Andrew Revkin thinks so:
It is hard to interpret this as meaning anything other than the crisis of Arctic Sea ice melting too much and too fast is over. This is an important thing, because the rapid and widespread melting of sea ice in the Arctic seems to be causing a thing called Arctic Amplification, which means in normal human terms that the Arctic is warmer (amplified) than normal. This causes a decrease in the differential between equatorial heat and polar heat in the Northern Hemisphere which seems to change the way the Jet Streams operate which in turn causes Weather Whiplash, where we have days and days of warm air being drawn north into “ridges” under the Jet Stream or colder air being drawn south into “troughs” in the Jet Stream. Our Minnesota Snowy April, the current midwest Heat Wave, severe cold in Siberia a while back, flooding in Central Europe, etc. etc. all are effects of the warped and slow moving waves in the Jet Stream. Climate math seams to explain the warping and stalling of the Jet Stream as a function of Arctic Amplification, and Arctic Amplification is clearly the result of a warmer northern sea which is caused by exposure of the sea to more energy from the sun because the ice is reduced. The ice is reduced because of global warming, and this is positive feedback effect.
If the Arctic Sea ice melt is “on a decent track” than this might mean a) global warming isn’t really happening and/or b) the Arctic Sea ice to amplification to jet stream warping and stalling to weather whiplash connection isn’t valid. So, that would be important. So let’s see if Andy is Revkin the Right or Revkin the Wrong on this one.
Here is a graph of the track of Arctic Sea ice melt for a period of ten years for the first years in which good measurements are available, from the National Snow & Ice Date Center. Since the recent changes in the Arctic post date this time period, we can take this to be more or less “normal.”
The black, thicker line along the bottom of these other lines is the average ice track from 1981-2010. Note that the sea ice for this ten year baseline period is almost never below that line. The baseline for “on track” is the average of these ten years, and I’ll leave it to you to imagine a line running along the midpoint of the observed ice tracks from 1979 to 1988.
Now, here is the same graph but for the ten year period prior to 2012:
For this later time period, the nature of Arctic Sea ice is fundamentally different than before. This is the period of time that the Arctic Sea has been warming. This is the period of time that Arctic Amplification has becoming more severe. This is the period of time that the weather has been changing. This is the period of time that has been affected by anthropogenic global warming. Sea ice tracks that are within this range are not “on track.” They are probably better characterized as “messed up.”
The year 2012 was exceptional. It was the most melty of the measured years. This year, is in fact, “on track” but not “on track” to be normal. It is “on track” to be one of the years in which the melting is excessive, and it is “on track” to contribute to Arctic Amplification. It could be worse. It could look like 2012, or even worse, I suppose. But it is not good.
I know it is hard to see all the lines in these graphs when many are selected for display on the Charctic Interactive Sea Ice Graphing Tool, but the years that are not as melty as the present year are all the years prior to the shift documented above, and 2002, 2003, 2004, 2005, and 2006 from after the shift. So, one way of looking at this year is that it is more or less average for the “new normal.” It is “on track” for more weather whiplash.
It is actually good news that the Arctic Sea Ice melting is not worse this year than last year, or even as bad this year as some previous years. But it takes a bit of imagination, or perhaps serves some intent that I find difficult to fathom, to suggest that this year things in the Arctic are on a decent track. Arctic Sea ice melt this year is not decent.
And, all this is about sea ice coverage. There is a more severe problem happening that these graphs don’t show; the melting of old ice, ice that is thicker, with multiple years all jammed up into thicker ice, has been severe over recent years. This ice is important because it forms the foundation on which new sea ice forms every year. Even if the climate went back to “normal” because some technology was invented that sucked all the extra Carbon Dioxide out of the atmosphere to return us to pre-industrial levels was implemented, the lack of old ice would mean that regeneration of sea ice in the Arctic each year would be difficult, and it would probably take several year get the Arctic Sea back to a decent track. For a change.
Here’s Mike Mann’s tweet response to Revkin’s tweet, which says the same thing I say in this blog post but in fewer than 140 characters:
(Professor Mann’s link is to the same data source I use above.)