Experiencing a sand or dust storm can be frightening. As rolling clouds engulf everything in their path, the tempests turn day into night and wreak havoc on humans and nature. The most ferocious are like tsunamis of sand.
These storms affect some 330 million people around the world, from Sub-Saharan Africa to Northern China to Australia.
That tally is poised to rise.
A combination of climate change and land mismanagement is stripping semi-arid areas of vegetation, leading to desertification and feeding a series of more frequent, more brutal storms.
The United Nations earlier this year designated July 12 as the first International Day of Combating Sand and Dust Storms. The move was designed to raise awareness about the threats posed by these squalls and to spur on the international effort to counter them.
“We don’t have to resign ourselves to a future where communities in arid and semi-arid environments are continually battered by dust storms,” said Doreen Robinson, the Head of the Biodiversity and Land Branch at the United Nations Environment Programme (UNEP). “By restoring parched landscapes and meaningfully lowering greenhouse gas emissions, we can lessen the chances of monster storms and make life better for tens of millions of people.”
With that in mind, here’s everything you need to know about sand and dust storms, and how humanity can rein in their destructive impact.
What causes sand and dust storms?
These tempests occur when strong winds meet bare or dry soil, lifting large amounts of sand and dust into the atmosphere. Once airborne, the sand and dust does not stay in one location but gets transported hundreds or even thousands of kilometers away.
The main sources of these mineral dusts are dry regions in Northern Africa, the Arabian Peninsula, Central Asia and China. Australia, America and South Africa make minor, but still important, contributions.
Are sand and dust storms becoming more common?
Yes. Human activities, like deforestation, over grazing and the overuse of water, are causing deserts to spread and increasing the likelihood of sand and dust storms. Climate change – which is bringing droughts and more extreme temperatures – is amplifying these factors.
In some areas, desert dust has doubled in the 20th century, increasing the chance of sand and dust storms.
What is the impact of sand and dust storms?
They can have disastrous consequences for agriculture and industry. In northern China alone they caused economic losses of nearly $1 billion in just three years.
Beyond being bad for business, sand and dust storms can also trigger a range of respiratory ailments in humans.
Some 40 per cent of aerosols – a collection of tiny particles – found in the lowest levels of Earth’s atmosphere are dust particles carried by the wind. If the particles get trapped in the nose, mouth and upper respiratory track, they can lead to disorders like asthma or pneumonia.
Finer particles can penetrate even deeper, reaching the bloodstream and affecting all organs. A 2014 assessment estimates that 400,000 premature deaths were caused by exposure to dust particles.
Dust particles can also act as a carrier for infectious diseases. Meningococcal meningitis is a bacterial infection of the brain. If left untreated it leads to death in 50 per cent of cases. The occurrence is highest in Sub-Saharan Africa’s “meningitis belt”, where researchers have linked the disease to dusty conditions.
Alongside the effects on human health, sand and dust storms can destroy crops, kill livestock, foul machinery and ground flights.
What can people do to stop sand and dust storms, or limit their impact?
The phenomenon is difficult to control directly: drought or deforestation in one part of the world can lead to sand storms in another. But people can control the conditions that lead to land drying up and dust gathering in the air.
In the areas where sand and dust storms begin, states can restore land by being more efficient with scarce water supplies, protecting fragile topsoils and increasing vegetation cover, including by planting native shrubs and trees. All of these things help store water in the land and, as a result, less sand and dust are created.
In semi-arid regions, states can also help farmers to produce food without resorting to clearing land and overgrazing, giving soil a chance to rest and recover.
Given the link between climate change and creeping desertification, the world must also make real progress in lowering the greenhouse gas emissions that are feeding the climate crisis. Already the world is 1.1°C warmer than it was in pre-industrial times and as temperatures continue to rise, they will spark more droughts and create fertile breeding grounds for sand and dust storms.
Finally, as states battle the causes of these tempests, they can continue to invest in early warning systems that alert vulnerable people to incoming storms. These can save lives and limit economic damage.
- United Nations Environment Programme