I think LRC has a good point. Anyone who lives in a NH area that gets a real winter with consistent cold can attest to the durability (or not!) of ice formed at different times during a winter. While it is not scientifically accurate or truly comparable, I know the ice around the deeply shaded glacial erratic in my woods behaves and melts quite differently (slower) than the ice that accumulates in areas with more sun. The shaded ice is hard and resists melting, while the other stuff is fragile and goes away much sooner. If this is the case over a few months, it certainly matters over multiple winters with ice in the Arctic. Quality of ice is hard to measure, especially remotely(!), but is a factor in how the FY ice that accumulates this winter behaves come next summer.

Have a fine holiday, Neven and thanks for all you do on this terrific blog. I've not been able to spend much time with it this summer, but it's wonderful and valuable information, aided and abetted by the regular suspects who post here with so many thoughtful insights. The ice, at least some of it, will still be here two weeks hence as we approach the end of melt season... unless it also doesn't go according to the "normal" schedule. Be well!

I think Superman and Aaron Lewis said it well. While they describe "the unthinkable," it is also what we are seeing in the Arctic and in the weather. At least in the U.S., people (especially politicians) refuse to think. They are willing to attribute big shifts in weather --heat, drought, storms-- to natural variability, and can't see much beyond a couple of seasons, so the impact of greater change is pretty much unfathomable. Until it happens. Then they want instant fixes, easy solutions, money from the government, etc. This reactive mindset is every bit as pernicious a problem as rising CO2 levels and increasing temps, because it breeds inaction. Climate change is basically not covered by the sound-bite-driven world of media, with the exception of a few stalwarts like Andy Revkin. And the mainstream media doesn't even know what questions to ask someone like James Hansen. The U.S. might very well be deluged with rain next year, have great crops. And people would think it was fine, believing it proves things are OK. In talking with people, I continually find that lacking any education about climate and the importance of the Arctic, they don't care, and think the changes are too far in the future to affect them. And very few will make any changes in their lifestyle to do more than adapt to a warmer world. Sadly, it means we're going to have the climate we're going to have, and not much will be done about it.

This is just delightful. Well done! This is a piece I'll re-read a few times and keep for some time. Thanks!

Neven, thanks for all your amazing efforts, fine commentary, and for bringing the whole crew here together this summer. It has been an exciting (and quite educational) one for sure. And I somehow think next melt season will bring more changes. Now to watch what happens this winter... while hoping it brings good snow and skiing.

Chris R, Yes, those are the 3 factors I'm thinking about. The Siberian one doesn't have enough data yet (at least as I understand it) but there at least seems to be some influence beyond regional cooling. The other factors do seem to be having pretty far reaching effects. The high pressure that hovered over the Arctic last winter did push cold air south, and I'd guess most of us are waiting to see what happens this year. (On the upside, it brings more snow and the skiing is great!). The downside is not so good. And Ned Ward, no we're not related. But enjoy your "retirement" and the accolades of your prediction. I was predicting about 4.85 but did not go public!

Chris R. Interesting work! Have you also looked at winter changes? NH winter weather also seems to be shifting in recent years with more cold and snow.

Gee, I wonder what he has to say now about 2011. Of course, he gets paid to say what he does, so as long as he has a good imagination, he can keep on going!

For many years Parry Channel wouldn't open and the explorers looking for the NW Passage went for the southern route. Now they both are open. When you think about how this changes the shape of the Arctic and the ways humans can move about in it, it's pretty significant. Next we will have to watch the date they open.

Ian, the lack of media fuss has lots of reasons. At least here in the U.S. (where everything is spun and politicized) there is declining interest in anything to do with global warming. I don't know about people in Europe and elsewhere, but in the U.S. people only react to disasters that make the 24 hour news cycle. Slow motion ones like the Arctic don't count. Very discouraging. But maybe this year can get some press and attention, especially if it influences NH weather again.

This is fun. But I have one question. The turbulence from the impellers in the slushie machine I understand. And there is motion in the ocean, too. But how much sugar has been added to the sea water?

