The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology Evolution of Ozone Depleting Substances in the Australian Atmosphere Presented at: A Silver Lining: Celebrating 25 Years of the Montreal Protocol The Australian Academy of Science Canberra, 13 September 2012 www.cawcr.gov.au Paul Fraser FTSE CSIRO Marine and Atmospheric Research, Aspendale
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Evolution of Ozone Depleting Substances in the Australian … · Nature, 1974 Stratospheric sink for chlorofluoromethanes: chlorine atom-catalysed destruction of ozone M. J. Molina
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The Centre for Australian Weather and Climate Research A partnership between CSIRO and the Bureau of Meteorology
Evolution of Ozone Depleting Substances in the Australian Atmosphere
Presented at:
A Silver Lining: Celebrating 25 Years of
the Montreal Protocol
The Australian Academy of Science
Canberra, 13 September 2012
www.cawcr.gov.au
Paul Fraser FTSE CSIRO Marine and Atmospheric Research, Aspendale
What are ‘Ozone Depleting Substances – ODSs’?
In the context of the Montreal Protocol, an ODS is any chemical containing chlorine (Cl) and/or
bromine (Br), after release into the lower atmosphere, can be transported to the stratosphere,
where it breaks down releasing reactive Cl and/or Br that can significantly destroy stratospheric O3
There are more than 100 ODSs identified for regulation under the Montreal Protocol – an
international agreement designed to protect the stratospheric ozone layer (O3) by controlling ODS
production and consumption
examples:
CFCs (CFC-12: CCl2F2) - refrigerant
HCFCs (HCFC-22: CHClF2) - refrigerant
halons (H-1211: CBrClF2 - fire-fighting agent
The Centre for Australian Weather and Climate Research
A partnership between CSIRO and the Bureau of Meteorology
Nature, 1974
Stratospheric sink for chlorofluoromethanes: chlorine atom-catalysed destruction of ozone
M. J. Molina & F. S. Rowland
Department of Chemistry, University of California at Irvine
‘Chlorofluoromethanes are being added to the environment in steadily increasing amounts. These
compounds are chemically inert and may remain in the atmosphere for 40–150 years, and
concentrations can be expected to reach 10 to 30 times present levels. Photodissociation of the
chlorofluoromethanes in the stratosphere produces significant amounts of chlorine atoms, and leads
to the destruction of atmospheric ozone’
CSIRO job interview: ‘What chemicals might be important to measure in the atmosphere?’
Answer: ‘CFCs – they might destroy the Earth’s ozone layer’
1995 Nobel Prize for Chemistry
The Centre for Australian Weather and Climate Research
A partnership between CSIRO and the Bureau of Meteorology
Where did it all begin?
1974: wrote to Jim Lovelock
1973 ‘CFCs in and over the North and South Atlantic’, Lovelock et al., Nature
Question: ‘How do I measure CFCs in the atmosphere?’
Answer: ‘GC-ECD – I will visit your laboratory in Australia and teach you’
June 1975: Lovelock & Fraser made the first CFC-11, CH3CCl3 & CCl4 measurements
in the Australian atmosphere The Centre for Australian Weather and Climate Research
A partnership between CSIRO and the Bureau of Meteorology
Professor James Lovelock FRS
1969 - the electron capture detector (ECD)
1974 - Fellow Royal Society
1979 - Gaia: A New Look at Life on Earth
1997 - Blue Planet Prize
1976: Cape Grim, Tasmania - Australia’s first
GHG & ODS Monitoring Station
caravan donated by NASA (previously used in Apollo 13 mission)