The Environmental Case
Fighting climate change will require a dramatic shift in our transportation policies, priorities, and spending. As the Alliance to Save Energy recently observed, the transportation sector “is on the verge of a major transformation,” and “we cannot approach this challenge with the same thinking as in the past.”
We agree. The U.S. is stuck in a rut of outdated ideas and norms. It’s urgent that we get unstuck, especially since the transportation sector is the biggest contributor of greenhouse gas emissions in the U.S. And we’ve been moving in the wrong direction on transportation emissions in recent years.
What’s the solution?
Electric cars and low-emissions airplanes are creating a lot of buzz. But the hype is mostly hot air. Better cars and planes are just a tweak to the status quo, meaning they’ll give us more roads and runways and sprawl. The batteries also pose a big problem: Making and disposing of them comes at a huge environmental cost. No matter how fuel efficient they become, cars and planes aren’t transformative.
We need something much more—and much better—than minor improvements to the old ways of doing business.
Only high-speed rail can solve the transportation challenges we face. Only high-speed rail creates a clean break with the norms that are pushing us to the climate-change brink.
Exactly how “green” are trains?
You can find one answer to that question at carbon calculators like Ecopassenger, which shows the emissions created by different modes of transportation for different routes, mostly in Europe. In the chart for the trip from Paris to Barcelona (below), the left bar represents the emissions created by (and energy used by) rail travel. The middle bar represents driving. The right bar represents flying.
It shows that trains produce dramatically fewer greenhouse gas emissions than cars and planes for the trip from Paris to Barcelona. Rail is also far superior on two measures, and it’s much better than flying (but slightly inferior to driving) on the other two.
These results are typical. On most routes and by most measures, trains beat flying and driving by a wide margin. When they don’t, they’re at least competitive with them. Rail is, in short, the environmentally friendly choice.
That kind of clarity is nice, but it doesn’t really answer the question of “exactly” how green rail is relative to driving and flying. There are too many variables in play. In the chart above, for example, rail’s green advantage is even stronger when you assume the car has just one passenger (rather than two, which is the assumption in the calculation).
And there scores of other factors at work. For example, high-speed trains aren’t all the same. Some are greener than others. In electrified trains, for example, about 95 percent of the energy created by combustion transfers to the wheels from overhead powerlines, versus 30 to 35 percent in diesel-powered trains. So electrified trains use much less energy.
A lot also depends on “hidden” costs, such as greenhouse gas emissions created by construction materials and equipment. Some critics doubt the green value of rail because of these costs. Supposedly, the emissions created by building the infrastructure cancel out the green benefits of running low-emissions trains.
Fortunately, there’s been serious research on this question. It focuses on California’s high-speed rail project and takes a “life-cycle effects” approach. That means it weighs the relevant but hidden costs in each mode, including the costs of building the infrastructure, maintaining it, replacing and disposing of aging stock, and other factors not reflected in a simple analysis of the emissions created by getting from point A to point B.
The chart below, drawn from the authors’ research and published here, compares the energy consumption of several different modes of travel.
Note the dramatic difference that passenger volume makes. At 90 percent capacity, high-speed trains are comparable to passenger, commuter, and light rail systems. They easily beat a gasoline sedan with five passengers, and they blow away a midsize aircraft at 90 percent capacity.
That research was published in the early stages of the California high-speed rail project, which has since evolved and is now much greener than the analysis accounted for. For example, the California High Speed Rail Authority is committed to running the system entirely on renewable energy. And the system is being built with tier 4 construction vehicles and equipment, the newest and most energy efficient available.
Even so, a lot hinges on high ridership volume. To be truly green, California’s high-speed rail system must be well used.
So here’s the great news: California’s rail plan is the most visionary and sophisticated in the nation. It looks forward to 2040 and strategizes for how the different elements of the system can support and improve each other. That integration will drive a massive increase in ridership, since a coordinated system is more convenient and accessible for more people.
Here’s a chart showing what that looks like. It illustrates ridership across the system in 2010 versus projected ridership in 2040. The right column shows the massive multiplier effects of building a coordinated, integrated system:
California’s planning creates a virtuous cycle. High-speed trains will boost ridership across all the state’s rail and transit systems, and vice versa. In turn, high passenger volume on trains and transit systems will take cars off the road, which will drive down greenhouse gas emissions.
Every state and project is different, obviously. The big-picture point from California is that trains are as green and as game-changing as we’re willing to make them. With smart planning and robust investment, they’ll create few (or no) greenhouse gas emissions, stimulate economic growth, foster urban density rather than sprawl, and improve the efficiency and value of other transportation modes.
You don’t get those benefits from low-emissions airplanes. And you sure don’t get them from electric cars. When trains are full, you run them more frequently. When interstates and airplanes are jammed, you build more roads and runways—and perpetuate the vicious cycle of sprawl and inefficiency.
The U.S. has a lot to contribute as high-speed rail expands its reach, globally, and becomes ever-greener with new technology. And we have a lot to learn. California’s project is a good start. But it’s only a start.
The business-as-usual transportation norms have run their course.
They’ve left us in a rut of dysfunction, facing a climate-change emergency. It’s time to get moving on a new path.