The Chlorofluorocarbon Problem

Chlorofluorocarbons are a series of chemical compounds containing chlorine, fluorine, and sometimes hydrogen directly bonded to carbon; hence the name Chloro-fluoro-carbon, abbreviated CFC.

CFC compounds were developed by DuPont research chemists a half-century ago to meet the needs of the refrigeration industry, and in this they have performed admirably. CFCs are nontoxic, nonflammable, and have optimum thermodynamic properties—boiling point, freezing point, and heat of evaporation—for all types of mechanical refrigerators. They also are very stable and inert toward the metallic components of the refrigeration system. Despite the passage of time, CFCs still are the best fluids for all refrigeration uses, including the direct-immersion fast-freeze food industry. All substitutes require compromise of some performance characteristics.

Chemists later discovered that CFCs are very good solvents and that mixtures of CFCs make ideal aerosol propellants for hundreds of household and commercial substances. These uses range all the way from hair sprays and pesticides to making polyurethane foams and degreasing parts for heavy machinery. Cans filled with CFCs even power fog horns for small boats. The demand for CFCs for these nonrefrigeration uses—sometimes referred to as "nonessential" uses—eventually far exceeded the capacity of plants built for the refrigeration industry. New plants were constructed in most of the developed countries of the world and in some emerging nations, and production soared. In 1975 1.5 billion pounds of CFCs were released into the atmosphere; only 19 percent of this was from refrigeration systems. Since CFC releases are estimated to double about every five to seven years, the present (1982) release is about 3 billion pounds.

CFCs and ozone

The very desirable property of inertness that makes CFCs so useful means that the huge outpourings of CFCs accumulate in the lower atmosphere, known as the troposphere: nearly 90 percent of all the CFCs released from 1955 to 1975 are estimated to be still present in the troposphere.

But a very small portion diffuses into the upper atmosphere—the stratosphere—where eventually the CFCs play havoc with stratospheric ozone (03), a high-energy form of oxygen. In brief outline, the CFC molecules are exposed to intense, shortwave length ultraviolet radiation from the sun and are decomposed, releasing the chlorine atoms. These atoms enter into a regenerative cycle whereby one chlorine atom destroys thousands of ozone molecules before the cycle is interrupted by a side reaction that binds the chlorine atom to a hydrogen atom. This forms the very water-soluble hydrogen chloride molecule that eventually is rained out.

Ozone also is destroyed by other regenerative cycles involving oxides of nitrogen, hydrogen, and bromine. However, most observers believe that the chlorine cycle will be dominant in the future.

If CFC releases continue to rise as in the past decade, stratospheric ozone may be reduced by about one-quarter by the year 2025 and perhaps by as much as 57 percent (at steady state) about one hundred years from now. Even at the 1975 release rate—considerably lower than the present rate—ozone reductions of 11 to 16 percent are predicted, at steady state. What are the consequences of these ozone reductions?

Ozone absorbs solar radiation in the ultraviolet, visible, and infrared regions of the spectrum, to varying degrees, with absorption in the ultraviolet range being the most important to society. According to scientific consensus, a 1 percent de-crease in stratospheric ozone is accompanied by a 2 percent increase in biologically damaging ultraviolet radiation, generally designated as DUV, and a 1 percent increase in DUV produces a 2 percent increase in skin cancer incidence. Thus, a 1 percent decrease in ozone results in a 4 percent increase in skin cancers. Accordingly, the 11 to 16 percent ozone reduction corresponds to a 44 to 64 percent increase in the incidence of skin cancer—about 162,000 additional cases per year in the United States. Most of these will be of the relatively less dangerous nonfatal variety, but some 5,770 probably will be melanotic and result in 1,890 deaths within five years. Again, these skin cancers and deaths are in addition to the current annual U.S. incidence of 300,000 skin cancers, including 10,500 melanomas and 3,500 deaths.

Exploratory studies also indicate adverse impacts on human and animal immune systems and on agriculturally important crops, forest tree seedlings, and commercial fisheries.

The greenhouse effect

But biologically damaging ultraviolet radiation is only part of the problem posed by CFCs. Even wider in scope is their contribution to the potential warming of the planet—the so-called greenhouse effect prominently associated with atmospheric accumulations of carbon dioxide (CO2).

CFCs contribute to temperature change in two ways. The first is through stratospheric ozone reduction, but the computed effects in this case are small and somewhat uncertain. The second is the role played by CFC compounds in the troposphere, which is much larger than the stratospheric effect and indeed may dwarf that attributed to CO,. CFCs appear to be almost 100,000 times as effective as CO, in raising the temperature of the earth's surface due to the greenhouse effect. Hence, as the concentration of CFCs in the troposphere rises, the CFC contribution to the greenhouse effect could outstrip that due to CO2 and may do so in the not too distant future, if CFC releases are not curbed. As the contributions of both CFCs and CO, are rising, serious geologic and sociopolitical problems could loom ahead, including changes In national and worldwide agricultural patterns and rising sea levels that theoretically could swamp major coastal cities.

