Climate Feedback and Polar amplification
Climate models generally predict amplified warming in Polar Regions due to climate feedbacks. This is called Polar amplification. This can be understood by the fact that due to the climate changes, the Arctic has warmed much leading to Arctic Shrinkage. Most simple climate models predict warming at both poles but please note that the Antarctic has not warmed as much as the Arctic.
It is the Polar amplification that has led to the Arctic shrinkage.
Arctic Shrinkage refers to the decrease in size of the Arctic region and is agreed to be a result of global warming. As per the projections, Arctic may be free of the summer ice at anytime between 2060 and 2080. This is the reason that Arctic is often seen as a high-sensitivity indicator of climate change.