It is difficult to determine useful explanations for the disparity in the responses to ozone depletion and global climate change.  Several explanations are plausible and there is certainly more than a single cause for the differing treatments.  The explanations yield differing amounts of utility in encouraging a successful response to global warming.

One of the most probable explanations for the disparity is the inherent nature of the problems.  The threat of large-scale ozone depletion is the result of ‘exotic’ man-made molecules.  The chemistry involved in the ozone depletion is complex but accurate basics are easily understood.  The science behind ozone depletion and its effect is also generally well accepted.  The expected result of unabated production of ozone depleting substances is also easy to understand and easy to fear: increased ultraviolet radiation resulting in increased occurrence of skin cancer and possible severe disruption of eco-systems and the food chain.  These ramifications of ozone depletion are underscored by the fact that life did not occur on land until the ozone layer was formed.

In contrast to the well-accepted and easily understood basis of ozone depletion, the science of climate change is often ridiculed as unreliable or inaccurate.  Additionally, the substance often credited as the main cause of the enhanced greenhouse effect, carbon dioxide, is a natural product expelled by animals through respiration and is necessary for plant life to grow.  Severe climate change (glacial periods) has occurred during the existence of man.  The predicted result of a continued increase of carbon dioxide concentrations, a 1-3.5ºC increase in the global average surface temperature, is more difficult to internalize and fear than the results of ozone depletion.

Another rationale for the success of the global response to ozone depletion can be attributed to the history and timing of events surrounding ozone depletion.  The fear of ozone depletion resulting from a proposed fleet of U.S. supersonic transports (SST’s) allowed environmentalists to successfully block their implementation in the 1970’s.[i] After the concept of ozone depletion was used in blocking the SST’s it was a small step to ban the use of CFC’s in aerosol spray cans.  The rapid assessment and response to the use of CFC’s would not have been as swift if scientist and policymakers were not already familiar with stratospheric ozone.[ii]  The CFC aerosol ban took effect in December 1978; although the U.S. was not the only country to implement this ban, it was the only major producer of CFC’s to do so.[iii]

The United States continued in its efforts to curtail CFC usage.  The U.S. was one of the main proponents of what was to become the provisions of the Montreal Protocol.  The EEC countries and Japan feared that the U.S. might take unilateral action and impose trade sanctions if there was no international agreement.[iv] 

A fear of economic hardship is not as readily applicable to global warming.  The coupled nature of energy consumption and the economy growth creates trepidation in many nations.  In addition to this concern of stagnating or destroying economies, global warming does not enjoy the same pedigree of successful regulation, as did ozone depletion.  In fact, it was barely twenty years ago that U.S. Congressional Hearings were held on climate change.  Congress, at the behest of the scientific community, was primarily concerned with implications of a global cooling.  This switch in belief does not facilitate a strong legislative encouragement for reductions in greenhouse emissions, especially in light of the perceived economic ramifications of reductions.

The most cynical explanation for the inconsistency in treatment of these global threats would attribute the difference to self-preservation.  The developed countries, the main source of the basis of the threats, are more susceptible to effects of ozone depletion than developing countries, while the developing countries are more prone to global warming effects than developed countries.  Although it is true that (almost) no one would survive if the ozone layer was destroyed, the developed countries would be placed in higher risk if the ozone layer was significantly reduce.  Generalizing, the developed countries are located closer to the poles, where the ozone depletion is the more dramatic and the developed countries inhabitants are lighter-skinned than those in developing countries.  The lower concentration of melanin greatly increases the risk of developing a melanoma from increased exposure to ultraviolet radiation.[v]    

            In contrast to this lowered sensitivity for ozone depletion, developing nations are more vulnerable to the likely effects of global warming.  Many developing countries are low-lying and are therefore more susceptible to coastal flooding from a sea-level rise; additionally these developing countries would have difficulty marshalling the resources to prevent the inundation of seawater.  Developing countries would likely be more prone to the predicted increases of diseases and less able change agricultural practices to compensate for the higher temperatures.  Developed nations would be subjected to many of these effects, but they have greater access to technology and resources to counteract the effects of global warming.    


In order to facilitate a successful global response to climate change a few lessons can be learned from the preceding explanations.  Targeting specific areas of greenhouse emissions for reduction could allow for a gradual acceptance of the viability of further reductions.  Increase the scientific effort in order to produce more accurate predictions, thereby fostering more confidence in the underlying science.  The most important step would be to construct provisions outlining the participation of developing countries in reduction programs; this would be in the developing country’s interest and would mitigate fears of economic disruptions.    


[i] Morrisette, Natural Resources Journal, 29: 793-820 (1989).

[ii] Bastian, The Formulation of Federal Policy, in 2 Stratospheric Ozone and Man, 166 (1981).

[iii] Morrisette.

[iv] Id.