The most recent studies conducted under the auspices of the National Academy of Sciences indicate that ozone reductions may be one-half the amounts predicted in a 1979 National Academy report—the 11 to 16 percent reduction cited above. But biological effects of given levels of ozone depletion now are seen as likely to be more severe than previously expected, as regards both the incidence of skin cancer and negative impacts on human and animal immune systems. Hence, though considerable uncertainty still pervades the issue, the effects of ozone reduction could be quite serious and surely should not be Ignored. Moreover, even if the 11 to 16 Percent reduction in ozone is scaled back to 5 to 8 percent, the effects are not halved forever, but only postponed by a time factor of two. Eventually—if no corrective measures are taken now—the problems and damages will occur.

What can be done?

Neither precipitous nor wide-ranging action probably is appropriate given the broad uncertainty of the CFC-ozone set problems and the high costs of imposing additional limits on CFC use. Also, much valuable information can be gained by letting current emissions levels continue at least to the point where definite physical links can be established among CFCs, ozone damage, and changes in climate.

But the cost of doing business as usual rises sharply if inaction begins to lead near irreversible catastrophe. Where does that point begin, and how can we anticipate it in time to pull back effectively? No one knows. Clearly, more research is needed on this key issue and on the other pieces that now is mostly a puzzle. To err on side of prudence, however, should not some action be taken now?

The United States, of course, already has taken an important step that has slowed the rate of increase in CFC emissions: a federal ban on CFC aerosol propellants spray cans was announced in 1977 and became fully effective two years later. But the emissions are a global, not a national problem—no national frontiers exist in the stratosphere—and few countries have followed the U.S. initiative. Moreover, as the affluent nation that invented CFCs and introduced their use on a broad scale, the United States is not in a strong position to urge other nations—some of them much poorer—to cut back on, say, refrigeration or air conditioning.

The options include further unilateral U.S. controls over domestic CFC production and use (although this may boomerang: U.S. production facilities may simply relocate in other countries). And the United States could affect other producing nations through a variety of import and export controls. Or U.S. foreign assistance could be denied to projects to develop CFC production facilities or that otherwise involve major use of CFCs.

Multilateral action needed

Even leaving aside high dollar and diplomatic costs, however, unilateral U.S. actions can make only a partial (if large) difference to stratospheric levels of CFC compounds. Thus, most observers agree that the problem CFCs pose can best be dealt with multilaterally.

At least at the start, this does not mean involving all nations emitting CFCs or potentially affected by them. Since a dozen countries account for 80 percent of CFC production, an agreement on limitations among this group would go a long way toward solving the problem. Principles that might help to foster an agreement would include Principle 21 of the Declaration of the United States Conference on the Human Environment: "States have . . . the responsibility to ensure that activities within their jurisdiction or control do not cause damage to the environment of other states or of areas beyond the limits of national jurisdiction," and the Organisation for Economic Co-operation and Development's principles of conduct in trans-frontier pollution that call for "good neighborship."

In due course, a treaty or agreement among the major CFC-producing and -consuming nations that prohibits or restricts CFC emissions could emerge. Legal precedents and bilateral or multilateral agreements do exist regarding environmental damages that range across national boundaries (for example, the Great Lakes Water Quality Agreement, the Convention on Third Party Liability in the Field of Nuclear Energy, the Convention on Civil Liability for Oil Pollution Damage, and the Scandinavian Convention on the Protection of the Environment). The history of diplomacy indicates, however, how difficult it is even to achieve agreement, let alone effective multinational programs. Precedents for managing the stratosphere by an international agency are not encouraging.

Given the pessimistic outlook for a multilateral agreement and the fact that the United States appears to be more risk averse in CFC emissions management than other nations, the United States may find it useful or necessary to "bribe" or compensate "holdout" nations to achieve CFC emissions reductions overseas. The victim-must-pay principle naturally strikes most people as unjust, but unilateral CFC regulation by the United States may change the structure of incentives for other nations. Hence, side payments in exchange for emissions reductions may leave both the United States and other nations better off.

U.S. leadership

But the United States is the major user of CFCs, accounting for about half the world's total consumption, though its share recently has been declining. If further research and information-gathering narrow the broad uncertainties that now characterize the CFC problem, and the benefits of unilateral action are deemed to outweigh the costs, the United States could substantially reduce the global risk and serve as a moral example. Morality does not equal efficacy in global affairs, but further U.S. self-deprivation coupled with a range of incentives to reduce CFC emissions might persuade other nations to follow the U.S. lead.

But the problem clearly is international, and the United States should seek ways, beyond example, of persuading other countries to act together in the interests of the world as a whole. If the United States feels strongly that procrastination cannot be permitted in ozone layer and climate protection and finds multilateral efforts to be unsuccessful or bogged down in interminable delay, it could turn to unilateral measures aimed at reducing CFC emissions overseas. As suggested, such tools are likely to be highly controversial and unpopular, both at home and abroad. Some even could strain relations with other nations and induce retaliatory actions against the United States.

But if the case against CFCs becomes strong enough, such costs will have to be borne.