http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.1_CY.png
Note: The blue line is the record-breaking low ice year of 2012.
Arctic Ice volume is one of the two basic metrics I use to demonstrate the loss of sea ice. The other is “ice extent” or area of sea with a least 15% ice cover.. Those figures will be released for May by NSIDC within the next few days, and I will post them here.
There are other metrics that measure the state of the Arctic Ocean, but these are the two I use because they are the least ambiguous, and the ones hardest to spin by the denialist community.
During May, Arctic sea ice volume began to decline from its annual maximum for 2017. The volume maximum occurs one month later than the extent maximum because some areas continue to thicken while the extent begins to recede. Arctic sea ice volume through May 2017 continued substantially below prior years. May 2017 sea ice volume was 19,800 km3 , 1200 km3 below the previous record from May in 2016. The low sea ice volume results of anomalously high temperatures throughout the Arctic for November through January discussed here and here. May volume was 39% below the maximum May ice volume in 1979, 27% below the 1979-2016 mean, and more than 1.3 standard deviations below the long term trend line.
Average ice thickness in May 2017 over the PIOMAS domain is also the lowest on record (Fig 4.) Average ice thickness from PIOMAS is 20cm thinner than the last few years and about 80 cm thinner than in 1980.
http://psc.apl.uw.edu/research/projects/arctic-sea-ice-volume-anomaly/
Look carefully at those colored lines. If the ice continues to vanish at the rate it has for the last ten years, in about another ten years there will be no ice in the summer Arctic at all. After that, if the temperature continues rising, the ice-free periods will start earlier, and last longer , until eventually the Arctic Ocean will be ice-free all year long. We’ll probably all be dead by then, but our kids will probably live to see it. Whatever happens, I’m sure they’ll be thinking of us, and our role in making it all happen.