Between 2002 and 2006, the U.S. and European Union devoted $1.8 billion to hydrogen fuel cell research. Leaders in the U.S. government and other countries around the world believe that hydrogen will eventually replace petroleum as the fuel that powers cars and reduce the environmental impact of burning fossil fuels.
Hydrogen fuel cells only release radiant heat and water as byproducts, according to the Public Broadcasting System. A "clean-burning" fuel in cars would go a long way to reducing carbon pollution.
A 2002 future energy "road map" called for 90 percent of hydrogen to come from fossil fuels. This means that current hydrogen production still contributes carbon pollution to the atmosphere.
According to John Heywood, Massachusetts Institute of Technology automotive expert, extracting hydrogen from fossil fuels does more damage than good to the environment and wastes money.
Massachusetts Technology Collaborative theorizes that if the world were to adopt hydrogen as its main fuel, leaking hydrogen could rise into the atmosphere and destroy portions of the ozone, which protects the Earth from harmful ultraviolet light.
In addition, some speculate that the water vapor (a known greenhouse gas) from hydrogen could warm the Earth more than carbon dioxide (because water can hold a lot of heat). The U.S. National Oceanic and Atmospheric Administration believes that water vapor from hydrogen would form clouds that could reflect even more heat.
As of 2006, about half of all the world's carbon pollution comes from cars and other modes of transportation, according to the U.S. Environmental Protection Agency. Eliminating most of this would help stop global temperatures from increasing.
