1ºC is 20 m, sea level rise

Image from http://www.ausmarinescience.com/
I read this post recently and found it a terrific explanation of one of the most direct and frightening consequences of climate change: sea level rise. (I also bought his book High Tide on Main Street but I will try have to read it later).
One of the figures he gives is the best summary for me: Roughly sea level raises 20 m for each ºC, based on historic data. It does not happen immediately, the huge ice sheets need time to thaw but once the temperature is fixed it is unstoppable. Considering a moderate target of 2 ºC for our future warming if we do things relatively well and stop current business as usual in a reasonable time, this would lead to a terrifying figure of 40 m sea level rise. Others sources mention basically 21st century predictions as this article ( Antonio Zecca, Luca Chiari, Global and Planetary Change.). It calculates a lower limit of 80cm this siecle and more for the next 200 years; or the NOAA, witch estimates between 20 cm and 2m.
The problem to solve in order to predict the sea level rise is very complicated. Even knowing the exact amount of water coming from Greenland or west Antarctica, or the exact temperature rise and subsequent water dilatation it would be complex as the seas are filling the land floating in the magma. So, we have to be conscious or the great error margins and the difference between coasts.
But anyway, going back to the 40 m, I think my house would be included there, some years ago, in some floods just 3 m were enough to reach the lower floor, so I will not be here to see it but it could be sad to my grandsons to say this part of the sea was our grandfathers house.
A long time before that, with much less, it is likely that some housing market will realise about that and the wonderful coastal second houses or investment values will drop sharply causing an economical and maybe financial crack, and even before the strong storms will become a great problem for inhabitants owners and insurance companies.