No 'tipping point' for Arctic sea ice

[meteorologist]

http://www.theregister.co.uk/2011/02/10/no_tipping_point_for_arctic_sea_ice/

[skierinvermont]

http://www.theregist...arctic_sea_ice/

I don't know if anyone ever said it truly was a "tipping point" and once it was gone it could never come back. Mostly what has been said is that there is a positive feedback, which is still true. As the ice melts, albedo decreases and the arctic absorbs more heat and warms further. That's a positive feedback to regional and global temperature.

I object to the article's characterization of arctic sea ice in recent decades as "gradual." It has been anything but gradual and I assure you that in the actual scientific study (as opposed to the article you have linked to from the right-wing fringe blog The Register) you will not find the word "gradual" used. The amount of ice at the annual minimum has nearly halved in the last 30 years. The amount of multi-year ice is less than 1/6th of what there was 30 years ago.

[BethesdaWX]

I prefer not to use NSIDC.

Its clear that the extent and concentration of Ice has increased steadily since the 2007 PDO flip.

The +AMO has owned the arctic like a b**ch since it went positive in the mid 90's. The PDO has less domiance over the Arctic, but the -PDO has been overwlemed by the +AMO. The strong +PDO from 1981 onward had itsimpact as well. If the Arctic Ice does not bounce back when the AMO goes negative, there is something else propbably going on. You can see it here in Skier's Graph too, the AMO switch started the downward spiral, but the slow downward trend from the +PDO was already in place.

Look what happened in 2007! The -PDO/+AMO fight, but the AMO has dominance in the end.

[tacoman25]

I don't know if anyone ever said it truly was a "tipping point" and once it was gone it could never come back. Mostly what has been said is that there is a positive feedback, which is still true. As the ice melts, albedo decreases and the arctic absorbs more heat and warms further. That's a positive feedback to regional and global temperature.

I object to the article's characterization of arctic sea ice in recent decades as "gradual." It has been anything but gradual and I assure you that in the actual scientific study (as opposed to the article you have linked to from the right-wing fringe blog The Register) you will not find the word "gradual" used. The amount of ice at the annual minimum has nearly halved in the last 30 years. The amount of multi-year ice is less than 1/6th of what there was 30 years ago.

And to be fair, it is unfortunate that we only have about 30 years worth of data...considering the often cyclical nature of the Arctic and nature in general, it gives us little reference for how "gradual" or not the drop has been.

If it is anything like global temperature trends, the trend for Arctic ice over the past 100 years could accurately be described as gradual.

[skierinvermont]

I prefer not to use NSIDC.

lol.

Its clear that the extent and concentration of Ice has increased steadily since the 2007 PDO flip.

yeah maybe in your freezer it has

Both JAXA and National Snow and Ice data center put the 2010 minimum as much lower than 2009, and essentially tied with 2008. The four lowest extents have all been in the past 4 years - since the PDO went negative.

[WeatherRusty]

And to be fair, it is unfortunate that we only have about 30 years worth of data...considering the often cyclical nature of the Arctic and nature in general, it gives us little reference for how "gradual" or not the drop has been.

If it is anything like global temperature trends, the trend for Arctic ice over the past 100 years could accurately be described as gradual.

Gradual in terms of a human life time. Very rapid in geological terms.

In terms of a "tipping point", it may already have been passed for all we know given the later autumnal freeze dates of arctic sea ice and the great depletion of thicker multi-year ice.

[BethesdaWX]

lol.

yeah maybe in your freezer it has

Both JAXA and National Snow and Ice data center put the 2010 minimum as much lower than 2009, and essentially tied with 2008. The four lowest extents have all been in the past 4 years - since the PDO went negative.

So what? It depends which datasource you use.

I must have a pretty big freezer

You'd be more sucessful in debating if you knew what "overall concentration increase" meant.

[skierinvermont]

I don't see any increase on that graph. The 4 lowest years minimums were the last 4 years, IE since the PDO went negative.

