The Arctic lost 36% of its September ice since the 1980s. In March, only 9%.
The winter freeze-up still looks healthy. The damage is in the summer. Draw 47 years of Arctic sea ice around a clock and the shrinking happens on one side only.
Your guess first
Compare the average September ice extent of 1979-1989 with the average of 2016-2025. How much has disappeared?
50%
The ice clock
January at the top, then clockwise. Distance from the centre is ice extent, in million km2. Rings show decade averages; drag the year to overlay one.
2012
Loss by month
2016-2025 average versus 1979-1989 average. Tap a month.