For my money, Ice loss is the biggest «in year» story if you are being purist about what constitutes a climate story (other stories are bigger if you take a longer view than the year just ended, but the effects haven't really hit yet -
the ongoing ice collapse is happening right now).
Gladstone et al. (2012) also investigated the future of PIG, and they too found
ongoing ice mass loss to be likely under a «business as usual scenario» (IPCC), with full
collapse of the main trunk of PIG during the 22nd century still a possibility.