Action on Ozone
`2000 Edition
`
`UNEP
`Ozone Secretariat
`United Nations Environment Programme
`
`001
`
`

`

`UNEP
`
`Ozone Secretariat
`United Nations Environment Programme
`P. O. Box 30552, Nairobi, Kenya
`E-mail: Ozoneinfo@unep.org
`http://www.unep.org/ozone
`http://www.unep.ch/ozone
`
`ISBN: 92-807-1884-3
`
`Published 2000
`
`Produced by
`The Secretariat for
`The Vienna Convention for the Protection of the Ozone Layer &
`The Montreal Protocol on Substances that Deplete the Ozone Layer
`
`Printed and bound in Kenya by UNON. Printed on recycled paper.
`
`Cover design by UNON Printshop (June 2000)
`
`Co-ordination:
`
`Research and Editing:
`
`K. Madhava Sarma, Executive Secretary, Ozone
`Secretariat, UNEP
`Nelson Sabogal, Senior Scientific Affairs Officer,
`Ozone Secretariat, UNEP
`Gilbert M. Bankobeza, Senior Legal Officer, Ozone
`Secretariat, UNEP
`
`Duncan Brack, Consultant(dbrack@dircon.co.uk)
`Michael Graber, Ozone Secretariat, UNEP
`Ruth Batten, Ozone Secretariat, UNEP
`Gerald Mutisya, Ozone Secretariat, UNEP
`
`Layout and Formatting:
`
`Bo Sorensen, UNON Printshop
`Martha Adila, Ozone Secretariat, UNEP
`
`002
`
`

`

`Table of Contents
`
`Foreword
`
`1. The Shield in the Sky
`Ozone depletion
`
`2. The ‘Holes’ in the Layer
`Miracle substances
`The ozone ‘holes’
`
`3.
`
`Saving the Ozone Layer
`Beginnings
`The Vienna Convention for the Protection of the
`Ozone Layer
`The Montreal Protocol on Substances that
`Deplete the Ozone Layer
`
`4. The Montreal Protocol
`Control measures on ozone-depleting substances
`Institutions and procedures
`Developing countries and the Multilateral Fund
`
`5. The Impact of the Ozone Regime
`The record of the ozone regime
`Alternatives to ozone-depleting substances
`New challenges
`
`6. The Future of the Ozone Regime
`
`i
`
`1
`1
`
`4
` 4
` 5
`
` 8
` 8
`
` 9
`
`9
`
`12
`12
` 13
`14
`
`16
` 16
`17
`18
`
` 19
`
`003
`
`

