You can't make this stuff up

The latest report from the NSIDC on Artic sea ice is out, and states:

Record ice loss in August

Following a record rate of ice loss through the month of August, Arctic sea ice extent already stands as the second-lowest on record, further reinforcing conclusions that the Arctic sea ice cover is in a long-term state of decline. With approximately two weeks left in the melt season, the possibility of setting a new record annual minimum in September remains open.

Extent is now within 370,000 square kilometers (140,000 square miles) of last year's value on the same date and is 2.08 million square kilometers (800,000 square miles) below the 1979 to 2000 average.

i-58906be759aea40e5e45c9a2b69d4395-200800904_Figure5.png

Now, if you are into global warming denial, you might decide that it's time to stop talking about Artctic sea ice and start calling Al Gore fat. For instance, on September 2, Anthony Watts posted that the "Arctic sea ice melt season appears to be over" but then he dropped that post down the memory hole.

But not Michael Asher, whose take on the NSIDC's data is subtly different from the NSIDC's:

Arctic Sees Massive Gain in Ice Coverage

Data from the National Snow and Ice Data Center (NSIDC) has indicated a dramatic increase in sea ice extent in the Arctic regions. The growth over the past year covers an area of 700,000 square kilometers: an amount twice the size the nation of Germany.

With the Arctic melting season over for 2008, ice cover will continue to increase until melting begins anew next spring.

More like this

August sea ice extent in the Arctic this year was 640,000 square kilometers below the previous record set in 2007.  It is also already a record monthly low for any month, though that record will not last as it is going to be broken this September when the lowest extent of the year is normally…
NSIDC has (preliminarily) announced the new record low ice extent for 2012. On September 16, 2012 sea ice extent dropped to 3.41 million square kilometers (1.32 million square miles). This appears to have been the lowest extent of the year. In response to the setting sun and falling temperatures,…
This is the headline on a press release from the National Snow and Ice Data Center (NSIDC) at the University of Colorado at Boulder. They are one of the goto sources for data about sea ice, either arctic or antarctic. The final extent of arctic sea ice melting this year, as in any other single…
The North Polar ice sheet continues to recede, setting yet another record: Sea ice extent continues to decline, and is now at 4.78 million square kilometers (1.84 million square miles), falling yet further below the record absolute minimum of 5.32 million square kilometers (2.05 million square…

If you have done anything you are really, really sorry for, and you need to do some serious penance, forget about the hair shirt and the fishhook scourge. Just read the comments in that thread.

Your graph shows actual extent in august, not the amount of ice lost in august.

llewelly:

More from the NSIDC report:

> August 2008 average extent compared to past Augusts

> Arctic sea ice extent averaged over the month of August was 6.03 million square kilometers (2.33 million square miles). This is 1.64 million square kilometers (633,000 square miles) below the 1979 to 2000 August average,

> However, August 2008 was still 670,000 square kilometers (260,000 square miles) above August 2007, despite the record-breaking rate of decline over the past month. Why would this be? The best explanation for this is that this summer did not experience the "perfect storm" of atmospheric conditions seen throughout the summer of 2007.

> Even though August ice extent was above that of August 2007, the downward trend for August ice loss has now gone from -8.4% per decade to -8.7% per decade.

So Asher's figure is correct, but he omits to mention the long term downward trend. It's again the time-honoured technique of presenting only those facts that support the inactivist thesis.

Q. And what's happening at the same time with global temperatures?

A. They are dropping.

So, it doesn't look particularly good that a small part of the earth is a good proxy for global temperatures. In reality, it looks like falling sea ice coverage is correlated with falling global temperatures

So, it doesn't look particularly good that a small part of the earth is a good proxy for global temperatures.

There go nobody's hopes, beaten down like a straw man.

If you have done anything you are really, really sorry for, and you need to do some serious penance, forget about the hair shirt and the fishhook scourge. Just read the comments in that thread.

I could only stomach about a third of the thread. That dude is STOOOPID.

Hopefully I read enough to atone for my sins and get to heaven, I'll never be able to bear reading the rest of the thread.

Or revisit the site.

In 2015 he'll probably explain that sea ice has recovered to 3x the size of Malta.

Damn you Tim. I looked at the Asher thread.

