Arctic Sea Ice

When the Arctic was 8 °C warmer

You won't see it in any travel guides, probably because of its name, but Lake El'gygytgyn offers many wonders. Lately it's been in the news because of fascinating paleoclimatic data the lake has yielded to researchers drilling its bottom. They managed to extend the climatic chronology of northern latitudes by a couple of millions of years and showed, besides a lot of other interesting stuff, that the last time the atmosphere contained 400 ppm of carbon dioxide, the Arctic was around 8 °C warmer than it is now.

In this video one of the authors of the paper explains what was done exactly (hat-tip to commenter Boa05att):

Edit: There's been some confusion due to my not being precise enough. The video below is from a previous paper, a couple of months ago, by the same group. The second paper extends the paleoclimatic data even further. Still the video below explains what was done exactly to retrieve the data and has fancy images of Lake El'gygytgyn. See the end of this blog post for links to more info.

Blogger Alexander Ač sent me this short blog post to explain the implications:

Why Arctic sea ice shouldn't leave anyone cold

The sea ice is leaving us a bit more every year. It's time to start contemplating its absence, which is why I teamed up with Kevin McKinney to write an extended version of the shorter piece you might see pop up here and there. Because you know, disappearing sea ice isn't without consequences.
And that's why it shouldn't leave you cold.

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Why Arctic sea ice shouldn't leave anyone cold

The first world in ancient Norse mythology, Niflheim,
sounds just like the Arctic ice. Its snow- and ice-melt gave rise to the frost giant Ymir, from whose body the whole cosmos was formed. Today, science tells us a different story about the sea ice, but in that story, too, the ice is far older than humans. According to Polyak et al. (2010):

…sea ice became a feature of the Arctic by 47 [million years before the present], following a pronounced decline [in carbon dioxide concentrations]… Ice was apparently most widespread during the last 2–3 million years, in accordance with Earth's overall cooler climate.

Since modern humans are just 200,000 years old, the ice might as well be eternal.

But not unchanging. We live in that part of an ice age that is termed an interglacial, when some of the ice retreats in summer. During modern human history the ice cap has melted back each summer as Earth tipped toward the sun, then grown again with new freezing as the year turned toward the Winter solstice.

Polyak et al. continues:

December 2011 Open Thread

We sleepily await the newest updates from NSIDC and PIOMAS. In the meantime over at the SciencePoles website from the International Polar Foundation there's a very interesting interview with professor Martin Jakobsson: Investigating Arctic Paleoclimates.