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Science 25 November 2011: Vol. 334 no. 6059 p. 1039 DOI: 10.1126/science.334.6059.1039-b * News of the Week Random Sample Mongolia's 'Ice Shield' Figure View larger version: * In this page * In a new window Hot zone. Flanked by desert, Ulan Bator will be cooled in summer by an "ice shield." "CREDIT: BRÜCKE-OSTEUROPA/WIKIPEDIA" As the coldest capital on Earth, you might think the last thing Ulan Bator needs is more ice. But that is just what it's about to get under a geoengineering trial aimed at "storing" freezing winter temperatures to cool and water the city during the summer. At the end of this month, engineers will drill a series of bores through the ice on the Tuul River, pump up water from below, and spray it on the surface where it will freeze. This process will be repeated throughout the winter, adding layer after layer to create a chunk of ice that will be 7 or 8 meters thick by the spring. It's an attempt to artificially create the ultra-thick slabs-known as naleds in Russian-that occur naturally in far northern climes when rivers or springs push through surface cracks. Nomads have long made their summer camps near such phenomena, which melt much later than normal ice. Flanked by desert and plagued by summer temperatures that can rise close to 40°C, Ulan Bator's municipal government hopes the $724,000 experiment will create a cool microclimate and provide fresh water as the naled melts. ECOS & EMI, the Anglo-Mongolian company behind the plan, has still greater ambitions. "Everyone is panicking about melting glaciers and icecaps, but nobody has yet found a cheap, environmentally friendly alternative," says Robin Grayson, a geologist in Ulan Bator for ECOS & EMI. "If you know how to manipulate them, naled ice shields can repair permafrost and build cool parks in cities." The process, Grayson says, can be replicated anywhere where winter temperatures fall below −5°C for at least a couple of months.