Arctic Sea Ice Extent Is Not Extensive

September is when the melt of the Arctic Sea Ice stops, and the re-freeze starts. We are probably not at the minimum yet, but the amount of melting is starting to level off so we can see where we are. The above graphic, made here (go and play with the interactive graph) shows the first ten years of ice freezing and remelting in the data set to use as a baseline for comparison, and the present year. Yes, there is much less sea ice on the northern end of the planet than usual.

This version of the graph shows the years with less ice, so far, than the present year. This includes the famous 2012 when the ice melted a lot lot more than usual, instead of merely a lot more. 2007 probably had less ice than this year will see, but we can't be sure yet. 2011 and the present year are almost the same. Again, we'll see but currently 2011 had a tiny bit less sea ice extent.

Screen Shot 2015-09-13 at 11.25.31 AM

So, 2015 will end up being the second or third most ice free year on record. Keep in mind this is only surface, not volume. Still, surface is very important because it is part of a feedback system; the more surface ice the more reflection of sun's energy back into space, the less surface covered with ice, the more the Arctic sea is warmed by the sun during the summer.

More like this

Every year the sea ice that covers the northern part of the Earth expands and contracts though the winter and the summer. The minimum extent of the sea ice is usually reached some time in September, after which it starts to reform. Human caused greenhouse gas pollution has increased the surface…
The Arctic Sea freezes over. The Arctic Sea melts. This happens every year. The average date for the maximum extent of Arctic Sea ice, based on a period of 1981-2010, is March 12. The minimum extent is reached, on average, about September 15h. Every year for the last several years, the minimum…
Everything is about ice these days, what with the Winter Olympics in full swing. Concerns that the temperatures at the mountain venue of Sochi would be problematically high have panned out; the lower parts of the downhill slopes are slushy and the bottom of the half-pipe is all bumbly wumply.…
During the northern Winter, much of the Arctic is covered with sea ice. Some of this ice melts during the summer, then it regrows. Over recent years, the amount of ice loss in the summer has tended to increase, almost every year, year after year. In 2012 the loss of sea ice was extreme, falling…

Greg: Your second chart looks like the same chart as the first chart (at least on my chrome browser).

From the text I gather it should look different.

It does seem to have changed since I first viewed it. The one I recall had a dashed line... ???

By Brainstorms (not verified) on 13 Sep 2015 #permalink

Pretty pointless to track ice over a 5-year period. Earth is millions of years old. Look at larger trends. Also, south pole ice is expanding.

By Mike Johnson (not verified) on 13 Sep 2015 #permalink

Mike, the data here start in 1979. !979 to the present is not five years, it is longer. You may need to get yourself a new calendar.

It is pointless to track ice in relation to the age of the Earth, which is billions, not millions, of years. That would entirely miss the point.

South pole ice is indeed doing something different. But that is pretty useless ice when it comes to the arctic. It is in the south, not the north. It does not "make up" for arctic ice.

The south pole and north pole are such utterly different situations that they can't be compared, and it turns out that the expansion of extent of sea ice in the south is both a) not the same thing at all as sea ice extent changes in the north and b) caused by ... guess what .... climate change!

So, you're kinda wrong on all points.

Mike, if you get ill and get a high fever, do you think it's appropriate to track your temperature since you were born or since you got ill?

Thomas, good analogy. Or, extended, to track the temperature of the atoms you are made of since the big bang.

Surely the point of tracking is to try and help us understand cause and effect, so that we can make informed guesses about what is likely to happen in the future - tomorrow, next week, next year, in 20 years, and to test theories to see which ones best predict the effects of particular causes.

By Robert Morgan (not verified) on 14 Sep 2015 #permalink

Both charts are exactly the same, it looks like the second one is a copy/paste of the first one whereas it should be different as RickA correctly said.