There's also less ice in the image on the right of Feb 8 2011, than there is in the Feb 8 2007 image on the left. 2007 had much more ice in Baffin Bay, the Labrador Sea, and the Gulf of St Lawrence. Every source agrees that Feb 8 2011 had less ice than Feb 8 2007.

[Clifford]

Here is the original download link.

http://www.seas.harvard.edu/climate/seminars/pdfs/Tietsche_GRL_2011.pdf

I think the authors have some very good points, and we should not ignore the insulating properties of the ice.

Winter sea ice seems to recover very well after a drop-off of summer sea ice, especially throughout the central areas of the Arctic Ocean north of Canada, Greenland, and Russia. And, without forcing agents, this should be able to build up to multi-year ice.

However, this paper also ignores the extremely dynamic nature of the Arctic Ocean, and the Arctic can't be viewed in isolation.

There is a strong transarctic current running from the Pacific Ocean and the Bering Straight North, and across the Arctic, and down into the Atlantic between Greenland and Svalbard.

Shut down this current, and the Arctic sea ice would recover very quickly.

However, this current is important, at least in part, in maintaining the temperature gradient in the deep oceans, and maintaining the methyl hydrates/methyl clathrates in the deep ocean.

Anyway, much of the older sea ice is being (or has been) flushed out of the Arctic and melted on the surface of the Atlantic. This process actually even occurs in the mid-winter.

So, yes, with a -4°C annual average temperature, or even a -1°C annual average temperature, one would expect sea-ice to form, but it could only build up in isolation. And, while we could artificially isolate it, doing so might create pretty ice, but have dire consequences for the rest of the planet.

The point of the 30 year record is a good point.

Like many of our "Global Warming" records, the sea ice measurements begin immediately after one of the coldest decades since at least 1940, and with or without CO₂, the planet has been warming since the mid 1600's.

[BethesdaWX]

I don't see any increase on that graph. The 4 lowest years minimums were the last 4 years, IE since the PDO went negative.

There's also less ice in the image on the right of Feb 8 2011, than there is in the Feb 8 2007 image on the left. 2007 had much more ice in Baffin Bay, the Labrador Sea, and the Gulf of St Lawrence. Every source agrees that Feb 8 2011 had less ice than Feb 8 2007.

Can you read a post?

- Ice cover as a whole has been increasing since 2007, minimums = my ass. The AMO has the Arctic Dominance...the -PDO/+AMO have caused the wild swings.

-Ice Concentration is Higher now than in 2007 (more thick ice).....ice cover anomalies have increased in general since 2007, depending on the datasource you use.

I use objective data only, biased data can kiss my ass several times over.

[skierinvermont]

Can you read a post?

- Ice cover as a whole had been increasing since 2007, minimums = my ass. The AMO has the Arctic Dominance...the -PDO/+AMO have caused the wild swings.

-Ice Concentration is Higher now than in 2007 (more thick ice).....ice cover anomalies have increased in general since 2007, depending on the datasource you use.

I use objective data only, biased data can kiss my ass several times over.

Concentration is not the same thing as thickness. All of the major data sources, JAXA, NSIDC, BREMEN agree the four lowest minimums were the last 4 years. Studies of volume and ice age show that thickness and ice age has continued to decline since 2007. A major exodus of multi-year ice out of the arctic occurred in 2008.

[BethesdaWX]

Concentration is not the same thing as thickness. All of the major data sources, JAXA, NSIDC, BREMEN agree the four lowest minimums were the last 4 years. Studies of volume and ice age show that thickness and ice age has continued to decline since 2007. A major exodus of multi-year ice out of the arctic occurred in 2008.

You mean volume, right? Concentrated ice will result in a thicker ice pack...there is something called compaction.

Again, the ice loss in all aspects fit its in perfectly with changes in the AMO. WWII submarines surfaced at the north pole in the 1950's, during March. The Late 1800's saw ships treking into areas we now cannot even go today.

All 3 time periods coincided with +AMO's. Its quite ordinary.

[Clifford]

I don't see any increase on that graph. The 4 lowest years minimums were the last 4 years, IE since the PDO went negative.

