https://www.youtube.com/watch?v=Xh3oakgxZ9w
To be clear, this graphic does NOT show the ice volume on the Arctic Ocean as it has melted away for the last 38 years.
What you’re looking at here is how the ice volume in mid-September has diminished over the last 38 years. The ice always comes back in winter, just not as soon, not as fast and not as much.
The volume of Arctic sea ice in mid-September 2017 is 27% of what it was in 1979. By contrast, the Arctic sea ice extent in mid-September 2017 was about 44% of what it was in 1979.
Once the thick multi-year ice is gone (I’d guess in about another 10 or 20 years), the only ice left on the Arctic basin will be a thin crust (<1 meter) that will mostly melt away every summer, and re-form every winter.
In the summer, with the hot sun up all day long in the Arctic sky, there will be no protection for the dark sea, the rays will penetrate deep, warming it up further. Then, with a thin layer of insulating ice cover to keep that heat in during the winter darkness, the temperature of the Arctic Ocean will gradually rise until it eventually becomes ice-free all year long.
No one knows what this will do to the earth's climate, or to our agriculture and industry and human settlement patterns. But I suspect the changes will be profound.
I don't expect most of us will be around to see this, but I suspect our kids will.