Mongolia bids to keep city cool with ‘ice shield’ experiment. Geoengineering trial aims to ‘store’ winter temperatures in a giant block of ice that will cool and water Ulan Bator in summer.
The project aims to artificially create “naleds” - ultra-thick slabs of ice that occur naturally in far northern climes when rivers or springs push through cracks in the surface to seep outwards during the day and then add an extra layer of ice during the night. Unlike regular ice formation on lakes - which only gets to a metre in thickness before it insulates the water below - naleds continue expanding for as long as there is enough water pressure to penetrate the surface. Many are more than seven metres thick, which means they melt much later than regular ice.
