I'm pessimistic because I suspect that the ice shelves are being modelled as more stable and warming-resistant than they really are. A while ago I wrote:

A lot of the climate models seem to have modelled the ice sheets as ice cubes when they behave more like a drop of honey. Ice cubes are very poor heat conductors, insulate their own interior, and only melt on the surface. A drop of honey gets less viscous and flows more easily as it warms up. But I am not an expert on climate modelling.

ARGeezer:replied with

Lately I have been reading articles in Science News and elsewhere about glacial lakes melting holes through very thick glaciers and disappearing through said holes. It appears that this additional water further lubricates the interface between the ice and the rock below, increasing the rate of glacier flow.

I was recalling an article we had discussed in the Salon a couple of years back where some climate scientists suggested that the "ice cube" model used in climate simulations led to melting times of the order of 1,000 years whereas the actual dynamics of the ice shelf might lead it to disintegrate on much shorter timescales.

Then I have seen footage of how meltwater pours into deep crevasses in the Antarctiva ice sheet, going directly to the bedrock where it lubricates the interface between the ice and the rock. I am not convinced large chunks of the Antactica ice cap couldn't simply slide into the sea as a result of this lubrication.

The brainless should not be in banking. — Willem Buitler