This month, the Mongolian capital of Ulan Bator will begin conducting an ambitious "geoengineering trial" that will see the formation of an urban glacier that will cool the city throughout the summer months. As the Guardian reports, the scientists behind the 1 billion tugrik ($700,000) project believe that the glacier will emit enough cool air to be pumped throughout the city in the summer, while also supplying valuable water resources for drinking and irrigation as the ice gradually melts in the hot temperatures.
The Mongolian engineering firm ECOS & EMI will begin "building" the glacier by forming artifical naleds–essentially, meters-thick sheets of ice formed over rivers in the winter as water pressure breaks through the ice envelope and the subsequent water seepage freezes. Layer by layer, the method will be repeated continuously over the coming months, ultimately yielding a full-fledged glacier. Interestingly, naleds have been repurposed for construction projects over the past several hundred years, more recently in North Korea where they were used to build bridges for tanks and, as BLDGBLOG points out, by the U.S. military, which has experimented with growing whole ice roads and bridges in the Arctic. If the Mongolian effort proves successful, then engineers hope to implement more "ice shields" in other northern cities to help reverse urban heat island effects and offer additional water reserves.