Interesting. About what time is this supposed to start?
Well, if you read the article, it basically says that it would start when/if the Greenland Ice Cap starts melting at an accelerated rate. Tbey don't specify a time for that other than it could potentially happen this century. Or next. Or not.
IN case you think I'm being glib:
Greenland glacier crack points to disintegration
From: PHOTOS: Huge Greenland Glacier Disintegrating
I recommend reading the text. The pictures were from July, as you can see, the first linked article from 4 days ago.