Are trains really environmentally friendly? Well that type of question is answered more easily if we would narrow it down to just one or two countries, and for the sake of it we are going to take the train loving country Germany as an example, and Sweden to compare the two countries.
When we look on trains there are generally two types of energy sources trains are using:diesel and electricity. The diesel type of train is a very direct form of energy. When the liquid burns in the combustion chamber the pistons starts to move which starts a movement in the wheels. This is of course a very easy explanation of something slightly more advanced but you get the picture. With electricity however it’s harder to determine the ”real” source of energy. It could be nuclear energy,various forms of coal, wind or water. So depending on what was used to ”shape” the energy into electricity it can be more or less environmental friendly. If diesel has been burnt in a powerplant to produce the electricity, the train that runs on it will be no more environmental friendly than the train that b urns diesel directly into its engines. However an electric train that draws its energy from nuclear energy would be from a global warming perspective be an excellent choice, although it wouldn't be a good choice for the environment due to the damages the gamma radiation is capable of doing
If we assume that a diesel engine in a car and a train have,give or take the same efficiency then they run at 25% efficiency while a coal fed propellant runs at up too 49% efficiency. So even while an electric train uses coal to produce its electricity it’s more efficient than a diesel one.
I mentioned Sweden and Germany in the beginning;in Germany there are diesel trains. They’re are a small minority however, the problem is that in Germany over 70% of the domestic energy production stem from fossil fuel. Which means that taking the train in Germany isn’t so good for the environment after all which gives me good cause to call this ”environmental delusions”. Because that’s what they are;aslong as you are in Germany. However when you are in Sweden 100% of the domestic power is produced by energy sources that doesn't’t let out any CO2 in the air. Which means that taking the train in Sweden doesn't’t emit any CO2 at all since all the trains are of the electric type of train. On the other hand it isn't’t environmental friendly, 36%  of our electricity in Sweden is nuclear which means that if the radiation omitting elements in the powerplant would start leaking, we would face major biological destruction. Which leads me to say that in Sweden we are also very delusional about the environment .