The West Antarctic Ice Sheet has already destabilized. The only question is how long it will actually take to crumble into the Southern Ocean. The result will be a rise of nearly 20 feet. Check out
Global warming and the stability of the West Antarctic Ice Sheet : Abstract : Nature
Reef drowning during the last deglaciation: Evidence for catastrophic sea-level rise and ice-sheet collapse
Reef drowning during the last deglaciation: Evidence for catastrophic sea-level rise and ice-sheet collapse
http://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=1155&context=ers_facpub
Paleoclimatic Evidence for Future Ice-Sheet Instability and Rapid Sea-Level Rise | Science
From the last one:
Abstract
Sea-level rise from melting of polar ice sheets is one of the largest potential threats of future climate change. Polar warming by the year 2100 may reach levels similar to those of 130,000 to 127,000 years ago that were associated with sea levels several meters above modern levels; both the Greenland Ice Sheet and portions of the Antarctic Ice Sheet may be vulnerable. The record of past ice-sheet melting indicates that the rate of future melting and related sea-level rise could be faster than widely thought.
And what caused that warming 130,000 to 127,000 years ago?
A CO2 level of 300 ppm. Only 20 PPM above that of 18th century, 100 ppm below that of today. We are simply in uncharted territory with a level of 400+ ppm CO2, and 1800 + ppb CH4. How fast this will affect the cryosphere, permafrost, and clathrates is unknown at this point. Indictations are that we will see affects far sooner than we have previously thought.
Oh? Well it seems you're wrong about that. Or did you miss in the Mesozoic about 146 million years ago or so where CO2 levels were much higher, coinciding with a drastic drop in temperature. Or at the beginning of the Silurian Period.
What on Earth are you prattling about? First, you ask what caused the warming during the last interglacial. And I answered. Then you start yapping about the CO2 level 146 million years ago. With absolutely nothing to back up a single statement you have made.
What is happening today is happening at a speed that exceeds the delta V of the changes that occurred during the major extinction events.
Extinction and Climate
Species can adapt to gradual changes in their environment through evolution, but climate change often moves too quickly for them to do so. It’s not the absolute temperature, then, but the rate of change that matters. Woolly mammoths and saber-toothed tigers thrived during the Ice Ages, but if the world were to shift back to that climate overnight, we would be in trouble.
Put simply, if climate change is large enough, quick enough, and on a global scale, it can be the perfect ingredient for a mass extinction. This is worrying, as we are currently at the crux of a potentially devastating period of global warming, one that we are causing. Will our actions cause a mass extinction a few centuries down the line? We can’t tell the future of evolution, but we can look at the past for reference points.
There have been five major extinction events in the Earth’s history, which biologists refer to as “The Big Five”. The Ordovician-Silurian, Late Devonian, Permian-Triassic, Late Triassic, Cretaceous-Tertiary…they’re a bit of a mouthful, but all five happened before humans were around, and all five are associated with climate change. Let’s look at a few examples.