TL: SAVING OUR SKINS SO: Anun Makhuani, PhD., Kevin Gurney, Annie Makhuani DT: February 19, 1992 Keywords: environment atmosphere greenpeace ozone policies / The Causes and Consequences of Ozone Layer Depletion and Policies for Its Restoration and Protection Anun Makhuani, PhD. Kevin Gurney Annie Makhuani February 19, 1992 Preface This report is a condensation of the findings and recommendations of a three-year project on the causes and consequences of ozone depletion, the technologies that are available to replace ozone-depleting chemicals and policies to arrest and reverse the damage to the ozone layer. The full report of this project will appear as a book of the same title in the spring of 1992. It will be published by Apex Press, 777 U.N. Plaza, New York N.Y. 10017, phone 212-953-6920, fax 212-573-8362. Since 1987, people around the world have been trying to find ways to end the reckless global experiment with the ozone layer. Persuasive arguments, models and evidence have indicated since 1974 that, at least as a protective measure, corporations and governments should have taken actions to drastically cut back CFC usage and prepared contingency plans for a quick total phase-out of CFCs. But action was scattered and weak, compared to the need. Findings of an immense and unexpected ozone hole over the Antarctic, which had been appearing each southern hemisphere (austral) spring since the late 1970s, were published in 1985. Since that time there has been a continual stream of negative news about the ozone layer. The findings have generally been far worse than those predicted by models of the atmosphere. And now we face the possibility of catastrophic levels of ozone depletion in the spring of 1992 over highly populated northern latitudes. Until late 1987, when the Montreal Protocol was signed, the world witnessed an approach contrary to the principles of preventive medicine. Instead, a postmortem approach to environmental problems has prevailed - let the damage be done and the corpses appear before we take serious action. The Montreal Protocol has already been through one revision, known as the London amendments (agreed to in June 1990 but not yet signed by most countries) and it will be revised again in November 1992. With each burst of bad news there has been widespread recognition that previous actions were not be enough to protect the ozone layer. But each time the new actions taken were not forceful enough. That is also the case for the official proposals being considered today, including that put forth by President Bush on February 11, 1992. Today, we again face the danger is that action may not be strong enough. Some large chemical manufacturers as well as corporations with strong financial interests in the most common refrigeration and air-conditioning technology (the vapor compression system), may be able to stretch out the period of the use of partially halogenated compounds, called HCFCs. These compounds, while less ozone-depleting than CFCs, contribute far more ozone-depleting chlorine in the short- and medium-term than conventional calculations of ozone-depleting potential would indicate. This is likely to be our last chance to enact regulations to protect the ozone layer to try to prevent catastrophic depletion in the next few years. Even such action will be too late for events this year, but it can reduce the risk in the years to come. Whether we take forceful enough actions that correspond to the severity of the crisis is one of the great issues that confronts us today. Beside the Executive Summary and Recommendations, this report contains two chapters. Chapter I presents our main findings on several issues: the extent of ozone depletion; the health, epidemiological and ecological consequences of ozone depletion; the uses of industrial halocarbons and the alternatives to them, and the various sources of emissions which are resulting in a build-up of chlorine and bromine in the atmosphere. Chapter II discusses the three scenarios that we have constructed to depict the consequences of various policies on the build-up of ozone-depleting chlorine and bromine in the atmosphere. The three scenarios correspond to the implementation of the London amendments of June 1990 (the first revision to the Montreal protocol), an accelerated version of this assuming full compliance with it (most countries have not yet signed the London amendments), and a "Saving-Skins" scenario, which corresponds to the policies that we recommend. All figures are in metric units unless otherwise specified. One metric ton equals 1.1 U.S. (short) tons of 2000 pounds each. The use of the term "industrial halocarbons" generally refers to those compounds which contain bromine and/or chlorine and are therefore ozone-depleting. In some cases, we make a broader use of this term, as defined in the glossary, to include all industrial halocarbons, including non-ozone-depleting compounds, and this is made clear in the context. Our statistics are for worldwide production and emissions, unless otherwise specified. Citations for material in the Executive Summary and Recommendations can be found in the main text of the report. We would like to thank Dr. Abha Sur for her assistance in research regarding ozone depletion potentials. Funding for this work was provided by the C.S. Mott Foundation, the Levinson Foundation, and a general support grant from the Public Welfare Foundation. Arjun Makhijani Kevin Gurney Annie Makhijani Takoma Park February 1992 Executive Summary and Recommendations Summary of Findings 1. Ozone layer damage is severe The Antarctic ozone hole, which produces ozone depletion of 50 percent each austral spring, was the first sign of serious ozone depletion. Levels of chlorine monoxide concentrations over the Arctic about 50 percent larger than those in the ozone hole (measured in January 1992) threaten to produce catastrophic levels of depletion over heavily populated areas in northern North America, Europe, and northern Asia. Non-linear effects are occurring whereby additional emissions of chlorine and bromine are producing effects more damaging than previous emissions. Sudden increases in depletion, such as the Antarctic ozone hole, have been observed. Such effects work on the model of "the straw that broke the camel's back". Now the "back" of the atmosphere appears set to break over highly populated northern latitudes as early as the spring of 1992; overall ozone depletion levels may reach 15 percent. 2. The health, economic and environmental consequences could be severe and even catastrophic Depletion of the ozone layer will adversely affect health and ecosystems generally in a variety of ways; severe depletion would be utterly catastrophic. An ozone depletion level of 20 percent would produce a severe blistering sunburn in a couple of hours of exposure. It may cause widespread blindness in wildlife and a severe disruption of oceanic and terrestrial ecosystems. A study by the U.S. National Academy of Sciences (done in the context of the long-term consequences of all-out nuclear war in the northern hemisphere), described the consequences of persistent, severe ozone depletion of about 50 percent, such as that which occurs over the Antarctic each spring: ...outside daytime work in the northern hemisphere would require complete covering by protective clothing...It would be very difficult to grow many (if any) food crops, and livestock would have to graze at dusk if there were any grass to eat. In areas such as northern China, where millions people depend on cattle to perform essential agricultural tasks, ozone depletion of 15 percent or more may severely disrupt agricultural production and possibly cause famine if it persists. These possibilities are so extreme that they are the basis of our conclusion that severe ozone depletion is the most serious and immediate environmental problem facing us, and that life on Earth itself may be threatened with extreme kinds of damage. These effects are in addition to the more widely discussed effects of increases in skin cancer, cataracts, and immune system damage. 3. Partially halogenated compounds (such as HCFCs) are more damaging than assumed by the Clean Air Act The short-term ozone depletion potential of HCFCs (on a ten to twenty year timescale) is far larger than indicated by their Ozone Depletion Potential (ODP), which is a long-term average figure. For instance, HCFC-22 is three to five times more ozone- depleting over a ten to twenty year period than its long-term (200 year average) ODP of 0.05. ODPs are the basis for regulating compounds under the Clean Air Act. 4. HCFC-22 and methyl chloroform emissions are increasing HCFC-22 and methyl chloroform have come into increasing use in the past few years, in part due to substitution for fully-halogenated halocarbons such as CFC-12 and CFC-113. Both HCFC-22 and methyl chloroform, which are partially-halogenated compounds, are important sources of chlorine build-up. 5. Existing equipment will soon be the dominant source of emissions An increasing proportion of the emissions will come from the industrial halocarbons stored in existing equipment (known as "service banks"). At current levels of production in the US (58 percent of 1986 levels from July 1990 to June 1991), emissions from the service banks of CFC-11, CFC-12 and HCFC-S (the main compounds which are in service banks) are of the same order of magnitude as emissions from new production. Emissions of these chemicals from service banks are about half-a-million tons per year, and will pre dominate over those from new production after about two years. The total amount of CFCs and HCFC-22 in service banks is about 2.7 million tons, which is about three times the world production in the July 1990-June 1991 period. Of this about 2 million tons is CFC-11 and CFC-12, and the rest is HCFC-22. 6. Increases in Third World use, allowed under present regulations, would cause serious increases in chlorine build-up Increases in CFC use among the rich and upper middle classes in the Third World as allowed under current regulations could become a major source of emissions over the next decade. Our estimate of the peak emissions of CFCs from the Third World, assuming that only the relatively wealthy use industrial halocarbons (including partially halogenated ones) extensively, is that by the year 2000, emissions from this source alone could grow to about 35 percent of worldwide use before beginning to decline. There are some indications that some Third World countries may accelerate their phase-out schedule, but others, notably India, have not agreed to even the June 1990 London amendments to the Montreal Protocol because of the inadequacy of financial assistance. 