Biofuels: the cons
Whilst the use of wood is
potentially sustainable, in many ‘developing’ countries wood fuel is being used
at a rate that exceeds its re-growth. This is not only unsustainable but also
results in villagers having to travel ever-increasing distances, often
involving great hardship, to gather sufficient firewood for their daily needs.
Also, when it has been gathered, firewood is often burned very inefficiently in
open fires – as was the case in Britain and many other ‘developed’ countries
until quite recently.
This not only results in
excess greenhouse gas emissions, as we have seen, but also gives much less
effective warmth than if an efficient stove were used. Moreover, it usually
results in high levels of smoke pollution, with very detrimental health
effects..
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Beyond air pollution, a
reliance on wood as a source of fuel often leads to deforestation. Not only
does this reduce the amount of vegetation, so useful for ‘metabolising’ CO2
but, without trees roots to
stabilize the land surface, rates of soil erosion tend to increase. This may,
in turn, lead to pollution of water sources (as we shall see later on).
For instance, Nocete et
al. 2005. demonstrated that the arrival of intensive metallurgy in Iberia
during the third millennium BC was widespread with widespread deforestation
(the wood utilised for smelting ores). This is indicated by a clear decline in
tree pollen and an increase in wood charcoal in the archaeological record.
This is just one of many
examples from human history where demand for combustion fuels has led to
extensive deforestation and resulted in environmental pollution.