News: a conceptual proposal for huge buoyant umbrellas that rebuild polar ice caps has been awarded first prize in this year's eVolo Skyscraper Competition.
Designed by American architect Derek Pirozzi, the Polar Umbrella concept would see giant umbrella-shaped structures freeze sea water to replenish arctic ice shelves in areas worst affected by global warming.
The vast canopies would harvest solar energy and reduce heat gain underneath, and be integrated with a system of polyethylene pipes to pump up brackish water. The structures would contain a desalinisation plant, research facilities and accommodation, plus use salt water to produce renewable energy by osmosis.
An idea to use stacks of modular, prefabricated housing units to regenerate industrial neighbourhoods in Paris (above) came second in the competition and third place was awarded to a floating city extension suspended beneath a giant balloon (below).
Organised by architecture magazine eVolo, the annual competition recognises inventive and futuristic skyscraper proposals. A tower constructed from rubbish in São Paulo was one of last year's entries.
More fantastical skyscrapers on Dezeen include a tower that uses algae to produce energy and a building with observation decks floated on helium balloons.
Sign up for a daily roundup
of all our stories