Frihed og fristeder - LøS

24
LØSNET nr. 53-54, September 2007
Miljø og prutter
Af Daniele Fanelli og Ian Roberts, kommenteret af Niels Bandholm
Jeg læste dog om en tankevækkende beregning i sidste nr af New
Scientist fra d. 18. juli: Spiser man et kilogram kød (hvilken frygtelig
tanke) så svarer energi og ressourceforbruget til produktionen til at
A
kilogram of beef is responsible for
more greenhouse gas emissions
and other pollution than driving
for 3 hours while leaving all the lights
on back home.
This is among the conclusions of a
study by Akifumi Ogino of the National
Institute of Livestock and Grassland
Science in Tsukuba, Japan, and colleagues,
which has assessed the effects of
beef production on global warming, water
acidification and eutrophication, and
energy consumption. The team looked at
calf production, focusing on animal management
and the effects of producing
and transporting feed.
By combining this information with
data from their earlier studies on the
impact of beef fattening systems, the
researchers were able to calculate the
total environmental load of a portion of
beef.
Their analysis showed that producing
a kilogram of beef leads to the emission
of greenhouse gases with a warming
potential equivalent to 36.4 kilograms
of carbon dioxide. It also releases fertilizing
compounds equivalent to 340
grams of sulphur dioxide and 59 grams
of phosphate, and consumes 169 mega
joules of energy (Animal Science Journal
Animal Science Journal 78 (4), link: DOI:
10.1111/j.1740-0929.2007.00457.x.
In other words, a kilogram of beef
is responsible for the equivalent of the
amount of CO2 emitted by the average
European car every 250 kilometers, and
burns enough energy to light a 100-watt
bulb for nearly 20 days.
The calculations, which are based
on standard industrial methods of meat
production in Japan, did not include the
impact of managing farm infrastructure
and transporting the meat, so the total
environmental load is higher than the
study suggests.
Most of the greenhouse gas emissions
are in the form of methane released from
the animals’ digestive systems, while the
acid and fertilising substances come primarily
from their waste. Over two-thirds
of the energy goes towards producing and
transporting the animals’ feed.
Possible interventions, the authors
suggest, include better waste management
and shortening the interval between
calving by one month. This latter measure
could reduce the total environmental load
by nearly 6 per cent. A Swedish study in
2003 suggested that organic beef, raised
on grass rather than concentrated feed,
emits 40 per cent less greenhouse gases
and consumes 85 per cent less energy.
”Methane emissions from beef cattle
are declining, thanks to innovations in
feeding practices,” says Karen Batra of
the National Cattlemen’s Beef Association
in Centennial, Colorado. ”Everybody is
trying to come up with different ways to
reduce carbon footprints,” says Su Taylor
of the Vegetarian Society in the UK: ”But
one of the easiest things you can do is to
stop eating meat.”
Det får mig til at tænke på en anden artikel
for en måned siden: How the obesity
epidemic is aggravating global warming
fra den 27 June 2007 i New Scientist af
Ian Roberts:
WE KNOW the world is warming and
we know humans are causing it,
but the headaches really start
when we try to predict how hot it will
get. This is partly because of the many
subtle environmental and lifestyle factors
driving climate change.
One of these is the feedback that
could amplify warming. Once the powerful
greenhouse gas methane starts
to be released from warming oceans or
permafrost, it could rapidly ratchet up
the global thermostat. The same goes for
decreasing snow and ice cover. Because
of this, researchers are keeping a close
eye on the oceans, ice caps, forests and
tundra for signs of such changes.
Now consider what may seem a more
unlikely driver of climate change: the global
obesity epidemic. We tend to think
of obesity only as a public-health problem,
but many of its causes overlap with
those of global warming. Car dependence
and labour-saving devices have cut the
energy people expend as they go about
their lives, at the same time increasing
the amount of fossil fuel they burn. It’s
no coincidence that obesity is most prevalent
in the US, where per capita carbon
emissions exceed those of any other major
nation, and it is becoming clear that
To planeter mødes:
Jorden siger: Jeg er så varm.
Jeg tror jeg har fået Homo Sapiens.
Den anden svarer:
Bare rolig - det går over.
obese people are having a direct impact
on the climate. This is happening through
their lifestyles and the amount and type
of food they eat, and the worse the obesity
epidemic gets the greater its impact
on global warming.
”Obesity is most prevalent in the US,
where per capita carbon emissions are
the highest of any major nation”
One reason is the extra food that obese
people eat - about 40 per cent more in
terms of calories than their lean counter-