Arctic Amplification

From a paper published in Communications Earth & Environment titled "The Arctic has warmed nearly four times faster than the globe since 1979":

[W]e show, by using several observational datasets which cover the Arctic region, that during the last 43 years the Arctic has been warming nearly four times faster than the globe, which is a higher ratio than generally reported in literature.

In addition, some Arctic regions have warmed as much as seven times the global average. 

Update (August 15):  Jonathan Bamber discusses the implications of the findings.

Although there are some regional differences in the magnitude of Arctic amplification, the observed pace of Arctic warming is far higher than the models implied. This brings us perilously close to key climate thresholds that if passed will have global consequences.