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THE IMPROBABLE MONTREAL PROTOCOL:
SCIENCE, DIPLOMACY, AND DEFENDING THE OZONE LAYER
Richard Elliot Benedick
Introduction
In January 1985, not long after I took over the international environment portfolio at the
State Department, I led a small American delegation to a little-noticed meeting in Geneva.
There, the U.S., Canada, and a few like-minded countries tried, and ultimately failed in the
face of strong opposition from other governments, to achieve a multilateral agreement to
limit use of chlorofluorocarbons (CFCs). The event attracted only perfunctory attention in
the press, and its unremarkable results occasioned no diplomatic ripples in national capitals.
For three years, this awkwardly titled Ad Hoc Working Group of Legal and Technical
Experts for the Preparation of a Global Framework Convention for the Protection of the
Ozone Layer, an assemblage of diplomats, environmental officials, and government lawyers
under the auspices of a small UN agency, the United Nations Environment Programme
(UNEP), had struggled in vain to reach a consensus on controlling CFCs. Two months later,
a handful of countries signed the Vienna Convention for Protection of the Ozone Layer, a
toothless treaty to encourage ozone research that did not even mention CFCs in its text.
The following year, I was asked by Secretary of State George Shultz and Ambassador
John Negroponte, then Assistant Secretary of State for Oceans, Environmental, and Scientific
Affairs (OES), to lead negotiations for a protocol on controlling CFCs. Very few gamblers
would have wagered at that time that such negotiations could succeed. CFCs were virtually
synonymous with modern standards of living, finding new uses in thousands of products and
processes. Billions of dollars of international investment and hundreds of thousands of jobs
worldwide were involved. Technological alternatives were nonexistent or considered too
costly or unfeasible. Powerful governments and global economic interests were aligned in
adamant opposition to controls, as were ideological elements within the administration of
President Reagan. Still other governments and publics were unaware or indifferent to an
arcane threat. Perhaps most significant of all, the arguments for control rested on unproven
scientific theories: throughout the protocol negotiations there was firm evidence neither of
the predicted ozone layer depletion nor of any harmful effects.
Yet, in September 1987 an international accord was signed in Montreal that made
headlines around the globe. By 1989, protection of the ozone layer figured prominently in
discussions among the world’s political leaders. Within a short time, whole classes of
hitherto indispensable chemicals were being phased out and industries were being
transformed. CFCs and ozone had become, literally, household words.
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The heads of the World Meteorological Organization (WMO) and UNEP later wrote
that “the action to defend the ozone layer will rank as one of the great international
achievements of the century.”1 Under conditions of great scientific uncertainty and political and
economic opposition, the negotiators of the Montreal Protocol averted grave dangers to life on
Earth. The protocol also set a number of important precedents that influenced the great wave of
environmental diplomacy of subsequent years, including several international treaties as well as
the 1992 United Nations Conference on Environment and Development and Agenda 21. What
happened between the publication of controversial scientific theories in 1974 and the signing
of a landmark treaty in 1987, together with the subsequent evolution of that treaty, is a
fascinating and instructive example of how science and diplomacy can effectively interact to
address a global threat.
Disturbing Theories
Ozone has been characterized as "the single most important chemically active trace gas
in the earth's atmosphere."2 Two singular characteristics of this remote, unstable, and toxic
gas make it so critical. First, certain wavelengths of ultraviolet radiation (UV-B) that damage
and cause mutations in animal and plant cells are absorbed by the thin layer of ozone
molecules dispersed throughout the atmosphere, particularly in the stratosphere six to thirty
miles in altitude; the harmful radiation is thus prevented from reaching the earth's surface.
And second, differing quantities of ozone at different altitudes have major implications for
global climate. Indeed, the ozone layer, at its natural concentration and diffusion, is es-
sential to life as it has evolved on earth.
In 1973, two University of Michigan scientists, Richard Stolarski and Ralph Cicerone,
in the course of examining possible effects of chemical emissions from National Aeronautics
and Space Administration (NASA) rockets, theorized that chlorine in the stratosphere could
unleash a complex chain reaction that would continually destroy ozone over a period of
decades; fortunately, very little free chlorine was thought to exist at that altitude.3 However,
a year later, Mario Molina and Sherwood Rowland at the University of California, Irvine,
became intrigued with some peculiar properties of anthropogenic chlorofluorocarbons.
Molina and Rowland discovered that, unlike almost all other gases, CFCs were not
chemically destroyed or rained out in the lower atmosphere, but rather migrated slowly up to
the stratosphere. There they remained for many decades -- some for more than a century.
