Montreal Protocol
From Freepedia
The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer from depletion by phasing out the production of a number of substances believed to be responsible for ozone depletion.
Image:Ozone cfc trends.png The treaty was opened for signature on September 16, 1987 and entered into force on January 1, 1989. Since then, it has undergone five revisions, in 1990 (London), 1992 (Copenhagen), 1995 (Vienna), 1997 (Montreal), and 1999 (Beijing). Due to its widespread adoption and adherence it has been hailed as an example of exceptional international cooperation with Kofi Annan quoted as saying it is "Perhaps the single most successful international agreement to date...".
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Terms and purpose
The treaty is structured around several groups of halogenated hydrocarbons that have been implicated to play a role in ozone depletion. For each group, the treaty provides a timetable on which the production of those substances must be phased out and eventually eliminated.
The stated purpose of the treaty is that the signatory states:
- ...Recognizing that world-wide emissions of certain substances can significantly deplete and otherwise modify the ozone layer in a manner that is likely to result in adverse effects on human health and the environment, ... Determined to protect the ozone layer by taking precautionary measures to control equitably total global emissions of substances that deplete it, with the ultimate objective of their elimination on the basis of developments in scientific knowledge ... Acknowledging that special provision is required to meet the needs of developing countries...
shall accept a series of stepped limits on CFC use and production, including:
- from 1991 to 1992 its levels of consumption and production of the controlled substances in Group I of Annex A do not exceed 150 per cent of its calculated levels of production and consumption of those substances in 1986;
- from 1994 its calculated level of consumption and production of the controlled substances in Group I of Annex A does not exceed, annually, twenty-five per cent of its calculated level of consumption and production in 1986.
- from 1996 its calculated level of consumption and production of the controlled substances in Group I of Annex A does not exceed zero.
There is a slower phase-out (to zero by 2010) of other substances (halon 1211, 1301, 2402; cfc's 13, 111, 112, etc) and some chemicals get individual attention (Carbon tetrachloride; 1,1,1-trichloroethane).
There are some exceptions for essential use. The full terms are available from [1].
The substances in Group I of Annex A are:
Science
In 1973 Chemists Sherwood Rowland and Mario Molina, at the University of California-Irvine, began studying the impacts of CFCs in the earth's atmosphere. They discovered that CFC molecules were stable enough to remain in the atmosphere until they got up into the middle of the stratosphere where they would finally (after an average of 50-100 years for two common CFCs) be broken down by ultraviolet radiation releasing a chlorine atom. Rowland and Molina then observered, based upon work by Paul J. Crutzen and Harold Johnson, that small amounts of the chlorine atom might be expected to breakdown large numbers of ozone (O3) in the statosphere. Two other chemists, Ralph Cicerone and Richard Stolarski came to the same conclusion at the same time. Crutzen, Molina and Rowland were awarded the 1995 Nobel Prize for Chemistry for their work on this problem.
The environmental consequences of this discovery was that stratospheric ozone reduced the amount of ultraviolet-B (UV-B) radiation reaching the surface of the planet. Thus CFC led to reduction in stratospheric ozone, which led in increased in UV-B radiation at the surface of the earth would result in increasing skin cancers and other impacts.
After publishing their privotal paper in early 1974, Rowland and Molina went public with the implications and the first hearin before the U.S. House of Representatives in December, 1974. As a result significant funding was made available to study various aspects of the problem and to confirm the initial findings.
In 1976 the U.S. National Academy of Sciences (NAS) confirmed the validity of the work done. NAS also carried reviews and assessments of related science for the next decade.
The provisions of the Protocol include the requirement that the Parties to the Protocol base their future decisions on the current scientific, environmental, technical, and economic information that is assessed through panels drawn from the worldwide expert communities. To provide that input to the decision-making process, advances in understanding on these topics were assessed in 1989, 1991, 1994, 1998 and 2002 in a series of reports entitled Scientific assessment of ozone depletion.
Parties
At present, 189 nations have become party to the Montreal Protocol (see external link below). Those 6 that are not as of March 2005 are Andorra, Equatorial Guinea, Iraq, San Marino, Timor Leste, & Vatican City (Holy See).
References
Some information in this article has been taken from the CIA World Factbook, 2003 edition. (referred to as Ozone Layer Protection)
It is not to be confused with the Montreal Convention governing compensation for air disasters.
External links
- The Parties involved
- The Montreal Protocol
- THE CFC-OZONE PUZZLE:Environmental Science in the Global Arena by F.Sherwood Rowland and Mario J.Molina
