The total combined abundance of ozone depleting substances (ODS) in the lower atmosphere peaked in about 1994 and is now slowly declining. While total chlorine is declining, total bromine is still increasing, as is the abundance of CFC substitutes. If reductions in the use of ODS continue as envisaged in the [Montreal Protocol], then concentrations of these substances in the stratosphere should have peaked between 1997 and 1999, and should begin to decline during the next century. The rate of decline in stratospheric ozone levels at mid-latitudes has already started to slow. The unusually low ozone values above the Arctic in late winter/spring observed in six out of the past nine years could have been accentuated by the unusually cold and prolonged stratospheric winters experienced during those six years.
CFC production in developing countries, notably Brazil, China, India, Republic of Korea, Mexico and Venezuela, more than doubled between 1986 and 1996, while consumption rose by some 10 per cent. Because production levels in the years 1995-97 will be used as base levels to determine the timing of phase out in developing countries, scheduled to begin in mid-1999 with elimination due by 2010, the current high production will inflate the allowed levels of production for years to come. The Russian Federation will not eliminate its production of CFCs before the year 2000, and some of the European transition economies are experiencing economic and technical difficulties with CFC substitution.
This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities.
The [Montreal Protocol] was developed in 1987 and is tied to the Vienna Convention on the Protection of the Ozone Layer. The signatories to the Protocol agreed to a plan to reduce the use of Chlorofluorocarbons (CFCs) by 50 percent by the year 2000. Additionally, they agreed to freeze future halon use at or below the 1987 consumption levels. In 1992, the Protocol was re-negotiated, and the signatories agreed to more ambitious goals for the phase-out plan of CFCs and halons. In addition, they agreed to establish phase-out dates for 1,1,1 trichloroethane and carbon tetrachloride. A fund was established to co-finance the phase-out in developing countries and these countries were also granted additional time to achieve the phase-out.
The Parties to the [Montreal Protocol], who met in Beijing, China, from 29 November to 3 December 1999, agreed to freeze the production of HCFCs (Hydrochlorofluorocarbons) for developed countries in 2004 and developing countries in 2016. HCFCs are widely used in refrigeration and foam blowing operations, but European industries have taken a lead in adopting alternatives for these ozone-damaging compounds. Trade controls agreed at the meeting will bring further benefits as they will encourage all parties to sign onto previous Protocol agreements.
Under the [Montreal Protocol], an international agreement to reduce ozone-dangerous chemicals, patched together in record time and signed by more than 100 countries, industrialized countries promised to phase out ozone-destroying chlorofluorocarbons (CFCs) between 1997 and 2000, and developing countries planned to do so by 2010.
Major reductions in the production, consumption and release of ozone-depleting substances (ODS) have been, and continue to be, achieved by the [Montreal Protocol] and its related amendments. The abundance of ODS in the lower atmosphere peaked in about 1994 and is now slowly declining. This is expected to bring about a recovery of the ozone layer to pre-1980 levels by around 2050.
The Multilateral Fund and the Global Environment Facility are helping developing countries and countries in transition to phase out ODS. Since 1 July 1999, these countries have, for the first time, had to start meeting obligations under the Montreal Protocol.
Global consumption of chlorofluorocarbons (CFCs), the most prevalent ozone-depleting substances (ODS), fell from 1.1 million tonnes in 1986 to 160 000 tonnes in 1996, thanks to an almost complete phase out by industrialized countries. Several factors contributed to the success of policies directed at reducing the consumption of ODS: damage to the ozone layer could be ascribed to a single group of substances, alternative substances and processes were developed at acceptable costs, a scientific assessment was introduced to make adjustments to the [Montreal Protocol] as required, the Protocol contained flexible implementation schemes and evaluation procedures, and the principle of 'common but differentiated' responsibilities was recognized for the developed and developing countries.
In September 1994, the International Trade Commission reported a reduction in the USA CFC-12 output by 50% from 1993 to 1994 (50,000 tonnes for the first six months of 1993 compared to 26,000 tonnes for the same period of 1994.