It is almost a given at this point that as global warming continues, seaside and port commuities worldwide will need to come up with ways to mitigate the rising ocean levels. Okurshiri Island may prove to be an indirect case study in the potential of such high-tech adaptations, but also the environmental and cultural pitfalls.

In 1993, a tsunami struck the small island, killing 198 people and destroying a third of the houses. The Japanese government has since built an array of devices to protect the island and its people, including nine miles of seawalls with automated floodgates, emergency alarms in every home, and 22 escape routes to higher ground lit with solar-powered signs. It cost $1.3 billion to rebuild the island--not a cost scalable even to the whole of Japan.

Some residents feel safer with the seawalls, but others say they instill a false sense of security: many island residents don't bother going to evacuation drills anymore. Proponents and critics also debate the impact of cutting the fishing community off from the sea, and their long-intimate understanding of that environment that could prove equally or more important in another disaster.

"No matter how high we build the seawalls, there will always be a higher tide," said Takehiko Yamamura, director of the Disaster Prevention System Institute in Tokyo. "Even though seawalls can somehow soften the force of a tsunami, they are not perfect. They weaken with time. And we can't build seawalls surrounding all of Japan."

The technologies are out there to create sustainable energy sources, materials, and more, that can prevent or mitigate the worst results of global warming. High-tech fixes to actually living alongside rising oceans may prove a lot more elusive.

(via The New York Times)