I've dreaded this moment for awhile now. For over a year I've been following the progress of the fracture along the Larsen C ice shelf in Antarctica. The images coming from the flyovers were incredible. Here was this gash across the ice shelf, an ominous warning of what to come. But the iceberg that was just produced from Larsen C is not important for the reasons you might think. At the moment, most scientists in the field are hesitant to say that this event had roots in climate change. That might be true, but it certainly is a red flag that the ice shelves in Antarctica are destabilizing---both by natural means, and due to anthropogenic (or human) contributions to climate change.
The ice shelves around Antarctica are already what we consider as sea ice. Meaning, that entire shelf, while anchored to the continent of Antarctica, is essentially floating atop the Southern Ocean. As the ocean warms, which it is steadily doing (see coral bleaching of the Great Barrier Reef for more evidence), that warm water gets underneath and chips away at the ice shelves. BUT! Sea ice will not be a contributor to sea level rise. That is reserved for land ice.