skierinvermont

I think your overall point has some validity. There are a lot of pressing problems facing humanity today. There could be even more in the future, regardless of climate change. But I would suggest reading some more scientific sources about the effects of climate change. Increases in flooding, drought, and sea level will have huge costs to humanity. It affects the entire planet and the problem is not temporary.

I've been listening to people like you say the cooling is coming for over 10 years. In fact, I had a radio show in college 10 years ago where I actually said we could see some cooling and AGW might be greatly exaggerated. Mostly I was overreacting to learning that some news articles, Al Gore, and even some science was skewed towards AGW and I went off too far in the other direction. I learned from my mistakes. Some never do. We've already been through one very weak solar cycle for 10 years now. The earth didn't cool down. It didn't even stop warming.. it warmed a lot the last 10 years. This is where you introduce some magical lag period you read about on some internet blog that doesn't make any logical or physical sense. Let me tell you a secret.. these magical "lag" people were the same ones saying cooling was imminent 10-15 years ago. Then they invented the lag, because instead of the warming reversing or stopping, if anything it actually accelerated.

With our current very low volume we could get an ice free summer if we got a summer weather pattern similar to or worse than 2007 or 2012. (if you use the commonly used convention that 'ice free' = <1,000,000 km2). If we don't see a rebound in volume, ice free could occur any year in the next 10 years with bad enough summer weather. On the other hand, we might not see an extreme summer weather pattern in the next 10 years. By the 2030s even a modestly bad summer weather pattern would likely put us over the edge. To get really statistical about it I'd put the odds like below. I think my odds are pretty consistent with CaWx's estimate above (maybe bumped back 5 years). A lot depends on weather and trends but it will probably be somewhere between 2020-2035. <1,000,000km2 15% chance before 2020 35% chance before 2025 55% chance before 2030 80% chance before 2040. If you define it more strictly as <200,000km2 (basically a few icebergs and bays that got filled with ice by the wind) I think the odds drop. Because of currents and winds, there's always a pretty good area of thick ice blown near Ellesmere and Greenland and you'd have to melt pretty much all of that (other than some that gets blown into bays) to get below 200,000km2 5% chance before 2020 20% chance before 2025 35% chance before 2030 60% chance before 2040 These odds factor in the reality that the earth will very likely warm significantly over the next 25 years (very likely 0.45C+/-0.2C). The arctic will likely warm 1C+/-1C.

It looks to me like most of the ice is thicker than last year. It's just the ice north of Greenland and Ellesmere that is much thinner but that ice never melts out anyways. The only important area that looks thinner is the Laptev which looks a little thinner. That could get things going early there. But the Chuchki, Beaufort, Barents, Kara and East Siberian all look thicker overall. Especially the northern Beaufort and northern Chuchki which look much thicker. And those two areas are critical in August/September.

Yeah except the ice is barely half as thick. Be quiet until you learn something. Some of us have been following this thread for a decade. We've seen arrogant newbies like you come and go. A few stay and learn something. But nobody that's been around the block would say something as foolish as what you've just said.

The "back to 1870" project that the author of that blog post references hoping they will show less ice 1920-1940 than the early 2000s was completed recently. It did not live up to the author's expectations. It did increase the variability somewhat, but the lowest years of the 1930s is similar to the 1980s. The study produced was titled " A database for depicting Arctic sea icevariations back to 1850. " and was published earlier this year in the journal Geogrpahical Review. https://www.carbonbrief.org/wp-content/uploads/2016/08/Walsh-et-al.-2016-Fig8.png http://cires.colorado.edu/news/reconstructing-arctic-history

I read through most of that article and the comments and am fairly unimpressed. It's a stew of anecdotes (no saying how cherrypicked they might be) without any objective data compilation and analysis.

I would be greatly interested in such evidence. I hope you are not referring to anecdotal reports of submarines surfacing at the north poll etc. Studies that actually compiled airplane recon and ship data come to a very different conclusion. The highest years of the early 80s might have been similar to the lowest years of the 40s: Also I don't want to hear the same old dismissal of these studies because they look too "flat". As you go back farther on the graph the data is smoothed because there is less data and more uncertainty. To reduce uncertainty they combine data from multiple years. Thus it represents the multi-year average well, but doesn't capture all the annual variability. The data is smoothed. That doesn't make it "wrong" or "suspicious" as you and others have suggested.

Well I wouldn't say that. But as the climate warms we're going to see more and more extreme anomalies like this. We're so far below even the modern average for the date. And what so often gets forgot in discussions of sea ice is that 1980-2000 is not "average" or normal for sea ice. There's strong evidence that there was lots more sea ice earlier in the century. The highest years of the early 1980s might be a little closer to an early 20th century normal.

