Ice Sheets are past the point of NO RETURN!

http://www.newscientist.com/article/mg22229752.600-ice-sheets-may-have-already-passed-point-of-no-return.html#.U6tyOqiT5wk

The finding, along with data from Antarctica, suggests both of Earth's big ice sheets may have already passed a crucial tipping point, condemning them to collapse – either melting, or sliding into the ocean. That will mean sea levels rising by as much as 13 metres, leading to massive coastal flooding. So how fast will the ice collapse, and can we stop it?