Melting Ice does not make the volume increase!
Try this, Place a pitcher of ice water on the table with the ice floating on the surface the the water to the brim and let it melt.
The floating ice exactly displaces the amount of water equal in weight to that of the ice. As the ice melts, its water replaces the exact same volume as the part that is underwater when it’s floating.
Ice is less dense than water so when it melts it will result in a steady or lower water level not increase it.
These charlatans are preying on the public’s ignorance.
It does if it is sitting on land when it melts. The real point is, this alarm is over an unlikely event as far as 1000 years in the future. What a crisis.
This applies to ice that is floating freely in the ocean, or an ice cube in a glass. The ice shelf is, or part of them are, but the glaciers that feed into the ice shelf are not. These are flowing off the land and into the sea. So, depending on a lot of other factors, they might add to sea rise.
One factor is the water cycle. If we experience global warming, more water becomes vapor and may wind up as snow on the Antarctic, or rain over Africa. Lets hope for warming!