Could floating cities provide refuge for climate refugees? Can one colossal structure house 1 million people? Should offshore oil rigs be turned into luxury hotels? Around the planet, architects are pushing the limits of the possible as they explore ways to shelter and provide for a burgeoning global population without further destroying our natural world.

What follows is a run-down of some of the most inspiring and/or far-fetched ideas from architectural visionaries. Their ideas may not always seem plausible, but they provide a glimpse of a possible future in which development is driven by ecological necessity.

This image shows a floating city at night. Read on for the full details.