This story appears in the July 2020 issue of National Geographic magazine.
Ladakh, a high plateau at the northern tip of India, beyond the Himalaya, is under attack. The enemy is cutting off its water sources, drying its farmlands. Desperate farmers, who long raised pashmina goats, wheat, and barley on the arid land, are fleeing to Leh, a city on the Indus River. Sonam Wangchuk and I are driving over passes and valleys above 9,000 feet to inspect his defenses: tall cones of ice that he calls stupas.
“This enemy wears no uniform, bears no allegiance to any nation-state, and carries no automatic weapons,” says Wangchuk, an engineer who also founded an alternative school in Ladakh. “Undeterred by borders, it bides by no international laws. We Ladakhis are on the front lines of a very different war.”
The enemy is climate change. A rise of around one degree Celsius (1.8 degrees Fahrenheit) in average winter temperatures during the past four decades has severed a crucial link in Ladakh’s water cycle. Wedged between Pakistan and India, shielded by the Himalaya from the southwesterly monsoon, Ladakh averages only four inches of rain a year. Its lifeblood is winter snows and glaciers in the mountains. The snows, however, have become fickle, melting before the spring planting, while the glaciers have retreated far up the mountains and are melting later.
“The gap between a late winter snowmelt and springtime glacier melt is yawning ever wider,” Wangchuk explains. That gap, that drying of spring, is making agriculture impossible. “We have a negligible carbon footprint, but we are bearing the brunt of a changing climate,” he says. Ladakhis can’t stop climate change—but ice stupas might bring back some water in spring.
As we turn off the highway and up a gorge near the Pakistani border, Wangchuk tells me his story. In 2013 he noticed that ice, even at a low altitude and at the height of summer, stayed frozen in the shade of a bridge. He realized that he could help villages freeze water in winter for use in spring. Shading vast expanses of ice was impractical, but a tall mound would shade its own interior—and the steeper the sides, the better, because that reduces the area exposed to the sun. “High school math told me that a cone was the simple answer,” Wangchuk says as he negotiates a hairpin bend.
In Buddhism, a stupa is a mound of stone or mud that houses revered relics. Wangchuk and his students built their first ice stupa in November 2013. They routed a stream near Leh through a pipe down a mountain, then sent it up a vertical pipe to a nozzle. That’s it: Stupa building is not high-tech. Wangchuk’s team opened the nozzle at night, when the air was below freezing. The fine spray froze as it fell. Slowly a mound of ice rose around the pipe, tapering toward the top.
That first test stupa was 20 feet high, held 40,000 gallons of water, and lasted until May. Since then, Wangchuk has taught villagers around Ladakh to build stupas. In 2019 they made 12, two of which were more than 100 feet tall. This year they built 26, with nine cresting 100 feet.
Climate change is not only drying springtime in Ladakh; it also is causing flash floods from freak summer rains. Maybe, Wangchuk thinks, irrigation water from stupas could help revegetate hillsides to soak up rain. “If a stupa’s size and location are optimal, it might survive the summer into the following winter,” he says. “The stupa would grow, year on year,” becoming perennial—like a glacier.
Driving along the precipice, we reach the village of Karith. Wangchuk is welcomed as a hero by students at the middle school. They built the village’s first small stupa in 2016. “We want to make the children aware about what is happening in the world and how it is affecting us,” says headmaster Mohammad Ali. Wangchuk wants to make the world aware of what it’s doing to Ladakh. Stupas are “a wake-up call to change carbon-intensive city lifestyles,” he says.
Karith’s stupa last year was 73 feet high. Nestled in the shade of a peak, it lasted through August, allowing farmers to water their fields. This year, farmers and students together built a higher stupa. “One day,” Ali says, “we will build an ice stupa that keeps growing.”