Major Set-Back To Ozone Layer Recovery

March 04, 1999

Recovery of the ozone layer is likely to take years longer than expected, CSIRO scientists warn. Latest research shows that global emissions of a key ozone-depleting halon are 50 per cent greater than previously supposed, says Dr Paul Fraser of CSIRO Atmospheric Research.

Emissions of halon-1211, a fire retardant, are increasing at the rate of approximately 200 tonnes per year, based on measurements in the atmosphere made in Tasmania.

Until now, Montreal Protocol calculations assumed that halon-1211 had peaked in 1988. In fact, emissions have since risen by about 25 per cent. Halon-1211 is one of the three ozone-destroying halons that the Protocol seeks to control. Current emissions make it the most damaging of the halons.

The finding on halon-1211 has been made by Dr Paul Fraser from CSIRO Atmospheric Research and UK colleagues. The team measured the halon levels in CSIRO's unique archive of pristine air collected at the Cape Grim baseline air pollution station in north-western Tasmania.

"Halons are now responsible for about 20 per cent of global ozone destruction. The continued growth of halon-1211 could be due to increased legal manufacture and release in China," says Dr Fraser.

China is responsible for about 90 per cent of the world's production of halon-1211. Under the Montreal Protocol, designed to protect the ozone layer, developing countries such as China have until the year 2010 before they must completely phase out halon production.

"I anticipate that China will begin reducing halon production soon," says Dr Fraser. "Montreal Protocol calculations based on production data indicate that halon levels in the air will stabilise during the next few years. Unfortunately, growth of halon-1211 is likely to delay this stabilisation by years."

While concentrations of most of the ozone-damaging CFCs are either steady or falling, halon levels continue to rise.

The research team led by Dr Fraser includes scientists from the University of East Anglia, and from ICI in the UK. The Journal of Geophysical Research has accepted the team's results for publication.

The Bureau of Meteorology runs the Cape Grim station. The station is located in the path of the 'roaring forties', which blow unpolluted air across the Southern Ocean. CSIRO's research into ozone depleting chemicals is being done in collaboration with the Co-operative Research Centre for Southern Hemisphere Meteorology.

A graph showing the rise in the atmosphere of halon-1211 is available on request from CSIRO. Broadcast quality video footage of Cape Grim is also available on request.
-end-
For more information please contact: Paul Holper
03-9239-4661 (W)
0419-894-427 (m)
03-9583-9903 (H)
E-mail:paul.holper@dar.csiro.au

Dr Paul Fraser
03-9239-4613 (W)
03-9787-2161 (H)
E-mail:paul.fraser@dar.csiro.au

CSIRO Australia

Related Ozone Articles from Brightsurf:

Investigating the causes of the ozone levels in the Valderejo Nature Reserve
The UPV/EHU's Atmospheric Research Group (GIA) has presented a database comprising over 60 volatile organic compounds (VOC) measured continuously over the last ten years in the Valderejo Nature Reserve (Álava, Basque Country).

FSU Research: Despite less ozone pollution, not all plants benefit
Policies and new technologies have reduced emissions of precursor gases that lead to ozone air pollution, but despite those improvements, the amount of ozone that plants are taking in has not followed the same trend, according to Florida State University researchers.

Iodine may slow ozone layer recovery
Air pollution and iodine from the ocean contribute to damage of Earth's ozone layer.

Ozone threat from climate change
We know the recent extreme heat is something that we can expect more of as a result of increasing temperatures due to climate change.

Super volcanic eruptions interrupt ozone recovery
Strong volcanic eruptions, especially when a super volcano erupts, will have a strong impact on ozone, and might interrupt the ozone recovery processes.

How severe drought influences ozone pollution
From 2011 to 2015, California experienced its worst drought on record, with a parching combination of high temperatures and low precipitation.

New threat to ozone recovery
A new MIT study, published in Nature Geoscience, identifies another threat to the ozone layer's recovery: chloroform -- a colorless, sweet-smelling compound that is primarily used in the manufacturing of products such as Teflon and various refrigerants.

Ozone hole modest despite optimum conditions for ozone depletion
The ozone hole that forms in the upper atmosphere over Antarctica each September was slightly above average size in 2018, NOAA and NASA scientists reported today.

Increased UV from ozone depletion sterilizes trees
UC Berkeley paleobotanists put dwarf, bonsai pine trees in growth chambers and subjected them to up to 13 times the UV-B radiation Earth experiences today, simulating conditions that likely existed 252 million years ago during the planet's worst mass extinction.

Ozone at lower latitudes is not recovering, despite Antarctic ozone hole healing
The ozone layer -- which protects us from harmful ultraviolet radiation -- is recovering at the poles, but unexpected decreases in part of the atmosphere may be preventing recovery at lower latitudes.

Read More: Ozone News and Ozone Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.