No, the mass doesn’t increase, but that is kind of irrelevant. The issue here is volume. In a closed system, like your ice cube in a glass, the volume would actually decrease if the ice melted, since ice is less dense than water (water expands when frozen). That’s why ice floats.
Now the oceans aren’t a closed system. There are plenty of glaciers that are not floating on the ocean, but located on land, like Greenland, or Antarctica. If these melted and the waters ran into the oceans, then the resulting additional water in the oceans might offset the DROP in sea level that would be caused by the melting of floating ice enough to cause the sea levels to rise.
Now, I don’t think this is going to happen due to man-made circumstances, but that is how their line of reasoning must go (I think).
There is no drop in sea leave due to melting of floating ice.
Thanks.
>>There are plenty of glaciers that are not floating on the ocean, but located on land, like Greenland, or Antarctica. <<
And the Antarctica mass is increasing.
And that is a MASSIVE part of the ice. After all, the north pole is not a land mass.
What many people don’t consider is that the South pole could get colder, but if there is no precipitation, the ice does not thicken and, over time, could even decrease. Meanwhile, it could warm up considerably, but get massive precipitation, effectively draining water from the ocean.
And that’s just the tip of the iceberg of complexity. Pun intended. ;)