When I saw the University of Washington’s Polar Science Center presentation of Arctic sea ice volume last month, I thought that perhaps its latest reading might be a transient graphing error:
But a month later, Arctic sea ice volume remains down after a staggering drop:
The astute among you may notice that the y-axis measures an anomaly in ice volume: specifically, deviation from the 1979-2009 average for the calendar day on which measurement occurs. If you’re a climate change skeptic, you might think, “Aha, I bet that the change in Arctic sea ice volume is nothing compared to the magnitude of the sea ice that is there.”
Given the appearance of the graph, that might be a reasonable suspicion, but it would also be wrong. At its nadir last September, the volume of Arctic sea ice was 5,800 cubic kilometers, a value 67% lower than the September Arctic sea ice volume in 1979. At the latest assessment made as of July 17, the volume of Arctic sea ice was more than 10,000 cubic kilometers below the average July volume from 1979-2009, and the 1979-2009 average July Arctic sea ice volume is only about 19,000 cubic kilometers:
In short, more than half of the Arctic sea ice volume you would have seen in a late 20th Century July is gone now.
Like the Gulf “spill” (oopsie): Nothing to see here, keep moving folks, let’s go about our business now, step lively . . .
i notice this stuff NEVER makes the news. Neither does all the illegal spying on us, the war blunders or the cost of the new “fin reg” to us. i feel like we’ve become what the old communist regimes used to be like – all propaganda and distractions all the time.
Am I the only guy who can do arithmetic here? If the “anomoly” is -3.4 cubic kilometers per decade, that’s 340 per year, and the anual minimum (“nadir”) is only 5800, then that means in about 16 years or so, it will be all gone. Is that right – - am I wrong? I’d actually LIKE to wrong here, but I’m afraid that’s correct.
I wish an expert here would interpret the implications. I have to guess that a mostly-water pole cap would mean much stronger temperature gradients – and therefore stronger storms – during the (Northern Hemishphere) winters.
I’m thinking sooner. As the bulk of ice gets smaller, won’t the ice temperature rise? Like from zero degrees (F) to 20 or 25? Still ice but closer to melting.
I’m going to put an ice cube in water and watch it till it melts away and keep some kind of time based log; try to figure out if it melts faster toward the end. ( How could it not?) Sounds relaxing too.
Homework: Before getting into bed, point to where the sun is. ( You can figure it out!) Using the moon, if it’s out, is recommended.
Cheers.
Jim, Correct – if the trend is linear. Looking at that graph, I’d say its not linear.
I agree, Ben. The loss of volume looks to be accelerating, with recent ice loss more than 2 standard deviations away from what we’d expect given the overall trend from 1979-2009.
An ice-free Arctic would also absorb more solar radiation than an ice-cap Arctic (see “albedo”), further warming the Earth.