The new national focus on biofuels seems to have glossed-over a fundamental principle of the universe: when something burns, smoke happens. This goes for any combustible fuel, be it gasoline, diesel, propane, wood, coal, biomass, biodiesel, ethanol or anything else, and just so happens to be one of the greatest drawbacks of the internal combustion engine; a great idea, but not so great when millions of people start using it in a small area. Most alternative fuel emissions fair better than regular gasoline or diesel, but concerns have been raised that ethanol, the most heavily subsidized and nationally celebrated biofuel (at least officially), may not be as clean as we would like:

WASHINGTON — Federal scientists want to tighten smog standards, a step that would allow tens of millions of Americans to breathe easier. The plan also would run head-on into President Bush's hopes of weaning Americans from gasoline by using more smog-producing ethanol. Environmental Protection Agency scientists on Wednesday will say that tougher standards "would provide greater health protection for sensitive groups, including asthmatic children and other people with lung disease, healthy children and older adults — especially those active outdoors, and outdoor workers."

The emissions profiles of both ethanol and biodiesel have previously been questioned due to their potential to increase smog-forming nitrogen oxides (combustion products that can react with oxygen to form smog), although B20 biodiesel blends have recently been vindicated. President Bush in his State of the Union speech advocated reducing gas consumption by 20 percent over 10 years, a transition that would heavily rely on ethanol fuel blends.

Ethanol, a focus of Bush's gasoline-reduction plan, helps cut carbon monoxide in winter but can raise smog levels in summer, air pollution experts say. Ethanol releases more nitrogen oxides, a key element of smog, and evaporates more easily than gasoline, adding other air pollutants.
EPA documents show that more ethanol use could raise smog levels about 1 percent, mainly in parts of the Midwest that don't use cleaner-burning reformulated gasoline.

This could be cause for concern, since ethanol is such a major player in the biofuel arena. But would a massive shift to using ethanol fuel blends significantly increase air pollution? The EPA officially does not think so, noting "a possibility of a very small increase" in smog formation. Industry advocates claim additional refinement will solve part of the problem, although others aren't so sure:

As long as refiners spend enough to offset the volatility in ethanol that leads to smog, there's no problem, said ethanol lobbyist Bob Dinneen of the Renewable Fuels Association.

"A lot of concerns that have been out there are unfounded," he said. "It's not an air quality issue, it's an economic issue for refiners."

Stanford University atmospheric scientist Mark Jacobson said that would add 200 deaths a year to the 4,700 now blamed on smog. "It's a significant concern," said Jacobson, who believes the worst effects would be around Los Angeles and along the Boston-New York-Washington corridor.

According to the same news release, 160 million people in the U.S. already live in areas with illegal levels of smog.

That's more than 1/2 our total population.

Any increase of smog-forming emissions in highly populated areas is clearly undesirable (for a visual, just look at Salt Lake City in the wintertime). There may also be more to the equation than just what comes out of the tailpipe. An oft-quoted study from the University of Minnesota stated that when the total life cycle emissions of growing and processing corn are taken into account, corn-based ethanol incurs "greater environmental and human health impacts because of increased release of five air pollutants and nitrate, nitrite, and pesticides" when compared to regular gasoline.

Whether or not tighter smog standards will actually conflict with increased ethanol use remains to be seen.

In the mean time, we may be better off supporting public transportation and just plain driving less. A fuel is still a fuel, even by another name…

Stay tuned for more information on the emissions profiles of various alternative fuels.

Check out the Green Life Guide for more information on biodiesel and ethanol.

• ENN: EPA Plan to Tighten Smog Standards Collides with Bush Goal to Cut Gas Use
• University of Minnesota Study: Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels.