In 2012, the maximum Arctic sea ice extent was reached on 18 March at 15.24 million square kilometres according to National Snow and Ice Data Center (NSIDC). Nonetheless, this was far from a record low—indeed, only number eight historically. The year 2011 held (and still holds) pole position for the freeze season maximum low, at 14.64 million square kilometres.
However, for the 2012 melt season, we all know what happened next (or at least the sentient part of mankind knows what happened next). The NSIDC announced the crash in sea ice extent to 3.41 million square kilometres at its September 16 low (smashing the previous 2007 record of 4.17 million square kilometres) with all the gory detail here.
The upshot of all this? Basically, current sea ice extent won’t tell us if we will hit a new record low this coming September. So we need to be patient if we want to answer the big question of whether we will continue to see a jagged descent this year (with even a possible year-on-year marginal gain) or a further phase change (setting us up for an ice free summer Arctic within a decade). In other words, will the patient cling on for a while longer or opt for a quick death.
With two kids aged 11 and 16, this must be one of the most depressing data tracking exercises I have ever done. In short, my children will surely now inherit an ice free summer Arctic (and possibly spring and autumn too by their middle age), with all the consequences that this implies. But how quickly?
So what will I be looking at? First stop is always the NSIDC’s daily image update, which gives you this chart:
And while I am at the NSIDC site, I will be checking their new Greenland Ice Sheet Today page, which shows the latest domino to fall: Greenland ice sheet melt.
The only problem with the NSIDC image is that it does not contain a daily ice extent number. For that, I like the Japan-hosted IARC-JAXA Information System (IJIS) sea ice extent data series that can be found here. If you look at this series, then it is possible that we have already peaked for the year (but watch out for the last reported day to be always revised substantially).
Next, I go over to Neven’s incomparable blog for all things sea ice. Currently, Neven is reporting good news, bad news. The good news (well let’s say goodish news) is that sea ice volume (as opposed to extent) is above last year’s level. The bad news is that many parts of the Arctic sea ice are showing large unseasonal cracks that could herald further record sea ice lows in the months to come.
Neven’s site is also a chart fest and live-cam orgy. It is like having a ring-side seat of the sea ice collapse. Comments area also generally very interesting.
After that, I will periodically check on the Open Mind blog, in which Tamino will be statistically slaying the latest nonsense from Anthony Watts and his ilk (good example here). If you want to dust off your stats, read Tamino’s series of posts on ice sheet loss in preparation for the new melt season. They start here.
Finally, I will try to bring the dire state of the Arctic sea ice into conversations with those I meet. Most will, in turn, change the subject. Planeticide is such an unseemly topic—best not to talk about it and pretend it isn’t there.