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 Simple calculations
show that biofuels come nowhere near providing enough fuel for
all the World's current transport demands. As mentioned,
photosynthesis is simply not efficient enough for such an
absurd undertaking (unless you have access to a time-machine).
For a given area wind-turbines produce 20 times more energy
whilst photovoltaic panels generate 100 times more. Biomass
crops need a lot of land.
In the current
period of 'Globalisation' rich westerners in the north tend to
just export this problem to some poor third world country. There
is little point clearing a forest to grow bio-fuels if that
forest would have absorbed more CO2 if you left it as it was.
Even if we don't export these problems abroad then our current
model of agriculture suggests we apply liberal amounts of
oil-made fertiliser to everything to make it grow bigger. When
taken into account this means there is little or no net saving
in fossil fuels.
However if we adopt
organic farming practices there is a future for some biofuels
near to where they will be used. Biofuel can be sourced from
short-rotation forest, coppice and arable land. Rotation farming
is a traditional way of using 'break' crops to maintain the
health of the soil. Hence bio-diesel may be the by-product of a
farming practice we will have to adopt anyway when the fossil
oil runs out.
We mentioned
Miscanthus earlier. What is that? Well it is perennial grass
that can be under sown with clover to improve nitrogen fixation.
Successive harvests of Miscanthus deplete soil nutrients very
little but improve soil structure. In some areas hemp can be
used instead. And Miscanthus is a fuel crop. In future it is
thought that wood from a forest
 could be processed into a liquid
or gaseous biofuel that displaces fossil fuels, leaving a char
residue that can be returned to the soil, where it improves
yields. This process also sequesters carbon at a rate much
greater than that of traditional humus.
However good this
sounds it only works within the framework of a radical overhaul
of the way farming works in the North. Welcome to the real
world.
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