THE CAR OF THE FUTURE - The Power Surge: Energy, Opportunity, and the Battle for America's Future - page 139

grows means burning diesel in tractors; so does hauling the harvested
crop to a rei nery. Once it gets there, it still needs to be turned into
fuel, a process that requires a lot of natural gas. When you do the math,
many ethanol operations actually turn out to be energy losers, particu-
larly if they use corn. 99
For many ethanol opponents, this is case closed for the fuel. But
things aren't so simple; whether this arithmetic really mat ers depends
on the problem you're trying to solve. Most of the energy gobbled up
by an ethanol operation comes from natural gas. h e United States,
though, doesn't have a natural gas problem, at least not in the same
way it has an oil problem. From this perspective, biofuels look like just
any another technology that converts natural gas into liquid fuels that
can displace oil. In a country long on gas and short on oil, this is a
good deal.
Unless, that is, you're worried about climate change. Biofuels have
long been touted as a way to cut U.S. greenhouse gas emissions. h e
basic reaction that propels plants' growth pulls carbon dioxide out of
the air and produces carbohydrates, oxygen, and water. When bio-
fuels are ultimately burned, the carbon dioxide is released back into
the atmosphere, just like carbon dioxide that is released by burning
gasoline or diesel. In the case of biofuels, though, the two parts of
the cycle balance out. h e net result, which scientists refer to as “life-
cycle” emissions, should be zero emissions. h

at's a big environmental

boon.
But it doesn't count all the emissions involved in converting crops
into fuel. Estimates are all over the map. Some scientists conclude
that, when you add everything in, the life-cycle emissions from corn
ethanol are nearly as bad as those from gasoline. Others note that if
ethanol rei neries are powered with natural gas, their environmental
performance increases, with the corn ethanol they produce turning
out to be about 30 percent bet er than gasoline. 100 Either way, the
emissions reductions aren't radical. And most other crops grown in
the United States do barely bet er than corn. Unless the country can
move to cellulosic fuels, which do far bet er from a carbon standpoint,
it's hard to think that greater use of U.S. biofuels will do much for
climate change.