Melting Glaciers: Monitoring Global Warming at World's 'Third Pole'
How are high-altitude glaciers in central Asia reacting to global warming? A team of German-based scientists is measuring the little-known frozen world of the Tian Shan mountain range. Though conditions there are much colder than in other ranges, they've already found evidence of gradual ice sheet shrinkage.
Martin Hölzle has crossed glaciers the world over; in the Arctic, the Rocky Mountains, New Zealand and in the Andes. "I've almost lost count how many," he says.
Today Hölzle is 48, a professor of glaciology and a board member of the World Glacier Monitoring Service. "Have a look how much ice there still is under the rubble of that moraine down there," he calls to three fellow researchers.
Hölzle glances up the flanks of the valley at a dome of ice that doesn't have the large crevasses typically found on glaciers in the Alps. "This one flows really, really slowly" he says, rocking his head from side to side. "That's typical for cold glaciers."
He relishes precious moments like these at an altitude of 4,000 meters (13,000 feet) above sea level in Kyrgyzstan's Tian Shan Mountains, which also straddle neighboring China and Kazakhstan. "This beauty," he murmurs reverently, and then adds: "But I want to know how this beauty works."
To do this he grabs a hose hissing steam, directing it at the sheet of ice before him. The team of scientists operating under the auspices of the German Research Centre for Geosciences (GFZ) in Potsdam hopes to find out about any changes that are taking place -- not just on this particular glacier in Kyrgyzstan, but every one on the planet.
The scientists are investigating the effects of global warming, and every climatalogical fever that has ever gripped the world. "If you want to know how it will affect us in the future, you have to understand systems like these glaciers," the professor from the Swiss University of Fribourg explains as his hose melts a deep hole in the ice.
Central Asian Glaciers Neglected
Glaciers are seen as yardsticks for the impact of global warming. Their shrinkage indicates that temperatures have risen over the long term. But though they are crucial in assessing atmospheric changes, relatively little is known about glaciers. "That's especially true in the mountains of central Asia," Hölzle says. These form a massive belt stretching northwest from the Himalayas, becoming the Karakorum, Pamir and finally the Tian Shan ranges. The peaks of the Tian Shan range reach as high as 7,500 meters (24,500 feet), crowned by strange icecaps that Hölzle and his research colleagues have dubbed "the Earth's third pole."
The livelihood of millions depends on this ice. In the summer months, it delivers life-giving meltwater to the dry valleys below. "That's reason enough to find out more about changes in the size of these glaciers," Hölzle says.
The absence of data only encourages speculation -- even among scientists. Thus it was probably no coincidence that one of the most embarrassing scientific blunders in recent years was connected to the same area Hölzle and his colleagues are now studying.
"By 2035," the last report by the Intergovernmental Panel on Climate Change (IPCC) said, the glaciers of the Himalayas will have melted away. The statement was false on two counts. First, it was based on a Russian study that actually referred to 2350; and second, such a prediction is practically untenable. "We don't know enough to be able to make such assertions," Hölzle says. "What's more, the idea that the glaciers in this region will simply disappear is just wrong."
The ice masses in the Himalayas, Pamir and Tian Shan ranges differ from their more volatile counterparts in the Alps in one key respect: It is so cold in the extremely high altitudes of the central Asian uplands that even global warming couldn't destroy all the permafrost there. "Apart from that, a glacier's survival depends not only on temperature but also on precipitation," Hölzle explains.
This is the issue the four researchers traveled to Asia to study this summer: The still mysterious interplay of temperature, rainfall and conditions on the ground.
Just getting close to these white giants proved difficult. The researchers had to take a legendary Russian GAZ heavy-duty truck for the last part of their journey from the Kyrgyz capital Bishkek to the high-altitude plateau of the Ak-Shyyrak Massif, past yak herds and herdsmen's yurts. Their tents now stand at an altitude of 3,800 meters (12,500 feet), where a diesel generator recharges their batteries.
With their instruments strapped to their backs, the researchers hike out of their camp. Some of the equipment looks like it could have been used by Austrian filmmaker Luis Trenker to shoot his Alpine movies in the 1920s and 1930s. Hölzle, for example, dragged an old-fashioned steam kettle up with him to melt holes in the ice. Erlan Azisov, a Kyrgyz researcher from the Central-Asian Institute for Applied Earth Science (CAIAG), carried the wooden poles that the men are sticking into the holes.
Deep down in the ice, meltwater gurgles in its frozen shell. Now and again, a distant crack can be heard above the murmuring of the streams that flow through the white landscape like veins down an arm. "These sorts of glaciers are like living beings," Hölzle philosophizes, as his hot-air drill slowly works its way downward.
The physical reasons for the formation of these huge ice sheets are relatively simple. "Glaciers form wherever more snow falls than melts over the course of the year," Hölzle explains. "As such, every glacier consists of an area where it grows and another in which it melts in the summer. If something disrupts this balance, the glacier shrinks."
The wooden poles are used to determine how much ice melts over the summer. The GFZ scientists sunk similar poles into the ice last year. Two of these now lie on the ice, while an arms-length of a third is exposed - a sure sign that the ice around it melted in the summer sun. The scientists measure the lengths of the poles with a tape measure. "Almost six meters," Hölzle says, noting it down in his yellow expedition logbook.