`

`UNEP
`
`We must remember, however, that
`although the fight is being won,
`there is still much to be done in the
`field of ozone protection. Although
`there is still some scope for
`tightening the control schedules for
`the remaining ozone-depleting
`substances, in order to hasten the
`recovery of the ozone layer, the
`ozone regime, as it continues to
`evolve, is facing new and different
`challenges. Implementation of the
`control measures in developing
`countries, who met their first
`targets under the Protocol just last
`year; cases of non-compliance;
`evasion of the controls through
`illegal trade: all pose new threats to
`the health of the ozone layer and to
`the planet beneath it.
`
`We can be proud of our
`achievements. We can learn lessons,
`and continue to adapt and innovate.
`And we can continue to meet these
`challenges, so that we all may strive
`for a better life for the peoples of the
`world.
`
`Klaus Töpfer
`Executive Director, UNEP
`
`Foreword
`
`Imagine a world without the
`treaties designed to protect the
`Earth’s stratospheric ozone layer.
`
`Production and consumption of
`industrial chemicals such as
`chlorofluorocarbons (CFCs) and
`halons would be climbing steadily,
`bringing products such as
`refrigerators, air conditioning,
`aerosol sprays, insulating and
`furniture foams into the homes and
`vehicles of hundreds of millions of
`families around the world.
`
`Part of the attraction of these
`substances is their stability; they do
`not break down easily under heat,
`or pressure, or chemical reactions.
`But this very stability means that
`when they are released into the
`atmosphere, they survive to diffuse
`up into the stratosphere. In this
`world without the treaties,
`concentrations of these chemicals
`reach five times today’s value and
`nine times the value now projected
`for 2050.
`
`High in the atmosphere, these
`chemicals are finally broken apart
`by solar radiation and in turn react
`with and destroy the planet’s
`protective layer of ozone. By 2000,
`ozone levels have fallen by 50% of
`pre-industrial levels north of the
`tropics, and by 70% southwards.
`
`Without the stratospheric ozone layer
`to stop it, an ever-rising intensity of
`ultraviolet radiation penetrates to
`the planet’s surface by 2050, double
`current levels in the north and
`quadruple in the south. Skin cancers,
`eye damage and immune system
`suppression are rife in those who
`expose their bodies to the sun.
`Walking in the open air cannot be
`risked without sunscreen and
`sunglasses; sunbathing is banned.
`
`This is the world as it might have
`been, without the ozone treaties –
`the 1985 Vienna Convention for the
`Protection of the Ozone Layer and
`
`the 1987 Montreal Protocol on
`Substances that Deplete the Ozone
`Layer. The international regime
`created by these two agreements –
`revised, and made more effective, on
`no less than five occasions over the
`last decade – is saving the world
`from that alternative.
`
`This is the fourth edition of Action
`on Ozone produced by UNEP. And
`although the depletion of the
`Earth’s ozone layer has now reached
`record levels – thanks to the last
`seventy-five years of production and
`use of ozone-damaging chemicals –
`this is the first edition in which we
`can say it is now at its peak. The
`scientific evidence clearly shows the
`beginnings of a fall in the
`concentrations of the dangerous
`chemicals in the lower atmosphere –
`which is now being translated into a
`similar fall in the stratosphere,
`where the ozone is destroyed. The
`ozone layer is predicted to start to
`recover in the next one or two
`decades, and should be restored to
`full health by the middle of the new
`century.
`
`It is one of UNEP’s proudest
`achievements to have led the
`international effort to protect the
`Earth’s ozone layer. The Montreal
`Protocol, which was negotiated
`under our aegis, has, rightly, been
`regarded as a model for other
`international environmental
`agreements. It has proved a flexible
`and adaptable regime. It has helped
`to bring together scientists,
`industrialists and governments,
`with their different but essential
`viewpoints. It has dealt effectively
`with the different needs of
`industrialised and developing
`countries in meeting a common
`threat. There is much that can be
`learned from the story of the ozone
`regime of value to other areas of
`international environmental action,
`including biodiversity,
`desertification and climate change.
`
`004
`
`

`

`1928:
`
`1970:
`
`The first CFCs (CFC-11 and -12) are developed in the US, initially to be used as coolants for refrigeration. Beginning in the 1960s, consumption
`grows rapidly in developed countries, encouraged by the versatile and favourable properties of CFCs: stable, non-toxic, non-corrosive and non-
`flammable.
`A scientific paper points out the possibility that nitrogen-oxides from high-flying supersonic aircraft and from fertilizer applications might deplete
`the ozone layer.
`
` 1
`
`1. The Shield in the Sky
`
`A ll life on Earth depends on
`
`the existence of a thin
`shield of a poisonous gas
`high in the atmosphere: the ozone
`layer.
`
`Ozone is a molecule made up of
`three oxygen atoms. It is an
`extremely rare component of the
`Earth’s atmosphere; in every ten
`million molecules of air, only about
`three are ozone. Most of the ozone
`(90%) is found in the upper
`atmosphere (the stratosphere),
`between 10 and 50 kilometers (6–30
`miles) above the Earth’s surface.
`This ‘ozone layer’ absorbs all but a
`small fraction of the harmful
`ultraviolet radiation (UV-B)
`emanating from the sun. It
`therefore shields plant and animal
`life from UV-B, which in high doses
`can be particularly damaging.
`
`Ozone depletion
`
`Any damage to the ozone layer
`therefore allows more UV-B
`radiation to reach the surface of the
`Earth. Throughout the 1970s and
`1980s, scientists began first to
`suspect, and then to detect, a steady
`thinning of the layer. This was
`accompanied by increases in the
`amount of UV-B reaching the
`surface. In northern hemisphere
`mid-latitudes (25–60°, i.e. north of
`the tropics but south of the polar
`regions), UV-B levels are now about
`7% higher than twenty years ago in
`the winter and spring, and about 4%
`higher in the summer and autumn.
`In southern hemisphere mid-
`latitudes, UV-B levels are about 6%
`higher all the year round. UV-B
`radiation has increased dramatically
`nearer the poles, particularly in the
`spring – 22% higher in the Arctic
`and 130% higher in the Antarctic
`
`relative to values in the 1970s. The
`next chapter explains why this
`damage to the ozone layer is
`occurring.
`
`Moderate exposure to UV-B poses no
`dangers; indeed, in humans it is an
`essential part of the process that
`forms vitamin D in the skin. But
`higher levels of exposure have
`potentially harmful effects on human
`health, animals, plants, micro-
`organisms, materials and air quality.
`
`In humans, long-term exposure to
`UV-B is associated with the risk of
`eye damage, including severe
`reactions such as ‘snowblindness’,
`cancer and cataracts; UV-B
`radiation can cause effects on the
`immune system, but may be both
`adverse and beneficial. Increases in
`UV-B are likely to accelerate the
`rate of photoaging, as well as
`increase the incidence (and
`associated mortality) of melanoma
`and non-melanoma skin cancer,
`basal cell and squamous cell
`carcinoma with risk increasing with
`fairness of the skin. The risk of the
`more serious melanoma may also
`increase with UV-B exposure,
`particularly during childhood;
`melanoma is now one of the most
`common cancers among white-
`skinned people.
`
`Fig. 1.1 The thin layer of ozone in the stratophere is at its thickest between about 20-40 km up.
`It also accumulates near the ground in the troposphere, where it is a troublesome pollutant.
`
`005
`
`

