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In the 13th Century,

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Genghis Khan embarked on a mission[br]to take over Eurasia,

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swiftly conquering countries and drawing [br]them into his expanding Mongol Empire.

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With his vast armies he became almost [br]unstoppable.

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But, legend has it that there was [br]one obstacle

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that even the impressive Khan couldn’t [br]overcome:

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A towering wall of ice,

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grown by locals across a mountain pass

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to stop the Khan’s armies from [br]invading their territory.

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No one knows how historically accurate [br]that particular story is,

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but remarkably, it draws on fact:

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For centuries, in the Karakoram [br]and Himalayan mountain ranges,

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people have been growing glaciers [br]and using these homemade bodies of ice

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as sources of drinking water and [br]irrigation for their crops.

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But before we get to that fascinating [br]phenomenon,

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it’s important to understand the [br]difference between

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glaciers that grow in the wild,

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and those that humans create.

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In the wild,

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glaciers require three conditions to grow:

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Snowfall, cold temperatures, and time.

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First, a great deal of snow falls and [br]accumulates.

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Cold temperatures then ensure that the [br]stacked up snow

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persists throughout the winter, spring, [br]summer, and fall.

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Over the following years, decades, [br]and centuries,

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the pressure of the accumulated snow

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transforms layers into highly compacted [br]glacial ice.

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Artificially growing a glacier,

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however, is completely different.

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At the confluence of three great [br]mountain ranges,

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the Himalayas, Karakoram, and Hindu Kush,

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some local cultures have believed for[br]centuries that glaciers are alive.

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And what’s more,

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that certain glaciers can have different [br]genders including male and female.

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Local Glacier Growers ‘breed’ new glaciers[br]by grafting together—or marrying—

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fragments of ice from male and [br]female glaciers,

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then covering them with charcoal, [br]wheat husks, cloths, or willow branches

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so they can reproduce.

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Under their protective coverings,

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these glacierets transform into fully [br]active glaciers

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that grow each year with [br]additional snowfall.

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Those then serve as lasting [br]reserves of water

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that farmers can use [br]to irrigate their crops.

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These practices have spread [br]to other cultures,

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where people are creating their own [br]versions of glaciers

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and applying them to solve serious [br]modern challenges around water supplies.

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Take Ladakh, a high-altitude desert region[br]in northern India.

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It sits in the rain shadow of the [br]Himalayas

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and receives on average fewer than ten [br]centimeters of rain per year.

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As local glaciers shrink because [br]of climate change,

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regional water scarcity is increasing.

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And so, local people have started growing [br]their own glaciers

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as insurance against this uncertainty.

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These glaciers come in two types: [br]horizontal, and vertical.

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Horizontal glaciers are formed when [br]farmers redirect glacier meltwater

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into channels and pipes,

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then carefully siphon it off into a series[br]of basins made from stones and earth.

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Villagers minutely control the release of [br]water into these reservoirs,

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waiting for each new layer to freeze

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before filling the basin [br]with another wave.

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In early spring,

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these frozen pools begin to melt,

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supplying villagers with [br]irrigation for their fields.

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Local people make vertical glaciers using [br]the meltwater

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from already-existing glaciers [br]high above their villages.

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The meltwater enters channels [br]that run downhill,

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flowing until it reaches a crop site

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where it bursts forth from a pipe pointing[br]straight into the air.

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When winter temperatures dip,

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this water freezes as it arcs [br]out of the pipe,

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ultimately forming a 50 meter ice [br]sculpture called a stupa,

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shaped like an upside-down ice cream cone.

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This inverted form minimizes the amount[br]of surface area it exposes to the sun

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in the spring and summer.

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That ensures that the mini-glacier [br]melts slowly

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and provides a reliable supply of water [br]to feed the farmers’ crops.

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These methods may be ancient,

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but they’re becoming more relevant

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as climate change takes its [br]toll on our planet.

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In fact, people are now growing their own[br]glaciers in many regions beyond Ladakh.

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Swiss people, utilizing modern glacier [br]growing technology,

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created their first stupa in 2016 [br]in the Swiss Alps.

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There are plans for over 100 more in [br]villages in Pakistan,

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Kazakhstan, and Kyrgyzstan.

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Perhaps one day we’ll be able to harness[br]our homegrown glaciers

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well enough to build whole walls of ice–

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this time not for keeping people out,

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but to enable life in some of the planet’s[br]harshest landscapes.