7. There are several unregulated sources of ozone-depleting chlorine build-up Two chlorinated compounds not yet included in public policy for protecting the ozone layer are contributing to chlorine build-up, on the same order of magnitude as the less-used CFCs, namely CFC-114 and CFC-115. They are methylene chloride and perchloroethylene. There are numerous other compounds which contribute in similar ways to chlorine build-up, such as dichloroethylene, which is a feedstock for the production of plastics. 8. Methyl bromide is an important source of bromine build-up Methyl bromide is a fumigant that contributes to bromine build-up in quantities likely to be of the same order of magnitude as regulated halons. Yet methyl bromide is not yet regulated. There are also natural sources of methyl bromide. 9. Biomass burning is a contributor to the build-up of ozone- depleting chlorine Biomass burning in smoldering fires due to human activities, such as the burning of tropical forests and savannahs, probably contributes about 3 to 4 percent of global chlorine build-up. While far smaller than industrial halocarbons, it is an important component of emissions from many Third World countries. There are also natural sources of methyl chloride. 10. Industrial halocarbons can be rapidly phased out Our survey of industrial and other literature on technologies to replace industrial ozone-depleting compounds shows that it is possible to essentially eliminate production of all fully halogenated industrial compounds, such as chlorofluorocarbons (CFCs), halons and carbon tetrachloride in the short-term, without recourse to partially halogenated ozone-depleting compounds (HCFCs). 11. The use of waste heat could eliminate ozone-depleting compounds in large scale air-conditioning applications and also save energy Air-conditioning technologies based on use of waste heat from on-site electricity generation have the potential to greatly reduce energy consumption by using waste heat to drive absorption air-conditioning systems. This would eliminate CFC use in many large-scale applications immediately. The waste heat can also be used for heating in the winter in place of natural gas or oil that is burned in heating systems on site today. Energy savings of 20 percent or more are often feasible, while eliminating ozone-depleting compounds altogether. Yet this option is not being actively pursued by the EPA, the Department of Energy, or the United Nations Environment Programme as part of ozone layer protection programs. Recommendations Our recommendations for industrialized countries (defined in the Montreal Protocol as countries which used more than 03 kilograms of CFCs per person in 1986 and which do not come under the provisions of Article 5) are listed first, followed by recommendations for Third World countries: 1. The production of CFCs, carbon tetrachloride, HCFCs and halons for all uses except certain fire suppression, refrigeration, air-conditioning applications and limited insulating foam applications, should be eliminated by January 1, 1993. Exceptions: Production for use in new mobile air-conditioners should be phased out after September 1, 1993; in residential-type refrigeration and air-conditioning systems, mobile (truck) refrigeration systems, and insulating polyurethane foams used in refrigerators and other similar appliances by January 1, 1995. Limited exemptions to the 1992 and 1993 deadlines may be allowed until January 1, 1995, upon a petitioner submitting proof that no reasonable alternative is available. No exemptions, apart from essential pharmaceutical applications, should be allowed after January 1, 1995. Permits for use in case of such exemptions should be conditional upon installation of recovery equipment, whenever feasible. 2. New production of CFCs should be subjected to a tax of $25 per pound for CFCs or halons beginning January 1, 1993, until total phase-out two years later. HCFCs should be subjected to a tax of $5 per pound in the same period. These taxes on new production would greatly encourage recovery of CFCs and HCFCs from existing equipment. 3. Consideration of electricity generation systems which generate electricity on-site and use the waste heat for all or part of the air-conditioning and heating requirements should be made mandatory for all new buildings and developments that would require more the 300 kilowatts of electrical power for all purposes, including CFC-using air-conditioning. 4. Policies to recover CFCs, halons, and HCFC-22 from existing equipment should be fully implemented by the end of 1992. This must include recovery from existing mobile air-conditioning systems. Recovery from residential refrigeration and air-conditioning equipment should be effected after this equipment is discarded. 5. Polices to begin systematic acquisition and destruction of CFCs, halons and HCFC-22 in existing equipment should be put in place by the end of 1992. These policies should then be implemented in the 1993-2010 period. This will mean conversion of existing systems to other compounds and technologies. For instance, most existing car air-conditioners can be converted to HFC-134a, which is not an ozone-depleting compound, at a cost of about $200 per car. Complete replacement of CFCs and HCFC-22 should be targeted for the year 2000 (except for residential-type refrigerators and air-conditioners), and for halons by the year 2010. These CFCs, halons and HCFC-22 can be destroyed by high-temperature incineration, using the best available technology to minimize the emissions of pollutants. A part of the proceeds from taxation of CFCs and HFCs should be used to provide economic assistance to convert existing equipment to non-ozone depleting substitutes (in cases of need) and to provide for the destruction of CFCs and HCFCs with the best available pollution control technology. Chemicals needed to service existing equipment would come from stocks of recycled materials. This should be discouraged in favor of collection and destruction by a system of fixed incentives for replacement and taxes increasing with time for a failure to do so. 6. A ban on methyl bromide should be enacted with immediate effect. Exemptions may be granted for one year, with a tax of $25 per pound to be levied on all uses. 7. Methyl chloroform production should be eliminated by the end of 1992, with exemptions granted until the end of 1993, upon demonstration of a lack of any suitable alternatives. No exemptions should be granted after January 1, 1994. There should be a tax of $10 per pound on new production in 1993. 8. The existing program for reducing the emissions of methylene chloride and perchloroethylene under the Clean Air Act should be accelerated. Financial assistance to small commercial users of perchloroethylene (notably dry-cleaning establishments) to eliminate emissions should be made available from a tax of $2 per pound levied on these two compounds. 9. An urgent survey of all chlorine and bromine containing compounds with a lifetime of more than one month, and emissions of more than one thousand tons per year, should be undertaken in order to limit and eventually eliminate emissions of these compounds. This could have a significant effect in the short-term because their short atmospheric lifetimes would result in their rapid elimination from the atmosphere, decreasing chlorine burdens during the peak of the crisis. 10. Urgent negotiations on ways to end the burning of tropical forests should be included in the Montreal Protocol process. Policy-oriented as well as scientific studies of the contribution of biomass burning should be initiated as part of the Montreal Protocol process. 11. The subsidiaries of multinational corporations and joint ventures in which multinational corporations have more than 10 percent ownership should be required to have the same phase-out schedule as that for the industrialized countries. Laws mandating this will be needed in industrialized countries. This should also be made a part of the Montreal Protocol revision. 12. In general, the timetable for the phase-out of ozone-depleting industrial halocarbons in the Third World needs to be accelerated to match that of industrialized countries. 13, A slower phase-out of industrial halocarbon use in certain applications in the Third World may be necessary in some areas due to differences in use patterns. For instance, carbon tetrachloride, which is highly toxic and ozone-depleting, is widely used as a solvent and even as a fire suppressant. It may be necessary to use HCFCs or methyl chloroform in certain applications for two or three more years beyond the deadlines for the industrialized countries in order to recover and destroy carbon tetrachloride in existing systems and enable vastly dispersed uses of carbon tetrachloride (as for example in workshops in small towns) to be eliminated rapidly. Recovery, recycling and destruction of CFCs, and HCFCs needs to be instituted, though the timetable may be different than that for the industrialized countries. 