`

`Two scientific papers suggest that CFCs emitted to the atmosphere will diffuse to the upper atmosphere and be broken down to release chlorine
`atoms, which will catalytically destroy ozone molecules. Nitrogen oxides emitted by high-flying supersonic aircraft are also suggested as a
`potential cause of ozone depletion.
`UNEP’s Governing Council launches a programme of research on risks to the ozone layer; in the United States, a federal task force concludes that
`atmospheric release of CFCs is a ‘legitimate cause for concern’ and that uses of CFC-11 and -12 might have to be restricted. The National
`Academy of Sciences (NAS) launches an assessment of human impact on the stratosphere.
`
`2
`
`1974:
`
`1975:
`
`Report of the UNEP Enviromental Effects Assessment Panel (1998)
`
`and Dr. Sasha Madronich
`
`Animals are subject to similar
`effects of increased UV-B levels.
`Squamous cell carcinoma associated
`with ambient solar exposure has
`been reported in cattle, horses, cats,
`sheep, goats and dogs. In addition,
`marine life is particularly
`vulnerable to UV-B, a matter of
`some concern as more than 30% of
`the world’s animal protein for
`human consumption comes from the
`sea. Recent studies continue to
`demonstrate that solar UV-B and
`UV-A have adverse effects on the
`growth, photosynthesis, protein and
`pigment content and reproduction of
`phytoplankton, thus affecting the
`food chain. Plant growth may also
`be directly reduced by UV-B
`radiation (though responses vary a
`good deal depending on species),
`harming crop yields and quality,
`and various effects in forests.
`Effects of increased UV-B on
`emissions of carbon dioxide and
`carbon monoxide and on mineral
`nutrient cycling in the terrestrial
`biosphere have been confirmed.
`
`Synthetic materials such as plastics
`and rubber, and naturally occurring
`materials such as wood, paper or
`cotton, are affected by UV-B; the
`damage caused ranges from
`discoloration to loss of mechanical
`strength. Increases in UV-B may
`limit the lifetimes of these materials
`and require more expensive
`production processes.
`
`Finally, reductions in stratospheric
`ozone and the accompanying
`increases in UV-B radiation interact
`with other sources of pollution and
`environmental change. Increased
`levels of UV-B change the chemical
`activity of the troposphere, the
`lower region of the atmosphere. In
`
`Fig. 1.2 Daily erythemal (skin-reddening) UV radiation with clouds. Significant progress
`has been made in recent years in utilizing satellite-based measurements of cloud cover as
`well as atmospheric ozone, to derive estimates of surface UV radiation levels.
`
`Fig. 1.3 Euglena gracilis is a green
`flagellate organism which occurs in
`freshwater habitats and is common in
`lakes, ponds and rivers; Above: these
`organisms have a spindle form and swim
`in their elongated form. Below: After UV
`irradiation the cells twist and turn and
`then become rounded and cannot swim.
`
`Dr. Donat Häder, member of the Enviromental Effects Assessment Panel
`
`006
`
`

