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A vegetarian diet produces much less GHG
over a lifetime. The average consumption of grain and forage for
production of
one kg of animal products shows that producing lamb and beef requires
between
four and ten times more grain than producing pigs or chicken. For
ruminants,
methane production further increases GHG emissions per unit of food.
Therefore,
the consumption of less meat will save GHG, and so will poultry instead
of beef
or lamb. The average amount of kcal fossil energy used per kcal of meat
produced is 25. This is more than 11 times that of plant-based
products, with
an average input/output ratio of 2.2 (Pimentel and Pimentel, 2003).
Using
numbers from Pimentel and Pimentel (2003) we calculated that 385 kcal
of fossil
fuel per person per day could be saved by substituting just 5% of the
meat in
the diet with vegetarian products, assuming an average US diet as
baseline.
Considering that fossil fuels emit different amounts of CO2 per kcal
(Sims et
al., 2006), this amounts to between 95 and 126 g of CO2.
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Recent
research, summarized in the New Scientist magazine of 18th
July 2007,
suggests that modern methods of intensive beef production generate
large
amounts of greenhouse gases. This is, of course, not a new hypothesis:
we have
gradually become aware of the huge amounts of grain needed to feed our
animals,
and of the troublesome amounts of energy needed to produce the
fertilizer
needed to get our cereals to grow. The scientist David Pimentel has
suggested
that it takes seven times as much grain to feed all meat animals in the
US
as it does to directly feed the human population. The new research,
carried out
in Japan
but
surely representative of the impact of modern farming methods in the
rest of
the industrial world, suggests that one kilogram of meat creates the
equivalent
of over 36kg of global warming gases. [1]
Generally, small, mixed farms and those operated in a sustainable
manner, such
as organically or bio-dynamically, are more environment friendly than
large-scale factory farms. But the research as to whether or not
organically-raised meat generates lower levels of greenhouse gas
emissions is
uneven. A 2003 Swedish study that was recently cited in the New
Scientist,
apparently suggested that organic beef, raised on grass rather than
concentrated feed, emits 40 percent less greenhouse gases and consumes
85
percent less energy than non-organic beef. But a 2000 Swedish study
from the
Department of Applied Environmental Sciences at Goteborg
University
compared organic and conventional dairy production and found a much
less
dramatic difference. Life Cycle Assessment of Milk Production concluded
that
the organic system generated slightly fewer greenhouse gas emissions
than the
conventional. Carbon dioxide and nitrous oxide levels were lower,
largely due to
the absence of energy intensive nitrate fertilizers, but methane
emissions were
higher in the organic system due to the cattle's higher intake of
roughage
fodder. [2]
What can be done? There's no simple answer. Better waste management,
for one.
Improved farming practices would help, too. Mark W Rosegrant, director
of
environment and production technology at the nonprofit International
Food
Policy Research Institute, says, "There should be investment in
livestock
breeding and management, to reduce the footprint needed to produce any
given
level of meat." Another solution is to encourage grass feeding than
protein rich diet to our live stocks but do we have that much amount of
land to
grass feed our cattle and goats?
Perhaps the best hope for change lies in consumers becoming aware of
the true
costs of industrial meat production. "When you look at environmental
problems in the US,"
says Professor Eshel, "nearly all of them have their source in food
production and in particular meat production. And factory farming is
'optimal'
only as long as degrading waterways is free. If dumping this stuff
becomes
costly - even if it simply carries a non-zero price tag - the entire
structure of
food production will change dramatically"
Animal welfare may not yet be a major concern, but as the horrors of
raising
meat in confinement become known, more animal lovers may start to
react. And
would the world not be a better place were some of the grains we use to
grow
meat directed instead to feed our fellow human beings?
[3]
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