At the risk of getting more egg on my face, I'd like to point out two minor typos in Kevin McKinney's otherwise excellent paper: One, You typed "namy" instead of "many". Two, Each water molecule has only one oxygen atom, not two.

Facepalm! Kevin McKenney was completely correct. Everyone else labeled theirs mean versus min, and I somehow read his backwards. Sorry for any confusion.

I'm curious at the difference that some people have between their "Mean" and "Min" September values: Name Mean Min Diff Kevin O'Neill 2.9 2.5 14% DoomComesSoon 1.7 1.478 13% NLPatents 3.0 < 3.0 At least 0% Kevin McKinney 3.24 3.43 -6% wili 1.5 0.9 40% Noting that the historical difference is between 1.0% and 7.5% (with an average of 3.4%) -- although admittedly it has been trending upwards, though not by that much. I am most concerned by Kevin McKinney, who raised his estimate. I'd guess that he applied his correction in the wrong direction, since 6% seems not unreasonable. Note that NLPatents makes sense, I am including it only for completeness.

2.8 Mkm2 +- 0.7 Mkm2 Trying to estimate where the trend is going by eyeball.

@Chris Reynolds Thanks for that analysis on our shrinking volume. However, I spent a few minutes scratching my head over one line before realizing that it was just a typo: And for comparison... 2013 3.261 actual That would be "2012 3.261 actual", right?

@Boa05att It may not be as much of a shock as you claim, as they also say: "The general view that the ice-cap is not at risk of a summer collapse in the next few years may need to be revisited and revised."

Just pointing out that crandles didn't disprove the paper. The paper said "increased area" and crandles demonstrated "near-constant volume". I bet both are correct.

I don't know what Kris means by "twice as high" (given that the temperatures are below 0 Celcius) but the average of the average values is -1.85C and the average of the normal values is -6.57C.

Oh, discussing nits reminds me, on the Rob's Masie spaghetti plot there is an extraneous "13) Baltic Sea" in the lower left hand corner of the map.

The "shining star" is the area where not enough sunlight falls for MODIS to capture an image. (Also called the "Pole hole" on this blog if you want to search for it.) I am pretty sure that the green is real, and it seems likely to be algae or something similar (though I am no expert).

@Wayne Kernochan In other words, 2 1/2-5 meters may be a low estimate. Actually, I believe that it is similar to "Moore's Law" (the prediction of the doubling of computer processor capabilities every 18 months). Hanson isn't specifying "why" the doubling should continue, and it is possible that this is simply one of the unknown unknowns that will cause it. @Peter Ellis Sorry, that's plain wrong. Assuming a constant doubling time is simply projecting an unbounded exponential, which is not just physically implausible, but literally impossible. Any exponential increase will stop, what matters is when. Well, of course the doubling would stop when there is no more ice to melt. :( With that said, however, some people on this blog prefer a Gompertz curve because the last little bit will be the bit that is most resistant to melting. Only the future knows for sure, but any scenario of runaway ice loss is a very bad thing.

@George Phillies I think the answer is "instantly" (given your rather magical assumptions). The volume of the Antarctic Ice Cap is ~25M km2 and the volume of the ocean is @1.3B km2. That's a ratio of over 40:1. Since the heat of fusion of ice is roughly 80cal/g, the average temperature of the ocean would need to be about 2C. Looking at this graph and noting that the average depth of the ocean is only 4000m, I'd say there's probably enough heat right there. http://www.windows2universe.org/earth/Water/temp.html

Looking at this graph from google: http://www.google.com/publicdata/explore?ds=d5bncppjof8f9_&met_y=ny_gdp_mktp_cd&idim=country:USA&dl=en&hl=en&q=us+gdp I'd agree that the US GDP has grown all but one year. That doesn't mean that the per capita has, but I'd assume that the per capita is not what's relevent to total energy use/electricity use/CO2 emissions.

@Seke Rob, I've been meaning to point this out for a while. You put "9.10.12" for the date of the prior record on PIOMAS daily, which I assume should be "9.10.11" bill

@SekeRob The thing I was noticing was that your old graph has the date of minimum information: http://i137.photobucket.com/albums/q210/Sekerob/Climate/CT_SIA_Annual_MinimaProj.png but the new one doesn't: http://i137.photobucket.com/albums/q210/Sekerob/Climate/NSIDC_SIE_Annual_Minima.png so the y-axis is confusing in this context. Either that or my browser isn't rendering correctly..... Thanks for all of the time you've put into this project -- I'm just a nit-picker.... bill

@Seke Rob Love that graph. However, you need to either include the date the minimum was reached or remove the y-axis on the right.

Sorry about that, Tor. You are, of course, correct that we've set a record for the CT Arctic Basin Anomoly. (Somehow, I missed the "Basin" when I read your claim. The claim it self was clear enough when I re-read it...)

@Tor Bejnar Actually, we haven't broken the record. During the refreeze, 2007 set a record which should survive until this year's refreeze (unless the area falls below 2.1). 2012.6246 -2.2613978 2.9423456 5.2037435 2007.8000 -2.6349814 4.4081578 7.0431390

Hey, Neven. Did you notice they called it the Great Arctic Cyclone of 2012?

New update on Artic Sea Ice News: http://nsidc.org/arcticseaicenews/

Looking at your excellent graph, Seke Rob, I noticed a very small error. In 1989, even though the minimum went below 7 million, there is no purple. Thanks for the cool visualization, though...

@Frank D. Artful Dodger recently addressed the issue of the reported temperature of ice: http://neven1.typepad.com/blog/2012/04/20112012-winter-analysis.html?cid=6a0133f03a1e37970b01630581c6a2970d#comment-6a0133f03a1e37970b01630581c6a2970d Basically, the temperature assigned to ice is the freezing point of water of the same salinity. So it should never get colder as it melts. But it could be warmer than usual if the ice is fresher than usual.

Excellent! In particular, the vertical grain on the "front" wall makes everything clear.

I just looked over the second one in detail and thought about it some more. 1. I see why the stripes are vertical, it's because the data is chronological. That might be hard to avoid..... 2. This angle looks much better, but is still hard to visualize correctly. And the other angle seems like it would be the better choice theoretically, as none of the details are hidden by other years. 3. Could you try connecting each end-point with a black line straight down to the floor. Maybe the fact that those lines are different lengths would help.... 4. Looking at the year-long graph, I see that you colored the "2012" wall. That looks pretty good and might also help. 5. I can tell that you've already tried lots of stuff in order to produce what you have. Please don't take any of this as criticism. I'm just trying to make it even better....

Thank you for the 3-D graphs, Heraclitus. However, something doesn't quite feel right about them. I'm going to try to analyze the first graph (http://i1167.photobucket.com/albums/q622/OPatrick1/IJISseaiceextentgraph.jpg ), in detail and see if I can explain it.... But first, a quick question for everyone. Does the light seems to be coming from over your left shoulder, your right shoulder, or somewhere else? My first observation was that it looks as though the front "skirt" were horizontally level, wiggling forward and backward. However, based on the way it is colored, it must be vertically straight and dip up and down. This illusion seems related to the fact that my brain keeps insisting that the light is coming from the left, even though, intellectually, I realize that it must be lit from the right. I think that that problem is caused by the stripes in the shading, which feel intuitively like they ought to be in horizontal layers (like sedimentary rock), but which must actually be vertical. It seems a trivial problem, but it makes the graph much less compelling/meaningful to me. Does anyone one else have this problem? And does your graphics package have enough control to make the stripes go horizontally instead of vertically?