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

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.

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: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.

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.

Permafrost is not your friend

[Tenebrousedge]

This would be funnier if it weren't completely retarded. Let me draw you a map.

I've explained enough times to want to make this short, but most of the ground up here is some variant on permanently frozen. At some point, all of that is likely to melt, and subside. We Alaskans know a lot about what that looks like, because if you build in the wrong way in the wrong place, you'll be filling out your cross-stitch with "Home Sweet Bog". Houses built on permafrost are built on stilts.

Also, while the Arctic is warming at a significantly greater pace than the rest of the world (1.6 degrees C up from last century, compared with .8 degrees C globally), the winters are still going to be cold as fuck (<-40) for a long time to come.

Plus, there's <1% of the land up in Alaska that's actually owned privately. The rest is owned either by the Feds, the State, or the Natives.

This is really just the tip of the iceberg. Your suggestion, and its underlying premise, are so wrong-headed that it's turning my stomach. Perhaps you can go be a real estate agent in Shishmaref, or one of the other villages that we're having to relocate due to climate change. Hopefully at that point you might understand exactly what it is that is offensive about your comment.