This is an image of a high speed train pulling into a train station.

Credit: GlueGunGlory/Public Domain

Public transportation, like this high speed train, reduces the amount of fossil fuels used to move people from place to place. High speed trains run on electricity instead of diesel fuel. Because much of the world's electricity is still generated at fossil fuel burning power plants, high speed trains do contribute to carbon emissions, however the climate impact of one train is significantly less than that of many personal vehicles.