There's also less ice in the image on the right of Feb 8 2011, than there is in the Feb 8 2007 image on the left. 2007 had much more ice in Baffin Bay, the Labrador Sea, and the Gulf of St Lawrence. Every source agrees that Feb 8 2011 had less ice than Feb 8 2007.

Right, the Arctic Ocean is essentially 100% covered with ice. The areas not covered appear to be the sea of Okhotsk, north of Japan (not in the Arctic Ocean), as well as south of Greenland.

In fact, by AMSR-E, the Arctic sea ice today (Feb 9) is listed as once again the lowest in the decade, slightly below both 2007 and 2010, and essentially equal to 2005 & 2006. However, note that 2010 went from near the lowest in February to the highest in a decade at the first of April, then back to the lowest in a decade by June

http://www.ijis.iarc...ce_Extent_L.png

What is interesting about the photo above (larger link below) is that the Arctic Ocean North of Russia is a darker pink color in 2011 than 2007. According to the key, that is a representation of "Sea Ice Concentration", varying from about 80-90% in 2007 up to 90-100% in 2011.

http://home.comcast....ryo_compare.jpg (larger photo of Arctic Sea Ice).

In fact... If I had to fathom a guess about a predictor of the summer sea ice extent, it would not be the ice in the sea of Okhotsk, north of Japan, but rather the thickness/concentration of the sea ice in the Arctic Ocean. Thus I would have to doubt that the 2011 summer curve would follow the 2007 summer curve.

[nzucker]

I don't see any increase on that graph. The 4 lowest years minimums were the last 4 years, IE since the PDO went negative.

There's also less ice in the image on the right of Feb 8 2011, than there is in the Feb 8 2007 image on the left. 2007 had much more ice in Baffin Bay, the Labrador Sea, and the Gulf of St Lawrence. Every source agrees that Feb 8 2011 had less ice than Feb 8 2007.

The reason you don't see a lot of increase is because the ice loss was so devastating in 2007; it takes time to recover from an event like this, although the article suggests it is a natural process for the arctic to regain ice after an unusually low summer minimum. Also, we haven't gotten into the heart of the -PDO regime since we're just beginning the sequence of intense La Nina years, unlike the 40s and 50s where the -ENSO regime started as soon as the PDO flipped. We've talked about this difference many times, but you still don't seem to comprehend fully. Also, the -NAO has made it harder to gain ice in the Labrador Sea and Gulf of St. Lawrence; with this blocking regime breaking down, we're likely to see large increases in these areas in the next few weeks. We've already seen the pack ice make its way to the Labrador coastline in the far north of that province.

Concentration is not the same thing as thickness. All of the major data sources, JAXA, NSIDC, BREMEN agree the four lowest minimums were the last 4 years. Studies of volume and ice age show that thickness and ice age has continued to decline since 2007. A major exodus of multi-year ice out of the arctic occurred in 2008.

It is interesting that the 2011 Cryosphere Today maps show a much higher concentration in the Arctic Ocean than other years. We clearly have a very robust ice pack in the Arctic Ocean, which will retard melting when we get into the warm season. Now that the NAO has broken down, we need to work on developing ice in Baffin Bay and Labrador to catch up with the other years for winter maximum. This won't matter in the end, though, given that these areas only have seasonal ice; what's important is the high concentration we've attained in the Arctic Ocean.

[BethesdaWX]

The reason you don't see a lot of increase is because the ice loss was so devastating in 2007; it takes time to recover from an event like this, although the article suggests it is a natural process for the arctic to regain ice after an unusually low summer minimum. Also, we haven't gotten into the heart of the -PDO regime since we're just beginning the sequence of intense La Nina years, unlike the 40s and 50s where the -ENSO regime started as soon as the PDO flipped. We've talked about this difference many times, but you still don't seem to comprehend fully. Also, the -NAO has made it harder to gain ice in the Labrador Sea and Gulf of St. Lawrence; with this blocking regime breaking down, we're likely to see large increases in these areas in the next few weeks. We've already seen the pack ice make its way to the Labrador coastline in the far north of that province.

