Climate change poses a huge threat to railways. Environmental engineers have ideas to combat this
Much of the world still relies heavily on railways to move people and goods. But rail infrastructure, from overhead wires to tracks, is under serious threat from climate change and associated extreme weather conditions.
Without efforts to adapt to future climate threats, the rail industry will face deteriorating infrastructure, safety risks and skyrocketing operating costs, according to experts in transport planning and civil engineering.
Many point out that so-called nature-based solutions – projects that harness the power of nature to solve social or environmental problems – could offer railways practical and cost-effective ways to minimize the effects of extreme weather, while providing environmental benefits. .
But so far, the railways have done little to take advantage of these strategies.
A new study by researchers at the University of Glasgow is the first to review industry efforts to date to use nature-based solutions to prevent climate change-related disruption. Researchers have identified several potential nature-based solutions that railways could apply, including green corridors to protect tracks from heat and high winds, habitat restoration to cushion the effects of storms, and areas moist to absorb water during heavy rains and retain it during drought.
These kinds of strategies, said Lorraine Blackwood, a PhD student in environmental sustainability at Glasgow and lead author of the study, would also create habitat for wildlife, reduce noise and air pollution, improve water quality and ensure the privacy of neighbors along the road.
But, while Blackwood and his colleagues found several examples of nature-based solutions being successfully implemented by railways, their review suggests the industry still has a long way to go.
“It’s still very early days,” she said. “There is still a long way to go to really trust and test these solutions in the railway environment.”
Extreme weather conditions threaten railway infrastructure
Climate-related weather extremes, from hot to cold and wet to dry, pose serious challenges for railway infrastructure. Heat waves can cause tracks to warp and expand, causing train derailments, while frost can damage overhead power lines. Floods undermine embankments that line the tracks and can cause landslides that block trains, while droughts cause subsidence and dry out soils, leading to misalignment of tracks.
When Hurricane Ida hit the East Coast in 2021, Amtrak’s northeast corridor from Boston to Washington, the nation’s busiest rail route, was closed for an entire day. About 75 million gallons – over 100 Olympic pools of water – had to be pumped from the New York City subway after the storm.
With climate change, flooding is only expected to get worse in the future. A recent study predicted that Boston’s commuter rail system could be operating at 40% less capacity within a decade due to increased flooding.
Extreme heat is another major technical challenge for the railways. Steel tracks are only designed to operate within a narrow range of temperatures. If it’s too hot, the tracks will warp and expand, which can cause a train to derail. To avoid this kind of disaster, most routes impose speed restrictions on trains when temperatures rise. But this strategy comes with its own setbacks. In a 2019 study, researchers estimated that delays due to temperature-related speed limit reductions could cost the U.S. rail network up to $60 billion by 2100.
The risks to railways go beyond the direct impact on a single line or the effect of a single storm. Climate change could alter the balance between different modes of transport in ways that are difficult to predict. For example, experts suggest that changing water levels in the Great Lakes could cause more goods to be transported by rail rather than by barge. A single major weather event can also cause cascading outages across an entire network, resulting in major regional disruptions to industries and people’s daily lives.
Additionally, thousands of miles of track in the United States are well over 100 years old. These systems were designed with outdated construction standards, which puts them at greater risk of failure and means that any repairs or upgrades could be prohibitively expensive.
To date, most railway efforts to adapt to climate change have involved “hard” engineering solutions – so-called “grey” infrastructure – such as raising stations, installing dykes and of pumps and the stabilization of hillsides next to railway tracks. In Boston, for example, the city spent nearly $2 million last year installing barriers at a flood-prone station.
“It’s just not a particularly durable or attractive solution,” Blackwood said of the hard-engineered solutions. “Even from a mitigation perspective, with things like concrete and steel, the gray solutions themselves are very carbon intensive.”
Green opportunities for adaptation
This is where systems built to work in concert with nature come in – often referred to as “green” infrastructure, as opposed to “grey” infrastructure.
“Nature-based solutions offer so many benefits to people,” Blackwood said.
Additionally, while gray solutions are often rigid and costly, green infrastructure can be more adaptable.
Michael Martello, a civil and environmental engineering doctoral candidate at the Massachusetts Institute of Technology, points out that under the climate change scenario, sea level rise in Boston Harbor could be from less than a foot to more than eight. feet by the end of the century. . “It’s a huge range to try to design,” Martello said.
Green infrastructure, he said, can help solve some of that uncertainty, because vegetation only gets stronger with age, as trees grow and plants take root. Gray infrastructure, on the other hand, degrades over time.
But Martello said there are several barriers to the widespread use of green infrastructure.
“A public body that operates any type of rail network, in general, will only own the right-of-way,” Martello said. “There’s a huge jurisdictional hurdle there, and there’s obviously a lot of inter-agency cooperation that needs to happen.”
In the United States, unlike Great Britain, where the researchers are from, there is also no single national railway. Instead, the railways are operated mostly by private companies. Martello said that from an economic perspective, most operators want to stick with proven solutions.
Blackwood agreed that a lack of familiarity with nature-based solutions and concerns over safety could make planners feel like these projects were more difficult to build, even though gray-engineered projects are often more difficult. on the technical side. Working on an existing track, she said, comes with space and land-use constraints that can also make it difficult to try out new designs.
Paul Chinowsky, professor of civil engineering at the University of Colorado at Boulder, said implementing nature-based solutions is “big business,” especially in the United States, given the sheer size of the world. network. Like Martello, Chinowsky said there was no incentive for private companies to use untested strategies. There is also no incentive to maintain them.
“A natural solution is a great idea, but someone has to maintain it, especially for the first two years while it becomes established,” Chinowsky said.
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He noted that green infrastructure projects come with a “lifetime benefit” and require relatively simple and inexpensive maintenance. But, because they demand After maintenance, he said, it can be difficult for these solutions to compete with advanced engineering technologies.
“I think you have a perception barrier that a nature-based solution is pushing back,” Chinowsky said, “a perception that anything that requires more maintenance is going to be a draw.”
Given the climate change threats facing railways, experts say the industry is going to need a variety of approaches and finding ways to tie nature-based solutions to gray infrastructure. Although the long lifespan of railways poses a challenge for setting up new projects on old tracks, it also means that there is plenty of time to recover the initial costs of these projects. It’s like an insurance policy, Martello said, where companies pay now to avoid disruption later.
“I think it’s really important that we continue to explore these natural solutions. There will be great places where we can put them,” Chinowsky said. “When you have a life cycle of 50, 75 years, you can afford to invest.”
The United States, he said, should also look to other countries, like Britain, that are further along in adaptation to learn from their experience.
“Railroads have been built in much the same way for 180 years now,” Blackwood said, “so there’s a lot of work to be done to change and advance certain traditions and attitudes.”