Steve Mcsweeny/iStock
READ MORE ABOUT:
There might be some people out there that don't like to travel, but I'm not one of them. Not in the slightest. In fact, I'll go just about anywhere and enjoy exploring, whether it's someplace I've never been or someplace I've been before. I really can't get burnt out (for long) on traveling. Unfortunately though, flying frequently is pretty high up there in terms of environmental impact.
How to reconcile wanderlust and concern for the planet? Short of setting out using your own two feet or a bike—perfectly good options, but unless you're Satish Kumar walking from London to Delhi very well may not be your idea of a good time—what mode of motorized travel has the least global warming impact?
I looked at three trips in the United States: New York City to Washington DC (230 miles or so), NYC to St Louis, Missouri (about 950 miles), and NYC to San Francisco (about 2900 miles).
What Travel Method Has Lowest Emissions
I wanted to know which of the following modes of transit had the least carbon emissions: Flying, taking the train or bus, or driving in either the average US car (23 mpg) or in a Prius (46 mpg). I was confident going into it that flying would come out the worst, and that was borne out by the stats, but the rest surprised me a bit.
Time and cost were not considered. This wasn't just to simplify the calculations, but because I genuinely enjoy taking my time in transit. What can I say? I like to stop and smell the proverbial roses. Also, all these are one-way trips. For all of the trips the ratio of emissions was similar:
Driving in a Prius (or another car that gets similar fuel economy, like many modern diesel's do) and sharing that car with three other people had the lowest carbon emissions. Going from New York to San Francisco this way would mean that each person's emissions would be about 305 lbs of CO2.
Long Distance Bus Travel Beats the Train
Taking the bus for long distances was consistently the lowest emissions of all public transit methods. (This isn't the case for inner city travel, but hold that thought for a moment.) From New York to San Francisco, St Louis or Washington DC the emissions are about 1.7 times those of packing the Prius to the maximum. A trip from NYC to San Francisco would emit 520 lbs of CO2.
Trains Much Better Than Flying Though
Roughly equal in emissions are either taking the train or driving all by yourself in a car with high fuel economy. Either way, this is about 4 times the emissions of sharing that car (duh! only one person's in it...) or somewhere between 2.25 and 2.5 times the emissions of taking the bus. From New York to San Francisco, you're emitting about 1,220 lbs of CO2 on the train.
Driving By Yourself Almost as Bad as Flying
In fourth place is driving all by yourself in a car that gets 'average' fuel economy. That's about 23 mpg for all of the US auto fleet. This is just about as bad as flying for a cross country trip, at roughly 2,446 lbs of CO2 in one direction. That works out to be eight times worse than sharing your highly fuel efficient car with your friends, or five times worse than the bus.
Flying May Be Fast, But Emissions Huge
It's probably little surprise that the fastest way of traveling has the highest carbon emissions, but this one gets a bit more complicated, because there are genuine differences between the amount of emissions per mile on a short-haul flight versus a long haul flight. Due a variety of factors (the type of plane used, altitude, number of passengers) short haul flights have significantly higher emissions per mile than do long haul.
What this means is that a one-way trip from NYC to San Francisco emits about 2,500 lbs of CO2 including radiative forcing: About five times the emissions of taking the bus or eight times sharing that Prius. While a commuter flight from New York to DC emits about 240 lbs of CO2: Six times the emissions of take the bus, or about ten times those of sharing your Prius.
For Short Trips Though, Trains Better Than Buses
Remember how I said the emissions of trains and buses get reversed for inner city travel? According to Carbonfund.org (which I used to calculate all of the bus, train and airplane emissions) for trips under 20 miles, due to differences in the type of vehicles used on these routes, train comes out ahead: That 20 mile trip into the next county on a train would emit about 7 lbs of CO2, while in a bus it would emit about 13 lbs of CO2. The best short distance public transit option is clearly the train.
What to Do With All This?
Let's leave aside going on a road trip with friends or family in your fuel efficient hybrid. If you're the solo traveller, no matter if you've got a hybrid sedan or a gas guzzler, driving really doesn't fare well in terms of emissions. That leaves us with public transit options:
For long distance travel in the US the bus is the least emitting option, with trains coming out at about double the emissions. The advantage of the train though is, at least on some routes, you might have internet access. In terms of getting work done and making the best use of your travel time, this could tip the scales in the train's favor for some people.
No matter how you cut it, flying is the most carbon-intense option. It also is the least comfortable (at least if you're not in first class)—though I admit long distance bus trips aren't paragons of comfort either. Then you add in security hassles, high priced and dubious quality food at most airports, and the only thing flying has going for it is speed.
Read more about carbon emissions:
Air Travel and Climate Change: Take the Train
Book a Direct Flight and Reduce Emissions
Make 2009 the Year of Green Travel
-
- {}