14. The fund to assist the rapid phase-out in the Third World is grossly inadequate. This fund, which is already a part of the London amendments, should be considerably expanded to cover the actual costs to Third World countries of a rapid phase-out. The adoption of our recommendations would mean that ozone depletion would end about three to four decades earlier than the London amendments and about one-and-a-half to two decades earlier than the accelerated phase-out scenarios now being considered in the United States. President Bush's plan of February 11, 1992, asking for a phase-out of CFCs by the end of 1995. He did not specify a new timetable for HCFCs, but only asked for a review of the matter. Moreover, his plan does not contain provisions for recovery and destruction of CFCs from existing equipment, for example after it is junked. This failure would allow for about half-a-million tons of CFCs and HCFC-22 per year to be released to the atmosphere every year from existing equipment until after the turn of the century. It is noteworthy that some major chemical companies have chosen not to manufacture HCFCs. They believe that they can compete very well without relying on ozone-depleting compounds. These companies include ICI, a multinational corporation based in Britain, and Hoechst of Germany. As a result, the Bush plan would allow ozone-depleting chlorine concentrations to continue increasing throughout this century. In the Saving-Our-Skins scenario, recommended here, chlorine concentration would peak in 1992, and begin to decline in 1993. All told, President Bush's plan will allow millions of tons of unnecessary emissions, and millions of additional skin cancers and cataracts, as well as unnecessary harm to immune systems, and other ecological and economic damage. His recommendations are not much better than the worst case of chlorine accumulations presented in our calculations and are seriously deficient compared to what can be accomplished to protect the ozone layer. The course recommended in the Saving-Our-Skins scenario would minimize harm and also considerably reduce the risk of utterly catastrophic ozone depletion over northern latitudes in the next several years. Chapter I Ozone Depletion and Its Consequences 1. Extent of Ozone Depletion The reality of depletion of the stratospheric ozone layer has consistently outpaced predictions. For instance, the most recent reevaluation of depletion in the 1979-1991 period puts the depletion over populated northern latitudes at about double the previous estimates. There is no doubt that the damage is occurring from the build-up of industrial chemicals, known as halocarbons, which contain chlorine and bromine. Most notable among these are the fully halogenated halocarbons, such as chlorofluorocarbons (CFCs), halons and carbon tetrachloride. The concentrations of chlorine monoxide, a chemically active form of chlorine, have a close anti-correlation with stratospheric ozone concentrations, demonstrating a strong connection between ozone depletion and chlorine build-up. Theoretical and laboratory studies also show that chlorine plays a catalytic role in the process of ozone destruction, with each atom of chlorine destroying about 100,000 molecules of ozone. Bromine in the stratosphere is about 75 times more destructive than chlorine on an atom-for-atom- basis. Moreover, there are mutually reinforcing reactions that deplete ozone when both these elements are present. The most recent findings include: Chlorine monoxide levels in the Arctic stratosphere as high as 15 parts per billion by volume in January 1992, which could presage ozone depletion anywhere from serious to catastrophic in the northern latitudes in the spring of 1992, depending on weather patterns. Total chlorine levels in the atmosphere have reached about 3.9 parts per billion by volume, about eight to ten times the natural level of about 0.4 to 03 parts per billion. The total chlorine levels include about O v parts per billion from a host of miscellaneous unregulated compounds such as methylene chloride and perchloroethylene. The Antarctic ozone hole continues to appear in as severe a form each austral spring, with ozone depletion of as much as 50 percent. The ozone hole was triggered by a chlorine level of about 2 parts per billion, about four to five times the natural chlorine level. Ozone depletion over densely populated areas in northern Europe, much of North America, northern Russia and northern China is twice as severe as previously thought, amounting to 2 to 3 percent through the year and as much as 5 percent in high southern latitudes, on an annual average basis. 2. Health and Environmental Consequences The ultraviolet (UV) spectrum is split up-into three parts - UV-A, UV-B and UV-C. UV-A is the long-wavelength UV radiation (320 to 400 nanometers spectrum), necessary for vitamin-D synthesis, and has relatively few seriously harmful effects. UV-B has wavelengths in the 290 to 320 nanometers range and causes serious damage, especially in the shorter wavelength portions (290 to 300 nanometers) of the spectrum. These shorter wavelengths are almost entirely screened out by normal ozone levels, but there is some natural transmission of radiation in the 300 to 320 nanometer region of the spectrum. UV-C consists of the 40 to 290 nanometer region which is almost entirely screened out by normal oxygen (O2) and ozone (O3). A one percent decrease in ozone would produce different increases in the transmission of various wavelengths of UV-B, with a larger percentage increase for the more damaging shorter wavelengths. Each wavelength in turn produces different degrees of biological effects, depending on the effect and the specific organisms being considered. Therefore, it is quite a complex matter to calculate the effects of increases in UV radiation on living beings. There is also the further complication that some of the increased UV penetrating the stratosphere may not reach the surface of the Earth due to physical and meteorological factors. As a rule of thumb, a one percent decrease in stratospheric ozone may be considered to produce approximately a two percent increase in biologically effective UV-B radiation in terms of DNA action spectrum. The actual amounts of deleterious biological effects produced will depend on the amount of increased UV, the spectrum of the increased UV radiation, and the specific effect being considered. For instance, one research paper concluded that a 1 percent decrease in ozone would produce a 1.56 percent increase in annual "carcinogenic radiation" leading to a 2.7 percent increase in non-melanoma skin cancers.1 There is, however, a considerable range reported in the literature even for these relatively common cancers: 1 to 10 percent increase in non-melanoma cancers for a 1 percent ozone loss, with a common range being 1 to 3 percent.2 1. Gert Keliens et al., "Ozone Depletion and Increase in Annual Carcinogenic Ultraviolet Dose, Photochemistry and Photobiology, vol. 52, no. 4; pp. 819-823. This calculation is based on the assumption that all the increased UV actually reaches the surface of the Earth, and therefore ignores physical and meteorological phenomena decreasing the amount of UV reaching the Earth under certain conditions. In urban areas, tropospheric ozone, which is a harmful pollutant, may screen out the releases in UV-B radiation masking the effects of stratospheric ozone depletion up to a few percent increase in UV during some periods. 2. R.L. McKenzie et al., "Intensity of Solar Ultraviolet Radiation and Its Implications for Skin Cancer", New Zealand Medical Journal, vol. 103, no. 887, April 11, 1990, p. 152. The following list summarizes the separate effects of ozone depletion: 1. Malignant melanoma: A 10 percent increase in UV leads to a 3.5 percent to 9 percent increase in incidence of malignant melanoma in light-skinned people and possibly an as yet unknown increase (from a relatively small base) increase in dark-skinned people. 2. Non-melanoma skin cancers: A 10 percent increase in UV leads to a 10 to 30 percent increase in incidence of basal and squamous-cell cancers. 3. Cataracts: A 10 percent increase in UV leads to a 5 percent increase in the incidence of cataracts. There were about one million cataract operations in the U.S. in 1990. 4. Plants: A 25 percent reduction in column ozone leads to a 20 to 25 percent reduction in soybean yield for UV sensitive varieties. 5. Aquatic plant life: (a) A 10 percent increase in UV-B leads to a 25 to 5 percent loss of photosynthetically-active radiation. (b) A 25 percent reduction in column ozone could lead to a 35 percent reduction in primary production near the water surface and a 10 percent reduction in the entire euphotic zone (the warm, biologically-rich upper layer of the ocean). 6. Aquatic animal life: A 7.5 percent reduction in ozone would reduce the shrimp breeding period by 50 percent and cause injury to other aquatic micro-organisms, with consequent adverse effects on other life forms higher in the food chain. Besides these effects, which can be roughly quantified at present, based on limited laboratory and field studies, there are a number of effects which are at present impossible to quantify. 1. Damage to the immune system, including a decrease in cellular immune function, leading to increased occurrence of many diseases, and the aggravation of preexisting immune system disorders. 2. Increases in diverse infectious diseases-such as leishmaniasis, leprosy, and schistosomiasis. 3. Possible increases in genetic effects due to damage to the DNA. 4. Increases in tropospheric ozone, and attendant ill-effects on health and agriculture. 3. Epidemiological Consequences It is not possible at present to make a quantitative analyses of simultaneous interdependent changes in health status, economy, and ecology. Severe changes in any of these areas could by themselves be very socially disruptive. It is a challenge merely to even identify the potential combined effects. Persistent declines of stratospheric ozone would produce effects for life on Earth ranging from serious to catastrophic. Increases in the incidence of diseases could strain the ability of economic and medical systems to respond, particularly in Third World countries. For instance, epidemics may be triggered by a combination of decreases in immunity, declines in food production and the direct disease-producing effects of UV-B radiation. Severe depletion would also disrupt ecological systems considerably, with unknown effects. Agricultural systems may also be disrupted considerably. In the industrialized countries there may be large increases in health care and insurance costs, further straining health care systems. Some effects of severe ozone depletion have been studied in the context of ozone depletion hypothesized to occur as the result of all-out nuclear war. While the possibility of such a war has greatly diminished with the end of the Cold Wars the theoretical studies of its effects turn out to hold some lessons for ozone depletion. Of course, nuclear war would have a great many horrendous and destructive effects which would result in tens or hundreds of millions of people being killed immediately or within a few days. This comparison does not refer to the explosive and high-level radiation effects of nuclear war which would produce these deaths or to widespread radioactive contamination. Rather, it refers only to one of the most destructive long-term effects of nuclear war, which a 1975 study of the National Research Council of the U.S. National Academy of Sciences (NAS) identified as severe ozone depletion.3 3 National Research Council, Long-term Worldwide Effects of Multiple Nuclear Weapons Detonations, National Academy Press, October 1975. Hereafter cited as NAS 1975. The NAS study was