Question

[Kenn]

As a frequent air traveler to the far north can any one answer this question?
I use a large aircraft that carries 180 passengers, the flight lasts 1hour and 15mins depending on the wind speed and direction.
Now if I was to use my car and say 2 people to each vehicle that would equal 90 vehicles on the road for 12 hours minimum to Inverness.
Which is the greater polluter?

[Ali]

I dont know but cars better as can fit more shopping in boot without paying extra.....

[brokencross]

How many engines are on the plane?

[MadPict]

According to this lot - http://www.planestupid.com/

...the CO2 levels from London – Edinburgh by plane are 96.4 tonnes, compared with 71 tonnes by car, 11.9 by rail or 9.2 by coach. (Transport 2000)

[Kenn]

2 engines brokencross.

Madpict do I read that correctly?
96.4 tonnes for a plane, 71tonnes for a car so would that mean that 90 cars would emit 6390 tonnes?

[j4bberw0ck]

Madpict do I read that correctly?
96.4 tonnes for a plane, 71tonnes for a car so would that mean that 90 cars would emit 6390 tonnes?

The figures make no sense; and yes, I looked through the website to find the quote. If they mean per single journey (they don't define their terms) than a motor vehicle would have to burn something well in excess of 71 tons of fuel on tha journey, which it clearly doesn't (would you buy a car which burned 71tons of petrol to get from London to Edinburgh?)

It's selective misquoting of figures again, to make a point. I'm pretty sure they're right in saying aircraft are a substantially greater danger than cars, but you always need to be careful with single-interest groups and their numbers.

[MadPict]

Does sound completely crazy - full quote - found under "10 reasons To Ground The Plane" link

AVIATION IS MOSTLY UNNECCESSARY

80% of worldwide flights are within Europe and 45% of these air journeys are less than 500km – about the distance from London to the Scottish border. (Department for Transport/Transport 2000) These journeys could quite easily be made by other means of transport like bus, ferry and train – all of which are over ten times less polluting. For example, the CO2 levels from London – Edinburgh by plane are 96.4 tonnes, compared with 71 tonnes by car, 11.9 by rail or 9.2 by coach. (Transport 2000)

The figures from transport 2000's site -

Carbon dioxide emissions for journeys from London to Edinburgh and London to Bristol by different modes: London to Edinburgh: plane 96.4, rail (modern high speed electric) 11.9, car 71, coach 9.2. London to Bristol: rail (modern diesel) 10.6, car 21.3, coach 3.3. (Figures show carbon dioxide emissions in kilogrammes per passenger per journey. Car emissions based on loading of 1.56 people per car.)
Source: Department for Transport/National Atmospheric Emission Inventory 2004

[DrSzin]

A quick guesstimate suggests that the Transport 2000 figure for the car journey is in the right ball-park - assuming they're quoting the CO2 emitted per car (or per person) per journey and the figures are all in Kg.

400 miles at (say) 40 miles per gallon gives 10 gallons or 45 litres of petrol. The latter weighs roughly 45 kg and is largely hydrocarbon, so most of its mass is due to the carbon. If all the carbon were to burn and become CO2, and all the oxygen came from the atmosphere, then roughly 150kg of CO2 would be emitted. (Oxygen atoms are 25% heavier than carbon atoms and CO2 contains two times more oxygens than carbons.) This dumb estimate puts an upper limit on the CO2 emission. The real figure might be less by a factor of (say) two, and we obtain the Transport 2000 figure.

It seems that planetstupid describes itself rather well. Their people don't know the difference between a kilogramme and a tonne. What's a factor of 1,000 between "experts" on the environment? Who cares? These guys are saving the planet so it doesn't matter that they're innumerate and haven't a clue.

[Kingetter]

I had an idea that the figures for aircraft needed looking at pretty closely. There will be a difference between propellor driven aircraft and jet planes. Also, the greater volume of 'exhaust' with planes when taking off or landing (reverse thrust?) in comparison with the aircraft at cruising altitude. Furthermore, there are I believe, different densities of air as one goes higher and higher - will this not need to be assessed?
In the good old bad old days of smog, this was I seem to think, fairly low lying. It had more to do with surface vehicles (and other causes of course) than aircraft.