It is interesting that the 2011 Cryosphere Today maps show a much higher concentration in the Arctic Ocean than other years. We clearly have a very robust ice pack in the Arctic Ocean, which will retard melting when we get into the warm season. Now that the NAO has broken down, we need to work on developing ice in Baffin Bay and Labrador to catch up with the other years for winter maximum. This won't matter in the end, though, given that these areas only have seasonal ice; what's important is the high concentration we've attained in the Arctic Ocean.

The PDO doesn't have the Arctic effect that the AMO does though. The Arctic Ice, and temperatures, correlate to the AMO rather than the PDO.

[nzucker]

The PDO doesn't have the Arctic effect that the AMO does though. The Arctic Ice, and temperatures, correlate to the AMO rather than the PDO.

I think the PDO matters somewhat since it allows for more La Niña years which cool down the Arctic generally.

However, you are correct about the influence of the AMO: arctic temperatures generally follow the changes in the Atlantic regime fairly closely. The arctic sea ice is definitely affected by the AMO since warm waters can get drawn into Baffin Bay, the Labrador Coast, and the Fram Strait during a +AMO/-NAO regime; this retards ice formation in marginal areas, as we've seen with the tongue of ice east of Greenland which has been slow to develop this year. On the latest NOAA SST anomaly map, you can see some cooler anomalies showing up south of Iceland; the +NAO means we're going to see a parade of storms tracking from the Canadian Maritimes to Iceland, including this current low pressure which may approach 930mb. That will cool down the arctic waters some...

[BethesdaWX]

Agree

I guess the problem has been...La Nina can't influence when the -AO/-NAO dominate in a +QBO and -QBO, which seems to be the case since the solar min. The -NAO also tends to correlate with a +AMO.

The AMO regions are also at a higher lattitude in general, and if they influence blocking when in the negative phase, it really puts a damper on anything the PDO/ENSO tries to do.

The SH PDO and the NH PDO also feedback off the AAO and AO/NAO in the sense of wavelengths changing storm tracks, thus affecting surface SST's. This may not change the PDO/-ENSO base state we have now entered, but it DOES effect what happens at the high lattitudes.

So if we have the UOHC in the PDO regions being negatively effected by unconductive changes in wavelengths, there is little atmospheric response to manifest, even when the "indice" itself may represent something that would, in theory, leadto higher ice.

Example..we can see the issue right here (Map Below), the PDO regions being scewed by opposing forces! This is what happens during the phase change of the globe, we get drivers contradicting eachother, and a mess of all sorts sets up shop, and drives objective scientists insane!

We probably will not see the increase in arctic sea ice REALLY begin until 2015-2020, when the AMO goes negative,and we settle into a NEW base.

[skierinvermont]

The reason you don't see a lot of increase is because the ice loss was so devastating in 2007; it takes time to recover from an event like this, although the article suggests it is a natural process for the arctic to regain ice after an unusually low summer minimum. Also, we haven't gotten into the heart of the -PDO regime since we're just beginning the sequence of intense La Nina years, unlike the 40s and 50s where the -ENSO regime started as soon as the PDO flipped. We've talked about this difference many times, but you still don't seem to comprehend fully. Also, the -NAO has made it harder to gain ice in the Labrador Sea and Gulf of St. Lawrence; with this blocking regime breaking down, we're likely to see large increases in these areas in the next few weeks. We've already seen the pack ice make its way to the Labrador coastline in the far north of that province.

It is interesting that the 2011 Cryosphere Today maps show a much higher concentration in the Arctic Ocean than other years. We clearly have a very robust ice pack in the Arctic Ocean, which will retard melting when we get into the warm season. Now that the NAO has broken down, we need to work on developing ice in Baffin Bay and Labrador to catch up with the other years for winter maximum. This won't matter in the end, though, given that these areas only have seasonal ice; what's important is the high concentration we've attained in the Arctic Ocean.

I didn't say the PDO would not help the arctic recover.. I said that it HASN"T recovered. Seriously is incredibly frustrating when you try to criticize something I have not said.

