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Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
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The Trouble With Hydrogen
13 June 2003 (All day)
Hydrogen has been heralded as the clean fuel of the future; even President George W. Bush touted it in his State of the Union speech last February. But now, scientists say that switching the world economy over to hydrogen might enlarge the ozone hole. The modeling study, published in the 13 June issue of Science, is the first to look in detail at atmospheric changes that would result from wide-scale hydrogen use.
In theory, hydrogen is the ideal fuel. Its controlled oxidation in fuel cells produces only water, instead of gases that contribute to air pollution and global climate change. One way to produce hydrogen is using fossil fuels, which would not result in great environmental benefits; instead, proponents of the technology hope to find other ways, for instance, by using solar or wind power. But few studies have looked at the effects of replacing combustion engines with fuel cells. The problem is that when hydrogen is made, transported, and stored, small quantities will inevitably leak out.
Tracey Tromp, an environmental scientist at the California Institute of Technology in Pasadena, and colleagues teamed up to model what might happen if all cars and other systems that burn fossil fuels were replaced with fuel cells. They estimate that hydrogen levels in the atmosphere could increase as much as eightfold. More hydrogen would lead to more water in the stratosphere, where the ozone layer sits, making it cooler and cloudier, and creating more ice crystals, on whose surfaces ozone-destroying reactions occur. That would make the ozone hole wider, deeper, and more persistent in the spring, the team concludes.
The researchers point out that hydrogen's impact might be lessened by a reduction in atmospheric chlorofluorocarbons, which have been dropping since they were outlawed, or if the soil absorbs more hydrogen than scientists currently think. Designing storage systems and fuel cells to minimize leakage would also help.
"The general idea--that increasing hydrogen would influence the chemistry in the stratosphere--has been in the back of people's minds, but there hasn't been a lot of experimental or even theoretical work," says biogeochemist Richard Gammon at the University of Washington, Seattle. "That's why this is such an important paper." Now, other researchers will have to weigh in with their own models, Gammon says.