Readers may find of interest the analysis of historian Corelli Barnett, his Pride and Fall sequence on the century+ collapse of England, on the Liberal Arts education, not to be confused with the trivium or quadrivium. He viewed it as a major cause of the collapse of the English, not least because you ended up with managers few of whom had scientific engineering training. The US has had the same problem, leading, e.g., to the relative dates of adoption of the basic oxygen steelmaking process here and in Europe. The medieval liberal arts included, as an aside, the most advanced mathematics known at the time. OK, all you liberal arts majors, do you measure up? Are you familiar the theory of rings and fields, complex analysis, and differential geometry at the proof level? Yes, I do think it is reasonable to have history as a major. The number of history majors should be a reasonable multiple of the number of professional historians that we add each year.

"...the graduate who has memorized some rote procedures to perform on preset challenges..." The gentleman's defense of the liberals arts consists of slandering engineering, the sciences, mathematics, economics,... Let me suggest that to the contrary it is the people who work in the challenging disciplines who must learn to attack matters in an open-ended way, and the undergraduate majors in the liberal arts who get by with, well, whatever. If the useful disciplines were so much "... memorized some rote procedures to perform on preset challenges..." rather than learning how to think hard, a task so challenging that some people choose to die instead, then why do we not see more students dropping out of Feminist Theology to major in Physics? George Phillies Professor of Physics and Associated Biochemistry Faculty and Interactive Media and Game Development Associated Faculty (and yes I have published in all three areas) Worcester Polytechnic Institute

Going up to the first graph here, some of those empirical fits are subject to empirical confirmation or falsification very soon. For example, the log fit shows a zero this coming summer. The next fit hits zero two years later. Etc.

Antarctic melting, absolute worst case analysis: Suppose the entirety of our solar power input became available for melting the Antarctic, in the sense that the temperature over the globe dropped to 0.1 C and all excess solar energy were magically transported to Antarctica to melt ice; what is the upper limit on how fast the ice melts? You have to supply the heat of fusion, and Sol only supplies so much a year, of which a certain part in the end does not melt ice and re-radiates into space. Times much shorter than this are wrong via energy conservation. I infer that this time is not the time mentioned above, which was the time given that the energy has to reach Antarctica to make it melt. Comments?

Accuracy of these numbers? See the popular science report http://www.guardian.co.uk/environment/blog/2012/sep/13/less-arctic-sea-ice-satellites proposing that the amount of ice may be being overstated by satellite reconnaissance, to that there is actually a bit less ice than some numbers indicate.

The radioactive isotope is carbon fourteen. Carbon thirteen is the rarer stable isotope.

and based on the last few years, the anomaly will likely heal up to -7 or-7.5 thousand, and then flatten out until next year, when it will fall again.

I may have missed the prior announcement but the new 9/2 PSC ice volume curve is up http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/ showing progressive recovery of the anomaly.

September 2 AM early. There is some divergence of the trend on DMI and IJIS namely DMI seems to be leveling out, and IJIS is falling rapidly, no matter what you say about the final pixels. You could say that what is left is almost all quite substantial if thinner and thinner, except for the Laptev area, but it is a bit different that what was seen last month.

Looking at IJIS measurements from past years, one might convince oneself that a normal behavior seen in some years, looking back a while and forward for some weeks, is that the ice amount declines roughly linearly in time. The end comes at different dates in different years. That pattern appears to be repeating this year as the JIS ice quantity appears to be falling close to linearly with time, just at a (much) steeper slope than in other years. Of course, if you believed that, you would conclude that IJIS will bottom someplace near 2-2.5 million square kilometers sometime mid-to-later part of the month.

With respect to mountain snow, recall that if it falls as rain, or melts sooner, it still flows downhill. Indeed, if the precipitation in depth of water does not change, if it falls as rain rather than snow more of it flows downhill because it does not spend months ablating first. Only if precipitation amounts change does the water flow down local rivers change a great deal.