It is an undeniable and very well documented fact that the arctic sea ice has continued to deteriorate since 2007. Whether the PDO will help it to recover, that remains to be seen.

[ORH_wxman]

I didn't say the PDO would not help the arctic recover.. I said that it HASN"T recovered. Seriously is incredibly frustrating when you try to criticize something I have not said.

It is an undeniable and very well documented fact that the arctic sea ice has continued to deteriorate since 2007. Whether the PDO will help it to recover, that remains to be seen.

No its not. That is an opinion based on a model that has plenty of questions (PIOMAS volume)...there is currently very little evidence to show that arctic sea ice is about to get as bad as 2007 again. The ice age thing is a dubious argument as it obviously will take a while to build up the age of the ice again after it was flushed out in the big '07 melt and the following insane +AO winter.

[BethesdaWX]

I didn't say the PDO would not help the arctic recover.. I said that it HASN"T recovered. Seriously is incredibly frustrating when you try to criticize something I have not said.

It is an undeniable and very well documented fact that the arctic sea ice has continued to deteriorate since 2007. Whether the PDO will help it to recover, that remains to be seen.

Absolutely Not.

Arctic sea ice in general has improved since 2007 by most measurements...maybe the minimums have been worse overall since 2006, but that is to be expected in summer seasons when the -PDO is less confluent . The AMO tends to peak in its deviation during the spring/summer months.

[Clifford]

It is interesting that the 2011 Cryosphere Today maps show a much higher concentration in the Arctic Ocean than other years. We clearly have a very robust ice pack in the Arctic Ocean, which will retard melting when we get into the warm season. Now that the NAO has broken down, we need to work on developing ice in Baffin Bay and Labrador to catch up with the other years for winter maximum. This won't matter in the end, though, given that these areas only have seasonal ice; what's important is the high concentration we've attained in the Arctic Ocean.

Yeah,

I went to the University of Illinois Page.

http://igloo.atmos.u...n/test/print.sh

http://arctic.atmos....edu/cryosphere/

When comparing years...

Feb 9, 2010 appears to have equal, of slightly greater "Concentration" than Feb 8, 2011

Feb 9, 2010 also appeared to have greater "Concentration" than 2009, yet the Sept 15, 2010 ice was less "healthy" than Sept 15, 2009 (by extent and concentration)

However,

Comparing any 2 successive years, the Ice "Health" on Sept 15 (extent/concentration) seems to have a strong correlation with El Niño/La Niña years (and of course, covering the period fall through spring/summer). Being less "healthy" on El Niño years than La Niña years.

With that in mind, the 2011 sea ice extent/concentration on Sept 15 will likely be better than 2010, but will likely depend on the duration of the current La Niña cycle. If the current La Niña cycle endures (and remains relatively strong) until July or August, we'll likely have sea ice levels returning to.... hmmm..... perhaps 2006 levels.

However...

The research article that began this subject:

http://www.seas.harv...he_GRL_2011.pdf

We find that ice extent recovers typically within two

years. The excess oceanic heat that had built up during the

ice‐free summer is rapidly returned to the atmosphere during

the following autumn and winter, and then leaves the Arctic

partly through increased longwave emission at the top of the

atmosphere and partly through reduced atmospheric heat

advection from lower latitudes. Oceanic heat transport does

not contribute significantly to the loss of the excess heat.

However...

For the Arctic, Oceanic Heat Transport doesn't contribute to loss of heat... it contributes to GAIN of heat.

2 years?

Probably not.

Looking at the Illinois Photos/Diagrams above.

1996/1997 had a significant gain over the 1995 El Niño.

However, 2008/2009 also had a gain over the previous 2007 El Niño. However, to a lesser extent.

Again, the error is likely ignoring the effects of the Oceanic Heat Transport, which will likely cause a much extended recovery time. Also, the loss of multi-year ice. I.E. doesn't it take 5 yrs to recover 5 yr ice? Or... perhaps 3 years to get beyond 1&2 year ice?

