine ), so on a 3600 mile trip with 400 passengers that takes 8 hours:

8 hours x 2000 gallons = 16,000 gallons

3600 miles x 400 passengers = 1,440,000 passenger miles

1,440,000 / 16,000 = 90 mpg per passenger or about equal to your Accord two up.



Emissions - cheddar
Thanks Cheddar, I am none the wiser although I am much
better informed! What is 90 mpg per passenger - where
does that figure come from? Does 90 mpg per passenger
imply 1800 mpg with 200 passengers or what? >>


90mpg per passenger is roughly the longhaul fuel consumption versus the number of passengers based on average pax numbers, around 360 IIRC so assuming the actual consumption is around 0.25 miles per gallon each of the 360 passengers are travelling that 0.25 miles on that gallon so 360 x 0.25 = 90 passenger miles per gallon.