Observe World Ozone Day 16 September 2009 About World Ozone Day In 1994, the United Nations General Assembly voted to designate 16 September as World Ozone Day, to commemorate the establishment of the Montreal Protocol on this date in 1987. The theme for 2009 is “Universal participation: Ozone protection unifies the world”.

1. S P E R
O I Observe WOrld OzOne day
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16 september 2009
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About ozone
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The ozone layer is a layer in the Earth’s atmosphere which contains
O
N
P relatively high concentrations of ozone (O3). This layer absorbs 93-99% of the sun’s
A high frequency ultraviolet (UV) light, which is potentially damaging to life on Earth. The
L L
E • P ozone layer is located mainly in the lower portion of the strato-
sphere from approximately 10 – 50 kms above the Earth, though the thickness varies
seasonally and geographically.
Prosperity People Planet
About World Ozone Day
In 1994, the United Nations General Assembly voted to designate 16 September as
and sustainability World Ozone Day, to commemorate the establishment of the Montreal Protocol
on this date in 1987. The theme for 2009 is “Universal participation: Ozone
protection unifies the world”.
About ozone and the 3Ps
As the ‘Earth’s sunscreen’, ozone is important to
sustainable development:
Prosperity —The potential consequenc-
es for Prosperity are the result of the
impacts to People and Planet and the
financial losses incurred in mitigating
these impacts.
People — Acute exposure to solar UV
radiation causes sunburn and can result
in damage to eyesight and, in the
long term, skin cancer. It has also
been found that UV radiation can nega-
tively affect the immune system.
Planet — Most plants have natural mech-
anisms that provide some form of UV
shielding, but do not always have
sufficient amounts for com-
plete protection and can suf-
fer detrimental effects. In clear
oceans and lake waters, UV radiation
can penetrate and affect shallow-water
fish and plankton.

2. About ozone depletion Ozone-oxygen cycle
in the ozone layer
Ozone is the Earth’s natural sunscreen, absorbing and block-
ing most of the incoming UV radiation from the sun and protecting
life from DNA-damaging radiation. The gas is naturally created and
replenished by a photochemical reaction in the upper atmosphere
where UV rays break oxygen molecules (O2) into in-
dividual atoms that then recombine into three-part
molecules (O3) – that is, ozone. As ozone is moved around the
globe by upper level winds, it is slowly depleted by naturally occur-
ring atmospheric gases. It is a system in natural balance.
But the chlorofluorocarbons (CFCs) in refrigerants and the inert
carriers for aerosol sprays, invented in 1928, upset that balance.
Researchers discovered in the 1970s and 1980s that while CFCs
are inert at the Earth’s surface, they are quite re-
active in the stratosphere (10 – 50 kms altitude, or 6 – 31
miles), where roughly 90 percent of the planet’s ozone accumulates. Ozone-oxygen cycle Source; Wikipedia
UV radiation causes CFCs and similar bromine compounds in the stratosphere to break up into elemental chlorine and bromine
that readily destroy ozone molecules. Worst of all, such ozone depleting substances can reside for several decades in the
stratosphere before breaking down.
About the Montreal Protocol
In the 1980s, ozone-depleting substances opened a wintertime “hole” over Ant-
arctica and opened the eyes of the world to the effects of human ac-
tivity on the atmosphere. By 1987, the World Meteorological Organization and Unit-
ed Nations Environment Program had brought together scientists, diplomats, environmental
advocates, governments, industry representatives, and non-governmental organizations to
forge an agreement to phase out the chemicals. In January 1989, the Montreal Protocol (full
name: The Montreal Protocol on Substances That Deplete the Ozone Layer) was brought
into force, the first-ever international agreement on regulation of chemi-
cal pollutants.
At Montreal, the participants agreed to freeze production of CFCs at 1986 levels and to
reduce production by 50% by 1999. After a series of scientific expeditions to the Antarctic
produced convincing evidence that the ozone hole was indeed caused by chlo-
rine and bromine from manmade organohalogens, the Montreal Protocol
was strengthened at a 1990 meeting in London. The participants agreed to phase out CFCs
and halons entirely (aside from a very small amount marked for certain essential uses, such
as asthma inhalers) by 2000. At a 1992 meeting in Copenhagen, the phase out date was
moved up to 1996.
“ Perhaps the single most successful
international agreement to date has been
the Montreal Protocol.” – Kofi Annan, Former Scientists believe that if the Montreal Proctocol is adhered to, the ozone layer will
Secretary General of the United Nations recover by 2050. Due to its widespread adoption and implementation it has been hailed
as an example of exceptional international co-operation.
About the way forward
Sappi and ozone – at a glance
de-
On 02 August 2003, scientists announced that the
pletion of the ozone layer had slowed down
signficantly over the previous decade due The Montreal Protocol has been ratified by the three
to the international ban on CFCs. Three satellites and major regions in which Sappi operates – Europe, North
three ground stations confirmed this view. Some break- America and South Africa.
down can be expected to continue due to CFCs used by
nations which have not banned them, and due to gases
At Sappi, we do not use ozone-depleting substances at
which are already in the stratosphere.
any of our manufacturing sites.

3. FAQ Q // What are CFCs?
A // Chlorofluorocarbons (CFCs), invented by Thomas
Midgley in the 1920s, were developed as a safe,
non-toxic, non-flammable alternative to dangerous
substances like ammonia for purposes of refrigeration
and spray-can propellants. Their usage grew
enormously over the years.
However, one of the elements that make up CFCs is
chlorine. Very little chlorine exists naturally in the at-
mosphere. But it turns out that CFCs are harmful
because they introduce chlorine into the
ozone layer. What happens is that the ultraviolet
radiation at this altitude breaks down CFCs, freeing World Production of CFCs
the chlorine. Under the proper conditions, this chlorine
has the potential to destroy large amounts of ozone. This has indeed been observed, especially over Antarctica.
Given the longevity of CFC molecules, recovery times are measured in decades. It is calculated that a CFC
molecule takes an average of 15 years to go from the ground level up to the upper atmosphere, and it can stay
there for about a century, destroying up to one hundred thousand ozone molecules during that time.
Q // What is the “ozone hole”?
A // Each year for the past few decades during the Southern Hemisphere spring, chemical reactions involving chlo-
rine and bromine cause ozone in Antarctica to be destroyed, leading to the “ozone hole” – essentially
a thinning of the ozone layer. It is a hole in the sense of a hole in the ground, that is, a depression; not
in the sense of a hole in a wall.
Q // Why does the ozone hole occur in spring and why is it more pronounced in Antarctica?
A // The ozone hole occurs during the Antarctic spring, from September to early December, as strong westerly
winds start to circulate around the continent and create an atmospheric vortex, or persistent large-scale cy-
clone, at the Earth’s poles. The Antarctic vortex is more pronounced and persistent than the
Arctic one because the distribution of land masses at high latitudes in the northern hemisphere gives rise
to Rossby waves (wave-like patterns in the atmosphere) which contribute to the breakdown of the vortex. In
the southern hemisphere, the topography is different, which means the vortex is less disturbed and explains
why Antarctica is more affected by ozone depletion than the Arctic.
Nasa images showing past and present ozone levels
1974 1994 2009
The Dobson unit is named after Gordon Dobson, a researcher at the University of Oxford. In the 1920s, he built the
first instrument to measure ozone, now called the Dobson ozone spectrophotometer. Currently, global average ozone
is about 300 Dobson units. Before 1980, ozone less than 200 Dobson units was rarely seen.
NASA projections of stratospheric ozone concentrations if chlorofluorocarbons had not been banned
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