`

`1977:
`
`1978:
`
`32 countries agree to a UNEP-brokered World Plan of Action on the Ozone Layer designed to stimulate research; UNEP establishes the Coordinating
`Committee on the Ozone Layer. The US Government requires warning labels on CFC-containing aerosols and announces its intention to phase out
`most CFC use as aerosol propellants. U.S.NAS estimates that continued release of CFCs to the atmosphere will deplete the ozone layer by 14%.
`Developed countries attend an international meeting on CFC regulation and recommend a significant reduction in CFC use in aerosols as a
`precautionary measure.
`
` 3
`
`Report of the UNEP Enviromental Effects Assessment Panel (1998)
`
`Fig. 1.4 UV change versus ozone change. Dependence of erythemal ultraviolet (UV)
`radiation at the Earth’s surface on atmospheric ozone, measured on cloud-free days at
`various locations, at fixed solar zenith angles. Solid curve shows model prediction with a
`power rule using RAF=1.10.
`
`areas already suffering from
`pollution such as vehicle exhausts,
`concentrations of ozone (which at
`this level is a pollutant, causing
`irritation to eyes and lungs) tend to
`increase.
`
`There are also complex interactions
`between ozone destruction and
`climate change. UV-B induced
`destruction of stratospheric ozone in
`recent years has led to a cooling of
`the lower stratosphere, masking to
`a certain extent the effects of the
`growing emissions of greenhouse
`gases. On the other hand, increases
`in tropospheric ozone contribute to
`global warming. In addition, the
`build-up of greenhouse gases in the
`atmosphere tends to reduce the
`frequency of sudden stratospheric
`warming in the northern
`hemisphere, adding to the severity
`of Arctic winters, which increase
`ozone loss (see next chapter).
`
`007
`
`

`

`4
`
`1979:
`
`A number of developed countries start to impose legal controls on CFC-11 and -12 production or use; in the United States, the NAS estimates
`eventual ozone depletion of 16.5%, or up to 30% if CFC production and release continues to grow, and calls on the US Government to lead a world
`effort to control CFCs.
`
`2. The ‘Holes’ in the Layer
`
`Miracle substances
`
`Concern began to be expressed in the
`early 1970s that the Earth’s ozone
`layer was vulnerable to damage by
`the release of chemicals known as
`halocarbons, compounds containing
`chlorine, fluorine, bromine, carbon
`and hydrogen. The most common
`ozone-depleting substances (ODS)
`were thought to be the family of
`chlorofluorocarbons, or CFCs, first
`produced in Belgium in 1892, and
`found, by General Motors chemists in
`the US in 1928, to be an effective
`refrigerating fluid. Stable and non-
`toxic, cheap to produce, easy to store
`and highly versatile, CFCs proved
`themselves an immensely valuable
`range of industrial chemicals. They
`came to be used as coolants for
`refrigeration and air conditioning, for
`blowing foams, as solvents, sterilants
`and aerosol propellants. Major new
`uses were found for CFCs each
`decade, and world production,
`concentrated largely in the USA and
`western Europe, doubled roughly
`every five years until 1970.
`
`As scientific knowledge developed,
`other chemicals – halons, carbon
`tetrachloride, methyl chloroform and
`methyl bromide – also came to be
`identified as ozone-depleters. Some of
`the substitutes for CFCs that were
`eventually developed – such as
`hydrochlorofluorocarbons (HCFCs –
`CFCs with hydrogen atoms) also
`damage the ozone layer, but at much
`lower rates.
`
`It is the high degree of stability of
`CFCs which causes their ozone-
`depleting properties. When released
`into the lower atmosphere, through
`the use of an aerosol spray, for
`example, or a cleaning solvent, or
`
`Fig. 2.1 Schematic sequence of the destruction of ozone by active chlorine (Cl)
`released from a CFC-12 molecule.
`
`008
`
`