Colder Than The Alps
They'll do the same thing next year with the pole they are driving into the ice now. "That gives us an idea how quickly the glacier is melting," Hölzle says.
It's a tedious undertaking. Time and again, the icy wind blows the burner out as dark snowstorm clouds roll in. Whenever the thunder roars and the lightening flashes, the men are forced to cower in a depression. The next morning they reach the glacier snout. Three, two, one-and-a-half meters -- the higher they trudge up the glacier, the lower the melt-off rate. "That's normal," Hölzle says. "Glaciers always lose the most mass at the bottom."
Overall, the glacier has a relatively low ablation rate, as the scientists' term for the speed at which it melts. Although little snow falls in winter, the melt-off is also low in summer because of the extremely cold temperatures. "The ice below us must be easily around -10°C [14°F]," Hölzle estimates. The cores of Alpine glaciers, by contrast, rarely get far below freezing.
While Hölzle wrestles with a fresh gas canister adaptor, David Kriegel and Abror Gafurov plumb even greater depths of the icy colossus with the aid of radar. Waves at a frequency of 100 megahertz penetrate the ice and bounce back off the rocks below. The laptop Kriegel is wearing around his neck turns the returning signals into a profile of the glacier. The hydrologist pushes up his sunglasses and squints at the monitor against the glare of the sun reflecting off the ice. "Ice depth: 160 meters [525 feet]," Kriegel says. "That's quite a lot, but we're right at the spot where the two arms of the glacier come together."
Abror Gafurov drags the antenna behind himself on a strap. The red plastic tub containing the cables scratches over glittering shards of ice on the ground.
The researchers don't return to their campsite until shortly before nightfall. Temperatures plummet the moment the sun goes down, so they quickly throw a bag of pasta into their cooking pot. When they get up the next morning, sparkling ice crystals have formed on the outside of their tents.
'We Desperately Need Old Data'
The men have to set off early. Today they will be working on the upper part of the glacier, where the snow doesn't melt. This area is known as the accumulation zone.
Hölzle leads the roped-up team, testing the ice ahead for hidden crevasses with a thin iron rod. At an altitude of almost 4,200 meters (13,800 feet), they reach what is known as the equilibrium line. "From here on up, the snow never melts, not even in summer," Kriegel explains. From there Hölzle has to check particularly carefully for crevasses. "The loose snow still covers them up here," says Kriegel, who is roped up directly behind Hölzle.
The scientists have already traversed this key part of the glacier with their GPS devices. "If the temperature rises, either locally or globally, the equilibrium line moves further up," Kriegel says.
The men climb ever higher. "To calculate changes in the glacier mass we have to know how much snow falls on it every year," Kriegel explains. He glances into the distance, toward the point where the so-called "seven-thousanders" - mountains higher than 7,000 meters (about 23,000 feet) -- rise out of the haze on the border with China. They come to a halt on a ridge of ice that slopes down for hundreds of meters toward the mountain pass. "It's better to admit your fear than to get nervous later and make a mistake," Hölzle says, driving his shovel into the loose snow.
The men dig until they reach solid ice. "This is the layer of snow that thawed last summer," Kriegel says, grabbing a steel pipe and driving it as far as it will go into the snow, before measuring the weight of the snow that has become wedged in the pipe. "This enables us to calculate how much snow fell last year," he says.
The team will have to keep coming back for a few more years. But it will take some time before they have concrete results. "Society demands quick answers," Hölzle says as they descend. "We therefore desperately need old data."
A Reason to Celebrate
But that's not easy to come by in a country that was ravaged by civil war just a few months ago. Although the GFZ has had its own measuring devices set up on the glaciers of Kyrgyzstan since the 1990s - "ultramodern automatic stations," hydrologist Kriegel assures -- equipment like that could easily be damaged in the south, where the Uzbek and Kyrgyz people meet, and Islamic terrorists are believed to be based. "Solar panels for generating electricity make the perfect target for shooting practice," Kriegel says laconically.
But the scientists want to look even further back into the past, and therefore decide to join a research team led by the Kyrgyz Ministry for Natural Resources, which is heading out the next day to the Karabatkak glacier in the east of the country, where an old Soviet-era survey station is apparently located.
The scientists give their luggage to herdsmen in the valley, who pack them on horses that will carry it to an old hut above a glacial lake. A destroyed weather station lies on the ground, a rusty rain gauge whistling in the wind. The last people to live in the hut were clearly poachers: The researchers find a snow-leopard trap.
The representative of the ministry has an old aerial photograph, presumably from secret military archives. Lines drawn on it show the position of the glacier snout in the past three decades. "According to this, the glacier came almost up to the lake," Kriegel says. Now they have to walk a few hundred meters until they reach the ice.
That's a sizeable retreat, though nothing compared to the shrinkage seen in Alpine glaciers. That's not surprising, though, as the Kyrgyz glaciers shrink considerably slower.
At the time, a meteorologist measured the temperature and rainfall every three hours. "Everything was noted down in precise detail," the official says. The records continue until 1990, when the Soviet Union fell apart. Students in Bishkek are now entering all the data on a computer, he adds.
That's a huge triumph for the researchers, whose expedition to the "third pole" has also become a journey back in time. The official unscrews the vodka bottle.
Translated from the German by Jan Liebelt
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