Over the next few years, ozone loss is projected to go from to worse
GLOBAL levels ofozone, which shields the
from the Sun's harmful ultraviolet
radiations, have fallen to a record
over the past 2 years. But the worst
R to come, according to the report of
an international scientific panel.
However, a redeeming feature of the
1994 Assessment Panel report, mandated under the 1987 Montreal Protocol on
Substances that Deplete the Ozone
Layer, is that the emissions of chemicals
harmful to ozone have also gone down.
The 'panel was set up under the auspices, of the Geneva-based World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) in Nairobi. It comprised 226 atmospheric science experts, drawn from 29 countries.
The report reveals that the atmospheric growth rates of human-made compounds that deplete the ozone layer, such as chlorofluorocarbons (CFCs), used in refrigeration, and halons, used in fire extinguish ers, have slowed in recent years following reductions in global emissions of these compounds. Says UNEP executive director Elizabeth Dowdeswell, "While the 1994 Assessment Panel report confirms that we are heading in the right direc tion, we cannot afford to be complacent. The line that divides complacency from cata strophe is very thin and now is not the time to break that momentum."
The report lists 4 steps that will steepen the fall from the peak halocarbon levels in the early decades of the next century. reductions in emissions of methyl bromide used as a soil and crop fumigant, reductions in emissions of hydrochlorofluorocarbons, the complete recapture (as opposed to recycling) Of CFcs, and halons banked in existing equipment.
The panel report contends that this record depletion probably owed, at least in part, to chemical processes linked to the 1991 eruption of Mount Pinatubo in the Philippines.
Scientists reckon that peak global ozone depletions would occur around 1998, mainly because of the past emissions. Thereafter, the levels of ozonedepleting chlorine and bromine are expected to slowly decrease and the ozone layer is expected to recover in about 50 years.
Nelson I Sabogal, an officer at, UNEWS Ozone Secretarias Nairobi, says that extrap olation of the rent trends 'suggests that ozone loss relative to the late '60s about 13 per cent at northern mid tudes in winter and spring - abow per cent above the current de levels. And it is estimated that im southern latitudes the ozone loss 11 per cent of the level in the late '60s.
According to UNEP, large inc uv radiation on the earth's surface been observej in the Antarctic and southern part of South America spring and winter, when the ozone is observed. Further, elevated Liat the mid to high latitudes observed in the northern hemi 1992 and 1993, corresponding low ozone levels in those yeam increase in ov radiation, experts could lead to an increase in skin cases and cataracts, especialiv people residing in the mid-latitudes.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.