`

`1980:
`
`Seven developed countries and the European Community call for an international convention to protect the ozone layer. The EC freezes production capacity and
`begins to limit use in aerosols. The US Environmental Protection Agency proposes the first legalcontrols on non-aerosol uses of CFCs. CFC manufacturers form the
`Alliance for Responsible CFC Policy, which argues that further regulation of CFCs would be premature in the absence of hard evidence of ozone depletion.
`
` 5
`
`The ozone ‘holes’
`
`These ozone-destroying reactions
`are particularly intense within the
`stratospheric clouds that form above
`Antarctica in the extremely cold
`night of the southern hemisphere
`winter. Reactions which occur on
`the surfaces of ice particles within
`the clouds release chlorine and
`bromine in active forms that
`accumulate through the winter.
`When the sun rises in the spring the
`clouds break up to release active
`chlorine and bromine which rapidly
`destroy ozone. The result is the
`‘ozone hole’, an area of sharp decline
`in ozone concentrations over most of
`Antarctica for about two or three
`months during the southern
`hemisphere spring. Ozone depletion
`is accelerated by atmospheric
`circulation, which moves CFCs in
`the stratosphere away from the
`tropics towards both poles.
`
`Currently the ozone layer above the
`whole of Antarctica thins between
`40% and 55 % of its pre-1980 level
`with up to 70% deficiency in short
`time periods, and at some altitudes,
`ozone destruction is almost total. In
`September 1998, the Antarctic
`ozone hole reached a record size of
`25 million km2, or two and half
`times the size of Europe. Although
`the hole shrank to 13 million km2 in
`November, this still marked the first
`time that the hole had measured
`more than 10 million km2 for 100
`days. The average ozone
`concentration for the whole of the
`area south of 65°S was the lowest
`ever recorded in November 1998.
`The Antarctic ozone hole of 1999
`was the second largest and
`strongest ozone-hole phenomena
`ever.
`
`Dr. Paul Newman, NASA/GSFC/code 916
`
`Fig. 2.2 Monthly Antarctic (South Pole) ozone levels in October 1970, 1971, 1972,
`1979 and 1996-1999. The Ozone measurements were taken by NOAA’s and NASA’s
`Backscatter Ultraviolet (BUV) and Total Ozone Mapping Spectrometer (TOMS),
`Goddard Space Flight Center (GSFC).
`
`through leakage of a refrigerant,
`CFCs persist long enough to diffuse
`up into the stratosphere, where they
`are broken apart by solar radiation
`to release chlorine atoms, which
`react strongly with ozone molecules.
`The chlorine oxide formed then
`undergoes further reactions which
`regenerate the original chlorine,
`allowing the process to be repeated
`many times; each chlorine atom can
`destroy an estimated 100,000 ozone
`molecules before it is removed from
`the stratosphere. Although UV
`radiation continually recreates
`ozone from oxygen, the presence of
`chlorine speeds up ozone
`destruction but not its creation,
`reducing the overall concentration
`of ozone. Similar reactions take
`place between bromine (found in the
`family of halons, used mainly as fire
`extinguishants and in methyl
`bromide) and ozone.
`
`Fig. 2.3 The Antarctic ozone hole in
`October 1999.
`
`Fig. 2.4 The monthly average total ozone
`in March 1999 for the Arctic (North Pole).
`
`Dr. Paul Newman, NASA/GSFC/code 916
`
`009
`
`

