 George W. Bush and Arnold Schwarzenegger introduce this video, and describe their commitment to this crucial energy technology. Scientists, researchers, professors and industry experts explain Fuel Cell technology: Hydrogen Fuel Cell Vehicles emit only water vapor; compared with gasoline engines, they will result in one third the amount of greenhouse gases per mile driven. Shot with the cooperation of the National Fuel Cell Research Center and the California Fuel Cell Partnership, the video showcases cars from 8 of the 10 largest car companies.