About 90 per cent of
the Earth's protective
ozone layer resides in
the stratosphere
between 15km and
50km altitude. Molecular
oxygen is broken down
in the stratosphere by
solar radiation to yield
atomic oxygen, which
then combines with
molecular oxygen to
produce ozone. Ozone is
destroyed naturally
through a series of
catalytic cycles involving
oxygen, nitrogen,
hydrogen and to a
lesser extent chlorine
and bromine species.
The abundance of
stratospheric ozone is
therefore chemically
controlled by the
stratospheric
abundances of
compounds containing
hydrogen, nitrogen,
chlorine and bromine.
Increases in the
abundances of methane
and nitrous oxide
(sources of hydrogen
and nitrogen oxides
respectively) thus
affect the abundance
and distribution of
stratospheric ozone.
Stratospheric ozone is
also affected by the
abundance of carbon
dioxide (CO2), because
the rates of the
chemical reactions that
control the abundance
of ozone are
temperature-
dependent, and the
abundance of CO2 plays
a key role in determining
the temperature
structure of the
stratosphere. While
methane is a more
potent greenhouse gas
than CO2, there is over
200 times more CO@ in
the atmosphere. Hence
the amount of warming
methane contributes is
28% of the warming
caused by CO2.
A United Nations report
has identified the
worlds rapidly growing
herds of cattle as the
greatest threat to the
climate, forests and
wildlife. Livestock are
responsible for 18% of
the greenhouse gases
that cause global
warming, more than
cars, planes and all
other forms of
transport put together.
Burning fuel to produce
fertilizer to grow feed
to produce and to
transport it - and
clearing vegetation for
grazing - produces 9%
of all emissions of CO2,
the most common
greenhouse gas. And
their wind and manure
emit more than one
third of emissions of
another, methane,
which warms the world
20 times faster than
CO2.
Livestock belch out or
release methane gas as
they digest their food.
And a methane
molecule released into
the atmosphere, has a
25 times greater
capacity for trapping
heat than a carbon
dioxide molecule. Rice,
meat, dairy products
and fish are associated
with high methane
emissions while wheat,
vegetables and fruits
contribute to an oxide
of nitrogen - another
greenhouse gas that
has an even greater
heat trapping capacity
than methane. Bananas
had the least global
warming potential,
according to the
research analysis
inasmuch as much of
the emissions
associated with
bananas emerge from
their transportation
from plantations to
retail outlets.
In early 1990s, the
Indian scientists were
caught by surprise
when the US
researchers had
suggested that India's
paddy fields were
producing a large
amount of methane
unmindful of the fact
that the livestock
industry had a much
bigger impact on the
environment. This
prompted an indigenous
research in the subject
that showed that the
US claims were far
exaggerated. The
research also led to the
assessment of the
greenhouse gas
emissions during each
stage of the lifecycle of
various food items
from the farm to the
dining table viz.
production, processing
and cooking, so to say,
to generate a
comparative chart.
The research designed
to generate raw data
about the global
warming potential of
Indian food items has
determined the Global
Warming Potential in
gram carbon dioxide per
kg thus: Apple (357),
Banana (98), Basmati
rice (859), Chapati (250),
Dosa (729), Fish (756),
Idli (682), Parantha
(261), Potato (132),
Poultry meat (801), Milk
(766), Mutton (9149),
Rice (712).
The data thrown up as
above clearly shows
that a kilogram of
mutton has a global
warming potential 12
times higher than a
kilogram of fish. The
global warming
potential of poultry
meat - chicken or duck -
is only slightly higher
than that of fish. It also
makes it abundantly
clear that vegetarians
are far more
environment-friendly
than the non-
vegetarians. For the
sake of the planet
earth and for their own
sake, the latter can do
their bit by eating a
little less meat - or
better still, shift over to
"mock meats" or
vegetarian meats, now
available in a large
number of Washington
area restaurants,
where the wizardry and
skill of counterfeiting
meat has become a
sophisticated art