World
16/07/2018

Death Due To Worsening Air Quality Could Increase In Australian Cities: Study




A new research claims that there would be more intense temperature inversion events in multiple cities in Australia as conditions of in the biggest cities in the country will worsen in the next few decades.
 
According to Jason Evans, a professor at the ARC Centre of Excellence for Climate Extremes and the co-author of the report that was recently published in the Climate Dynamics journal, the premature death toll in largest of the Australian cities because of urban air pollution would worsen in the future from the current rate of over 3000 premature deaths every year recorded irtghe country for the same reason.
 
Normal weather conditions are reversed in inversion events where cool air gets trapped near the surface under layers of warmer air. this results in a severe buildup of pollutants, dust and pollen near the surface which in turn has the potential to cause harm to human health.
 
Data gathered between 1990 and 2009 collected from nine weather sites were analyzed in the study. The weather sites included cities like Brisbane on the eastern seaboard, Adelaide, as well as some of the inland cities like Canberra.
 
The research then made use of regional climate models developed on a business-as-usual carbon emissions trajectory for predicting the possible weather in the large cities from 2020-39 and 2060-2079.
 
For all of the nine locations, during the latter period, the research detected large variations in the intensity of inversions which was based on the enhanced difference between the temperature at the top of the warm layer and that closer to the surface of the earth.
 
"Even though the overall number of inversions didn't change, we saw a substantial reduction in weak inversions and a marked increase in stronger inversion layers," Professor Evans said.
 
For Sydney, the increasing strength of daytime inversions was about 46 per cent for the 2060-79 period, compared with 1990-2009. The corresponding figures for Melbourne, Brisbane, Adelaide and Canberra were about 53 per cent, 64 per cent, 69 percent and 80 per cent respectively, concluded the study.
 
"With more than 80 per cent of Australia's population living [in the region studied] and large increases in population projected, the impact of more intense air pollution events in the future could be substantial," the paper said.
 
The study further predicted that the worst conditions were likely to occur during the winter months because inversions generally mature when there are relative calm winds, clear skies and long nights.
 
Professor Evans told the media that the negative health implications because of inversion would be enhanced during daylight hours because "that's when people are out and about and most exposed" and since inversion typically takes place at that time of the day.
 
One of the consequences of climate change would likely be more rainfall but during fewer events in cities in Australia - and elsewhere with the conditions warming up. That would result in prolonged periods of relatively clear skies that are helpful in triggering inversion events, he said.
 
Professor Evans said that a decline of wind strength over land has also bene projected by climate models. 
 
Smoke from hazard-reduction burning could be one of the major sources of pollution for cities such as Sydney and Melbourne even though the study did not include an examination of sources of pollution.
 
(Source:www.smh.com)

Christopher J. Mitchell
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