Growing fuel might not be as green as we think
http://www.theherald.co.uk/misc/print.php?artid=1599145
At first it seemed so simple: a new type of fuel derived from a
harmless flowering shrub. It could be used in existing vehicles
without modifying them and would provide not only a secure fuel supply
and a valuable cash crop for farmers but an endless, sustainable fuel
source that, unlike fossil fuel, did not add to the amount of carbon
in the atmosphere. Run your car with a clear conscience: this was the
solution wed been waiting for.
But biofuels arent quite the environmental dream they seem - at least
not according to the bus company National Express. The firm has just
announced that it is pulling out of a biofuels trial after consulting
with green groups and concluding, in the words of chief executive
Richard Bowker, that what appears to be the green option may not
actually be green after all.
The firm had embarked on the trial of biofuels - produced from crops
such as rapeseed, wheat and sugar cane and beet - as part of its drive
to cut its carbon footprint, with the ultimate aim of running some of
its London buses on up to 30% biodiesel. But Bowker said that while
the fuels may well have a role to play in helping us reduce the
emissions of greenhouse gases arising from transport operations in the
future, the company was not convinced of their green benefits at
present.
Its concerns follow studies indicating that intensive farming methods
can give biodiesel a bigger carbon footprint than traditional oil, and
the company added that there were also problems around sustainability
of supply.
So are biofuels better for the environment than fossil fuels, or
arent they?
Adam Harrison, senior policy officer at WWF Scotland, works on food
and agriculture issues, with a particular focus on biofuels. There is
no doubt, he says, that biofuels can indeed deliver high carbon
reductions, citing sugar cane grown efficiently in Brazil as one
example - it can save 70% of carbon emissions compared with petrol.
Other studies back this up: a report by Sheffield Hallam University
found that net savings of 71% in carbon dioxide emissions could be
realised by replacing ultra-low sulphur diesel with biodiesel produced
from oilseed rape and that net savings of 70% in carbon dioxide
emissions could arise from the substitution of unleaded petrol with
bioethanol produced from wheat.
Yet not all biofuels are created equal. The way a fuel is manufactured
can add greatly to its carbon impact. For example, if rainforest is
cut down to make way for a biofuel soya plantation, it will release a
lot of CO2 into the atmosphere. Intensive cropping may also contribute
to the release of soil-bound CO2. Then there are fertilisers to
consider, which put nitrous oxides (powerful greenhouse gases) into
the atmosphere, plus the carbon footprint associated with irrigating,
harvesting and transporting the crop.
Some fuels will produce substantially more greenhouse gases than if
you used petrol in the first place, says Harrison. As an example, he
cites bioethanol produced from maize in the US, which can generate
140% of the carbon you would use if you had gone for petrol.
If that seems a scandalous betrayal of the whole rationale behind
biofuels, its because the US governments backing for biofuel
production is nothing to do with carbon, but to do with fuel
security.
The problem is that consumers assume biofuel automatically means
greener than petrol. For this reason, WWF and other groups have been
pressing the UK government to set binding standards so that all
biofuels used in British vehicles deliver a minimum level of carbon
reduction compared to conventional fuels.
WWF has also lobbied the government to set standards on sustainability
of biofuel plantations, to limit their adverse effects on wildlife
habitats.
The government has responded: by 2010, the fuel blend at British pumps
must contain 5% biofuel; minimum greenhouse gas standards for biofuels
will be brought in the same year, with sustainability standards coming
in the year afterwards.
So, some of these problems are in the process of being sorted out.
There are other issues - the fact that the growth of the biofuel
industry is pushing up food prices in some places, for instance - but
biofuels are constantly evolving. In recognition of this, National
Express made clear that it was still interested in so-called
second-generation biofuels - that is, fuel made from wood chips, grass
or even small trees. As yet, the technology for mass producing
second-generation biofuels is some way off, but when they can be
manufactured, its likely that they will offer much more substantial
greenhouse gas savings, says Harrison.
All in all, then, environmental groups regard biofuels as a good
thing, provided they deliver confirmed greenhouse gas savings and are
sustainably produced. And in the meantime? We need to use our cars
less, says Harrison. Thats the really simple answer.
12:29am today
By REBECCA McQUILLAN