Think this is where some of the AGW orthodoxies may unravel. The Arctic is a piddle in the ocean compared with the Antarctic, in terms of the volume of ice but it is probably thus a good early warning indicator.
Notice some reports have the alarmists saying the Arctic ice is melting quicker than predicted so AGW is the culprit. The obvious response to that claim is that it more likely shows that the modelling (based on AGW) is flawed, or there is another mechanism in play such as the effect of ocean currents that is causing the ice to melt.
If the latter were the case, it is possible that there is a "secondary" GHG warming effect that comes about by a loss of the albedo effect. Though the reduction in ultra violet reflection was brought about by a natural occurrence and is not anthropogenic in origin.
There is still a lot of research to be done in this area to establish the proportions of natural and anthropogenic warming that go to make up the total amount of global warming observed (and predicted).