specifically directed at the long-term effects of an all-out nuclear war, stressing,particularly those aspects which had not until then been studied in depth. Perhaps the most serious of these "frequently neglected effects" was severe depletion of the stratospheric ozone layer. This was hypothesized to occur due to the sudden injection of large quantities of nitrogen oxides into the stratosphere as a result of the detonation of large numbers of nuclear weapons. The NAS results have been reaffirmed by other studies.4 4. R. P. Turco and G S. Golitsyn, A Status Report: Global Effects of Nuclear War; Environment; Vol. 30, No. 5; June, 1988. The NAS study was used by the Arms Control and Disarmament Agency to prepare "An Assessment of Frequently Neglected Effects of Nuclear Attacks" in 1978. It summarized these effects as follows: ...the worst case of 70% ozone decrease...would cause blistering sunburn after 10 minutes' exposure in temperate latitudes. The more probable lowering of 50% as a result of a nuclear war ...would cause blistering after 1 hour of exposure. This leads to the conclusion that outside daytime work in the northern hemisphere would require complete covering by protective clothing. It would be very difficult to grow many (if any) food crops, and livestock would have to graze at dusk if there were any grass to eat. Even if ozone depletion only reached the best expected case of 25-30% reduction the effect on post-war recovery operations is difficult to imagine.5 5. Arms Control and Disarmament Agency, An Assessment of Frequently Neglected Effects in Nuclear Attacks; ACDA Civil Defense Study, Report Number 5, April 19, 1978, p. 7. There may be other severe indirect effects of such ozone depletion. For instance, the "likelihood that ultraviolet burning of forests and grass lands would alter climatic patterns cannot be neglected."6 6. Ibid. Current chlorine-induced declines in ozone levels do not correspond to such catastrophic levels. But we should note that for a portion of the year, the declines in the ozone layer above the Antarctic is about 50 percent. The observed effects are not as severe as those described above because the sunlight comes in at a considerable angle to the vertical in the early Antarctic spring when depletion is at its worst. This means that sunlight goes through a great deal more of the stratosphere than it would if the sun were overhead at midday. This allows even an ozone-depleted stratosphere to filter out much or most of the excess UV radiation. That would not apply to lower latitudes, or to other times of the year, especially the late spring, summer or early fall. The measurements of chlorine levels over northern latitudes in excess of those found in the Antarctic ozone hole in January 1992 raise for the first time the possibility that there may be severe ozone depletion over populated areas as early as the spring of 1992, and each year in the spring after that, if similar conditions recur. Whether such depletion will occur will depend primarily on weather patterns over the Arctic. A relatively stable vortex over the region would mean a continuation of high chlorine concentrations when the spring sun first hits the chlorine-charged air in the Arctic vortex. Severe ozone depletion and large increases in UV radiation would result. It is possible that certain organisms and animals could adapt to higher levels of UV radiation by changing behavior patterns. Some aquatic organisms could migrate to greater ocean depths, for instance. However, this will not be possible for many species. As an example, coral reefs cannot migrate. What might then happen to the rich life in and around these reefs, already damaged by other pressures? Severe shortening of the breeding season for some micro-organisms may disrupt the entire oceanic ecological system. Since UV-B radiation induces cataracts, it is possible that there may be a large-scale blinding of many species of wildlife. In such a case, entire land-based ecosystems may also be disrupted or destroyed, particularly if increased susceptibility to diseases is also taken into account. In the Third World, most people depend upon farming for their existence. Cattle are the main source of power for tilling the fields. This work must be done in the daytime. While it may be possible to contemplate that cattle held for beef production may be able to graze at dusk, there is no possibility that agricultural work could be carried out in this way. Moreover, during the peak agricultural season, the amount of daytime outdoor work for human beings is very large. The work day is long and extends throughout the daylight hours. Any substantial curtailment of the workday for cattle or human beings could produce catastrophic reductions in crop production and consequent famines. Such famines may occur in northern China if severe ozone depletion occurs in the spring of 1992 due to the high levels of ozone-depleting chlorine and if it persists for some time. This is because among the northern latitude countries affected by high chlorine monoxide concentrations in the Arctic, China is the only one greatly dependent on draft cattle for agricultural power needs. There could also be great disruptions of the pastoral economy of Mongolia. Milk production, already in seriously short supply in the Third World, could also be seriously curtailed. The ability of cattle to reproduce and the effects on cattle population under these circumstances can only be a matter for speculation at present. The NAS report concluded that it was difficult or impossible to address these kinds of questions based on the state of knowledge in 1975. It further cautioned that "under extreme circumstances, certain habitats could become devoid of living organisms." 7 While knowledge of effects on individual living beings (animals, some plants species and humans) has increased, there has been very little advance in the state of knowledge of the potential epidemiological, ecological and economic consequences of severe ozone depletion. 7. NAS 1975, p. 149 (emphasis added). The possibilities for damage from such depletion are extreme - they are the basis of our conclusion that it is the most serious and immediate environmental problem facing us. Life on Earth itself is threatened with severe damage. It is therefore imperative that we make considerable, strenuous and extraordinary efforts to keep the peak concentrations of ozone-depleting substances from increasing and implement measures that would begin to achieve reductions in these concentrations as rapidly as possible. 3. Overall ozone layer protection policy Policies to protect the ozone layer so far have largely been based on regulating particular chemicals, rather than on overall goals for limiting damage to the ozone layer and eventually reversing the damage that we have caused. The overall goals need to be to limit the peaks of chlorine and bromine build-up to as low a value as possible and to take measures to ensure that these peak values begin to decline as rapidly as possible. The next goal must be to bring chlorine build-up below the level which triggered the Antarctic ozone hole (about 2 parts per billion) in the shortest possible time. The long term goal must be to reduce the build-up from human activities to a level considerably lower than the 0.5 parts per billion due to natural emissions of methyl chloride. 4. Ozone Depletion Potentials (ODPs) The principal chemicals responsible for the build-up of chlorine and bromine are fully halogenated halocarbons, including chlorofluorocarbons (CFCs), carbon tetrachloride, and halons. However, partially halogenated compounds are also important contributors to chlorine build-up. The most important chemical among these is the solvent methyl chloroform, whose use has been-growing rapidly. HCFC-22 is the next most important chemical in this class; it is a widely used refrigerant. Further, HCFC-22 and methyl chloroform have come into increasing use in the past few years, in part due to substitution for fully halogenated halocarbons such as CFC-12 and CFC-113. Both of them are important sources of chlorine build-up. For instance, in the past few years, since the restrictions on CFCs have come into force, HCFC-22 has come to be used in such non-essential applications as aerosol spray cans and blowing of foams for disposable tableware. Such goods are often advertised as being free of CFCs and "safe". For instance, Du Pont, the world's largest manufacturer of CFCs, advertises products containing HCFCs as "environmentally enlightened" and one Du Pont booklet describes such compounds as "safe and environmentally acceptable".8 This is simply contrary to scientific evidence that has been public for over two years. Du Pont scientists themselves have participated in the development of this work.9 8. Du Pont advertising and booklet quoted by Jack Doyle, Hold the Applause, Friends of the Earth, Washington, D.C 1991, p. 54. 9. Some of the models in presented in the World Meteorological Organizations 1989 report on ozone depletion which show far larger short-term effects of HCFCs were actually developed by Du Pont and run by the company's scientists. See World Meteorological Organization, Scientific Assessment of Stratospheric Ozone: 1989, Global Ozone Research and Monitoring Project - Report No. 20, WMO 1990, vol. 2, Figures 1, 2, and 3 in Chapter VIII, pp. 305-307. Partially halogenated compounds are, to varying extents, degraded in the troposphere before they reach the stratosphere, and therefore contribute less to chlorine build-up per unit of emissions. However, the short-term ozone depletion potential of HCFCs (on a ten to twenty year time-scale) is far larger than indicated by their Ozone Depletion Potentials (ODPs), which is a long-term figure. For instance, HCFC-22 is three to five times more ozone-depleting on a ten-to twenty-year time frame than indicated by its ODP of 0.05. This is because the ODP is a calculation that compares a steady-state value of chlorine contribution of CFC-11 with other chemicals. Such a steady state value is only reached after more than 200 years due to the long lifetime of CFC-11 (about 55 years). Figure 1 (omitted here) shows chlorine concentrations at 40 kilometers altitude produced by HCFC-22, HCFC-123 compared to CFC-11, as calculated by a Du Pont computer model. The peak contribution of HCFC-22 is about one-fourth that of CFC-11, or about five times the value indicated by steady-state (long-term) ODP. Similarly, ozone depletion calculations show that, assuming that all constituents react in the gaseous phase (which tends to underestimate ozone depletion), peak ozone depletion due to HCFC-22 is about three times the value indicated by its steady-state ODP. (See Figure 2. - omitted here.) These calculations are also from a Du Pont model. The crisis in chlorine build-up is, however, not on a 200 year time frame; rather its most acute phase extends over the next two or three decades. Therefore the contributions of HCFCs to chlorine build-up and to ozone depletion during this crisis will be far higher than indicated by their ODPs. Unlike the claim in Du Pont advertisements, they are not "environmentally enlightened". 