[nzucker]

No its not. That is an opinion based on a model that has plenty of questions (PIOMAS volume)...there is currently very little evidence to show that arctic sea ice is about to get as bad as 2007 again. The ice age thing is a dubious argument as it obviously will take a while to build up the age of the ice again after it was flushed out in the big '07 melt and the following insane +AO winter.

Even though Skier knows that the 2008, 2009, and 2010 September minima were all higher than 2007, in some cases by a million square kilometers, he doesn't seem to acknowledge any improvement. How can we say the Arctic has deteriorated further when last winter had one of the highest maxima in recent history, and overall the minimums have been improving? I agree that volume is another important measure of the state of the cryosphere, but coverage is not irrelevant either as it has vast effects on albedo and ecosystems. Overall, the extent has been improving whereas the volume has grown worse. Also, the Cryosphere Today maps show a very high concentration of ice in the Arctic Ocean, meaning that it may be harder to melt this year. Winter 2011 has put the center of the ice pack in great shape to withstand the summer, especially considering it may be a cool one in the higher latitudes with the Niña, low global temperatures, and a breakdown of blocking.

I entirely agree with you, Will, that ice age is a dubious argument at this point. How could you possibly have a lot of multi-year ice when 75% of the arctic melted in Summer 2007 and then we had one of the most +AO/+NAO winters on record, following 20 years of dominance from the non-blocking states? It just doesn't make sense to me at all.

[JBG]

And to be fair, it is unfortunate that we only have about 30 years worth of data...considering the often cyclical nature of the Arctic and nature in general, it gives us little reference for how "gradual" or not the drop has been.

If it is anything like global temperature trends, the trend for Arctic ice over the past 100 years could accurately be described as gradual.

Those facts won't calm alarmists.

[skierinvermont]

No its not. That is an opinion based on a model that has plenty of questions (PIOMAS volume)...there is currently very little evidence to show that arctic sea ice is about to get as bad as 2007 again. The ice age thing is a dubious argument as it obviously will take a while to build up the age of the ice again after it was flushed out in the big '07 melt and the following insane +AO winter.

I'm not saying there has been no recovery based on PIOMAS - I'm saying it based on the fact that there is FAR less multi-year ice left than there was even after Fall 2007.

You said it yourself winter and spring 08 saw large amounts of ice flushed out of the Fram strait. It continued to deteriorate AFTER 2007 into the winter and spring of 2008 and there hasn't been any improvement since then.

It's also been close to 4 years since summer 2007 and yet we have half the amount of 2 year ice that we did following summer 2007. There has been no recovery. It doesn't take 4 years for ice to turn 2. There's also less 1-2 year ice.

There are also surveys done of the arctic and peer-reviewed studies which show no recovery. But don't let facts get in the way of a good party.

I am sorry but anybody who denies that the current condition of the ice pack is inferior to fall 2007 is in denial. At the end of the 2007 melt season greater than 50% of the ice was 2+ years old. That number has since fallen to 17%.

The green area in the September 2010 image corresponds to the yellow area in the September 2007 image. You can see the amount of ice 2+ years old has decreased 80%+ since September 2007. Even the amount of 1+ year ice has decreased 50%.

[ORH_wxman]

I'm not saying there has been no recovery based on PIOMAS - I'm saying it based on the fact that there is FAR less multi-year ice left than there was even after Fall 2007.

You said it yourself winter and spring 08 saw large amounts of ice flushed out of the Fram strait and there has been no recovery since then.

It's also been close to 4 years since summer 2007 and yet we have half the amount of 2 year ice that we did following summer 2007. There has been no recovery.

There are also surveys done of the arctic and peer-reviewed studies which show no recovery.

That's not correct either...the 1-2 year multi-year ice has seen a decent rise. The NSIDC map from September 2010 had a big discrepancy too...they didn't date the ice like they did in the 2009 and previous maps so the ice didn't have a rise because they never dated the "newer ice" and didn't give it a "birthday"...they just kept it exactly what it was from September 2009 so it was quite misleading. They said "it wasn't time yet" when question by morons like McIntyre.

