Looking at the discussions going on about ice volume and area and extent, I was reminded of the constant statements from Gavin Schmidt at Realclimate about seasonal variations which are ironed out in the decadal averages and only the decadal averages really show the trend.
So I grabbed the
NOAA extent dataset from 1979 to 2014 and carried out that exercise.
Now we don't have the whole of the 2010's so I calculated two sets of figures. One for the decade on decade to 2008 and one for the first six years of each decade which can be compared to 2009 - 2014.
For the Maximum average the figures come out as this:
1979 - 1988 16.22
1989 - 1998 15.77
1999 - 2008 15.57
for the maximum on the first 6 years, it comes out as
1979 - 1984 16.21
1989 - 1994 15.84
1999 - 2004 15.34
2009 - 2014 15.13
For the Minimum it's somewhat more pronounced
Decadal:
1979 - 1988 6.96
1989 - 1998 6.54
1999 - 2008 5.53
for the Minimum on the first 6 years
1979 - 1984 7.02
1989 - 1994 6.57
1999 - 2004 5.93
2009 - 2014 4.56
So I have a few of questions...
What recovery? On any decadal figure.
What recovery on the comparable decade on decade for the first 6 years of the decade?
Who wants to bet that the 2010's will finish above the 2000's when we complete the decadal average in 2019???
Who is willing to bet that the decadal average Minimum for the 2020's will be over 4M?
Who is willing to bet that the decadal average Maximum for the 2020's will be over 14M?
I think that half the discussions we have about "recovery" are driven by the very narrow, year on year or even 2-3 year view we take. If you push it out to the decadal level, any talk of recovery is completely redundant.
Gavin was absolutely right. If you look at the signature over the decades the message is clear and the impact is crystal clear.
Whilst it doesn't help us determine exactly what this years Minimum will be, now that we know the maximum, or how the melt season will go. It does help us understand that the heat is having an impact and that even in a cold weather season the ice should be less than it would have been even in the 2000's.... Which is a starting point I guess.