Dust storms like the one that plagued Sydney are blowing bacteria to all corners of the globe, with viruses that will attack the human body. Yet these scourges can also help mitigate climate change
Huge dust storms, like the ones that blanketed Sydney twice last week, hit Queensland yesterday and turned the air red across much of eastern Australia, are spreading lethal epidemics around the world. However, they can also absorb climate change emissions, say researchers studying the little understood but growing phenomenon.
The Sydney storm, which left millions of people choking on some of the worst air pollution in 70 years, was a consequence of the 10-year drought that has turned parts of Australia’s interior into a giant dust bowl, providing perfect conditions for high winds to whip loose soil into the air and carry it thousands of miles across the continent.
It followed major dust storms this year in northern China, Iraq and Iran, Pakistan, Saudi Arabia, Afghanistan, east Africa, Arizona and other arid areas. Most of the storms are also linked to droughts, but are believed to have been exacerbated by deforestation, overgrazing of pastures and climate change.
As diplomats prepare to meet in Bangkok tomorrow for the next round of climate talks, meteorologists predict that more major dust storms can be expected, carrying minute particles of beneficial soil and nutrients as well as potentially harmful bacteria, viruses and fungal spores.
“The numbers of major dust storms go up and down over the years,” said Andrew Goudie, geography professor at Oxford University. “In Australia and China they tailed off from the 1970s then spiked in the 1990s and at the start of this decade. At the moment they are clearly on an upward trajectory.”
Laurence Barrie is chief researcher at the World Meteorological Organisation (WMO) in Geneva, which is working with 40 countries to develop a dust storm warning system. He said: “I think the droughts [and dust storms] in Australia are a harbinger. Dust storms are a natural phenomenon, but are influenced by human activities and are now just as serious as traffic and industrial air pollution. The minute particles act like urban smog or acid rain. They can penetrate deep into the human body.”
Saharan storms are thought to be responsible for spreading lethal meningitis spores throughout semi-arid central Africa, where up to 250,000 people, particularly children, contract the disease each year and 25,000 die. “There is evidence that the dust can mobilise meningitis in the bloodstream,” said Barrie.