Understanding dust storms: From how they form to their devastating effects

The powerful winds of a dust storm can carry dry earth far and wide, across oceans and from deserts to snow-covered mountaintops.

Human influence, combined with the forces of Mother Nature, may also lead to more severe storms and many harmful ecological impacts.

Those impacts were widespread and gained notoriety in the 1930s, one of the worst periods for dust storms in American history.

“[The] Dust Bowl has really heightened people’s awareness, for sure,” USGS ecologist Jayne Benlap said.

People living in the North American prairies in the 1930s witnessed one of the worst environmental disasters of their time when a period of drought and dangerous dust storms swept across the region.

The period known as the Dust Bowl, also referred to as the “Dirty Thirties,” caused millions to abandon their farms and relocate. The storms raged, causing immense ecological damage to the Plains.

Now, decades later, the same issues that caused the disaster are still prevalent as dust storms unfold.

The problems began during the drought period and were the result of poor agricultural practices in the years leading up to the 1930s.

“Much of the Plains had been plowed up in the decades before the 1930s as wheat cropping expanded west,” according to a report from Columbia University. “While natural prairie grasses can survive a drought, the wheat that was planted could not and, when the precipitation fell, it shriveled and died exposing bare earth to the winds.”

Major contributing factors that influence a dust storm's severity, especially in the southwestern U.S., include drought, invasive annual plants and off-road activities including recreation, as well as oil, gas and mining activities, Benlap said.

“Agriculture can be a major issue if fields are left fallow, drought prevents plant growth, fields are abandoned or plowing year after year can convert more or less stable soils to highly erodible ones,” she said, adding that it is not a major issue unless the first three occur in tandem.

The extent of human influence and meteorological contributions in dust storm severity in the southwestern U.S. over the past 50 years is blurry as there has not been much data systematically collected over the years.

Benlap compared the data pool to hurricanes, as it is unclear if more dust storms are occurring or if records are better kept.

“What we do know is that the vast majority of desert soil surfaces produce very low levels of dust unless disturbed,” she said.

Dust storms pose both immediate dangers and long-lasting ecological impacts as dust is carried by winds across the globe.

Saharan dust has been linked to the growth of poisonous algae in the Caribbean across the Atlantic, according to a report from the Washington Post.

Immediate dangers can lead to severe health problems.

If dust particles enter the lungs while trapped in a storm, it can lead to respiratory disease, Benlap said.

Other related health problems include Valley Fever and other pathogens, heightened asthma and allergic responses.

Reduced visibility can lead to accidents while driving, death and injury. Dust can destroy various farming machinery and other structures, adding economic woes.

Dust can also lower the fertility levels of some soils.

“Dust is made of fine particles, and soil nutrients are attached to those particles,” Benlap said. “So when you see a dust storm go by, some place is losing soil fertility.”

Deserts already have low soil nutrients, and few can afford to lose what they have, she added.

“Also, the place where dust is deposited, often mountains, have evolved to live with low fertility nutrient additions,” she said, adding that dust can disrupt ecosystem function.

In addition to damaging soil fertility, dust can bury or scour plant life, killing them, and can blind animals.

“Probably the biggest issue with dust deposition is that it lands on snow packs, making them darker and then they melt faster in the spring,” she said.

Snowmelt can cause greater water loss as well, Benlap said, citing estimates that dust in the Rockies results in 5-7 percent annual inputs to the Colorado River.

“This is huge and is happening globally,” she said, stating that it is occurring in the Himalayas.

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