2002 Findings of Assessment Panel - Public Information

Scientific Findings
Even with full compliance of the Montreal Protocol by all Parties, the ozone layer will remain particularly vulnerable during the next decade or so.

The total combined effective abundance of ozone-depleting compounds in the lower atmosphere continues to decline slowly from the peak that occurred in 1992-1994. Total chlorine is declining, while bromine from industrial halons is still increasing, albeit at a slower rate than was occurring previously. The abundances of HCFCs in the lower atmosphere are increasing.

Observations in the stratosphere indicate that the total chlorine abundance is at or near a peak, while bromine abundances are probably still increasing.

Springtime Antarctic ozone depletion due to halogens has been large throughout the last decade. In some recent cold Arctic winters during the last decade, maximum total column ozone losses due to halogens have reached 30%. Ozone remains depleted in the midlatitudes of both hemispheres.

The global ozone layer recovery has been linked mainly to decreasing chlorine and bromine loading. A return to pre-1980 total column ozone amounts in the Antarctic is expected by the middle of this century. Although Arctic ozone depletion is difficult to predict, a future Arctic polar ozone hole similar to that of the Antarctic appears unlikely.

Very short-lived organic chlorine-, bromine-, and iodine-containing gases have the potential to deplete stratospheric ozone. Quantitative estimation of their ozone depleting potentials is challenging but they could vary up to 0.1. The impact of very short-lived compounds can be significant if their emissions are large.

Other factors such as climate change and changes in atmospheric transport are likely to influence the recovery of the ozone layer. New research has begun to explore the coupling between climate change and the recovery of the ozone layer.

Environmental Effects
New studies continue to confirm the adverse effects of UV-B radiation on the eyes, skin, and immune system, including cortical cataract and skin cancer.

Phase-out of the ozone-depleting chemical, methyl bromide, may lead to increased use and numbers of other pesticides which may lead to additional health risks.

Interactions between global climate change and ozone depletion are likely to influence the risk of adverse effects of UV-B radiation on health.

Interaction of ultraviolet radiation with other global climate change factors may affect many ecosystem processes such as plant biomass production, plant consumption by herbivores including insects, disease incidence of plants and animals, and changes in species abundance and composition.

Recent results continue to confirm the general consensus that solar UV negatively affects aquatic organisms (zooplankton, as well as larval stages of primary and secondary consumers).

In addition to increasing solar UV-B radiation, aquatic ecosystems are confronted with other environmental stress factors including increased nutrient input, pollution, acidification and global climate change.

Global warming and enhanced UV-B radiation interact to affect a range of biogeochemical processes including microbial activity, nutrient cycling, and greenhouse gas emissions from soils.

Interactions between ozone depletion and climate change will have an impact on tropospheric hydroxyl (OH) radical concentration, the “cleaning” agent of the troposphere.

Climate change is likely to modify the rates of UV-induced degradation of natural and synthetic materials.

Technological & Economic Findings
The remaining 7,000 ODP tonnes of CFCs used annually in MDIs for asthma/COPD can be phased out. The timing is difficult to predict, but it depends on the availability of affordable alternatives and the adoption and effectiveness of transition strategies by Parties.

In the last four years there has been a substantial phase-out of CFCs in non-MDI aerosols and a complete phase-out for non-MDI aerosols is achievable. There are difficulties including the availability of hydrocarbon aerosol propellants, the conversion of small CFC users, and also the conversion of non-MDI pharmaceutical aerosols.

Most miscellaneous uses have been phased out, whilst some laboratory uses still remain under a global exemption.

The use of CFCs in foams has been reduced by over 90% since its peak in 1988 and HCFC use is also in decline from its peak in 2000. The phase-out of ODS in the foam sector has forced the industry to innovate faster than ever before. The first transition technology led to the introduction of substances such as HCFCs as well as the increasing use of hydrocarbons and other non-ODSs. Attention is now on the emerging HFC-based technologies as well as the further optimisation and use of hydrocarbon and CO2 technologies.

Halon fire extinguishants are no longer necessary in virtually any new installations, with the possible exceptions of engine nacelles and cargo compartments on commercial aircraft and crew compartments of combat vehicles. The very high cost of replacing many existing halon systems with substitutes, replacements or other alternative fire protection measures continues to be a major impediment to eliminating continued use of halons.

Production of methyl bromide (MB) for controlled uses was reported to be about 62,000 metric tonnes in 1998; it was reduced to at least 49,000 tonnes in 1999 and at least 46,000 tonnes in 2000. The decline in total global consumption of MB is attributed largely to reductions for soil fumigation. No existing technical alternatives for about 3,200 metric tonnes of MB per annum used for non-QPS treatments could be found yet.

With two exceptions (control of ginseng root rot and stabilisation of high-moisture fresh dates), the completed demonstration projects identified one or more alternatives comparable to MB in their effectiveness in the control of targeted pests and diseases and demonstrated that a similar range of alternatives to those in developed countries can be successfully adopted.

In the last decade, the refrigeration, air conditioning and heat pump industry made tremendous technical progress in phasing out CFCs and, in several applications, HCFCs as well. The mobile air conditioning and the domestic refrigeration industries have shifted rapidly from CFC-12 to non-ODS refrigerants. Other applications, such as chillers and commercial refrigeration, have shifted from CFCs to HCFCs, HFCs or other fluids. Worldwide, a significant amount of installed refrigeration equipment still uses CFCs and HCFCs. As a consequence, service demand for CFCs and HCFCs remains high.

There is much left to be achieved in the Solvents Sector. Effort is still required to phase out ODS solvents in developing countries, and especially the small- and medium-sized users. In particular, there is concern about the use of carbon tetrachloride (CTC) for solvent applications by both large and small enterprises in some countries.