Arctic Ice Extent Tops 2012's, But Is 6th Lowest In History

We mentioned recently the rebound in Arctic ice levels compared to those found at the end of last summer; now that the 2013 minimum has been reached, Forbes' Alex Knapp points out that 2013's figures still show the 6th lowest ice extent in recorded history. "This pattern is expected to continue as average global temperatures continue to rise, leading to further Arctic Ice melts. The volume of sea ice – that is, how thick the Arctic ice is, has also been steadily declining over the same period. And although the charts above only go back to the 80s, the loss of sea ice began several decades prior to that. In 2011, a paper published in Nature estimating Arctic ice extent for the past 1450 years shows a sharp decline in Arctic ice beginning in the mid-20th century."

Comments

So who said...

[LeadSongDog]

... that the trend of annual extent minima was supposed to be monotonic?

history?

[iggymanz]

Reliable monitoring with authoritative of sea ice extents began only with the Scanning Multichannel Microwave Radiometer (SMMR) on the satellite Seasat launched June 28, 1978.

Very spotty records before that time are not considered reliable.

Re:history?

[haruchai]

The Danes have excellent records going back to the '30s.
And let's not forget that the volume is also dropping precipitously but that's much more difficult to measure.

Re:history?

[TapeCutter]

There's some pretty good volume estimates based on declassified sonar maps from the cold war, volume is now roughly 1/5th of what it was when I was born in the late 50's.

Re:history?

[Anonymous Coward]

True, but you can make some deductions from biology. The existence of polar bears, not to mention their threatened status with receding ice, paints a picture of a lot of ice going way back: had there been no ice 100 years ago, there would be no polar bears. 100 years isn't time enough for them to evolve from brown bears.

Re:history?

[I'm New Around Here]

So where were they when it was warm enough that the Vikings had two separate colonies on the southern shores of Greenland? Or was Canada still frozen while Greenland was basking in warmth?

Re:history?

[I'm New Around Here]

They failed after being there for 500 years. The first 400 must have been warm enough to keep them there and in good health.

It was only later that the climate cooled, and they were forced to change their lifestyle, and finally leave Greenland.

So my point stands: When it was that warm in Greenland, it was certainly warm in Canada and Alaska. So where did the polar bears live, if warmer water is lethal to them?

.
PS. This article says the Vikings actually adapted to the colder climate, and ate more seal meat as their livestock dwindled over the colder years. They only left in the end because they couldn't trade for needed materials anymore.
http://www.spiegel.de/international/zeitgeist/archaeologists-uncover-clues-to-why-vikings-abandoned-greenland-a-876626.html

Re:history?

[orzetto]

It was only later that the climate cooled, and they were forced to change their lifestyle, and finally leave Greenland.

My favourite author, Jared Diamond, had an entire chapter on the Greenland Norse in his book Collapse. They are remarkable because many factors impacted them at the same time, and their demise was due to climate, international politics, and their own stupidity.

Climate did get colder, but the Norse also lost their most important export, walrus tusks, because the Muslims started trading elephant tusks again with the Christians after several centuries of embargo: no one wanted walrus tusks anymore. Also, the Norse had apparently a phobia for fish, which for some reason they were unwilling to eat (or were unable to catch). They were also horrible diplomats and could not have friendly relations with the Inuit (who arrived in Greenland after the Norse), who eventually displaced them. Also, they were a very religious and conservative society, using relatively enormous resources to build a cathedral that could rival that of Nidaros in Norway.

When it was that warm in Greenland, it was certainly warm in Canada and Alaska.

That's a way too bold statement. Latitude is not the only predictor of temperature. I live at the same latitude as Anchorage, AK, but out temperature average is 5-10 degrees Celsius higher because we are exposed to the Gulf stream. Climate change does not have the same uniform effects in every spot.

Wonder no more.

[gargleblast]

Wonder no more: it is a statistical effect called Regression toward the mean. Specifically: ... following an extreme random event, the next random event is likely to be less extreme.

Not that annual Arctic ice levels are entirely random. They are somewhat linked, hence this year's being among the lowest in observed history.

Arctic ice is a ridiculous liberal myth

[El Puerco Loco]

Nothing resembling "the arctic" is ever mentioned in the Bible.

Some data

[amaurea]

There is some discussion on this here.

In particular, these two images from the same article are interesting: Temperature anomaly for the medieval warm period and temperature anomaly for the period 1999-2008. Both are anomalies relative to the same 1961-1990 average, so they should be directly comparable, though of course the medieval warm period is a reconstruction with significant uncertainties.

So to answer your question. yes, you could say that "Canada was still frozen while Greenland was basking in warmth". Though temperatures slightly elevated in some parts of Canada, most of it was cold. And none of them were anywhere near as hot as they are now.

Re:Wow!

[mcvos]

The absolute asshole arrogance to think that anything man does will have a long-term effect on climate is unbelievable

Because your unfounded disbelief make for such a better argument than science, doesn't it?

Just another manufactured crisis to grab grant money and headlines

Have you actually looked at where the money is in this debate? Are those poor, poor oil giants so strapped for cash that they can't counter the manufactured PR campaign by publicly funded scientists?

- and the beauty is, if anyone disagrees, just claim they are not "educated" enough to understand....

That's certainly what it looks like. That, or they're simply bought by the people with the real money.