As the global population rises so to does the demand for land, especially for agriculture. One answer could be vertical farms.
French architects, Vincent Callebaut came up with this concept for a 'farmscraper', named Asian Cairns, to be constructed in the Chinese city of Shenzhen, a growing urban centre where space is at a premium. Six towers of pebble-like structures have been stacked together to create a productive, mixed-use project, with each pods' garden positioned to maximize sunlight and collect rainwater. The project also incorporates residential, work and leisure areas. Energy is generated using solar panels and wind turbines.