Here is one of many reports as a reminder. For years now, Greenland and the sea to its north have experienced never-before high temperatures.
A research report, dated 10 October, 2018 offers an explanation.
Reduced temperature differential between the Arctic and the tropics has made the Arctic jet stream wander all over the place. In 2011, its convolutions caused a cyclonic storm over the Sahara, lifting huge quantities of dust into the stratosphere. Then the jet stream took that dust and warm air into the Arctic.
This is what that looks like:
Meandering polar jet stream visible in red colours, upper-level trough visible in blue (graph by ECMWF).
The warm air directly caused warmth as it settled down. What the dust is doing is even worse: it reduces the reflectance of the ice.
These kinds of unprecedented, subtle interactions are the reason that every prediction of the rate of climate change has proven to be wildly optimistic. I have no doubt the latest IPCC predictions, urgent as they are, will also prove to be unrealistically positive. They say we must take urgent action within the next 20 years.
I say, we must take urgent action 40 years ago!
A sane society would be on the same kind of emergency footing as during the two world wars. Let’s do it personally, and pressure the politicians and moneybags to follow us. It’s not as if they could take their money and power with them.