Ozone Depletion Crisis Not Yet Over

NEW DELHI, India, October 27, 2006 (ENS) - The Montreal Protocol, signed almost 20 years ago to curb ozone depleting chemicals, has been successful but that does not mean the Earth's ozone layer is safe yet, according to the organizers of an international conference beginning in New Delhi next week.

Hosted by the United Nations Environment Programme, UNEP, the New Delhi meeting will attempt to set out a 10 year road map for governments to follow in protecting the ozone layer.

"The phaseout of harmful chemicals agreed under the Montreal Protocol has progressed so successfully that the sources of greatest concern 20 years ago will soon be virtually eliminated if the parties continue to comply fully with the Protocol," said UNEP Executive Director Achim Steiner.

"But this does not mean that the ozone crisis is over," said Steiner. "This year's Antarctic ozone hole was the largest on record, while several key CFC replacements are contributing to global warming."

The protective ozone layer over Antarctica annually undergoes a seasonal change, but since the first satellite measurements in 1979, the ozone hole has gotten larger.

This image, from September 24, 2006 shows that the Antarctic ozone hole was equal to the record single-day largest area of 11.4 million square miles, reached on September 9, 2000. (Image courtesy NASA)

Chlorine and bromine chemicals produced by humans destroy ozone in the stratosphere. Scientists estimate that these gases reached peak levels in the Antarctica stratosphere in 2001, but ozone-depleting substances remain in the atmosphere for more than 40 years.

CFCs, or chlorofluorocarbons, once commonly used in refrigeration and air conditioning, foam blowing, and industrial cleaning, were found to be depleting the ozone layer. The Montreal Protocol requires the phaseout of CFCs, and other ozone-depleting compounds such as halons, carbon tetrachloride, and methyl chloroform.

Ozone is a gas naturally present in Earth's atmosphere. Most of it is in the stratosphere, about 10 kilometers (six miles) above Earth's surface. There, about 90 percent of atmospheric ozone is contained in the ozone layer, which shields the planet from the Sun's harmful ultraviolet radiation.

As the ozone layer diminishes, ultraviolet radiation at Earth's surface can increase the incidences of skin cancer, eye cataracts, genetic damage, and crop damage.

Solar UVB radiation has been found to cause damage to early developmental stages of fish, shrimp, crab, amphibians and other animals. The most severe effects are decreased reproductive capacity and impaired larval development.

This red alder leaf shows a typical symptom of overexposure to ozone - discoloration of small groups of cells between the veins, appearing as uniformly sized red to brown or purple spots. (Photo by Pat Temple courtesy U.S. Forest Service)

To tackle the ozone issue, governments created the 1987 United Nations Montreal Protocol. Now ratified by more than 180 countries, the protocol establishes legally binding controls on the national production and consumption of ozone depleting gases.

Almost two decades later, the total abundance of ozone depleting gases in the atmosphere has begun to decrease. UN and World Meteorological Organization scientists predict that by 2065, the abundance of ozone depleting gases should fall to levels present before the Antarctic ozone hole began to form in the early 1980s.

But that decrease will occurr only if governments continue to adhere to the Montreal Protocol, which is why meetings like the October 30 to November 3 session in New Delhi are important, said Steiner.

"Governments need to reduce and shut down the remaining sources of ozone-depleting chemicals and ensure the safe disposal of stocks contained in building foams and in refrigeration and other equipment," said Steiner.

UNEP Executive Director Achim Steiner took the helm March 31 after serving as head of the IUCN-World Conservation Union. (Photo credit unknown)

Delegates to next week's meeting are scheduled to discuss requests from developed countries for continued exemptions from the Protocol - in particular, requests to continue using methyl bromide, a fumigant for soils and crops, beyond the 2005 phaseout date. The deadline for developing countries is 2015.

Recommended exemptions total 9,000 metric tonnes for 2007 and around 5,000 tonnes for 2008, down from the 16,050 tonnes agreed earlier for 2005 and the 13,418 tonnes agreed for 2006. The issue of how existing stockpiles of methyl bromide should be treated will also be discussed

The meeting will tackle requests from the United States and the European Union for the continued use of chlorofluorocarbons for asthma inhalers in 2007 and 2008.

According to data collected by UNEP's Ozone Secretariat, from 1986 to 1994 developed countries reduced their use of chlorofluorocarbons by 98 percent. Developing countries are expected to achieve a 97 percent phaseout within a few years.

But this scenario assumes full compliance with all provisions of the Protocol. The New Delhi meeting will consider how to ensure compliance through possible additional measures, including measures to address illegal trade in the ozone-depleting gases.

A BBC report in 2004 revealed how a black market for CFCs had sprung up in some Asian countries, particularly Pakistan and Afghanistan.