The two researchers concluded that the CFCs, which are not naturally present in the strato-
sphere, are eventually broken down by radiation and thereby release large quantities of free
chlorine.4
1 G.O.P.Obasi and Elizabeth Dowdeswell, Foreword to R. Bojkov, The Changing Ozone Layer, Geneva:
WMO/UNEP, 1995.
2 Daniel Albritton, et al., Stratospheric Ozone: The State of the science and NOAA’s Current and Future
Research, Washington: NOAA, 1987, p.1.
3 R.S. Stolarski and R.J. Cicerone, “Stratospheric Chlorine: A Possible Sink for Ozone,” Canadian
Journal of Chemistry 52 (1974).
4 M.J. Molina and F.S. Rowland, “Stratospheric Sink for Chlorofluoromethanes: Chlorine Atomic
Catalyzed Destruction of Ozone, Nature 249 (1974).
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The combined implications of these two hypotheses were nothing less than sensational:
the protective ozone shield would be seriously compromised. The enhanced levels of
ultraviolet radiation that would penetrate the atmosphere and reach earth's surface could have
potentially disastrous impacts on human and animal life and the environment. Scientists
projected millions of future deaths from skin cancer, millions of cases of eye cataracts and
blindness, dangerous suppression of the human immune system, losses in food production
and fisheries, damage to plastics and other materials, and intensification of the greenhouse
effect.
layer was in jeopardy had been serendipitous; no one had set out to condemn
chlorofluorocarbons. For decades, CFCs were considered a multifaceted wonder-chemical,
finding ever more uses without fear that they were in any way harmful. Since their invention
in the 1930s they had been thoroughly tested by customary industrial standards and declared
completely safe. Possible effects thirty miles above the earth had simply never been
considered.
Astonishingly, the research paths leading to the suspicion that the stratospheric ozone
The family of CFC chemicals, and their related bromine halon compounds, are stable,
nonflammable, nontoxic and non-corrosive – qualities that made them uniquely useful in
many consumer and industrial applications. Since CFCs vaporize at low temperatures, they
are highly efficient coolants for refrigeration and air conditioning, as well as excellent
propellants in spray containers for pharmaceuticals, household products, cosmetics, and
cleaners. They make energy-efficient insulators and found use in the manufacture of a wide
range of rigid and flexible plastic-foam materials. Their non-reactive properties make them
perfect solvents for cleaning microchips and telecommunications equipment, as well as for a
myriad of other industrial applications. As an added bonus, CFCs are inexpensive and
relatively simple to produce. The related halons are unsurpassed fire extinguishants in the
defense, oil, aircraft, electronics and other industries. Although consumed in much smaller
quantities than CFCs, halons posed, molecule-for-molecule, an even greater threat to the
ozone layer.
Rowland and Molina, together with Paul Crutzen of the Netherlands, became Nobel
Laureates two decades later, but the ozone depletion hypothesis was initially greeted with
disbelief and controversy in the scientific and business communities. Nevertheless, the
serious theoretical dangers prompted a wave of new scientific research over the following
years.
It would be difficult to exaggerate the complexities involved. To understand what was
happening to the ozone layer, researchers needed to go far beyond atmospheric chemistry. They
had to bridge traditional scientific disciplines and examine the earth as an interrelated system of
physical, chemical, and biological processes occurring on land, in oceans, and in the atmosphere –
processes that were themselves influenced by economic, political, and social forces. Scientists
developed ever more sophisticated computer models to simulate, for decades into the future, the
stratospheric interplay between radiative, chemical, and physical phenomena. They utilized
balloons, rockets, and satellites to track and measure remote gases measured in volumes as minute
as parts per trillion of volume.
Intrinsically unstable ozone molecules are continually created and destroyed by complex
Ozone itself amounts to considerably less than one part per million of the atmosphere.
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natural forces involving solar radiation and even more minute quantities of other gases. To
complicate the analytical challenge, ozone concentrations fluctuate naturally on a daily,
seasonal, and solar-cyclical basis. Indeed, during the 1960s ozone concentrations had
actually increased, notwithstanding expanding use of CFCs. Ozone abundance also varies
significantly over different latitudes and altitudes. The scientists thus faced an enormous
challenge in attempting to detect the miniscule “signal” of the start of a long-term trend as
postulated by the theory.
Transatlantic Differences
the market for CFCs, together accounting for more than 80 percent of the world’s output
in 1974. Notwithstanding shared political, economic, and environmental values, the
transatlantic partners had markedly different views on the potential threat.