6. Uses of and alternatives to ozone-depleting industrial halocarbons The technologies exist to essentially eliminate production of all fully halogenated industrial compounds, such as CFCs, halons and carbon tetrachloride in the short-term, without recourse to partially halogenated ozone-depleting compounds (HCFCs). The present uses of industrial halocarbons fall into several broad categories. The most important uses and some of the presently available alternatives are: 1. Refrigerants: CFC-11, CFC-12, CFC-114, CFC-115 as well HCFC-22 are used as the fluids for cooling systems of refrigerators, freezers, and car and truck air conditioners. They also are used in commercial and truck refrigeration, air conditioning, and freezing systems. Alternatives: On-site generation and use of waste heat in large air-conditioning systems., HFC-134a HFC-152a ammonia-water absorption systems. (Volvo, Mercedes Benz and Jeep Cherokee are already shipping vehicles with non-ozone--depleting HFC-134a). Evaporative cooling may be suitable in some areas. 2. Solvents: CFC-113 is used, usually in combination with other chemicals, as a cleaning agent for electronic circuit boards and for metal parts and assemblies. CFC-11 and CFC-113 also are used to service auto air-conditioning systems. Methyl chloroform and carbon tetrachloride have similar solvent applications. Alternatives: no-clean manufacturing techniques, aqueous cleaning terpenes (compounds derived from orange peels). 3. Aerosols: CFC-11 and CFC-12 were used extensively as aerosol propellants in most of Europe and Japan until the end of the 1980s. In the U.S., Canada, and Sweden most of these uses were banned in 1978 and replaced with other systems or chemicals. In the last few years, HCFC-22 has been coming into increasing use to replace CFCs. Alternatives: a combination of carbon dioxide, acetone and polymer pellets in reusable aerosol cans (the propellant is not emitted but conserved in the bottom portion of the can), carbon dioxide, nitrous oxide, manual pumps, and hydrocarbons. 4. Foam production: CFC-11 and CFC-12 are used to produce soft foam (such as that used in furniture, bedding and car seats), packaging material, and as insulating filler in the cells of rigid foam. In the last few years, HCFC-22 has been used to replace CFCs in foam-blowing. Alternatives: water blown foam, new manufacturing techniques which require no blowing agents, carbon dioxide, HFC-134a, and a variety of alternative insulating and packaging materials. 5. Sterilization: CFC-12 is used as the delivery vehicle for the sterilant ethylene oxide (EtO). EtO is used to sterilize some hospital equipment, some spices, and even books. Alternatives: carbon dioxide, use of unmixed-ethylene oxide. 6. Fire fighting halons, which contain bromine and which have a high ozone-depletion potential, are used in fire-fighting equipment, of the centralized variety (halon-1301) and in fire extinguishers (halon-1211). Alternatives: carbon dioxide, water, and, in life-threatening circumstances, HCFCs. A host of compounds being developed are expected to be available in the next few years. This list of alternatives is by no means exhaustive. We have listed many of the presently available technologies, chemicals and processes, without going into the potential for short-term developments to provide an even larger variety. The history of regulation of ozone-depleting chemicals since 1988 has shown that with reasonable goals which take account of potential short-term developments, it is possible to achieve far more than was thought possible. The most ambitious program for a CFC phase-out in 1988 was that of Sweden, which targeted a reduction of 50 percent by 1991 and full phase-out by January 1, 1995. The actual reduction achieved in 1991 was 80 percent and some phase-out dates have even been officially accelerated. Moreover, the development of technology which does not use HCFCs, but relies on non-ozone-depleting compounds has been faster in areas such as Scandinavia and Australia where regulations were more stringent. In these areas, where regulations are stronger, some corporations, such as ICI and Hoechst, have adopted corporate strategies of avoiding HCFCs. In addition to these organic compounds, there is also a major anthropogenic inorganic compound that contributes to chlorine build-up. This is the solid rocket fuel ammonium perchlorate. It was the investigation of the potential environmental consequences of frequent flights of the space shuttle which uses this fuel that resulted in the first theory about ozone depletion from a build-up of chlorine from anthropogenic emissions of industrial compounds. Liquid propellants can replace solid rocket fuel. This may not be possible in the next few years for the U.S. space shuttle. Alternative means of delivery of payloads into space are available. However, we have not investigated this area in detail. 7. Use of waste heat in large air-conditioning systems The use of CFCs in refrigeration is an area where there is a major overlap between policies to protect the ozone layer and those needed to limit the build-up of greenhouse gases, to conserve energy and to reduce other adverse environmental consequences of electricity consumption. The use of waste heat from on-site electricity generation has the potential for harmonizing the elimination of CFCs and HCFCs in this application with a broad range of goals in the electricity and energy sectors Yet, neither U.S agencies (the EPA or the Department of Energy) nor the United Nations Environment Programme have carefully considered the potential of this technology in the context of eliminating ozone-depleting chemicals. This commercial technology uses waste heat to drive an absorption air-conditioning system in the summer and to provide heating in the winter.10 It can save 20 percent or more of building energy use when compared to electrically air-conditioned and oil or gas heated buildings. Widespread use has the potential of reducing emissions of CFCs and HCFC-22 rapidly and at the same time contributing to the increasing electrical generation capacity, while reducing summer peak loads. But the UNEP panel on refrigeration has so far totally ignored this technology and the members of the panel refused to provide an explanation for this omissions at a recent International Conference on Alternatives to CFCs and Halons in Baltimore, Maryland (December 3 to 5, 1991). 10. Absorption air-conditioning uses the alternate absorption and desorption of ammonia in water to produce the same cooling effect as vapor compression and condensation in the more familiar, electricity-driven, CFC-using air-conditioning systems. Lithium bromide may be used instead of ammonia. Since absorption and desorption do not require compression but only a heat source, the system can be run using waste heat from electricity generation, or some other source of energy like natural gas. One of the authors of this report (Aliun Makhijani) asked some of the members of UNEP refrigeration panel who were present at a workshop during this conference to explain why on-site generation had been ignored. (The UNEP panel on air-conditioning and refrigeration had many members from both the CFC-making industry and from the manufacturers of CFC-using equipment, but apparently none representing the cogeneration industry, according to a DOE official.) He was told that this technology did not need to be considered because it was already commercial. When he pointed out that a large part of the purpose was to consider commercial technologies to replace CFCs, Dr. Kenneth Hickman, of York International, a maker of CFC-using air-conditioning equipment, and a member of the UNEP team that wrote a report on refrigeration technologies, simply said that was that on-site generation "was available and the marketplace will decide".11 The clear implication was that the UNEP panel was not going to consider this technology, even though it was commercial, and could be especially beneficial in immediately reducing ozone depletion, global warming impacts, and produce a number of other benefits, especially in the Third World. 11. Notes from the Workshop on Refrigeration and Air- Conditioning, International CFC and Halon Alternatives Conference, UNEP Overview Presentations, Baltimore, December 3, 1991. A U.S. Department of Energy representative at the conference was similarly evasive, claiming that there was no representative of the on-site generation industry on the panel and that none of the one hundred or so members had thought to bring it up for inclusion! None of the papers presented at the international conference dealt with this crucial technology. Thus, even as other parts of the government might be considering it as an energy conservation step or as a method of increasing electric generation capacity, it has not been integrated into an urgent schedule for ozone layer protection. 8. Emissions from existing equipment An increasing proportion of the emissions will come from the industrial halocarbons stored in existing equipment (known as "service banks"). At current levels of production, emissions from the service banks of CFC-11, CFC-12 and HCFC-22 from new production are of the same order of magnitude as emissions from new production. Emissions from service banks will dominate the totals after about two years. The total amount of CFC-11, CFC-12 and HCFC-22 in service banks is about 2.7 million tons, which is about three times the world production in the July 1990-June 1991 period. Of this about 2 million tons is CFC-11 and CFC-12, and the rest is HCFC-22. The leak rates from different equipment varies, being slowest for some insulating foams (20 years or more for total release), an fastest from mobile air- conditioners (two to four years). Household refrigerators are hermetically sealed and leak only very rarely; therefore almost all the CFC-12 can be recovered at the end of their service life. 9. Methyl bromide Methyl bromide is a fumigant that contributes to bromine build-up in quantities likely to be of the same order of magnitude as regulated halons. Yet methyl bromide is not regulated. It is used in specialized agricultural fumigation applications such as greenhouse cultivation of some fruits. Methyl bromide is also emitted from natural sources, largely from the oceans. Natural bromine, like natural chlorine, maintains the balance of the natural ozone layer. There are large uncertainties in the source term for methyl bromide. 