I also tend to agree with Werther. 2007 was a big year for ice loss, but mostly because it was so dramatic. 2010 was impressive, but what I think of is how this year's slush puppy is showing us more about how the ice can act and what it can mean for future summers. OK, the slush can perhaps freeze up faster as the melt season winds down, but that "new" ice is likely to be pretty fragile stuff that can melt sooner next spring. Add that to the continued loss of MYI and things appear to be going consistently downhill. (More data and a longer trend line, perhaps, for the deniers to find an excuse for.) Then there's the issue of NH weather. I'm in the U.S. and we've had some exceedingly bizarre weather the past 3 years, especially the past two. Cold in much of the nation, even where it usually isn't all that cold and all but one state had significant snow storms, which is not remotely normal. I live in New England and the number of really cold days and the amount of snow we had went into the record books. I know I burned more firewood and used more heating oil than ever last winter. Then there's this summer where the heat has been persistently high over much of the U.S., weeks at a time over 37 C in several places. There is certainly a connection, but as usual more data is needed to truly quantify the trends. Another "hard winter" from 30 to 55 degrees North latitude would be no surprise to me.

Great map and chart, Seke Rob. Makes the area-to area-comparisons easier to see and understand for a non-scientist like me. Nice work!

Neven, thanks for sharing the Science 2.0 piece, "Oldest Arctic Ice." It's well done and good reading.

Truly enjoyable piece on the "Oldest Arctic Ice." Thanks for sharing that, Neven.

I just pulled up NSIDC maps for August 5/6 for this year and last year. NWP was closer to open at this point in 2010, but other areas had more ice. But NWP today looks very loosely packed and appears passable with an icebreaker leading the way. With the weather and temps as they are, I don't think it will last much longer. Anyone want to wager on when NWP is really open this year? I'm thinking about August 24.

Peter's response confirms what I suspected. (thank you!) A tipping point is a point of irreversible change. I have long agreed with Dr. Hansen. I do think we are approaching a tipping point in some respects. Temperatures seem unlikely to drop back, barring some other forcing such as a super volcano putting enough into the atmosphere to dial back temps for a while. But the CO2 will prevail.

Something to think about is the terminology used and how stories like this get reported. The thing that's bound to come up and be misinterpreted is "tipping point." What does it really mean? It can certainly posit a massive change, but in the case of Arctic ice does it have to mean an ice-free Arctic? I suggest that it does not. It can certainly be a point at which there is dramatically less ice all year round, with limited recovery during winter, but not necessarily an ice-free Arctic ocean. Maybe this is just semantics, or ice-free is meant infer a navigable ocean. Still, the article is interesting and I'll get a copy of Science at my local library to read the whole thing. A pending tipping point or not, the global temperature is clearly going into uncharted territory, and with lots more people around than there were at the Holocene maximum. This is not the kind of risk that's good.

I'm thinking (somewhat sadly) 4.8 or 4.9-ish. I haven't been tracking this as long as you guys have, and I'm not a climate scientist, but I have a good sense of how trends work. And it wouldn't shock me if 2011 came in above 5.0. As "bad" as a level well below 4.5 may portend, I'd like to see it because it might help wake people up. I think we have to be thinking about thickness of the MY ice. I have a suspicion that it may be something we're just not paying enough attention to and it may show itself to be more important in a summer or two. But I'm just an amateur, trying to reason this all out. And convince skeptics and deniers I run into that we really have to think about this stuff.

The kind of conversation Wayne describes is frightening. Unfortunately, it's too common in the States when bureaucrats, civil servants and political appointees are involved. By making something absolutely clear, many people are still confused.

What troubles me is that this appears to be a move to actually suppress Monnett's findings by the Obama administration. George W. Bush did this deliberately and now Obama is doing the same thing. What was that Aldous Huxley line, something like "ignoring the facts doesn't make them go away." How many dead polar bears does it take to prove there is a problem?

Rlkittiwake, I fear you are right about inaction on carbon emissions. Here in the U.S. action only comes (if the stars align) after a few disasters in which there's a "smoking gun" that points to a cause. Even then action is slow... The mega heat wave this summer, the flooding in the northern plains and the heavy snows of last winter have no effect unless they could be conclusively linked to climate change and CO2 emissions. But this year, even if the evidence was solid or if all of Greenland melted, the government is too pre-occupied with other things to do anything.