"There's no one responsible for sea-level rise."

So says a frustrated David Holland, who directs New York University's Center for Atmosphere Ocean Science. And right now, according to an article in the Washington Post, no one has developed a computer model that can predict when sea level will begin to rise more rapidly, or how high it will rise.

Since the most serious contributor to rising sea level is the melting of glacial ice on Greenland and Antarctica, computer models must be able to account for the complex movement of these ice sheet across the unknown terrain that lies beneath them.

Without those models, scientists are left to guess on the timing and severity of sea level rise, and with estimates varying between the IPCC's forecast "that it would rise between 7.8 inches and two feet by the end of the century" and more catastrophic warnings that both ice sheets could slide into the ocean entirely, under certain conditions, policy makers are unable to move ahead with any planning to prevent or mitigate future coastal damage.

Worst case, as stated by Michael Oppenheimer, a Princeton University professor of geosciences and international affairs, is "if the Greenland ice sheet disintegrates, sea level would rise about 23 feet. If the West Antarctic sheet melts, as well, it would add an additional 17 feet or so." Such a scenario would wipe out coastal civilization as we know it. And no one can say, for certain, that such a scenario is impossible.