A lot of people have been wondering whether it takes just as much energy to make hydrogen fuel for hydrogen cars as is already burned by traditional cars that use oil (gasoline) as fuel. A study this week in Nature says that yes, carbon dioxide emissions may be the same for both types of cars, but:
"the problem with the internal combustion engine is not just its carbon dioxide emissions. It also produces poisonous carbon monoxide, smog-inducing nitrogen oxides, and ozone, an eye and respiratory irritant. Worst of all, it creates microscopic soot particles that cause a host of health risks and affect climate. Moreover, fossil-fuel vehicles tend to concentrate these pollutants in areas of high population density."
Score 1 for hydrogen cars!