10. Third World emissions Increases in the use of industrial halocarbons among the rich and upper middle classes in the Third World, which is allowed under international current regulations, could become a major source of emissions over the next decade. The use of these compounds has been increasing rapidly in some countries. For instance, in India it more than doubled between 1986 and 1991, from a relatively low base of about 5,000 tons. If, by the year 2000, only 5 percent of the people of India and China, 10 percent of the rest of Asia, 2 percent of Africa, and 15 percent of Latin America and the Caribbean reach levels of consumption equalling that which prevailed in the industrialized countries in 1986, the peak of emission could exceed 700,000 tons, which is about 35 percent of the 1986 level of worldwide emissions (including methyl chloroform). This would mean continued ill-health effects throughout the world, and an increased risk of catastrophic ozone depletion. 11. Unregulated Compounds Two chlorinated compounds not yet included in public policy for protecting the ozone layer may be contributing to chlorine build-up. They are methylene chloride and perchloroethylene. There are also a number of other chlorinated compounds such as dichloroethylene, a feedstock for polyvinyl chloride, which are contributing to chlorine build-up. These compounds have relatively short lifetimes, on the order of a few months. However, emissions of these compounds are large, on the order of several hundred thousand tons per year. The rapid reduction of emissions of these compounds could have a quick beneficial effect by rapidly reducing chlorine emissions precisely because of their short lifetimes. 12. Biomass burning in smoldering fires contributes about 3 to 4 percent of global chlorine build-up. Of the global chlorine build-up of about 3.9 parts per billion of chlorine, about 0.4 tb 0.5 parts per billion is due to natural emissions of methyl chloride. About 33 parts per billion is due to industrial emissions. However, one significant source, larger than some CFCs that are being regulated, is emissions of methyl chloride from biomass burning. The contribution of this source is likely to be in the 0.1 to 02 parts per billion range. In many Third World countries, such as Brazil and tropical African countries, where there is-large-scale burning of savannahs and tropical forests, methyl chloride emissions may exceed emissions from CFCs. This is in part due to the relatively low level of CFC consumption in these countries, but also to the large scale of biomass burning. We recognize that the burning of forests and savannahs in the Third World, not to speak of fuelwood use, is a complex issue which involves the livelihoods of billions of people and many other areas of environmental concern, including global warming, and genetic diversity. For a number of reasons, it is important to integrate this issue into the process of limiting chlorine build-up, even as it is pursued in other forums. First, it is likely to be an important contributor to chlorine accumulations and no significant source should be ignored in this global crisis. Second, in the allocation of financial resources to the Third World, sufficient resources should be devoted to those areas that would benefit the poor and not only the middle and upper classes. The achievement of actual results in practice in these areas is very difficult, since it involves issues of internal economic justice in the Third World. But we believe that that should not prevent us from addressing them. Chapter II Projections of Stratospheric Chlorine and Bromine Concentrations 1. Model Description and Assumptions The potential for ozone depletion in the future, beyond that which has already been committed to due to past releases of industrial halocarbons, is intimately tied to the amount and pattern of industrial halocarbon emissions in the future. To represent the effects of policy and implementation, we have constructed three emission scenarios that serve to illustrate the range of possibilities. We have called these three scenarios, the "London-Amendments scenario", the "Accelerated-Full-Compliance scenario", and the "Saving-Our-Skins scenario". The primary differences between the three scenarios involves five issues which we will briefly describe in turn. They are: A. The phase-out schedule of the industrial halocarbons B. The phase-out schedule followed by Third World countries (defined in article 5 of the Montreal Protocol) and global compliance. C. The nature (extent and compound choice) of alternative industrial halocarbon (HCFC and HFC) substitution. D. The growth of HCFC-22, an industrial halocarbon not presently regulated by the amended Montreal Protocol. E. The extent to which banked industrial halocarbon emissions are controlled or eliminated. A. Phase-Out Dates The London-Amendments scenario assumes the phase-out dates in the June 1990 London amendments to the Montreal Protocol. The Accelerated-Full-Compliance scenario assumes more rapid phase-out dates for CFCs and HCFCs, but has the same general features as the London-Amendments scenario. The Save-Our-Skins scenario moves the phase-out dates for the industrial halocarbons presently regulated by the amended Montreal Protocol further forward, according the practical possibilities that are available today. Since new technologies are being rapidly developed and since existing technologies are being refined for much broader ranges of applications, it nay be possible to increase the pace of these reductions. We have not assumed this, since it is difficult to make a judgment about precise dates of commercialization and regulatory approval of new technologies or new applications of existing technologies. Further, in the Saving-Our-Skins scenario, halons, CFC-113, and carbon tetrachloride are phased-out by the beginning of 1993. CFC-11, CFC-12, CFC-114, and CFC-115 are phased-out by the beginning of the year 1995. Methyl chloroform is reduced to 300,000 tons in the year 1993 for necessary consumption in Third World countries, and then phased-out between 1995 and 1997. This is to allow for rapid replacement of carbon tetrachloride, which is even more ozone-depleting than methyl chloroform, highly toxic and widely used in the Third World to an extent that has not yet been established. We do not recommend this level of use, but have assumed it for modelling purposes in order to recognize that some provision has to be made to get a rapid phase-out of an as yet undetermined amount of carbon tetrachloride production. We urge that use of methyl chloroform be avoided to the extent possible in a manner compatible with a rapid phase-out of carbon tetrachloride in the Third World. B. Third World Schedule and Compliance Levels The amended Montreal Protocol attempts to eliminate the production and consumption of many industrial halocarbons within the next 20 years. Predicting the nature of the phase-outs within the Protocol is complicated by two factors. First, it is difficult to predict the extent to which production and consumption in the Third World will grow before the turn of the century - the first compliance date for them. Recent data indicates that consumption may be growing at a significant rate in many Third World countries. For instance, use in India has more than doubled since 1986. The London-Amendments scenario assumes that 16 percent of the consumption of industrial halocarbons took place in the Third World at the beginning of the 1990s. As the industrialized countries proceed along the amended Montreal Protocol phase-out schedule, the consumption of industrial halocarbons in the Third World would continue to grow until their first compliance date is reached in the year 2000, 10 years later than the first compliance date for industrialized countries. This growth in production within the Third World was estimated by assuming that a small portion of the population in these countries (a relatively well-off, high industrial halocarbon using class) will increase their per capita consumption of the internationally regulated industrial halocarbons until the turn of the century, as allowed in the Montreal Protocol. We assume that this per capita consumption will be equivalent to the present average per capita consumption in the industrialized countries, approximately 2 kilograms per person (including methyl chloroform and carbon tetrachloride). Table 1 (omitted here) lists our assumptions about projected population in the year 2000 and the portion of the population consuming at 2 kilograms per capita. The Accelerated-Full-Compliance and Saving-Our-Skins scenarios assume that the Third World adopts the phase-out schedule as the industrialized countries in those scenarios. Another difficulty of estimating Third World use is the extent to which they sign-on to the amended Montreal Protocol and whether or not changes in the phase-out dates will occur. While a large number of countries have indicated that they will sign the London Amendments, only a few countries have actually done so to date. However, most industrialized countries, use from new production is declining as fast or faster than the London amendments. That is not the case in the Third World, and we have noted the case of India above. Further, India has signalled its unwillingness to sign the London amendments because of the inadequacy of the financial assistance provided. A survey of existing and/or pending legislation in major industrialized countries, the final number of signatories on the original Montreal Protocol, and rising concern over the issue of ozone depletion, convinces us that the amended Montreal Protocol will very likely include all existing and future countries which are significant industrial halocarbon producers and consumers. It also seems clear that the Third World is likely to comply in the next