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The Ventura County Star (February 8, 2007) covered James Hansen's UCSB talk with an eye to it's own local vulnerability to sea-level rise:

"Much of Hansen's presentation was old news to those who've been following the science and politics of climate change over the past decade. And to those without some grounding in the subject, the very technical material probably was just baffling. But he did make a couple of points about the latest IPCC findings that were largely overlooked or incompletely explained in last week's media coverage of the report. And the most significant of these relates to sea level rise — a subject of particular interest in low-lying coastal regions such as western Ventura County.

The IPCC report projects a sea level increase of 7 to 23 inches by the end of the century if temperatures continue rising at their current rate. That doesn't sound like much, and in most parts of the world it isn't. But the IPCC calculations take into account only the effect of melting alpine glaciers and the thermal expansion of the oceans, which occupy a greater volume as they warm.

These are trivial in comparison to the potential sea-level impact of melting continental ice sheets, which contain a prodigious amount of water.

The contribution of melting ice sheets in Antarctica and Greenland to sea-level rise is omitted from the IPCC calculations, the report says, because 'understanding of these effects is too limited.' The reason for that is that such melting does not occur in a linear fashion. Instead, the geological record shows that ice sheets are subject to profound and unpredictably sudden changes — a long period of stasis or gradual shrinkage in response to warming, followed by abrupt and rapid disintegration.

This has happened before: The Laurentide ice sheet, which covered Canada and much of the northern United States during the last ice age, melted virtually overnight in geological terms. And that melting was associated with a 3-degree Celsius rise in average global temperature — approximately what's predicted over the next century if greenhouse-gas emissions increase unabated.

'The last time the world was 3 degrees warmer, the sea level was 20 meters higher,' Hansen said. 'That's 80 feet.' Raise sea level by 80 feet, and every acre of Oxnard Plain farmland is under water. Half a billion people worldwide must find someplace else to live. And it took only 400 years for the melting Laurentide ice sheet to raise sea level by that much, meaning the water rose about 20 feet a century."

You can read the whole story here:

It's time to start packing:Climate-change report left out the scariest part