High-speed rail has been growing in popularity throughout the United States (U.S.), as other nations like Japan, China, Spain, France, Germany, Italy, the UK, Belgium, the Netherlands, and Austria have been leading the charge across the globe. The California High-Speed Rail Authority is currently constructing a 171-mile line between Los Angeles and San Francisco and another 218-mile line between Las Vegas and Southern California. Although these projects are popular, they are very expensive. The line between Los Angeles and San Francisco is estimated to cost $128 billion.
Regardless of cost, the idea of high-speed rail is appealing to many Americans, considering the congestion of U.S. highways. Many organizations have popped up across the U.S. in support of high-speed rail; one of which being the U.S. High Speed Rail Coalition which has helped “deliver over $10.6 billion in federal and state funds to America’s first bullet train projects.”
Because high-speed rail is growing in popularity, it is important to analyze it from an environmental perspective. There can be numerous environmental benefits like higher accessibility of transportation, thus decreasing overall carbon emissions. On the contrary, there are many potential environmental harms including habitat destruction, increased carbon emissions involved in construction of the rail and the exacerbation of environmental justice issues through increased noise and air pollution for environmental justice communities—potentially generated by the construction of high-speed rails through their neighborhoods.
Advantages of High-Speed Rail:
First, high-speed rail is important from an environmental justice perspective because it provides a more accessible means of travel. The average cost of a roundtrip Amtrak ticket from New York City to Boston is $44. The average cost of a flight ticket for the trip between the same locations in 2025 is $185.90. “In many low-income communities and communities of color, the burden of inadequate and unreliable [public] transportation options is compounded by the uneven distribution of [public] transportation facilities.” High-speed rail can provide low-income communities with a means of travel to places that they might not otherwise get to because of the associated costs.
Second, high-speed rail is one of the more efficient means of transportation. Benefits include “reducing greenhouse gases emissions, [vehicle] congestion, and air pollution.” Because high-speed rail runs on electric power, it can run 100% on clean, safe, and renewable energy. “America consumes 20 million barrels of oil every day, most of it on transportation.” Switching to high-speed rail would decrease this high consumption rate and be a much needed climate and energy solution.
“Carbon-footprint-travel-mode” by Our World in Data (by Hannah Ritchie) is licensed under CC BY-SA 4.0.
This graph displays the carbon footprint of different travel methods per kilometer traveled. Europe’s high-speed rail, Eurostar, has the lowest carbon emissions on the list. A research study done on high-speed rail in the Midwest shows that it could reduce carbon emissions by 3.3 million metric tons a year. In comparing short flights by Spirit Airlines, Delta JetBlue, American Airlines, and United Airlines, the International Council on Clean Transportation (ICCT) found that high-speed rail could reduce carbon emissions by 23%. Using a mathematical formula, another study found that for a 1200 km high-speed rail journey can save 213.924 kgCO2e when compared to average emissions from air travel going the same distance.
In 2024, a study published by faculty at the Macao Polytechnic University was released that aimed to show that high-speed rail openings reduce carbon emissions. The study found that first, high-speed rail openings “promote social inclusion and harmony, which is conducive of achieving environmental harmony and reducing carbon emissions.” Second, high-speed rail openings increase resilience of green innovation and environmental investment, which indirectly reduces carbon emissions. Lastly, the digital economy accelerates the reduction of carbon emissions.
In a similar study that looked at environmental sustainability of high-speed rail in China, it found that high-speed rail mitigates the usage of fossil fuels and urban carbon emissions. This effect is seen more distinctly in “high-polluting, capital-intensive, and human-intensive industries.”
Disadvantages of High-Speed Rail
The first environmental problem from high-speed rail is the carbon emissions associated with construction of high-speed rail. A large amount of emissions come from “earth movers, tunnel boring machines, bulldozers, trucks, cranes, etc..” In a 2010 study, UC Berkeley professors estimated that the “California high-speed rail project would generate 9.7 million metric tons of carbon dioxide during construction.” But, if high-speed rail could attract enough riders from air travel, it could offset the emissions created during construction.
In a 2012 study entitled Could High Speed Rail Offset its Embedded Emissions, the authors concluded that to balance the emissions from construction, high-speed rail volume needs to be large and mostly come from aviation. They estimate that a high-speed rail line would need to average 10 million one-way trips annually to compensate the construction emissions. In a 2010 study, UC Berkeley professors estimated that it would take 71 years of operation at medium occupancy to offset the construction emissions.
There is already a lot of existing infrastructure in the U.S. for highways ever since rail fell out of favor in the 1950s. Since 1950, the U.S. population has doubled and instead of relying on other types of transportation, the number of motor vehicles registered has increased sixfold. The drastic increase in population and number of motor vehicles registered could pose a problem for deciding where to put the new rail lines. High-speed rail lines cannot run on existing rail lines, so the construction of new rails is necessary.
From an environmental justice lens, there are certain factors that need to be considered when constructing high-speed rails. There is a lot of existing infrastructure in the U.S., but most of it is for cars. The history vehicular infrastructure is rooted in environmental racism and redlining–the South Bronx is an example of this. In the 1940s, there was an influx of minorities moving to the South Bronx. City planner Robert Moses presented a plan for the Cross Bronx Expressway, which went directly through low-income neighborhoods and cut them off from ‘wealthier’ neighborhoods. The effects are still felt on people living in this area today. This area in the Bronx is known as ‘Asthma Alley’, because of the disproportionate levels of air pollution caused by the highway and car emissions. If plans for high-speed rail are to move forward, the places where the rails are running through need to be considered to ensure that environmental justice communities aren’t disproportionately affected like they have been by highway construction and placement.
Along with considering environmental justice communities when building rail lines, biodiversity and natural environments also need to be considered. The creation of new railway lines can contribute to a phenomenon called ‘habitat fragmentation,’ which is when parts of a habitat are destroyed and leaves smaller unconnected pieces behind. This disrupts local fauna patterns and physically transforms the habitat.
Additionally, there are higher rates of fauna mortality from train strikes, severe noise and light disturbances, which can affect ecosystem degradation and photosensitive species. These projects are being monitored by the Fish and Wildlife Service, acting under Section 7 of the Endangered Species Act. In California’s high-speed rail project, they have many biologists who work on Section 7 consultation, mitigation efforts, and finding conservation opportunities. Working with the Fish and Wildlife Service can ensure that biodiversity and natural environments are protected during the construction of rail lines.
Conclusion
There are many considerations that have to go into the development of high-speed rail in the U.S.. Carbon emissions are a big factor, both from a positive and negative perspective. Carbon emissions released during construction of the rail lines can be a negative impact but can be offset by the energy efficient aspects of the trains running. The transition of aviation travel to high-speed rail could alone offset the carbon emissions produced during the construction of the high-speed rails.
There are additional negative impacts on environmental justice communities and biodiversity. Luckily, there are review processes that are required during construction of rail lines including the Endangered Species Act, the National Environmental Policy Act, and Comprehensive Environmental Response, Compensation, and Liability Act. These review processes necessitate the consideration of environmental concerns.
The construction of high-speed rail also has positive implications. From an environmental justice perspective, high-speed rail would provide easier and cheaper access to travel means. Additionally, high-speed rail has been proven to reduce greenhouse gas emissions, congestion, carbon emissions, and air pollution. As the idea of high-speed rail becomes more popular, the considerations mentioned in this article need to be discussed before moving forward with any U.S. high-speed rail projects.