few years to at least the London amendments, since considerable increases in consumption are allowed. Therefore, all three scenarios assume essentially global compliance with the amended Montreal Protocol. We should note as a caution that this is not the most pessimistic set of assumptions that can be made because some large Third World countries may not sign the London amendments. There may also be significant difficulties in the formerly socialist countries of Europe, since they are not currently slated to receive financial assistance for a phase-out. Thus, considerable efforts will have to be made to get the universal compliance that we have assumed in all three scenarios. C. Alternative Industrial Halocarbon Substitution All three scenarios rely on substitution, to varying degrees, with HFCs while the London-Amendments and Accelerated-Full Compliance scenarios also assume considerable use of HCFCs in order to meet total projected industrial halocarbon requirement. The total industrial halocarbon requirement in the future is derived from the growth rate of these compounds during 1985 to 1989. This "requirement" projection is an economic assumption in that it gives an estimate of the demand for the end-use products of the technologies which use ozone-depleting compounds today, such as refrigerators, foams, solvents and so on. This demand for end- uses is the same in any year in all three scenarios. The total industrial halocarbon requirement is assumed to grow at 3 percent per year for the remainder of the model period. Alternative industrial halocarbons, including HFCs, are assumed to meet a portion of the industrial halocarbon requirement deriving from reductions in the use of regulated compounds. In the London-Amendments scenario, 40 percent of the net industrial halocarbon requirement is met by alternative industrial halocarbons, including HFCs. In the Accelerated-Full-Compliance 20 percent of this requirement is met by alternative industrial halocarbons. President Bush's plan has not been fully spelled out as yet; based on the specifics that have been announced, it would lie somewhere between the London- Amendments and the Accelerated-Full-Compliance. (See Figures 3 and 4 discussed below - omitted here). In the London-Amendments scenario, the net industrial halocarbon requirement met by the alternative industrial halocarbons is split between two different compounds. One of the HFCs, HFC-134a (CF3CH2F), meets 60 percent of the net requirement while HCFC-141b (CC12FCH3, 10.8 year residence time and two chlorine atoms) takes the remaining 40%. The production of HCFC-141b is assumed to be frozen in the year 2010 and remains at that level until 2020 after which we assume a ten year phase-out. The Accelerated-Full-Compliance scenario divides the net industrial halocarbon requirement between two alternative industrial halocarbons, 75%/25%, and uses a shorter-lived HCFC, HCFC-123 (CF3CHC12, 1.71 year residence time and one chlorine atom), instead of HCFC-141b. The production of HCFC-123 is assumed to be frozen in the year 2010 and remains at that level until 2020 after which we assume a ten year phase-out ending in the year 2030. The Saving Our-Skins scenario relies principally non-ozone-depleting compounds to meet net industrial halocarbon requirements. We recognize that some of these uses are likely to be industrial halocarbons which do not contain chlorine and bromine and are not ozone depleting. We have assumed that about 20 percent of the requirements will be met by non-ozone-depleting industrial halocarbon such as HFC-134a This assumption does not play a role in our chlorine and bromine modelling since these compounds do not contain these ozone-depleting elements. This also includes some use for these compounds to replace CFCs in existing equipment, so that at least a portion of these CFCs may be destroyed and hence prevented from reaching the atmosphere. We make no assumptions in this work about the phase-out of non-ozone-depleting compounds, since they do not affect the policies that we have discussed here. We recognize that HFCs are greenhouse gases We also believe that we must make strong efforts to limit and to reverse the build-up of greenhouse gases in order to avoid the kind of crisis in this area that we are facing in ozone depletion, where we must worry about whether we are increasing the risk of cancer for our children merely by sending them to school or letting them play outdoors. However, we also recognize the immediacy and severity of the ozone-depletion crisis that requires us to replace CFCs in existing equipment if possible. For this need, HFCs could play an important role in some applications in the next few years. They will also alleviate economic disruption in the refrigeration and air-conditioning industry as we transition to technologies that are environmentally sound with respect to greenhouse gas accumulations as well. The assumptions we have made in our model for HFCs beyond the next decade or so are not essential to the chlorine and bromine calculations present. We believe that given appropriate efforts at recovery-and-reuse of these compounds, emissions can be kept to a minimum. This is a matter which must be addressed in more detail in the context of limiting greenhouse gas concentrations. D. The Growth of HCFC-22 While HCFC-22 has been commercially produced for the last 40 years, it is not regulated by the amended Montreal Protocol, apart from a general intent to phase it out over the next half century. In the London-Amendments scenario, we assume that HCFC- 22 production grows at its present production growth rate of 9.4 percent until the year 2000, after which it grows at 3 percent per year. We further assume that HCFC-22 production is frozen in the year 2015 and remains at that level until 2020 after it is phased out over a ten year period, ending in the year 2030. The Accelerated-Full-Compliance scenario is similar, except production peaks in 1995 and a full phase-out is assumed to take place in 2005. The Saving-Our-Skins scenario we recommend a phase-out of HCFC-22 by January 1, 1995. HCFC-22 has a significant impact on stratospheric ozone and the applications presently using HCFC-22 can use an HFC or switch to not-in-kind technology, therefore, it can and should be eliminated. E. The Extent of Banked Industrial Halocarbon Control The London-Amendments and Accelerated-Full-Compliance scenarios contain no provisions to control or eliminate banked industrial halocarbon emissions. The emissions from the existing banks of CFC-11, CFC-12 and HCFC-22 are of the order of half-a-million tons per year. The main sources of these are air conditioning equipment (mainly mobile air-conditioning and non-hermetically-sealed commercial air-conditioning systems). In the Saving-Our-Skins scenario, we assume the removal of 50 percent of the CFC-12 banked in non-hermetically sealed cooling systems such as car air-conditioners between 1995 and 2000 and essentially all of the CFC-12 banked in hermetically sealed cooling systems such as home refrigerators and air conditioners upon disposal (between 1995 and 2010). For non-hermetically sealed systems, recharging with a non-ozone depleting compound will be required after 1995. The recovered CFC-12 can be recycled in the remaining applications for which non-ozone-depleting alternatives are not available. The only requirement of these applications is that they be sealed systems or that recycling and/or removal of the industrial halocarbons be required when non-ozone depleting alternatives become available. At that time, these remaining CFCs should also be destroyed. Currently, the only means for destruction of CFCs is high-temperature incineration. The Saving-Our-Skins scenario assumes removal or destruction without removal of 50 percent of the CFC-11 banked in closed cell foams upon disposal of industrial halocarbon-containing foams (between 1993 and 2010). In addition, we assume that 50 percent of the HCFC-22 bank is removed between 1995 and 2000. This reflects recovery during servicing of central air-conditioning units. Halon banks are also assumed to be removed between the years 2000 and 2010 in the Saving-Our-Skins scenario. This will require reclaiming halons from fire-extinguishing equipment that presently contain halons from the end-user in addition to the various production stockpiles. Because of the dispersed nature of fire extinguishing equipment we have assumed collection will begin in the year 2000 and be completed by 2010. As with collected CFC-12, we assume that these halons will be destroyed to prevent their emission to the atmosphere. With these measures, emissions from the service banks would be reduced significantly in the next few years and, apart from emissions from some insulating foams, essentially ended around the turn of the century. The principal method of destroying CFCs known today is incineration. Fully-halogenated compounds, such as CFC-11 and CFC-12, are generally not flammable. Moreover, the partially halogenated compounds in use are also not flammable, since this is one of the properties that has been used to screen CFCs for commercial use. Thus high temperature incineration of some type, such as that used for destroying hazardous organic wastes, is necessary to destroy CFCs. Incineration of CFCs has been the subject of recent experimental investigation in Denmark.12 The CFCs destroyed in the incinerators appeared not to give rise to some of the toxic by-products common in municipal solid waste incineration, notably dioxins. At least measurements of dioxins were not reported in the experiment. This needs to be verified. There would be some trace contaminants in the exhaust gases from combustion as well as impurities in the CFC being incinerated. 