NSIDC begins their Arctic sea ice graphs in 1978-1979 – which creates the impression that Arctic sea ice is steadily declining.
They ignore satellite data prior to 1978, which shows that Arctic sea ice extent was two million km² lower in 1974. The graph below was in the 1995 IPCC report.
The Arctic is not melting down. Arctic sea ice is currently the thickest since 2006, and thickness is about the same (2 meters) as it was 75 years ago.