What has more impact on your carbon footprint, driving a car or flying by plane?

Question

For example, I drive approximately 10,000 miles a year but do not fly anywhere. Somebody I know does not drive anywhere but takes about three short haul (2-3 hour) flights a year + the return journey, so effectively 6 flights. Who leaves the greater carbon footprint?

Answer 1

So, are you saying that your friend basically is on foot or bicycle except for the flights? You should factor that in, even if he is using public transportation.

Many of the flight calculations were OK - Patrick's being based on range being the most accurate - but those values are for aircraft flying at cruise altitude. Jets are extremely inefficient at low altitudes and calculations have to consider the amount of time spent in the takeoff and landing evolutions of the flight. Commercial flying is highly variable in this regard, and depending on the airports an aircraft may actually burn less fuel flying a couple thousand miles than it will navigating the traffic patterns of many urban centers (not to mention the vast amounts sometimes used during taxiing and waiting to take off.)

Without the particulars, I'd guess that your use is going to be slightly lower.

Answer 2

1

Answer 3

An average sedan carries five people and gets 25 mpg. A 747 has 550 seats and gets about 0.3 mpg. On a per seat basis they both get about the same mileage. The problem is the number of passengers. The "average" car only has 1.2 passengers. So from a capacity factor approach the car is 4X worse than a jumbo jet for producing carbon footprint because it is carrying 1/4 of a full load.

A commuter train with 1500 seats and a 4000 HP diesel electric engine is about 5X more efficient than the car or plane on a per seat basis..

Answer 4

The annual death toll from road traffic accidents in the USA is around 40000, not 414000, so that's the first statistic you've got wrong. The second piece of bad news is that more than 50% of motorists believe they are better than average, which is impossible. Unless you have an advanced driving certificate, as I have, the likeliest probability is that you are only an average motorist. The third piece of bad news is that even if your driving standard were high, you would still be exposed on the road to the foolish and sometimes dangerous activities of others. The 4th piece of bad news is that "Safe drivers are 1 million times less likely to get involved in an accident" is a statistic you just made up. Per vehicle-mile you will always be safer in an aircraft of a reputable commercial airline.

Answer 5

a boeing 727 carries 189 passengers
fuel load is 8100 gallons
and range is 2700 nm

so it gets .33 nmpg

just a rough estimate, but
if the airplane has a full passenger load it has a lower carb footprint than if all the passengers would have driven (alone).

if half loaded it's a tie

if under half loaded the car wins

(not considering the different combustion properties of kerosene and gasoline or the fact that cars must use roads which increases tha mileage of a trip)

i would guess that if your driving alone, flying is a lower carbon foot print.

Answer 6

It depends on what type of car you're driving.

If it's a big V8 or something like that then newer fuel efficient aircraft are probably going to emit less carrying a full load of passengers than you're car will carrying just you (the aircraft is more likely to be full than your car and even if you've got a passenger you'll probably still emit more per person than the plane) and the plane isn't full adding an extra passenger to it isn't going to change the amount of CO2 it gives off.

Fuel efficient cars will probably emit less CO2 than aircraft for a given distance travelled although for all but the most fuel efficient cars you'll need to have passengers in your car to get less than a new full plane on per person CO2 emissions.

On the whole I suspect that the cars will be worse although it depends on what car you drive and what types of aircraft your friend flies on.

Of course your friend gets to relax on the flights and is less likely to get killed than someone who drives that distance, not to mention getting there much quicker.

Answer 7

It depends on what car you're driving, if you're driving by yourself, and how full the airplane is.

In the UK the average CO2 emissions per car is 190 g/km. In the US it's worse, so let's just assume you drive a car with 200 g/km of CO2 emissions.

http://www.carpages.co.uk/co2/

Assuming you're driving by yourself all the time, that's 320 g/mi * 10,000 miles = 3,200 kg of CO2. Or divide that by the average number of people in your car if you don't drive by yourself to get kg of CO2 per person.

An airplane will get about 85 g/km per person of CO2 emissions on an average flight.

http://www.atmosphere.mpg.de/enid/Information_ss/What_comes_out__5sv.html

So if your friend takes a 1700 km flight (roughly 2-3 hours) six times per year, that's 867 kg of CO2 released per person for those 10,200 km of flight.

However, the contribution of the contrail radiative forcing effect exerts an overall warming result that is approximately 2.7 times larger than carbon dioxide (see page 23 in the link below)

http://www.andrew.cmu.edu/user/jbistlin/files/Environmental%20Impacts%20of%20Aviation.pdf

So the net contribution to global warming from those flights is the equivalent of 2,341 kg of CO2 released. This is still just 73% of your 3,200 kg of CO2 from driving, but if you average 1.37 people in your car over the year's driving, or if you have a more fuel efficient car, you could come out as the guy with less of a global warming impact.

Answer 8

An airplane produces maore carbon emmisions, but they're a lot more people on a plane than a car, so if you divided up the carbgon, a plane would have less.

Plus the plane takes off no matter what, if the seats are empty or full. so you going on a palne won't add any carbon.

Answer 9

Notice that some of the answers use data to get you an answer. That's how science works.

They are, of course, correct. The plane is better unless you fill up the car with people.

The people who go by "logic" are often wrong.

The same thing is true about global warming. The data shows that it's 80-90% caused by us. The people who go by "logic" and say otherwise are wrong.

Answer 10

If you are diving a very long way like from florida to oregan than you should probably fly because there are so many things that could go wrong and make you waste lots of fuel. but other than that drive