Are ocean levels going to wipe us out?

A new tool to decipher changes in the Greenland Ice Sheet size
I want you to try an experiment at home. Fill a glass full of ice and then fill it with water. Mark the water level. After the ice cubes melt, observe the new water level. This is an experiment many of us conducted when we were children, in science class, when the object was to observe how water expands when it freezes. Does the glass overflow, or does the water level drop. Since the water level drops, we must accept that the Arctic Ocean Ice Field will not materially cause ocean levels to rise once it melts. It will cause the ocean levels to drop. There are other issues of a severe nature as freshwater alters the salination levels of the ocean (but that is a topic for another article).
A fundamental problem exists if the ice that covers Antarctica and Greenland melts. Since it is on land, it can raise sea levels in two ways. As the ice melts, it will enter the ocean but also as the land experiences the post-glacial rebound.

The section labelled (b) in the top image shows the calculated temperatures from the borehole GISP2. The data closest to the present is on the right side of the graph. We can see the drop in temperature during the Little Ice Age and the Medieval Warm Period was two degrees warmer than the present. I have added a black line to demonstrate all the times the temperatures were higher or lower than the present.

The section labelled (c) shows how deceptive charts can be when manipulating the data to achieve smoothing. One cannot see the Medieval Warm Period or any of the other times that there was a significant temperature change compared to (b).

The final section (d) shows several data models that show that historically the quantity of ice was much less than now. The most extreme model shows that about 7-9 thousand years ago, the ice was 16 gigatons less than during the last glaciation. The ice field has increased so that we are sitting at about five gigatons less than during the last glaciation. Even the more conservative model (7) acknowledges that the ice fields were two gigatons less a few thousand years ago compared to now.

If "Climate Science" only considered the data from this study (copyrighted 2021), all the conjectures they have would be wrong. While it doesn't talk about what might have happened in Antarctica, it does make one wonder if we are far off from seeing ice levels returning to near glaciation levels.

It would be interesting to plug the data into some of the tools that people use while investing. I would also like to know what happened 8 thousand years ago. This time corresponds with the submergence of Doggerland.

Temperatures dropped by four degrees and had been preceded by a similar drop a few hundred years before. Will we see a repeat of this soon as an echo of the Little Ice Age?