From NSIDC archive of daily Arctic sea ice concentration images
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/images/2012/07_Jul/N_20120708_conc_v3.0.pngvs.
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/images/2019/07_Jul/N_20190708_conc_v3.0.pngFWIW - Some amateur opinions for consideration and feedback:
1) to my eye July 8 2019 ASI concentration looks more vulnerable than same date 2012. The few areas where 2019 has more ice are doomed by Sept. anyway.
2) I don't think the extent and area metrics we use to compare between years fully reflect the degraded ice condition in 2019. Volume has a better chance of reflecting actual situation, but of course it has its own issues.
3) There is still a lot of melt season weather left to go, and as reported in the forum, late July-August 2012 weather was conducive to melt. While June 2019 was blistering, it remains to be seen what remainder of 2019 melt weather will be like, but it will be hard for 2019 to match late-season 2012. So that's gives an edge to 2012 in terms of the Sept. minimum extent/area/volume.
4) And 2012 had the Great Arctic Cyclone. I have to assume that an event of that impact is unlikely in 2019. But 2019 may bring its own events -- perhaps a couple of less intense events will have cumulatively equal impact as the 2012 GAC. A return of an Arctic dipole hinted at in the 10-12 day forecast yesterday is an example of hits 2019 could yet deliver to the weakened ice fortress.
5) Of greatest importance -- 2019 includes 7 additional years of a) continued decline of anchoring multi-year sea ice, b) what appears to be qualitative functional changes in ocean heat incursion, c) increased ice pack mobility, d) polar vortex weakening, e) higher atmospheric CO2e, and f) higher global SAT -- by about 0.3C increase between 2012 to 2019. That's a huge amount of extra energy in the surface layer of the climate system (not even counting the energy buried in the ocean, some of which could affect Arctic sea ice melting this year). There is a lot of additional heat embedded in the Arctic and surrounding system in 2019 vs. 2012.
6) Because of #5, I think we really can't know how close to the cliff we are. But we can be sure that we are getting closer to that cliff every subsequent year of not only persistent elevated GHG level, and not just year-on-year additions, but increases in the rate of increase of GHG loading.
7) So... 2019 vs. 2012? A toss up for Sept minimum only because 2012 was such a blow out. But on the current trajectory it's just a question of when, not if, cumulative progression will push the system below 2012 and make every year below 2012.
It's natural to focus on landmarks like Sept. minimum extent/area/volume, but in case you missed it, see the 365-day running average extent the industrious and appreciated gerontocrat posted at
https://forum.arctic-sea-ice.net/index.php/topic,2533.msg211770.html#msg211770. And the even more dramatic 365-day running average volume posted at
https://forum.arctic-sea-ice.net/index.php/topic,119.msg211798.html#msg211798.
More than the ASI status on a single September day, those trends show the larger story of what we are doing to a critical part of our climate system.
The world needs the people informed by this forum to spread the news of this existential threat to family, friends, neighbors, colleagues, and politicians. Please talk about it, that is the essential first step.