I’ve been following this story for a few weeks. A 160 square mile ice shelf has begun collapsing in Antarctica due to warming. It is theorized that warming waters melted floating ice that protected the shelf from large wave action, causing its connection to land to be broken.

No word on its affect on ocean levels but it is probably negligible. The real danger is that this is a harbinger of larger collapses to come.

Here is a video of the collapse. A much larger shelf may be in danger of breaking up as a result of this collapse.