12. Niels Moller Pedersen, "Destruction of CFC by Incineration of Refrigerators and Freezers", Proceedings of the International CFC and Halon Alternatives Conference, Baltimore, December 3-5, 1991, pp. 514-522 We are cognizant of the fact that no amount of pollution control can completely remove all pollutants from incinerator exhausts. Only the prevention of the manufacture of CFCs could have accomplished a zero pollution result. Today, we are confronted with the choice of allowing the accumulated CFCs to escape to the atmosphere or of recovering and destroying as much of service bank as feasible. The consideration of this technology in this context stems from the essentially complete destruction which this method can achieve and the reduction of the risk of catastrophic ozone depletion that we must strive for in the present circumstances. Further, this recommendation also allows more of the risk of CFC use to be borne by this generation rather than future generations, so far as CFCs in existing equipment are concerned. Incineration of industrial halocarbons makes sense only in the context of a rapid phase-out of the ozone-depleting substances, and as such is a one time sacrifice that our generation, which has benefited from the use of CFCs, must make to protect future generations. Were production of CFCs to continue, then incineration and creation of environmental risks would not make sense. It would then be much more like other municipal solid waste or other hazardous wastes where management technologies must take account of continued production. Table 2 (omitted here) shows the assumptions used in the scenarios in summary form. Tables 3a, 3b, and 3c, (omitted) briefly summarize all three scenarios. 2. Concentration Model and Summary Results Once emissions of the various industrial halocarbons and their residence times in the atmosphere are specified, industrial halocarbon concentrations can be calculated. We assume that all the industrial halocarbons considered in this study are thoroughly mixed in the troposphere regardless of the location of emission. Given the long lifetimes of the modelled industrial halocarbons compared to the global mixing times in the troposphere (weeks to months), this assumption is a good approximation. Concentrations, therefore, represent global annual averages. We have not modelled a few compounds with short lifetimes, but which are together important in chlorine accumulations. These include methylene chloride, perchloroethylene, dichloroethylene and others. The total contribution of these compounds to chlorine concentration is about 0.2 parts per billion. This figure must be added to the totals for 1992 shown in Tables 3a, 3b and 3c to get total current chlorine concentrations. We recommend action to minimize emissions of these compounds, some of which are covered under the Clean Air Act under provisions which do not involve ozone depletion. However, these efforts need to be universalized and made part of the Montreal Protocol process. Because of the relatively long lifetimes and rapid atmospheric mixing, industrial halocarbons emitted at the surface will eventually reach the stratosphere. When these compounds find themselves at the appropriate altitude, they are photodissociated. At the time of photodissociation, chlorine and/or bromine is released. The concentration of chlorine and bromine present in halocarbons serves as a proxy measure of ozone depletion potential at any time of all accumulated ozone-depleting compounds. Because bromine is more efficient at destroying stratospheric ozone, we consider two different methods of characterizing these concentrations. In the first, we combine the number of chlorine atoms and bromine atoms together to arrive at what will be called the "non-weighted equivalent chlorine concentration". In the second characterization we weight bromine release by a factor of 75 which is a rough measure of the comparative depleting ability of bromine. This measure will be called "weighted equivalent chlorine concentration". This highlights the true importance of brominated compounds and is the reason for our recommendation for a rapid phase-out of methyl bromide. We assume that the concentration of equivalent chlorine is achieved by calculating the atmospheric level of the industrial halocarbons and summing the chlorine and bromine atoms available. No lag between these related concentrations is included in the calculations. Figures 3 and 4 graphically depict the weighted and non-weighted equivalent chlorine concentration over time, respectively, for the three scenarios. Each of the measures described above will significantly reduce the total amount of chlorine and bromine in the atmosphere in the coming decades. The effect each of these measures has on the overall atmospheric chlorine and bromine loading is depicted in Figure 5. Starting with the London-Amendments scenario, each of the control measures is introduced into the model individually. It is clear from the figure that all of these measures have the same order of magnitude impact on non-weighted equivalent chlorine. The atmospheric chlorine reductions occur in both the magnitude of the absolute magnitude of the peak and the year in which the 2 parts per billion mark is crossed. This is the level at which the Antarctic ozone hole developed. Table 4 (omitted here) lists the extent to which each of these control measures affects the equivalent atmospheric chlorine peak and the time at which the 2 parts per billion mark is crossed. If we assume that ozone depletion will be eliminated when chlorine concentrations drop below the level that triggered the Antarctic ozone hole in the late seventies (which was the first manifestation of a serious problem of ozone depletion), we see that the Saving-Our-Skins scenario would result in an elimination of ozone depletion between one-and-a-half and four decades earlier than the other cases. Further, the peak of chlorine concentration would be reached in 1992 in the Saving-Our-Skins scenario, compared to 1996 for the Accelerated-Full-Compliance scenario, and 2003 for the London- Amendments scenario, declining thereafter. The benefits that adoption our the Saving-Our-Skins recommendations implies in terms of improved health, environment and economy are difficult to assess precisely, but they will no doubt be immense. For instance they will mean millions of fewer cases of skin cancers and cataracts over the next fifty years, lower damage to immune systems, lower medical costs, less blindness, and so on. The benefits of reducing the risk of truly catastrophic ozone depletion that might occur if we allow emissions to continue can hardly begin to be assessed in any reasonable fashion, for they are truly incalculable. Table 5 shows some measures of the increased benefits of adopting the approach recommended in the Saving-Our-Skins scenario. GLOSSARY OF COMMON TERMS Chlorocarbon: refers to organic chlorinated compounds. Chlorofluorocarbons (CFCs): refers to compounds which contain carbon, chlorine and fluorine, but no hydrogen, and which are regulated by the Montreal Protocol. Abbreviation: CFC This class of compounds is a subset of the fully-halogenated compounds. Column ozone: the total amount of ozone over any point on Earth - that is the total ozone over that point integrated over all altitudes. Fully-halogenated compounds: organic chemicals containing only carbon and the halogens. Global warming: the apparent recent trend of increasing world-surface and tropospheric temperatures, thought to be caused by pollutants, and their "entrapment" of heat. This phenomenon is popularly known as "the greenhouse effect". Greenhouse effect: see "global warming". Halocarbon: an organic chemical containing at least one atom of one of the halogens. This is the most general term used to refer to ozone-depleting halogenated compounds. Halogen: a class of non-metallic elements consisting of the elements Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), and Astatine (At). Hydrocarbon: a large class of organic chemicals made up of carbon atoms linked to hydrogen and, sometimes, oxygen. Hydrocarbons are used for fuel and other economically-important materials. Hydrocarbons can be altered by the addition of other chemicals, such as halogens. Hydrochlorofluorocarbon: An organic compound which contains fluorine and chlorine. It also contains hydrogen and for this reason is degraded to some extent in the troposphere, affecting the ozone layer less on a molecule-for-molecule basis than CFCs. Abbreviation: HCFC. Hydrofluorocarbon: An organic compound which contains fluorine, but no bromine or chlorine. Abbreviation: HFC. Industrial halocarbons: An organic compound containing one of the halogens. This is the broadest definition of this class of compounds. Nanometer (nm). the unit equal to one billionth of a meter, frequently used to measure wavelengths of electromagnetic radiation in the solar spectrum. Not-in-kind technology: Technology which replaces current CFCs-using technology but does not use any industrial halocarbons, including non-ozone depleting ones. On-site generation: Electricity generation at the point of use. This system can be connected to a utility grid. It is also called cogeneration, when the waste heat (see below) is used to make steam. The heat in the Exhaust gases from on-site generation can be used in a variety of ways, including air-conditioning, water heating and space heating. Ozone: a molecule consisting of three bound atoms of oxygen. Its chemical nomenclature is O3. Most oxygen in the atmosphere, O2. consists of only two oxygen atoms. Ozone layer: something of a misnomer, since ozone does not occur in a flat "layer" in the atmosphere. This term refers to ozone in the stratosphere, where it occurs in its highest concentrations - roughly from 1 to 10 parts per million. This atmospheric zone lies between 12 and 50 kilometers above the Earth's surface, depending upon latitude, season, and other factors. Photon: a quantum unit, or "particle," of electromagnetic energy. Polyurethane: a plastic which can be blown into various kinds of commercial foams, rigid and flexible. Sometimes referred to as "PU". Radiation: refers to electromagnetic energy in the context of this study, not to be confused with "radioactivity". Stratosphere: the zone of the atmosphere between about 12 and 50 kilometers above the Earth's surface. Most of the ozone in the atmosphere is in the stratosphere. The stratosphere is separated from the troposphere below by a boundary layer called the tropopause. Troposphere: the part of the atmosphere in which we live, ascending to about 15 km above the Earth's surface. The atmospheric dynamics we know as "weather" take place within the troposphere. Ultraviolet radiation: electromagnetic energy with frequencies higher than visible light or wavelengths shorter than visible light (less than 400 nm). Commonly abbreviated as "UV." Three energy levels of UV are UV-A (320-400 nm), UV-B (290-320 nm) and UV-C (40-290 mn). Waste heat: Hot gases discharged from an internal combustion engine. The heat in these exhaust gases contains a considerable amount of energy which can supply the energy for an absorption air-conditioning system in the summer and for heating in the winter.