According to a 2007 report by the Paris-based Organization for Economic Cooperation and Development, by 2070, rising sea levels due to climate change could have a devastating effect on coastal cities around the globe. As many as 150 million people would be at risk of having to flee flooded homes, and as much as $35 trillion in property would be at risk of ending up underwater [source: OECD]. We still might be able to stave off such a catastrophic scenario by dramatically reducing greenhouse gas emissions, but time is running out. That means low-lying communities may have no choice but to build higher and higher seawalls, or else relocate their populations.
But a Belgian architecture and design visionary, Vincent Callebaut, has suggested another alternative. What if, instead of fleeing the rising seas, we simply build new cities that float on them? In 2008, Callebaut unveiled on the Web his design for Lilypad, a 50,000-inhabitant floating city modeled in shape after the giant water lily native to the Amazonian basin. As a haven for climate change refugees, Lilypad would be a totally self-sustaining community, with aquatic gardens for growing food, a desalination plant to produce drinking water, and energy generation through solar, wind and wave power. Better yet, Lilypad would be outfitted with a titanium dioxide skin, capable of absorbing carbon dioxide from the atmosphere and making at least a small dent in global warming [source: Chapa].