`

`6
`
`1981:
`
`1982:
`
`UNEP’s Ninth Governing Council proposes to begin work on the elaboration of a legal framework convention for ozone layer protection and establishes
`an ad hoc working group of legal and technical exerts for this purpose.
`The UNEP working group begins to elaborate a framework convention for the protection of the ozone layer, based on a draft proposal from Finland,
`Norway and Sweden. The US National Aeronautical and Space Administration (NASA) estimates that eventual ozone depletion due to CFC use will
`be lower than previously thought, between 5 and 9%.
`
`over Britain fell by almost 50% in
`the first week in March, the lowest
`ever recorded over the UK. And in
`the spring of 2000 the ozone
`deviations were strongest (-20 to -
`30%), over Europe and the
`Canadian and Russian Arctic.
`
`radiation following a 50% fall in
`ozone. The highest UV occured
`whenever the ozone-hole region
`(220DU contour) elongated into an
`elliptical shape that rotated over
`South America and the cloud cover
`was minimal. See figure 3.2.
`
`UV-B intensities have increased
`accordingly; 1992–93 saw the first
`reported examples of persistent
`increases over densely populated
`regions in the northern hemisphere.
`In 1992 southern South America
`experienced a doubling of UV-B
`
`Increases in UV radiation in the
`Northern Hemisphere at high
`latitudes have been attributed to
`the low ozone amounts in the winter
`and spring of 1995, 1996, 1997 and
`2000.
`
`Report of the UNEP Scientific Assessment Panel (1998) and Dr. Lane Bishop
`
`Fig. 2.5 Global Ozone Trend. Deviations in total ozone, area weighted over 60oS-60oN.
`
`Stratospheric air above the Arctic is
`generally warmer and less confined
`than over the Antarctic, and fewer
`clouds form there. Arctic ozone
`depletion is therefore less severe,
`though in recent years it has proved
`worse than anticipated, largely
`because of unusually cold winters,
`with ozone losses of up to 50% at
`some altitudes. The minimum Arctic
`temperatures are near the threshold
`for major chlorine activation, and
`therefore rates of ozone destruction
`can be highly variable year on year.
`During the 1999/2000 Arctic ozone
`deficiency the ozone deviations
`reached -20 to -30% poleward from
`65°N. Ozone depletion at mid-
`latitudes (25° – 60°), between the
`poles and the tropics, is much less
`dramatic but is still observable.
`Between 1979 and 1991, ozone
`concentrations fell by about 4% per
`decade at mid-latitudes in both the
`northern and southern hemispheres,
`the losses being largest during the
`winter and spring. Particles formed
`from gases ejected into the
`atmosphere from the volcanic
`eruption at Mount Pinatubo in 1991
`accelerated ozone destruction for two
`or three years, but the rate slowed
`down again thereafter, and total
`losses from 1979–97 reached about
`5% per decade.
`
`However, local losses can be more
`significant at certain times,
`particularly as the areas of ozone
`depletion around the poles rotate to
`cover different inhabited areas from
`year to year. In the spring of 1995,
`for example, after an unusually cold
`Arctic winter, stratospheric ozone
`concentrations over Europe were
`10–12% lower than in the mid-
`1970s, and over North America 5–
`10% lower, although at times as
`much as 20% lower in some places.
`The winter of 1995–96 was even
`colder, and ozone concentrations
`
`010
`
`

`

`1983: UNEP’s Coordinating Committee on the Ozone Layer again reduces estimated eventual ozone depletion from current emission rates of CFC-11 and
`-12 to between 3 and 5%. The EC decides against further restrictions on CFCs in the light of these estimates.
`
` 7
`
`T.V. Callaghan, D.J. Erickson.
`Report of UNEP Enviromental Effects Assessment Panel (1998) and Dr. R.G. Zepp,
`
`C
`
`C
`
`Reduced Growth
`
`UV-b interception by living leaves
`
`U V-b interception by litter
`& m icroorganis m s
`
`CO2
`
`CO
`
`UV-b interception
`mainly by CDOM
`
`CO, OCS
`
`CO2
`
`DOC
`
`Increased
`decomposition
`& run off
`
`DOC
`
`N
`Reduced
`decomposition
`
`N
`
`UV-b interception by phytoplanton
`
`CO2
`
`Labile C,N
`
`Increased
`decomposition
`
`Microbial
`activity
`
`Fig. 2.6 Conceptual model illustrating
`the potential effects of enhanced UV
`radiation on biogeochemical cycles
`in freshwater, marine and terrestrial
`ecosystems. The effects involving
`living organisms, e.g. reduced plant
`growth, are species and/or exposure
`dependent.
`(CDOM — colored dissolved organic
`matter; DMS — dimethyl sulfide;
`DOC — dissolved organic matter)
`
`DMS
`
`Reduced
`biomass
`
`DOC
`
`Fig. 2.7 Monthly
`averages of total ozone
`for the Northern
`Hemisphere measured
`by satellites during
`March for the 1970-
`2000 period
`
`Dr. Paul Newman, NASA/Goddard Space Flight Center (GSFC)/Code 916
`
`011
`
`

