Train Vs Car: What are their Carbon Footprints?

The fight against climate change is a collective effort and it’s everyone’s responsibility to try to live more sustainably, but it’s not always easy to know which choice is the ‘greenest’ one to take. 

Most people tend to assume that when it comes to picking the ‘greenest’ option for their travel, going by train is better for the environment than the car. However, the reality is a lot more nuanced, and it’s not quite as simple as you might first assume. 

👉 In this article we’ll explore the carbon footprint of taking the train and the car, and will discover which method of transport is truly the most environmentally friendly.

This is because around 95% of the world's transport energy comes from fossil fuels such as petrol (otherwise known as gasoline) and diesel. In fact, the transport sector accounts for 57% of oil demand globally. The burning of these fossil fuels releases large amounts of carbon dioxide into the Earth’s atmosphere, where it traps excess heat and ultimately results in global warming. 

👉 To find out more about how global warming happens, or to read more on the threat posed by fossil fuels, why not check out Greenly’s articles on the topics. 

Given how much the transport sector contributes to climate change, it’s essential that we take efforts to decarbonise the entire transport sector. However, this is an ongoing process and something that won’t just happen overnight. Which is why it’s important that, in the meantime, we try to make environmentally conscious decisions when it comes to our own transportation choices. So, what is actually better for the environment - the train or the car?

It’s an almost universally accepted assumption that taking the train is much better for the environment than taking the car. After all, a train can hold many more passengers at the same time, whereas if you travel by car you’re usually taking an individual vehicle. But does this assumption actually hold up to scrutiny? 

If we take an overall view of the transport sector, 71% of transportation related carbon emissions come from road users, whereas only 1.8% of emissions stem from rail travel. So in absolute terms, trains are responsible for a lot less emissions than cars. However, this doesn’t paint the whole picture, and the situation is a lot more complicated when we make a passenger to passenger comparison.

The carbon footprint of travel via car or train will depend on a number of different factors. For example the type of energy that the train or car consumes (petrol, diesel, electric) and the class of the train ticket that you take (economy, business etc).

Note: emissions are per passenger kilometer traveled. Source.

These figures for car emissions can be compared with the emissions per passenger kilometer traveled by train. Some of the most energy efficient trains for example (such as the Eurostar which is transitioning to renewables to power its trains), only produce 6g CO2e per passenger km, whereas the most polluting trains (for example national rail services which usually rely on diesel power) produce an average of 41g CO2e per passenger km. These emissions are also increased when you travel in a business seat train ticket as the carriages tend to hold less passengers. 

What these figures make clear is that it is, in fact, always more energy efficient to take the train than a petrol or diesel car, or than traveling alone, regardless of the car type.

However, in the case of a low emissions vehicle or electric car, where the journey is split with other passengers, taking the car may actually be the greener option. And some even believe that the fast-paced green innovation within the car industry could mean that, within the foreseeable future, electric vehicles will become the more environmentally friendly option every time. 

👉 This example really showcases just how many different factors come into play when considering the most environmentally friendly form of transport. It’s not always as simple as the train = best.

You hear a lot about electric vehicles these days and electric cars are now a common sight on our roads. In some countries, the sale of petrol and diesel cars is even being slowly phased out. Take the UK for example, from 2030 no new petrol or diesel fuelled cars will be allowed to be sold. 

Consumer demand for more environmentally friendly car options, alongside the introduction of bans and stricter regulations concerning the sale of petrol and diesel cars, means that electric vehicles are becoming cheaper to buy and that their technology is progressing quickly. 

So does this mean that the cars of the future will be more environmentally friendly than our train? Or is the railway network also upgrading its infrastructure to become more green too? 

While trains are also becoming more environmentally friendly with time (electric trains are now commonplace), one other factor to consider is the lifespan of these different modes of transport. Cars tend to be renewed a lot more frequently than trains for example. In the UK, car owners keep their cars for an average of only 6 years. This short lifespan means that the car industry advances quickly, and new technology appears on our roads in a relatively short period of time. 

Trains on the other hand are built to last several decades. This means that a train that was built five years ago is still likely to be in use in 10-20 years time from now. The result of this is that transitioning to more energy efficient models takes a long time in comparison to the quick pace of the car industry.

While on one hand, the short lifespan of a car is a benefit as it allows technology to advance quickly and for older, more polluting models to be replaced with greener electric versions, this is a bit of a double edged sword. 

The reason for this is that the manufacturing process itself also produces a lot of greenhouse emissions. When a car is made, raw materials need to be extracted, refined and transported. The materials are then used to produce the car in a car manufacturing plant. All of these steps require energy and result in emissions.

This is where a longer lifespan can actually be an advantage. An electric vehicle for example quickly makes up for the larger manufacturing emissions, and its carbon footprint tends to catch up with a petrol powered car at around the 21,700 km mark. After this point the gap starts to grow and grow = basically the longer you keep your electric vehicle the lower its carbon footprint in the long run when compared to a petrol model.

The advancement of technology is not the only consideration that seems to undermine the arguments in favor of traveling by train. We also need to factor in the emissions generated by both car and train infrastructure and the actual materials that are used in their production. 

The maintenance of rail infrastructure and the construction of new train lines can have significant environmental impacts in the long run. In fact, one study found that railway infrastructure contributes an additional 141% of greenhouse gas emissions over emissions from passenger traffic. 

Not only this, but we also need to consider other factors - for example the destruction of green landscape to make way for new railway lines or motorways. And how the energy being used to provide the electricity is fuelled.

What’s clear - regardless of whether it's a car or a train, is that electric powered models are better than those that run on some kind of fossil fuel. However, we also need to examine the energy source that’s providing the electricity. 

The type of power providing the electricity that powers our electric trains or cars will depend on a number of factors. It will depend on the electricity provider for example - often energy suppliers rely on the burning of fossil fuels such as natural gas, petroleum or even coal to power their energy supply. However, these days it’s also possible to select a provider or plan that sources their power from renewable sources. 

Another factor to consider is the country that you’re in. The energy mix of different countries varies hugely. In the UK for example, gas accounts for around 38.5% of the UK’s electricity supply, followed by 26.8% from wind power and 15.5% from nuclear power. France does even better, with 66% of its energy coming from nuclear power sources, and 28% being provided from wind and hydro power. 

This is an important consideration because it affects the carbon footprint of the running of electric cars and trains. An electric train in France is more likely to have a lower carbon footprint than that of its British counterpart due its greener energy mix. By the same logic, cars manufactured in more energy efficient countries are also likely to have a smaller manufacturing carbon footprint.

While trains usually take the edge when it comes to the lowest carbon footprint, as we’ve discovered it’s not always quite so simple when we take into consideration car sharing and the emergence of electric vehicles. 

The situation is complicated even further when we consider the manufacturing impact of the different vehicles, and the faster paced emergence of green technology within the car industry. Some even believe that in the not so distant future, technological advances will mean that cars take the edge over rail travel when it comes to environmental impact. 

So while for the time being, the chances are that in most situations taking the train will minimize your carbon footprint, it’s also worth considering wider factors such as the car type, how many passengers will be sharing, and type of fuel used by the train (electric or diesel), before making your decision.

At Greenly we can help you to assess your company’s carbon footprint, and then give you the tools you need to cut down on emissions. Why not request a free demo with one of our experts - no obligation or commitment required. 

If reading this article has inspired you to consider your company’s own carbon footprint, Greenly can help. Learn more about Greenly’s carbon management platform here.