The United States and the then twelve-nation European Community (EC) dominated
that was, perhaps because of the U.S. space program, more sensitized than Europeans to
events in the stratosphere. Congress, media, and environmental and scientific organizations
in the U.S. were quick to voice concern. In contrast, for many years there was no
countervailing voice in Europe to the powerful chemical industry. The otherwise
environmentally conscious European public accorded higher priority to such closer-to-home
problems as acid rain and oil spills.
The ozone depletion theory seemed to capture the imagination of an American public
adamantly denied any linkage between growing CFC use and the long-term stability of the
stratospheric ozone layer. Industrialists mobilized research and public relations efforts to
highlight the scientific uncertainties, the necessity of CFCs for modern lifestyles, the
infeasibility of substitutes, and the presumed high costs and economic dislocations
associated with controls on these chemicals.
Differences slowly emerged, however, between American and European industrialists,
probably reflecting the relative depth of U.S. public concern. Millions of independent deci-
sions by worried American consumers reduced the U.S. market for spray cans by two-thirds
by 1977, even in the absence of governmental regulation. The threat of a patchwork of
varying state regulations made U.S. industry open to uniform and therefore relatively less-
disruptive federal controls.
Responding to public reaction, Congress authorized the Administrator of the
Environmental Protection Agency (EPA) in the 1977 Clean Air Act to regulate "any
substance … which in his judgment may reasonably be anticipated to affect the stratosphere,
especially ozone in the stratosphere, if such effect may reasonably be anticipated to endanger
public health or welfare" (emphasis added). This law attempted to balance the scientific
uncertainties with the fateful risks of inaction. And it opted for a low threshold to justify
intervention: the government was not obligated to prove conclusively that a suspected
substance could modify the stratosphere or endanger health and environment. All that was
required was a standard of reasonable expectation: CFCs would not be considered innocent
On both sides of the Atlantic, the chemical, automobile, and other involved industries
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until proven guilty.
Following this legislation, the United States banned CFCs as propellants for
nonessential aerosol sprays in early 1978, affecting nearly $3 billion worth of sales in a
wide range of products. Similar action was taken by Canada, a relatively small producer,
and by Sweden, Norway, Denmark, and Finland, all importing countries. In contrast, under
heavy pressure from such important companies as Britain’s Imperial Chemical Industries
(ICI), France’s Atochem, and Germany’s Hoechst, the European Community waited until
1980 before enacting painless measures, fully supported by industry, which gave an appear-
ance of control while permitting unhampered CFC expansion for two more decades.
The divergent U.S. and EC actions were reflected in subsequent economic
developments. The year of the ozone hypothesis, 1974, coincidentally represented an
historic peak for CFC production and use -- which had been growing an average 13 percent
annually since 1960. The United States was at that time by far the major producer, with
nearly half of global output, while all EC countries together accounted for less than 40
percent; Germany was the largest European producer, followed by the United Kingdom,
France, and Italy.
After its aerosol ban, the United States never regained its former market pre-eminence.
By 1986, global CFC production and consumption, which had fallen in the late 1970s
following the aerosol ban in the U.S. and elsewhere, had recovered due to new uses and
now exceeded the 1974 peak. The EC now dominated the market with an estimated 43-45
percent, while the United States had dropped to about 30 percent. Meanwhile, other
countries had increased their shares, especially Japan (11-12 percent) and the Soviet Union
(9-10 percent), with smaller amounts for Canada, China, Australia, Brazil, Mexico,
Argentina, Venezuela, and India. The European Community also supplied CFCs to the rest
of the world, particularly the growing markets in developing countries. EC exports rose by
43 percent from 1976 to 1985 and averaged almost one-third of its production. In contrast,
the United States now consumed virtually all it produced.
The EC Commission long based its ozone position largely on the self-serving data and
contentions of a few big companies. European industry's primary objective was to preserve
market dominance and to avoid the costs of switching to alternative products for as long as
possible. Both industry and government officials felt that panic had driven Americans into the
1978 aerosol ban and that the United States had only itself to blame for any market losses.
Epitomizing the close EC industry-government linkages, company executives often served on
official delegations to the negotiations. Indeed, during the Montreal Protocol negotiations in 1987
we actually came across an official EC instruction drafted on an Atochem corporate letterhead.
The Vienna Convention
recommended from the very beginning a global approach to ozone protection. UNEP began by
sensitizing governments and vigorously promoting research and data collection. The question of
international controls, which Tolba (himself a scientist) believed essential, was first raised during
UNEP, under the dynamic leadership of its Egyptian Executive Director Mostafa Tolba,