`

`8
`
`1985:
`
`The Vienna Convention for the Protection of the Ozone Layer is adopted by 28 countries. The Convention requires no restrictions on ozone-depleting
`substances, but allows for the future elaboration of specific controls; the resolution adopted along with the Convention lays the foundation for
`further work on a protocol on CFC control. Two months later Joe Farman, of the British Antarctic Survey, publishes a paper showing sharp seasonal
`depletion of the ozone layer over Antarctica - the ‘Ozone hole’.
`
`3. Saving the Ozone Layer
`
`Beginnings
`
`Since its foundation, the United
`Nations Environment Programme
`(UNEP) has been concerned with
`the protection of the ozone layer.
`The UN Conference on the Human
`Environment in Stockholm in 1972,
`which gave birth to UNEP,
`addressed the topic of ozone
`depletion, though damage from
`supersonic aircraft exhausts was
`then thought to be the main threat.
`
`The first major statement of
`scientific concern over ozone
`depletion from CFCs came in 1974,
`prompted by James Lovelock’s
`discovery of the presence of CFCs in
`the atmosphere all around the
`world. Sherwood Rowland and
`Mario Molina’s research (for which
`
`they were later to be awarded the
`Nobel Prize in chemistry) paved the
`way to the now thorough
`understanding of the processes by
`which CFCs diffuse up into the
`stratosphere, are broken apart and
`destroy ozone molecules.
`
`Although the hypothesis was
`initially disputed, the extent and
`growth of CFC use worldwide was
`enough to trigger calls for urgent
`action. In March 1977, experts from
`32 countries met in Washington DC
`to adopt the ‘World Plan of Action on
`the Ozone Layer’. The Plan included
`research into the processes that
`control ozone concentrations in the
`stratosphere; the monitoring of
`ozone and solar radiation; the effect
`of ozone depletion on human health,
`ecosystems and the climate; and the
`
`development of ways to assess the
`costs and benefits of control
`measures. UNEP was the
`coordinating agency, assisted by the
`Coordinating Committee on the
`Ozone Layer, made up of experts
`from intergovernmental agencies,
`governments and industry.
`
`In the US, the Washington meeting
`reinforced existing concerns over
`the impact of emissions from
`supersonic aircraft. An effective
`public campaign led to regulations
`prohibiting the use of CFCs as
`aerosol propellants in non-essential
`applications by 1978; Canada,
`Sweden and Norway soon followed.
`US production of CFC-11 and -12
`fell from 46% of the world total in
`1974 to 28% by 1985 as a result.
`
`Report of the UNEP Scientific Assessment Panel (1994)
`
`(Parties par Milliard)
`
`Concentration de chlorine réactif
`
`1.5
`
`1.0
`
`0.5
`
`Ozone
`(échelle de gauche)
`
`Chlorine réactif
`(échelle de droite)
`
`63
`
`64
`
`65
`
`67
`68
`66
`Latitude (degré sud)
`
`Air polaire
`antarctique
`
`69
`
`70
`
`71
`
`0
`72
`
`3000
`
`2500
`
`2000
`
`1500
`
`1000
`
`500
`
`0
`
`Concentration d’ozone
`
`(Parties par milliard)
`
`Fig. 3.1 Measurements of ozone and reactive chlorine from a flight into the Antarctic Ozone hole
`
`012
`
`

