While a downpour pounded Seoul on a recent morning, Kwon Byong Hyon had a different sort of storm on his mind.

It was fourteen years earlier, on the day he first landed in Beijing, as Korea’s ambassador to China.

“The first thing that met me was a thick yellow sand storm,” Kwon remembered.

The storm had blotted out the sun, and the air was thick and stinging. The next day, Kwon got a call from his young daughter back in Seoul.

“Daddy, Seoul is covered in a terrible dust storm,” she said. “I can’t stand (it).”

A cloud of talc-like particles had also blanketed Seoul, coating cars and houses and trees in butter-yellow powder.

It wasn’t the first time, and it wouldn’t be the last. Intense dust storms have blown across Korea throughout recorded history, but their frequency and intensity have increased in recent decades. And when they come, the noxious dust exacerbates asthma and sends people with heart problems to the hospital. It seeps into machinery, forcing factories to shutdown and grounding airplanes.

Kwon said that call from his daughter changed something for him.

“That was the start,” he said.

The start of a crusade to combat the yellow clouds at their source, hundred of miles away in the Gobi desert of China and Mongolia.

The Gobi is the nursery for East Asia’s dust storms. It’s where cool winds stir up dust on an undulating, arid, brown plain. The region has always been dry, but in recent times it’s been getting drier. That means more dust, and a more difficult life for traditional Mongolian livestock herders like Torsaikhan Tsoolon, who raises camels, sheep and goats.

“In the past we had good conditions,” Tsoolon said, sitting on the floor of his family’s portable yurt. “Now the conditions have changed. Less rainfall. Land degradation. We must work very hard.”

The Gobi has never been an easy place for nomads like Tsoolon to scratch out a living. But in recent decades temperatures here have shot up dramatically. The already spartan grasslands have become drier and watering holes have evaporated. Meanwhile, scientists say the nomads themselves have contributed to the problem with oversized herds of camels, sheep and goats, which are destroying the plain.

All of these growing difficulties are directly related to the dust storms that plague Korea. And that’s where Korean activist Dong Kyun Park comes in. For more than a decade, Park has worked to prevent those dust storms, sometimes alongside Kwon.

Not far from Tsoolon’s yurt, Park digs up some powdery yellow dirt and sifts it through his fingers.

“This is what we call sand,” he said, “(but) it’s not really sand. It is small, fine particles.”

And it’s what the harsh Mongolian winds pick up, carrying first to nearby villages and then miles up into the jet stream, eventually choking cities hundreds and even thousands of miles away in Korea and beyond.

To Park, the best strategy for fighting these dust storms is to try to keep the soil from leaving Mongolia in the first place. So a few years ago, he raised money in Korea to plant trees — living windbreaks — here in Mongolia’s southern Gobi, near China. At the time, Park was head of the Northeast Asia Forest Forum, and he and his colleague Jamsram Tsogtbaatar, a forestry scientist and an official at the Mongolian Academy of Sciences, wanted to prove that they could grow a forest in this unforgiving region.

One experimental plantation, outside the dusty town of Bulgan, runs about half a mile long by 100 yards wide. Tsogbaatar has kept an eye on it since he and Park planted the saplings, but in his first visit back, Park is pleased with what he sees.

“Nothing was here in 2006,” Park said. “There were no leaves. But now I can see the changes here.”

Native salt cedars now reach to Park’s waist, while slender Siberian elm branches wave just above his head. To a reporter from verdant New England, the trees look pitifully small and fragile. But Park said they’ll grow to about 16 feet high, and that their canopies will weave into an umbrella of dappled shade.

Already, other plants have sprouted from the moist soil beneath. Park points to yellow and white flowers — a “small nursery,” he calls it — and said this new ground cover will help hold the soil in place.

Tsogtbaatar said even now the trees are starting to catch dust from the air.

“You can see this kind of accumulation of sand. This tree makes some shelter,” he says.

Ultimately, Tsogtbaatar and Park hope the forest shelter will become big enough to catch enough windborne dust to make a difference in nearby Bulgan.

“Their life is very much miserable,” Park said. “Maybe we can reduce that impact, so people can live comfortably.”

Of course, Bulgan is only one small town. Most Gobi communities have no windbreaks and no plans to plant them. But Park said he and his partner have planted something more important: an idea.

“Ignite a small fire in the people’s mind,” he said. “See, you can do it.”

And the idea does seem to be taking root. There’s high level government talk of reforesting denuded areas here, and a huge new nursery for native tree species has opened in Ulan Bator, Mongolia’s capital. Ultimately, Park said, as more windbreaks sprout up, the benefits will reach all the way back to his home in Korea.

Of course, this isn’t certain to happen. Among other things, Park and Tsogtbaatar realize that global warming might overwhelm their efforts. Average summer temperatures in Mongolia are projected to rise up to 11 degrees Fahrenheit by mid-century, which could dry out the Gobi even more and kill the native elms and cedars in which the two have invested so much hope.

But the Korean and Mongolian tree planters say they can’t let that prospect stop them from doing what they can, while hoping the rest of the world tackles that bigger problem.