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.

Yes, virtually all modern bullet trains (high-speed rail) rely exclusively on electricity for propulsion. Unlike traditional freight trains that might use diesel engines, bullet trains require a massive and consistent amount of power to reach and maintain speeds of 200–350 km/h (125–220 mph). They receive this power through an overhead wire system known as a catenary, which the train connects to via a mechanical arm called a pantograph. The high-voltage electricity is then converted by onboard transformers and motor controllers to drive the powerful electric traction motors located under the cars. Using electricity is essential for high-speed travel because electric motors provide the "high torque" necessary for fast acceleration and are much lighter and quieter than internal combustion engines. Furthermore, electric bullet trains are highly sustainable, as they produce zero direct emissions and can be powered by renewable energy sources like wind or solar. In Japan (Shinkansen), France (TGV), and China, the entire high-speed infrastructure is built around a robust electrical grid, making these trains the most efficient way to transport thousands of people over long distances at incredibly high speeds.