`

`1986:
`
`International negotiations continue on a protocol to the Vienna Convention to control CFCs. CFC-producing companies support a ‘reasonable’ limit on
`future growth in CFC production, and estimate that at least five years would be needed to develop substitutes for CFC-11 and -12.
`
` 9
`
`Alternative, non-ozone-depleting,
`propellants were rapidly introduced
`and often proved more economic
`than the original CFCs. After 1982,
`however, CFC production in the US
`started to accelerate once more, as
`use increased sharply in vehicle air-
`conditioning and foam-blowing.
`
`In 1980 the European Community
`agreed to reduce its CFC use in
`aerosols by at least 30% from 1976
`levels by the end of 1981 and freeze
`its production capacity of CFC-11
`and CFC -12. Since EC production
`capacity was at the time
`substantially above consumption
`levels, a capacity freeze hardly
`contributed much to the control of
`CFC emissions. The combined effect
`of the various measures taken,
`however, was enough to reduce
`public pressure for further controls.
`UNEP was left with the
`responsibility of keeping the issue of
`ozone depletion on the international
`agenda.
`
`The Vienna Convention
`for the Protection of the
`Ozone Layer
`
`In 1981, UNEP’s Governing Council
`established an Ad Hoc Working
`Group of Legal and Technical
`Experts for the Elaboration of a
`Global Framework for the
`Protection of the Ozone Layer. The
`Group’s aim was to secure a general
`international treaty to tackle ozone
`depletion. The first step of a
`framework agreement was expected
`to be relatively easy to achieve, but
`differences between the proponents
`of control measures on the use of
`CFCs in various sectors (such as the
`US) and supporters of caps on
`
`existing production capacity (such
`as the EC) led to four years of hard
`work and negotiation.
`
`The Vienna Convention for the
`Protection of the Ozone Layer was
`agreed by 28 countries in March
`1985. It contained pledges to
`cooperate in research and
`monitoring, to share information on
`CFC production and emissions, and
`to pass control protocols if and when
`warranted. Although it contained no
`commitments to take any action to
`reduce CFC production or
`consumption, the Vienna
`Convention was nevertheless an
`important milestone. Nations
`agreed in principle to tackle a global
` environmental problem before its
`effects were clear, or its existence
`scientifically proven – probably the
`first example of the acceptance of
`the ‘precautionary principle’ in a
`major international negotiation.
`
`The Montreal Protocol on
`Substances that Deplete
`the Ozone Layer
`
`The Vienna conference in 1985 also
`adopted a resolution empowering
`UNEP to convene negotiations for a
`protocol to the Convention, to
`include control measures for ozone-
`depleting substances and to be
`signed if possible in 1987. Progress
`in this second set of negotiations
`was given a boost by the
`publication, just two months after
`the Vienna conference, of the
`findings of members of the British
`Antarctic Survey led by Dr Joe
`Farman. This was the famous ‘ozone
`hole’ paper, which revealed for the
`first time the existence of the
`dramatic declines in ozone
`concentrations over the Antarctic in
`the spring. (In fact US satellite
`observations had already detected
`
`Fig. 3.2. The Antarctic ozone hole of 17 October 1994, NASA’s Total Ozone Mapping
`Spectrometer (TOMS), Goddard Space Flight Center (GSFC)/Code 916.
`
`013
`
`

`

`10
`
`1987: After several rounds of negotiations, 46 countries adopt the Montreal Protocol on Substances that Deplete the Ozone Layer. The Protocol
`requires an eventual 50% cut in consumption of five CFCs by the end of the century, and a freeze in the consumption of three halons, with a ten-year
`grace period for developing countries to enable them to meet their basic domestic needs; the controls are to be reassessed at least every four
`years. During the year, a number of European countries legislate to restrict the use of CFCs as aerosol propellants.
`
`this in the late 1970s, but the
`unexpected findings were
`discarded as suspected instrument
`error.) Although the cause was still
`then unknown, suspicion fell on
`CFCs.
`
`By comparison with the protracted
`negotiations over the Vienna
`Convention, negotiations on the
`protocol proceeded remarkably
`quickly and achieved far more
`than was initially thought
`possible. On 16 September 1987,
`46 countries signed the Montreal
`Protocol on Substances that
`Deplete the Ozone Layer. (In 1995,
`the UN General Assembly declared
`16 September as the International
`Day for the Preservation of the
`Ozone Layer, and the signing of
`the Montreal Protocol has been
`commemorated in this way in each
`subsequent year.)
`
`The Protocol required parties to
`make 50% cuts from 1986 levels in
`both the production and the
`consumption of the five main CFCs
`by 1999, with interim reductions.
`Production and consumption of the
`three main halons was frozen at
`1986 levels from 1993.
`
`Although these reductions could be
`attacked as either too little (if the
`ozone depletion hypothesis was
`believed) or too much (if it was
`not), the agreement marked an
`important political and
`psychological breakthrough. And
`once again science validated the
`negotiators’ actions. March 1988
`saw the release of the report of the
`Ozone Trends Panel, which
`reviewed evidence particularly
`from US Antarctic expeditions in
`1986 and 1987, and provided, for
`the first time, convincing evidence
`of the linkage between ozone
`depletion and CFCs. Opposition to
`the principle of controls on ozone-
`depleting substances then largely
`collapsed, and industry started to
`concentrate resources on
`
`Fig. 3.3. Reports of the meetings of the Parties to the Vienna Convention and the Montreal Protocol.
`
`014
`
`

`

`1988:
`
`The scientific Ozone Trends Panel, sponsored by international agencies and US research bodies, concludes that CFCs are responsible for the
`Antarctic ozone hole. UNEP-administered i