Amtrak Is Still The Greenest Travel Choice

By Jim Mathews / President & CEO

People are drawing a lot of conclusions from a recent piece in the New York Times chronicling a Times journalist’s effort to reduce her carbon footprint by traveling coast-to-coast on Amtrak instead of flying, not least of which thanks to the scary headline: “Trains Are Cleaner Than Planes, Right? The surprising carbon footprint of an Amtrak trip across America.”

“That 3,400-mile journey would take a daunting 72 hours,” reporter Hiroko Tabuchi wrote, describing her trip from New York to Stanford University in California for a climate meeting. “But I convinced my editors to let me use a work day, plus a few vacation days, to take the trip. I was set. And I was doing my part to save the planet. Right? Wrong. In short, I took a train across America and ended up emitting more planet-warming emissions, not less.”

She says that after doing the math during her “epic” journey, she found two things. One, that flying that trip would emit more than the annual emissions of a single resident of Cameroon. But second, she also concluded that her per-passenger emissions on Amtrak came to anywhere from 13 percent to 35 percent more than flying.

I could quibble with the base numbers she used to arrive at her result, but beyond that I would submit that even if her analysis of her particular trip was correct, overall it represents an "edge case" which need not negate the benefits of rail travel versus air travel overall.

Trips like hers only account for perhaps 10% of the overall ridership on any given route. Most trips on these trains are shorter trips between intermediate stations, despite the overall length of the route. Thus, for most passengers if they flew their carbon footprint would be larger.

Incidentally, we've recently reviewed some of the emissions figures internally, and we continue to support the U.S. Dept. of Energy's calculations putting air travel BTUs per passenger mile at 2,341 and Amtrak BTUs per passenger mile at 1,535. The Times argues that Amtrak’s advantage is only on the fully electrified Northeast Corridor, and if the NEC were taken out of the equation trains would be much worse. But again, if we’re looking at per passenger the number of passengers you begin with very much shapes the remainder of your analysis.

In more detail, if only about 10 percent of passengers are doing this the environmental "damage" is somewhat limited. And if we were to be mathematically honest, running a single train 2,000 miles in order to facilitate literally hundreds of possible short-distance origin/destination (OD) pair journeys is much MORE efficient than, for example, trying to satisfy a few dozen OD pair journeys with several shorter trains...or worse yet, with a turbofan-powered aircraft carrying 200 passengers.

Let's take Southwest Airlines as an example. I've chosen Southwest because they fly each individual aircraft on more legs per day than any other U.S. carrier and therefore one could argue that in terms of utilization Southwest is the most efficient. Fleetwide, their maximum average daily number of segments per aircraft is generally about six...or, in other words, that particular tail number can facilitate 21 unique origin/destination pair journeys each day.

Now let's compare this to the Amtrak trip the Times took: the Lake Shore Limited to Chicago, picking up the California Zephyr for the rest of the trip.

The Lake Shore Limited serves 26 separate stations over a little less than 24 hours' run time. Therefore, that specific set of equipment, with a crew swap in the middle of the run, can facilitate 351 unique origin/destination pair journeys each day.

The Zephyr serves 35 stations...good for 630 unique origin/destination pair journeys per run (to be fair, that's across 30-plus hours so it's not quite the same as the Southwest Airplane. But given the magnitude of the numbers, it doesn't really matter. Zephyr for any given trip is much more efficient than that single Southwest aircraft.)

The Zephyr travels 2,438 miles end to end...but the average passenger trip on the Zephyr in Fiscal 2022 (still waiting for FY23 final figures) was only 535 miles.

So while it may be true that 11 percent of the Zephyr's trips don't compare favorably to the carbon footprint of a flight, the other 89 percent DO compare favorably. Very favorably. And that's where the economic and climate benefits come from.

The real comparison is between miles driven versus miles on the train, and here the comparison is even more stark. We know that rail travel removes many millions of vehicle-miles traveled (VMTs) from the highways, with between 8% to 11% of trips diverted from highways on to trains when they are available.

Putting a price tag on the damage from those VMTs, and the savings we could see from driving them down, is hard and has been all over the map in recent years. Right now the U.S. DOT estimates the social cost of carbon (SCC) at roughly $50 per ton, while the Trump Administration at one time actually proposed less than $10 per ton! Our own research modeling internally puts that cost at about $500 per ton (with a tip of the hat to one of our newest Rail Passengers’ Council members Dr. John Christoph, PhD). Thus, the entire Amtrak network operating on around 23,000 miles, diverting what we believe could be about 174 million VMTs annually, should produce a social cost-of-carbon benefit of more than $30 million each year, conservatively.

And none of this includes what would happen if we could spur widespread electrification. More electrically powered trains, and adoption of high-speed rail, could be not only an economic game-changer, but think about what would happen if we could replace the diesel-driven numbers above (already better than cars and planes) with electrified high-speed rail, driven by clean power like solar, wind, and geothermal?

Trains are clean. Cleaner than cars and cleaner than planes for all but the very longest trips. And electric trains could be cleaner still. All of which makes passenger rail the cleanest, greenest way to travel.