Fuel Cell Electric Vehicles (FCEVs) generate power through an electrochemical reaction between hydrogen and oxygen, which primarily produces water vapor as a byproduct. This technology exemplifies a significant advancement towards sustainable transportation, as it emits no harmful pollutants like carbon dioxide or nitrogen oxides commonly associated with fossil fuel combustion. Understanding the environmental benefits of FCEVs, which produce only water vapor, is crucial in discussions about reducing urban air pollution and combating climate change, aligning with the objectives of sustainable development highlighted in UPSC's curriculum on environment and ecology.