(Why do you study the arctic ice from space?) There's no way from the ground to look at the whole arctic and see how the ice is changing. (Why is this happening so quickly now?) some of the old models did not treat the sickness of the ice very well and didn't have data to verify. Most of the models did not include the heat that is flowing into the arctic from the Pacific and Atlantic. So both the atmosphere and the oceans are heating up. (If the biggest greenhouse gas emitting countries agreed to curb emissions tomorrow, would your predictions change?) No they won't, because there's too much inertia. It's going to take a few years to slow this down. (What's the net result?) First of all the native people there are changing their lifestyle, hunting, etc. the most serious impact is on the native polar bears. The retreat of ice means their hunting grounds are decreasing. But shipping might increase, fishing may be increasing, there will be shipping routes that weren't there before, and it may open it up for more oil drilling as well.