[stochtastic]

Archimedes would like a word. There are some small effects due mostly to salinity differences, but sea ice isn't a major contributor because it is already floating and thus displacing an equivalent volume of water:

https://en.wikipedia.org/wiki/Sea_level_rise#cite_ref-113

[hinkley]

Sea ice also reflects light. Remove the ice and the water beneath heats up.

That's part of the runaway effect we are freaked out about.