Outside its capital Ulan Bator, Mongolia is launching the world's largest ice-making experiment in hopes of combating global warming and the urban heat island effect. "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." If successful, the technique could be used in other northern cities.