We'll see how they show the ice progression this year, but that was another topic of discussion this past fall. The newer satellite named CryoSat 2 is measuring ice thickness now and should become operational pretty soon so we'll have more answers. Its also interesting to me that we haven't seen the "death spiral" predicted by so many "ice experts" since the 2007 minimum. We should have certainly seen something at least within shouting distance of 2007 if that truly was a death spiral or tipping point, right? Why haven't we seen that?

I mean, we had an ice extent going lower then 2007 last June...so everyone said the ice had a good chance of breaking the record, but it never sniffed it. I would think if it was so precariously thin and vulnerable like they said, then we would have at least come semi-close to the record. But we didn't. I think the CryoSat 2 measurements over the next several years should be interesting because this the first chance we have to get some better measurements instead of more pure speculation.

[skierinvermont]

That's not correct either...the 1-2 year multi-year ice has seen a decent rise. The NSIDC map from September 2010 had a big discrepancy too...they didn't date the ice like they did in the 2009 and previous maps so the ice didn't have a rise because they never dated the "newer ice" and didn't give it a "birthday"...they just kept it exactly what it was from September 2009 so it was quite misleading. They said "it wasn't time yet" when question by morons like McIntyre.

We'll see how they show the ice progression this year, but that was another topic of discussion this past fall. The newer satellite named CryoSat 2 is measuring ice thickness now and should become operational pretty soon so we'll have more answers. Its also interesting to me that we haven't seen the "death spiral" predicted by so many "ice experts" since the 2007 minimum. We should have certainly seen something at least within shouting distance of 2007 if that truly was a death spiral or tipping point, right? Why haven't we seen that?

I mean, we had an ice extent going lower then 2007 last June...so everyone said the ice had a good chance of breaking the record, but it never sniffed it. I would think if it was so precariously thin and vulnerable like they said, then we would have at least come semi-close to the record. But we didn't. I think the CryoSat 2 measurements over the next several years should be interesting because this the first chance we have to get some better measurements instead of more pure speculation.

I'm not saying we have seen a death spiral I'm just saying we have not seen a recovery and the overall condition has deteriorated further.

With the ice pack being much younger and therefore thinner than it was in September 2007, I think a similar weather pattern could produce a minimum up to 1,000,000 sq km less than 2007. That was a highly anomalous weather pattern though so I don't expect to see that any time soon.

We also saw this summer, even though conditions were no where remotely close to as poor as September 2007, the ice extent was only 500k sq km above 2007. You could just watch on the loops this summer how there was absolutely nothing holding back the wind and warmth from pushing the ice around and melting it because it was extremely young and thin.

[ORH_wxman]

I'm not saying we have seen a death spiral I'm just saying we have not seen a recovery and the overall condition has deteriorated further.

With the ice pack being much younger and therefore thinner than it was in September 2007, I think a similar weather pattern could produce a minimum up to 1,000,000 sq km less than 2007. That was a highly anomalous weather pattern though so I don't expect to see that any time soon.

We also saw this summer, even though conditions were no where remotely close to as poor as September 2007, the ice extent was only 500k sq km above 2007. You could just watch on the loops this summer how there was absolutely nothing holding back the wind and warmth from pushing the ice around and melting it because it was extremely young and thin.

What about NSIDC's failure to age the ice by a year?

[skierinvermont]

What about NSIDC's failure to age the ice by a year?

Link? I have not read this and it sounds quite dubious.

[BethesdaWX]

conditions have not deteriorated since 2007 though. There has been a higher max every year since then, 2011 summer anomaly should be quite high.

[stellarfun]

Good lord.

Can somebody point to a reputable scientist who posited that the Arctic would become ice free in the winter? The so-called tipping point is an ice-free Arctic by the end of summer, and there is insufficient old ice in future years with global warming to prevent the Arctic from becoming ice-free in succeeding summers.

As for the original article in the "Register", the same 'reporter' (?) who wrote "No tipping point' for Arctic sea ice" has also most recently reported on these developments this week:

"U S gov says it can't build an interstellar starship" Plans to spawn an organization that can."

"'Race against time' to find LOST TREES from the MOON"