Depletion of stratospheric ozone

Thesis Overview

<p> </p><p><strong>1.0 INTRODUCTION</strong></p><p>Representatives from 24 nations, meeting in Montreal in September 1987, signed the “Montreal Protocol on Substances that Deplete the Ozone Layer,”1 an international agreement designed to reduce the world¬wide production and use of chlorofluorocarbons (CFCs). This protocol is the result of years of negotiation fostered by the United Nations Environment Programme (UNEP) among the major CFC producing countries. Its formulation was a response to a growing international consensus on the need to protect stratospheric ozone from depletion by CFCs. The Montreal Protocol is a landmark agreement in that it is the first inter¬national treaty for mitigating a global atmospheric problem before serious environmental impacts have been conclusively detected. As such, the Montreal Protocol has stirred much interest, and both scientists and policymakers have suggested that it can be used as a model for international agreements on other global environmental problems, especially the problem of CO2 and trace-gas induced global warming.<br>Before such a comparison to other environmental problems can be made, however, it is useful to understand the Montreal Protocol in its historical and political context. Depletion of stratospheric ozone is an example of both the complicated and the global nature of contemporary environmental problems, and the Montreal Protocol shows that innovative approaches to such global environmental problems are possible. During the past two decades concern over stratospheric ozone has evolved from a fringe environmental issue to a major policy issue of national and international importance. An analysis of this evolution is important for understanding both the value of the Montreal Protocol and its implications for other global atmospheric problems.</p><p>The evolution of stratospheric ozone policy can be understood as a two-stage process: (1) the development of domestic regulations controlling CFC use in aerosol spray cans in the United States and several other countries in the mid- and late-1970s, and (II) the development of an international policy response to the problem of global stratospheric ozone depletion in the 1980s. These are not separate issues. The development of an international response clearly followed from the concern raised in the United States, Canada, Sweden, and other countries which had taken unilateral action to control CFCs in the 1970s. However, many important differences between stage 1 and II make this distinction a useful tool for analysis. I argue that four key factors are important in understanding the evolution of stratospheric ozone policy: (1) the recognition that ozone depletion is a global problem requiring an international response; (2) the evolving scientific understanding of stratospheric ozone depletion and its influence on policymakers; (3) increasing public concern based on the threat of skin cancer and the perception of the potential for global catastrophe associated with the discovery of the Antarctic ozone hole; and (4) the availability of acceptable substitutes for CFCs.</p><p>This paper analyzes the evolution of stratospheric ozone policy. The first section reviews the science behind the problem of CFC-induced stratospheric ozone depletion. The next two sections discuss the emergence of stratospheric ozone depletion as a national political issue in the United States during stage I, and its evolution to an international political issue during stage II. This is followed by a discussion of how the evolving scientific understanding of the problem, the catastrophic nature of the risks, and the availability of alternatives to CFCs influenced the final negotiations on an international agreement. The last section examines the Montreal Protocol and discusses its prospects for success.</p><p><strong>CFCs AND THE OZONE LAYER</strong></p><p>Chlorofluorocarbons are a group of inert, nontoxic, and nonflammable synthetic chemical compounds used as aerosol propellants, in refrigeration and air conditioning, in plastic foams for insulation and packaging, and as solvents for cleaning electrical components. There are many varieties of CFCs; CFC-11 and -12 are the most common compounds and CFC- 113 has important industrial applications as a solvent. Production of CFCs has increased significantly since the 1960s, reaching a peak in 1974 before declining as a result of the decreasing use of CFCs as aerosol propellants. However, non-aerosol use continued to increase and by the mid-1980s CFC production again reached mid-1970 levels (see Figure 1).</p> <br><p></p>