by P. Homewood, April 6, 2021 in NotaLotofPeopleKnowThat
Seventh lowest? The NSIDC would of course like you to believe that this is all part of a declining trend. In reality, since the sharp decline beginning in 2004, sea ice extent has gone up and down, but with little overall change. This year and last year, average March extent has actually been higher than in 2006.
This March, extent was the 8th highest in the last 18 years, putting it around the median.
What about prior to 2004 though? Should we not be comparing this year with the 1981-2010 average?
Like it or not, and whatever the reason, the loss of summer ice in 2007 has had a direct effect on sea ice at all times of year since. Much of the sea ice is now thin, new ice, which melts more readily in summer. Consequently, winter ice takes longer to form as well.
It would probably take a climatic regime shift, such as occurred in the 1960s, for ice to return to pre 2004 levels. But the evidence shows that winter sea ice extent is currently stable.