[ASC-media] Media release: national mercury emissions claims 'wrong'
crcamedia at starclass.com.au
Tue Aug 31 04:14:59 EST 2004
CRCA Media Release 04/33
CLAIMS OVER HIGH AUSTRALIAN MERCURY EMISSIONS SHOWN TO BE FALSE
A study by Australia's Cooperative Research Centre for Coal in Sustainable Development (CCSD) has found that an international report depicting Australia as the world's worst emitter of the toxic heavy metal mercury got it wrong.
A recent global anthropogenic (man-made) mercury emission inventory claimed that Australia emitted more than 105.5 tonnes of mercury per year making it the world's largest mercury emitter on a per capita basis.
The inventory covered emissions to the atmosphere from all sources - power generation, transport, domestic and bushfires.
However a new study by the CCSD, shows these international estimates of Australian mercury (Hg) emissions may have been in error by a factor of almost ten times.
The CCSD report shows that the much larger emission estimated in previous studies was caused by the use of inappropriate mercury emission factors, particularly those used for the combustion of Australian coals to generate power.
Author of the CCSD report, Professor Peter Nelson, from the Graduate School of the Environment at Macquarie University says "The origin of the error lies mainly in the fact that the international estimates were based on burning northern hemisphere coals. Australian coals are different, and in general have lower levels of mercury."
The CCSD study also shows that mercury emission inventories are subject to significant uncertainties.
CCSD estimates that the correct total for annual Australian anthropogenic mercury emissions is about 10 tonnes - less than one tenth the international estimate.
"This estimate of 10 tonnes might be increased by a further 2.6 tonnes if mercury emissions from the combustion of vegetation during bushfire hazard reduction, bush regeneration and agricultural land clearing were included," Prof. Nelson adds.
Mercury emissions from natural sources (including re-emission) were estimated to be in the range of 130-270 tonnes per annum, with the lower value being more likely.
"Our report demonstrates that Australia is not the world's largest per capita emitter of mercury," Professor Nelson says.
Professor Peter Nelson, CCSD, 02 98506958
Email: pnelson at gse.mq.edu.au
Copies of the CCSD report from the CRC, phone 07 3871 4404
Prof. Julian Cribb, CRCA media, 0418 639 245
August 31, 2004
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