Soldier4Christ
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« on: April 25, 2007, 11:39:06 AM » |
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Ethanol causes more smog? Study says fuel touted by Bush could be worse for environment
While ethanol is widely touted as a solution to air pollution, when Brazil promoted the alternative fuel in the 1970s the skies above the South American nation's cities actually became smoggier.
Mark Jacobson, an atmospheric chemist at Stanford University, says in a newly published research paper ethanol isn't the clean-burning, healthy alternative to gasoline it's made out to be, reports Environmental Science and Technology Online.
A move to E85 blends of auto fuel, as espoused by President Bush – 85 percent ethanol, 15 percent gasoline – actually could result in more ozone and about 185 more deaths per year across the U.S., Jacobson said in his paper, published by ES&T's Research ASAP.
In his State of the Union address this year, Bush argued for increased use of ethanol to decrease dependence on foreign oil sources, provide a new market for farmers and conserve the environment.
The president is making ethanol the keystone of a plan to reduce gasoline consumption by 20 percent in 10 years.
"Ethanol is good for the environment because it burns cleaner than gasoline and produces less air pollution and greenhouse gas emissions," says a fact sheet issued by the White House.
But Jacobson's study shows switching to E85 blends could result in slightly higher ozone-related mortality, hospitalization and asthma. Cancer rates would be similar for gasoline and E85, he contends.
"It's true that ethanol does decrease some pollutants, but it also increases some others," Jacobson says, according to Environmental Science and Technology Online.
Ethanol tends to produce less benzene and butadiene than gasoline but more acetaldehyde and formaldehyde.
Jacobson argues previous studies estimating pollution and health effects simply scaled up tailpipe emissions and plugged those numbers into outdated formulas, the science publication reports.
Unlike the other studies, Jacobson's atmospheric model accounts for the transport of tailpipe emissions across the U.S. along with chemical transformations in the atmosphere.
Mark Delucchi, a transportation analyst at the University of California, Davis, told Environmental Science and Technology Online biofuels such as ethanol "simply have not been well studied yet."
"We really don't know even the sign of the impacts, positive or negative" on climate, he says.
Nevertheless, corn planting has jumped 15 percent this year in the wake of Bush's January speech.
Ethanol is being studied by California as part of Gov. Arnold Schwarzenegger's executive order calling for 10 percent less carbon in fuels by 2020. But the state is not moving ahead just yet as it takes time to examine ethanol's effect on air quality.
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