Monday 04 August
2008, San José, Costa Rica
AGRICULTURE:
The Climate Costs of a
Glass of Milk
By Raúl Pierri*
MONTEVIDEO (Tierramérica)
- A simple glass of milk
on the breakfast table
can carry high
environmental costs.
Because of this, some
farmers and scientists
are looking for ways to
reduce the impacts of
agriculture and
livestock, which are
responsible for 12 to 14
percent of global
emissions of greenhouse
gases.
There are already
studies to measure the
climate costs of that
glass of milk, or of a
country’s entire milk
production, from raising
the cow to the final
product on the table.
The farming sector’s
emissions of climate
change gases grew nearly
17 percent between 1990
and 2005 worldwide, and
the biggest increase
took place in the
developing South (32
percent).
The intestinal
fermentation in ruminant
livestock, like cattle,
releases into the
atmosphere methane and
nitrous oxide, two
potent greenhouse gases.
Further emissions come
from animal manure and
urine, the burning of
plant biomass to clear
pastures, rice
production and
biological and chemical
processes occurring in
soil.
The two gases contribute
70 percent of the
emissions coming from
the agricultural sector.
Methane and nitrous
oxide, respectively,
have 21 and 300 times
more "greenhouse effect"
than carbon dioxide, the
principal gas associated
with climate change,
released primarily by
vehicles, industry and
electricity production.
While countries are
looking for ways to
produce more food and
overcome the current
food price crisis,
experts from LEARN
(Livestock Emission
Abatement Research
Network) are studying
ways to reduce emissions
without undercutting
productivity.
That was the focus of
discussion amongst
officials and
researchers gathered in
Uruguay Jul. 21-24 for
the international
workshop on agricultural
emissions of greenhouse
gases, organised by
LEARN. Tierramérica was
the only media outlet
present for the
technical segment of the
meeting.
In Uruguay, agriculture
generates 91 percent of
the country’s methane
emissions. In
neighbouring Argentina,
farming and ranching are
responsible for 44
percent of national
greenhouse emissions.
Because it involves a
sector that is very
important to countries
like Uruguay, the
reduction of emissions
must ensure that
pasture-raised livestock
continue to eat a
natural, chemical-free
diet, Luis Santos,
coordinator of Uruguay’s
Climate Change Unit,
told Tierramérica. One
option is to modify the
diet of the animals,
using varieties of
forage that are less
rich in methane, he
said.
Pastureland accounts for
26 to 40 percent of the
world’s productive
lands. And cattle emit
37 percent of the
methane and 65 percent
of the nitrous oxide
generated by human-led
activities. The vast
majority of these gases
come from pastures in
Latin America and Asia.
Tim Clough, a scientist
from New Zealand, noted
that the atmospheric
concentration of nitrous
oxide continues to rise
0.26 percent annually.
Globally, the nitrous
oxide output is
dominated by
agricultural sources, he
said, stressing the
urgent need to reduce
these emissions.
The main sources of
nitrous oxide in
pastures are manure and
nitrogen-based
fertilisers. Nitrous
oxide is produced in the
soil through microbe
processes like
nitrification or the
conversion of ammonium
nitrate, according to
Clough, an expert in
soil sciences from
Lincoln University in
New Zealand.
Clough suggested, as is
being done in his
country, the use of
nitrification
inhibitors, chemical
substances added to
nitrogen fertilisers
(mineral or organic) or
applied directly to the
soil, which inhibit the
activity of bacteria.
LEARN was founded last
year in New Zealand, and
includes representatives
from politics, science
and industry from some
40 countries, including
agricultural giants like
the United States,
Brazil, Australia,
India, China and
Argentina.
Its aim is to define
methods for measuring,
verifying, communicating
and mitigating the
production of greenhouse
gases from the livestock
sector.
"The first objective is,
in the context of the
Framework Convention on
Climate Change, to
determine the factors of
emissions in order to
carry out an inventory
of greenhouse gases
released by the sector,"
explained Santos.
"The countries of the
developing South,
according to the
Convention, must adopt
measures but are not
obligated, like the
industrialised
countries, to reduce
their emissions. That is
why we want to know, for
the countries like New
Zealand that do have an
obligation, how much
they emit and how they
are going to cut
emissions," he said.
To that end, a New
Zealand Project
presented at the meeting
demonstrated the
procedures for tracking
greenhouse gases in the
farming sector. In milk
production, for example,
this starts with
emissions from the cow
itself, to
industrialisation and
transport.
(*Originally published
by Latin American
newspapers that are part
of the Tierramérica
network. Tierramérica is
a specialised news
service produced by IPS
with the backing of the
United Nations
Development Programme,
United Nations
Environment Programme
and the World Bank.)
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