Thanks again for all the info and insights you're posting here. Are you a publishing scientist in this field, or did your learn all this another way?
Just to be sure I repeat my question above: do I understand correctly that under RCP 8.5 you think almost 4 meters of (globally averaged) SLR around 2100 not only possible, but likely? And that between circa 2070 and 2090 you think about 2 meters not only possible, but likely? Or should I read this differently?
And in addition, what is your thought on the risks of SLR after 2100? For example, what do you think of these figures from Meehl et al (2012):http://www.nature.com/nclimate/journal/v2/n8/fig_tab/nclimate1529_F3.html
At least they seem to take seriously a risk of about 10-12 meters of SLR by 2300, under BAU, which is more than any other explicit projections I've seen so far, such as from the Dutch Delta Committee. But the projection of Meehl et al is based on the semi-empirical method, not including possible non-linear responses of the ice sheets, so it may still be an under-estimate.
So I'm wondering how your collapse scenario would continue after 2200. Do you project one big surge around the end of this century, or beginning of the next, and a slower SLR afterwards? Or could the EAIS also contribute one or more follow-up surges in the coming centuries?
I ask this also in relation to Foster & Rohling (PNAS 2013):http://www.pnas.org/content/early/2013/01/03/1216073110
They conclude that at 400 ppm CO2 there's circa 84% chance of at least 9 meters of SLR over the coming centuries/millennia and about 50% chance of circa 24 meters of SLR over this longer term. So even at 400 ppm, which we will reach soon, EAIS will probably start contributing significantly to SLR. It doesn't seem likely we will return below 400 ppm any time soon, although if we would really try it might still be possible.
Also Hansen & Sato 2011 (p.23) pointed to signs that Totten Glacier in EAIS is already starting to lose mass, based on Rignot et al 2008: "satellite gravity and radar interferometry data reveal that the Totten Glacier of East Antarctica, which fronts a large ice mass grounded below sea level, is already beginning to lose mass". Pfeffer et al did not take Totten Glacier into account.
For the record: I'm just a lay-man interested in and concerned about the risk of rapid and large SLR, among other climate risks, working for a local environmental ngo in The Hague, Netherlands, and trained in public administration/political science. I'm trying to understand the science as well as I can, but the technical details are often too hard to follow. So bear with me if I sometimes seem to ask for the obvious.