27Review of Complexity and Complex Systems
however, can lead to hemorrhages and hemorrhagic stroke (again, the dark
side).
To satisfy the insatiable world demand for gasoline, ethanol distilled from
fermented sugar cane and corn is used as a fuel additive in concentrations
ranging from 10% to 85% in order to stretch the petroleum-based gasoline
supply. This ethanol is called a carbon-neutral (green) biofuel because it comes
from annual plant crops that use CO
2
to grow. The fermentation process that
produces ethanol releases CO
2
into the atmosphere (one CO
2
molecule is
released when one pyruvate molecule is enzymatically decarboxylated to
make acetaldehyde, which is enzymatically converted to ethanol) (Northrop
and Connor 20