Given this decline has been persistent and today's value is 160k lower than the value 3 days ago it's not due to cloud cover or measurement error. If we saw a 100k blip down and then it went right back up the next day then a big portion of the dip could have been measurement error. But when the measurement is consistent across 3 days, and in fact just keeps getting lower, it's not measurement error. A calving event or ice shelf breaking off would have no effect on sea ice area. If anything land ice or ice shelves calving would increase sea ice area because previously land bound ice would now be afloat and thus newly within the sea ice boundary area. Nor does an area of sea ice separating from (IE getting blown away from) the rest of the sea ice pack, decrease sea ice area. The resolution of the satellites measurements is such that this separated ice would still be included in the total. Obviously small icebergs would go unnoticed. But 100,000 sq km is several orders of magnitude bigger than what might go unnoticed. Sea ice decreases this time of year are probably largely due to wind compaction. We could also be seeing newly formed ice from the last week or two melting. When it first freezes it would be very thin and then if the weather changes it might melt again. Normally any compaction would be compensated for by the rapid freezing going on elsewhere. The ice area and volume should be exploding this time of year. So what we're really likely seeing is a general arctic-wide lack of rapid freezing combined with either compaction and/or melting of newly formed ice.

troll

troll

You're right it doesn't exaggerate it as much as I thought. But I think it does still exaggerate it somewhat. The area of Russia is 6.6 million square miles. The area of the arctic ocean including the Kara, Barents, Hudson and the seas on either side of Greenland is 5.4 million. Probably around 4 million if looking just at the high arctic ocean.

It's also worth mentioning that square depictions of the earth from the north pole (sorry don't know the cartography term) greatly exaggerate the size of arctic ocean relative to the lower latitudes. Those negative anomalies over Asia encompass an area several times the arctic ocean.

It seems like you are confused about what you are trying to say. You say one thing and then 2 posts later say you didn't say it.

OK let's try it again. What exactly are you trying to say? So far all I've heard is talk of previous "fall peaks" (IE back to historical averages) and "record fast re-freezes" (an inherent result of the faster decline in summer) and I have no idea what they have to do with the current 3+ standard deviation record and how people dismissed this (allegedly) positive data but are hypocritically not dismissing this negative record. And those are quotes.

Nobody has ever claimed that. I do remember people including myself saying that the trend in summer is more significant than the trend in winter because global warming is expected to cause greater declines in summer sea ice. But that's different. And you did reference "record fastest refreeze" or "high point in the fall" in relation to their significance vs a record low summer min. One is irrelevant and the other is a an apples to orange comparison.

First of all, the rate is really not relevant at all. Since the decline is expected/predicted (by climate models) and observed to be fastest in summer, the rate of ice growth in fall will continue to grow. That's why I'm sure when you've mentioned it, I and others have dismissed you. Second, we've never had a real "high point in the fall" anytime recently. Some years have been higher than others which I suppose has some very slight immeasurable benefit in slowing the decline. But none have been 3SD above the mean, as we are currently 3+ SD below the mean. You're comparing apples to oranges. You're comparing a "high point" (which is really just a temporary return to average) to a 3+ standard deviation drop below the mean. Plus the fact that sea ice extent is a much less comprehensive metric than volume. And we've never had a meaningful volume recovery. Extent has to be taken in the context of near perpetually decreasing volume. I don't remember anybody saying "what happens in winter is not as important as summer." If we actually saw some serious volume growth in winter, that would be significant. We've had some recent years with better volume in winter than others. And that has been discussed extensively. Anyways, I'm done. I don't really have an interest in debating the "significance" of individual extent days. The trend is clear.

As I said before, the main problem is part of your previous post was simply false. There has not been record high sea ice extent in the fall anytime recently. There have been many record lows, including this fall. If there had been, that would be significant, but it still wouldn't mean much of anything in the big picture. Likewise, I don't think anybody here is saying a record low min on 11/4/2016 means much of anything in the big picture, but the trend certainly does. It seems, as usual, you are more interested in semantics and playing "gotcha" than the actual issue.

I don't believe we have ever reached a record high sea ice extent in fall in the last 10 years. That is false. What's impressive is not the rate of refreeze but the fact that we are now well below the previous record for the date. The slow rate of re-freeze would not be all that impressive were we starting at a more normal minimum. But we started at a near-record low minimum and followed it with slow re-freeze to produce a record low extent for this date that is far below the previous record. In other words, highly anomalous. So no, there is no inconsistency. Your post kind of comes off like you are looking for one where there isn't anything.

It probably doesn't help to have such warm temps the last month or two, but there's lots of other more important factors at play.

I didn't disagree.. just skeptical given that we *do* hear it every year (a broken clock is right twice a day) and it would have been a near record early min.

We hear this every year..

Just put the CO2 back in the atmosphere... we're pretty good at that already without even trying.

I know. The most common geoengineering involves blocking the sun or sequestering CO2... both of which would have minimal impact unless done on a massive scale and sequestration is pretty reversible. I think the bigger issue with geoengineering is the side effects.