ONE OR TWO DEGREES OF WARMING CAN
MEAN THAT SNOWFLAKES NEVER FORM.
THAT’S WHY THE ALPS ARE IN DEEP TROUBLE.
happened over centuries, each fresh layer of
snow pressing on the ones beneath, until the
snow solidified into ice and began to flow down-
hill under its own weight. Snow accumulates
in winter, and snow and ice melt in summer,
mostly at lower altitudes. When winter gain
exceeds summer loss, the glacier’s snout
advances down into the valley; when summer
triumphs, the glacier retreats. Since the late
19th century, glaciers in the Alps have retreated
almost continuously.
Swiss glaciologist Felix Keller has an idea for
reversing that trend. Keller grew up in a village
next to St. Moritz, the birthplace of winter tour-
ism in the Alps. When I met him there last year,
he took me to the nearby Hotel Morteratsch,
where he showed me a black-and-white pho-
tograph of the last crown prince of Germany,
Wilhelm, taken in 1919. The prince and his
entourage stood beaming on the Morteratsch
Glacier, which at the time was right outside the
hotel. Thick ice covered the entire valley.
Keller and I went to the same spot. In the cen-
tury since Wilhelm’s visit, larches and pines have
taken over; in late summer, locals forage there
for mushrooms and cranberries. The Morte-
ratsch Glacier has retreated out of sight, more
than a mile up the valley.
Alpine glaciers overall have lost two-thirds
of their volume since 1850, and the loss is accel-
erating. “If we don’t act, all will be gone,” says
Matthias Huss, a glaciologist at ETH Zurich. By
“act,” Huss means drastically cut the carbon
emissions that cause global warming.
Keller has an additional action in mind. The
idea came to him on a balmy summer day in
2015, while he was fishing in a lake fed by melt-
water from the Morteratsch. Glacial silt clouded
the water, and the trout weren’t biting. That’s
when it occurred to Keller: Couldn’t some of that
meltwater be kept high in the mountains and
turned back into ice?
“I figured that within 10 minutes, I’d find outOn his way to work, Lejeune passes Le Sappey-
en-Chartreuse, a small village with a church at
its center and ski runs up the mountainsides. At
age five, he learned to ski here. But the village
lies low, at about 3,300 feet. “Now, it’s finished,”
Lejeune says bluntly. “Maybe they’ll have one or
two good years, but not more.”
Such areas already were plagued by a series
of snow-scarce winters in the 1980s and ’90s.
Machines that make snow became the Alps’ first
line of defense. In lower-lying regions, millions
in investments seemed justified to guarantee a
steady tourism season. Winters with light snow
were assumed to be outliers then.
Lejeune’s data prove that they weren’t. He
points to a graph comparing the snow depth at
Col de Porte in the past 30-year period with the
previous one. The line plunges downward, show-
ing an average snow-cover decrease of 15 inches.
“That’s a lot,” Lejeune says. “That’s really a lot.”
The warming now has reached higher eleva-
tions. “If someone had told me back then that
we’d ever need snow machines, I’d have said,
‘You’re crazy,’ ” says Peter Leo, Kitzsteinhorn’s
head of snow management. Today “we couldn’t
live without these machines.”
Neither can most of the Alps’ 1,100 ski lift
operators. Much of the snow in ski areas is now
human made. On Kitzsteinhorn alone, 104
grass-colored “snow cannons” are strategically
positioned around the slopes. Each weighs and
costs as much as a small car.
When Leo turns one on, it becomes hard to
hear him. On the machine’s outer ring, nozzles
infuse water droplets with air, and a massive
fan—“strong enough to suck you in,” he yells—
blows them into the sky. As they descend, water
droplets from the inner rings clump around the
initial crystals, forming snowflakes.
STANDING ON A GLACIER like Kitzsteinhorn,
it’s hard to grasp how tiny snowflakes could
have formed such an immense mass of ice. It
78 NATIONAL GEOGRAPHIC