Trains, Planes, Automobiles
By: Tom Mercer on 11 09, 2007
So, this month’s Travel & Leisure discusses the issue of whether it creates more greenhouse gases to drive, fly, or take a train. Their conclusion: train is by far the most eco-friendly solution and driving actually produces more emissions to travel the same distance than flying.
T&L’s data came from TerraPass, and without disputing their math (which isn’t laid out), I would say that there are a couple of factors left out of their analysis. For one, they ignore the NUMBER of people who will be driving versus flying. What I mean is that if you have a family of four, it is actually more efficient to drive to your destination than to fly. The reason is that the airplane emissions are on a per-person basis and calculated on plane capacity average plane fuel efficiency, etc.–whereas car emissions are for the vehicle and will not change much if you’re driving alone or if your traveling as a family.
Another factor that T&L conveniently ignores is the factor of fuel efficiency for different vehicles - from SUVs to sedans to hybrids. This obviously has an important effect on the desirability of flying versus driving.
We like to take a more nuanced approach, and so we’ve analyzed figures from the Department of the Environment in Britain which does a has done a more detailed job of comparing different modes of transportation, so we will use their figures and extrapolate from them.
The following are average figures for the amount of pounds of CO2 per mile released into the atmosphere for each type of transportation:
Total Emissions Per Vehicle
SUV (15mpg) – 2.29 lbs/mi
Average Car (25 mpg) – 1.39 lbs/mi
Prius (55 mpg) - .61 lbs/mi
Motorcycle - .57 lbs/mi
RV – 4.58 lbs/mi
Total Emissions Per Person
Average Car/Single Driver – 1.39 lbs/mi
Average Car/Family of 4 - .34 lbs/mi
Train - .32 lbs/mi
Bus - .48 lbs/mi
Plane (250 mi trip) - .85 lbs/mi**
Plane (600 mi) - .69 lbs/mi**
Plane (3500 mi) - .56 lbs/mi**
Bottom Line:
If you have a choice of how to travel, buses and trains have the fewest carbon emissions. Planes and cars are less favorable options, and which one is more efficient depends on how many people you are traveling with and what car you would drive. A family of four would be better off driving than flying, whereas an individual might actually save emissions by flying.
**One other note: these emissions figures, which are taken from the
9 Responses
Great catch that the analysis is done on the basis of single travelers rather then a family.
If I recall the stats correctly, I believe the average leisure trip has 2.8 travelers, so your re-calculation is important!
[…] Anyway, I don’t own a car in Shanghai, so I feel good at doing something stopping global warming in my daily life. My action is to get around by foot instead of bus or taxi. I was “proud” that I took train to Beijing in my recent trip instead of plane. Train is the greenest transportation in travel, according to Tom Mercer on Trains, Planes, Automobiles. […]
T & L’s analysis is right out of my old college textbook “How to Lie with Statistics.” Don’t you HATE it when they do that?
And thanks for breaking down the auto emissions by car type. I was in a Prius over the weekend; and as far as I’m concerned, it’s the only car to drive.
Thomas, thanks for the comment. The Prius IS a great car, and the good news is there should be more appealing hybrid and pure electric vehicles coming to market in the coming years.
I am looking to contact either Tom Mercer or Yen Lee. Is there any contact/email information here?
Thanks for the article. It is tough to find good data on this subject. The numbers that various sources put out on Carbon Emission are all over the place with regard to jet travel.
Thanks, EcoInteractive. The numbers vary so much, because the load factor assumptions, type of airplane, and many other factors change the emissions data so dramatically. I don’t claim that these are the right figures for every case, but we have cited our sources, so you can go there to get more information on what assumptions were made.
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