The Hydrogen Hummer

"Though Schwarzenegger arrived at the event in a low-pollution vehicle, he left in a gasoline-powered SUV that typically gets about 15 mpg. Officials said the hydrogen Hummer needs to refuel every 50 miles and there are only about a dozen fueling stations across the state."

Hydrogen is not an energy-dense fuel, as gasoline and other hydrocarbon fuels are, which is why a tankful only goes 50 miles. The belief that CO2 is a pollutant, while an environmentalist fundraiser's dream, is also not something we are likely to solve soon or cheaply.