A thick haze has settled over Sydney, blown in from northwest of the city.
The haze now engulfing Sydney isn't an isolated problem. Cities around the world struggle to manage the many sources of tiny airborne particles and the discomfort and illnesses these cause.
Satellite image from Himawari-8. The bright pink spot indicates the dust storm location.
UK Met Office
Dust storms look spectacular but are a serious health hazard. As climate change dries up many areas of the world, what can we expect from these storms in future?
Hazardous air quality is when fine dust levels are significantly elevated relative to Australian air quality standards.
PAUL BRAVEN/AAP Image
Even as the dust storm over NSW subsides, the unseen fine particles outside, or even inside your house, can still present a health risk.
Michael Reynolds / EPA
As grassland turns to desert, dust is blown into the atmosphere and across oceans.
Spot the opera house.
The dust storm that turned Sydney red in 2009 triggered plankton blooms in the Tasman Sea, demonstrating how we might fertilise the ocean to take up more carbon dioxide.
Sahara on the move.
Being perched off the northwest edge of Europe means that people in the UK are not often reminded of the vast Sahara desert situated only a few thousand miles to the south. This great desert is located…