The biggest environmental effect produced by trains is the amount of carbon dioxide they emit. The carbon footprint left by a train compared to an automobile really depends on how many passengers are using it. A train full of passengers, for example, leaves a significantly smaller carbon footprint per capita than a car with just one person. A half-empty train, on the other hand, will leave a larger carbon footprint than a four-passenger carpool. Trains vary greatly in efficiency as well. The Virgin Voyager trains in the United Kingdom are nearly three times worse for the environment than the highly efficient GNER electric trains that connect London and Edinburgh, Scotland.
Although trains are by and large more fuel efficient than automobiles, they still consume a tremendous amount of non-renewable fuel each year. Diesel trains consume fuel based on stopping patterns, the speed or throttle at which they are traveling and even weight. High-speed trains consume more fuel than freight trains. Trains consume fuel not just when they are running; fuel also is required to construct and maintain them.
Trains can disrupt local ecosystems in irreparable ways. A railway traveling through a rural area can interrupt migration patterns, destroy habitat and even kill animals attempting to cross the tracks. Railways are often built with little or no consideration of the local flora and fauna and the effect that pollution and habitat destruction will have on ecosystems.
Trains also produce a tremendous amount of noise, often reaching dangerously high decibel ranges. This can be stressful and irritating not only to human beings living near railways, but also to local wildlife. Prolonged exposure to the kind of loud noise produced by trains can cause permanent hearing loss in mammals, which in turn disrupts the delicate balance of predator and prey in nature.
Fortunately, many environmentalists and city planners are realizing the value of clean, fuel-efficient and non-polluting railway systems and designing them for a green future. In Arizona, a high-speed, solar-powered railway, the first of its kind in the United States, is in the works. Italy's PVTRAIN has solar panels that generate electricity for the train's air-conditioning, safety and lighting systems. It is hoped that these trains and others around the world will result in fewer cars on the road, reducing the number of greenhouse gases and slowing down the effects of global warming.
