The Chemistry of Atmospheric policy

The atmosphere is an ocean of air and a precious natural resource for sustaining life on earth. Unfortunately, human activities based on national/personal interests are causing harm to this common resource notably by depleting the fragile ozone layer, which acts as a protective shield for life on earth. The activities responsible for this damage may meet the developmental needs of the present generation, but as they compromise the ability of future generations to meet their developmental needs they will not sustain development in the long term.

Ozone molecules consist of three oxygen atoms as against oxygen molecules which consist of two oxygen atoms. Ozone molecules are exceedingly rare: fewer than ten in every million molecules of air. However, for nearly a billion years, their presence in the atmosphere has played a vital role in safeguarding life on earth. Depending on where it is located, ozone can either protect or harm life on earth. The ozone in the troposphere (up to 10 kilometers above the earth's surface) is "bad" ozone which can damage lung tissues and plants. But about 90 percent of ozone found in the stratosphere (between 10 and 40 kilometers above the earth's surface) is "good" ozone which plays a beneficial role by absorbing dangerous ultra-violet (UV-B) radiation from the sun. [Fig.1]

Without this beneficial ozone layer, humans would be more susceptible to skin cancer, cataracts and an impaired immune system due to the incidence of ultra-violet rays from the sun. Depletion of the ozone layer could also break up the marine food-chain and adversely affect agricultural productivity due to harmful effect of UV-B rays on plankton and crops. Ultra-violet rays also cause degradation of materials like plastics.

In 1974 it was hypothesized that chlorofluorocarbons (CFCs), due to their stable character, could drift up into the stratosphere where, when bombarded by the sun's high-energy UV radiation, they would release highly reactive chlorine atoms. These chlorine atoms would destroy ozone (each chlorine atom would destroy nearly 100,000 ozone molecules) that would disturb the natural balance of ozone. This meant that continued use of CFCs could cause substantial declines in the concentration of stratospheric ozone. [Fig. 2A]

Invented in the early 1930s, CFCs were "miracle" chemicals They were nontoxic, inflammable and very convenient to handle in industry and at home. Their use was considered irreplaceable in the field of refrigeration and air conditioning Many of the applications using CFCs were of enormous relevance to society: in food preservation, in the manufacture of life saving medicines, in the storage of vaccines. The list was long and crucial. Halons, another group of chemicals which are also ozone depleters, were "magic" fire extinguishants where no other substances could be employed IFig. 2B]

In 1975, UNEP launched a research programme on the risks involved due to depletion of the ozone layer, set up a coordination committee and initiated the World Plan of Action in 1977. However, evidence of ozone depletion was lacking. Scientific assessment of the cause-effect relations was not convincing enough to implicate CFCs.

Nonetheless, Government policy-makers moved forward according to the assessment made available to them by scientists and supported the adoption of the Vienna Convention in March 1985, the first international treaty based on risk management.

In September 1987, diplomats from around the world met in Montreal and forged a treaty unprecedented in the history of international negotiations. Environmental ministers from 24 nations, representing most of the industrialized world, agreed to set sharp limits on the use of CFCs and halons. Scientific uncertainties were not to be the excuse for inaction.

The Montreal Protocol is a telling example of science in the service of humankind. It has taught invaluable lessons about addressing environmental problems. It is like an apprenticeship for world leaders and scientists who now face an even more daunting environmental threat: global warming through greenhouse gases.

The "Chemistry of Atmospheric Policy" has revealed new ways of viewing environmental problems. They can be summed up as:

1. Residual scientific uncertainties must not inhibit policy-making if the possible consequences of inaction would be disastrous.

2. Policy action cannot wait for evidence of environmental damage as prudent, precautionary policies can avoid costly consequences.

3. Regular global assessment of science and technology development as well as environmental impacts could lead policy-makers to take informed decisions concerning amendments and adjustments to their original, negotiated agreements.

4. Developing countries need to be involved in the cooperative efforts to protect the global environment. They would need financial and technical assistance so as not to impede the developmental process to alleviate poverty and at the same time to nuture their fragile economies with equal vigor as the protection of the environment.