"Such a system, experts say, would effectively eliminate most of the benefits offered by hydrogen. Although the fuel-cell cars themselves may emit nothing but water vapor, the process of producing the fuel cells from hydrocarbons will continue America's dependence on fossil fuels and leave behind carbon dioxide, the primary cause of global warming."

"The fuel cell is being considered as an eventual replacement for the internal combustion engine for cars, trucks and buses. Major car manufacturers have teamed up with fuel cell research centers or are doing their own development. There are plans for mass-producing cars running on fuel cells. Because of the low operating cost of the combustion engine, and some unresolved technical challenges of the fuel cell, however, experts predict that a large scale implementation of the fuel cell to power cars will not occur before 2015, or even 2020."