The large variation in sea level rise projections has been an embarrassment for several decades, and reflects poorly on society's process for decision making in the face of uncertainty. Rignot has stated that his data indicates that the ASE marine glaciers have passed a tipping point and that they will enter a phase of rapid collapse within less than 200 years, if we assume the current rate of grounding line retreat in this area. However, the following reference by Spence et al 2014 indicates that upwelling of warm deep ocean water in this area will greatly accelerate this rate of grounding line retreat.
Spence, P, Griffies, S., England, M., Hogg, A., Saenko, O., and Jourdain, N., (2014), "Rapid subsurface warming and circulation changes of Antarctic coastal waters by poleward shifting winds", GRL; DOI: 10.1002/2014GL060613.
Nevertheless, authorities still have not increased their SLR guidance (in my opinion they should now be increased to reflect the PDF and CDF given in Reply #5 of this post).
The basic problem with our decision making process on SLR guidance is that: (a) the "Tyranny of the Commons" problem rewards those who game the system to their advantage no matter how much loss there is to the common good; and (b) there are so many opportunities to game the system given our current levels of uncertainty [i.e. (1) scientists are not responsible for decision making so they only need to discuss their model's internal uncertainties and they can ignore discussion of external uncertainties not addressed by their models; (2) engineers can say that they only advise owners and to get low costs on effected infrastructure they can take the low range of the internal model uncertainty levels provided by the global expert on SLR the IPCC AR5; and (3) policy makers can say that they are only following the advise given to them by their advisors].
As undesirable as it may sound, the original solution to the "Tyranny of the Commons" problem was to have any Overlord claim ownership of the commons to prevent them from being abused; and it seems to me that soon the only solution to protecting coastal lands/infrastructure from the impacts of SLR is to provide 50 to 100-yr concessions to private groups (in partnership with the public authorities) to provide defense against the SLR that is now certain to come (this century), or to be held responsible for the damages to the property that they were given a concession to protect.