Nowadays, transport is following an electrification process in which, for so long, railway leads the field. This process has the objective of achieving a more sustainable transport model, reducing the carbon footprint through the contribution of renewable energies, as well as pollutant emissions into the atmosphere, making the air we breathe cleaner. Institutions have been promoting this change through taxes and fees, with special mention to the creation, by the European Union, of the Emissions Trading System of greenhouse gases.This analysis includes necessary estimates for this study, both energetic and carbon footprint of the train movements. In addition, the way to value the greenhouse gas emissions involved in this activity is discussed.