If all glaciers and ice sheets on Earth melted, sea levels would rise roughly 65–70 meters (about 210–230 feet). It’s worth noting that a full melt of Antarctica alone would take many thousands of years even under extreme warming scenarios, so this is more of a thought experiment than a near-term risk. Current projections for this century focus on partial contributions, with estimates ranging from roughly 0.3 to over 1 meter of rise by 2100 depending on emissions pathways.

That's been known for a long time - it just hasn't been considered a likely scenario. It's the rise we'd expect if all the ice on Greenland and Antarctica were to melt:

https://sealevel.nasa.gov/understanding-sea-level/global-sea...