Indeed, while there are day to day wiggles and this first day issue, the slopes on dmi and ijis appear to be getting steeper rather than shallower,though not by a great deal.

It is perhaps noteworthy that the DMI graph at http://ocean.dmi.dk/arctic/icecover.uk.php has resumed the remarkably rapid drop that it was showing when the Great Arctic Cyclone descended. The amount of recent steep drop seems larger than 'hiccup without significance'. Extrapolating that rate through to the end of August, even though we are in a period when in past years the rate of decay of 30% ice cover seems to have been fairly constant over the month, appears optimistic; trending below the 2 million level. The rate of decline of the DMI 30% ice is still impressive.

Lake Vostok: That's under the ice, with the ice on top of it, and if it is under sea level, with water on the far side of the ice pushing back. That's very different than how thick a vertical plate of ice you need to support a hydrostatic pressure head, and how thick and cold the ice needs to be to do this. Perhaps Greenland will give us some experimental examples. Has anyone seen recent data on the Watson river flood?

Mentioning the Point Barrow web cam and the people quite close to the shore in this significant storm, it appears to be that on the upper left of the view, between the road and the water, there appears to be a substantial earth berm that yesterday appeared to have a gap and today had the gap filled, and that on a 2009 shot that I can no longer locate did not appear to have the berm. However, this may be tricks of the light.

July 28 From the Bremen images, there seems to be a drastic change in the last couple of days in the area from the Bering straits and East Siberia up to about 80 N; lots of melting and opening seems to be happening.

If you look carefully at the expanded form of DrTskoul's image http://ice-glaces.ec.gc.ca/prods/MODISCOM-F/20120716000000_MODISCOM-F_0006542744.jpg you will find that the Northeast passage is now open. Look along the coast and an occasional diversion out to sea. Whether you can get anything with more draft than a kayak through there is another question...I do not know.

Indeed, Crandles has another superb link, for example the http://ocean.dmi.dk/arctic/Ittoqqortoormiit.uk.php Ittoqqortoormiit MODIS/AQUA 2012-06-28 shot, where the ice on east Greenland has pulled away entirely from the coast, and if you look at the upper left corner of the shot you can see what appear to be cracks forming at the inland end of the fjord (or whatever it actually is). It's incredibly neat, but I lack the time.

I am profoundly grateful to all of you for all the advice. For those of you looking at the big picture, is is on the left side of the screen, about half way down, and the breakaway is I gather moving from left to right. On Phil's gorgeous morning shot, note also the fine additional line behind the breakup. It starts at the bottom of the screen, a bit to the right of center, and heads off in the two o'clock direction.

I am extremely grateful to you for finding this, but in this 'covers several screens each way' document I am not sure what I am looking at. For the benefit of those of us who are a bit slower at aerial reconnaissance, could you possibly be persuaded to say roughly where in those beautiful photos the ice arch is? Thank you.

It appears to me from the latest Uni Bremen map http://www.iup.uni-bremen.de:8084/ssmis/arctic_SSMIS_nic.png for June 24 that the ice that had been attached over a long distance to the Greenland East Coast has let completely go and is headed for Iceland. There is this long North-South patch of blue right at the coast. I don't recall having seen something quite this dramatic, which means that everyone else on the list now gets to point out that I am noting a regular event seen many times before.

5/18: Not quite a century break from yesterday, but down 400K from three days ago: 11.816.

Piomasss has put up its end-of-October graph at http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/ The anomaly is currently -8000 cubic kilometers, and is still more than two sigma below the linear decline trend line.

With respect to wind, air volume in and out of the Arctic must nearly match -- "nearly" because air pressure does fluctuate. Thus cold air blowing out in zone A must be balanced by some temperature air blowing in, in zone B.

Someone has probably caught this already, but to judge from the Bremen maps the Northwest passage appears to have opened in the last day or so. Not the big passage, but a passage. I believe that is ten days earlier than last year, if I remember correctly a post here. But I could be wrong there, too.