Melting Arctic ice segways to the Dead Sea scrolls....my head is still spinning.

But not Michael Asher,

Nor Mr Paul Joseph Watson, who thinks the mini ice age is upon us.

http://www.infowars.com/?p=4321

WARNING: Most of the comments on Watson's article are at least as stupid and venal as those on Mr Asher's. I went there so you don't have to. I will be spending the next few days in recovery.

I could make that stuff up.

We know.

By Chris O'Neill (not verified) on 05 Sep 2008 #permalink

BPL,
You can't have it both ways.

1998 is the standout, juiciest year in the true believers calendar.

10 years on and we are considerably cooler in spite of ever increasing ACO2.

Who are the deniers around here?

By spangled drongo (not verified) on 06 Sep 2008 #permalink

El Niño, La Niña, and your ass, drongo.

Umm..perhaps someone could help me with this?

I see claims that global temperatures are falling, countered by claims that they are rising. When you look at the details, it seems that 1998 was particularly hot for El Nino reasons, and 2007 was particularly cold for La Nina reasons. In between the temperature was essentially flat.

So even if you discount these years as exceptional, surely increasing CO2 means temperatures should increase, not remain flat?

By Dodgy Geezer (not verified) on 06 Sep 2008 #permalink

Spangled Drongo: You have a very apt user name since in Australia "drongo" is slang for stupid. If you want to be treated as a skeptic and not a 'denier' then please learn some basic statistics. Just the simple stuff like drawing a trend line through 10 data points would be sufficient.

Dodgy Geezer:

> So even if you discount these years as exceptional, surely increasing CO2 means temperatures should increase, not remain flat?

Here's a clue: how about using more data, instead of less data?

QED.

These weather watchers just haven't a clue!

NSID give the world the big story of a record melt in 2008 while showing ice extent was up. When a brave guy used graph saying but hey it is higher than 2007, but dumped the words which did not correspond, he got a very rough ride here at Deltoid. Later we heard claims that the first year ice was thin and so the 2008 minimum would still be below 2007. Note the claim was WOULD not COULD.
Some of us said that if a recovery was happening then it would look like what we were seeing. Clearly if it were a recovery, there would more new thin ice. So a big finish was and still is a possibility - at least for the next three weeks. However as it stands it still looks as if 2009
will have a better start than 2008 had.

By sean egan (not verified) on 06 Sep 2008 #permalink

NSID give the world the big story of a record melt in 2008 while showing ice extent was up.

Yes, that's because a - b can be bigger than d - c even if d > a.

That's not even algebra. That's arithmetic. People who don't even understand arithmetic are going to overthrow the work of a very large number of professional scientists?

Ha!

Are there any records for August ice extent that go back past 1978?

Not total records, no, but plenty of individual location records, proxies, etc.

We get your point - you're about to make something up again.

If the story was, "we predict less ice even though there is more now" the story would have played less well on the worlds TV than it did."

By de-stressing to the extreme that the current ice level was and still are time higher than 2007, and stressing the prediction a false impression was given that 2008 ice levels confirmed the trend. The trend down did not continue in 2008. Which is consistent with a recovery or a wiggle in the decline. A single year is just too soon.

Predictions are not proof and can not replace measurements.
I have no complaint the prediction was made, only that it was over sold. Those who pointed this out got a rough ride.

By sean egan (not verified) on 06 Sep 2008 #permalink

The trend down did not continue in 2008

The trend - a statistical concept - most certainly has, and is strengthened by the fact that this is already the second lowest year in both extent and area, behind only 2007.

By de-stressing to the extreme that the current ice level was and still are time higher than 2007, and stressing the prediction a false impression was given that 2008 ice levels confirmed the trend. The trend down did not continue in 2008.

Seriously? The impression I've always had was that there was a downward trend (looking at many years and not just a few) and 2007 was surprisingly below what was expected, even with the continuation of the trend. That means that 2008 is expected to be higher than 2007, but considering the surprise of 2007, all bets are off. 2008 could even be above the trend line and still be a part of the downward trend, but it's not; it's second only to 2007.

From what I've been able to understand, the trend continued would mean 2008 would be well above 2007, but there was an expectation that the thinness of the ice would mean it would be near or below 2007. And in spite of what some would have us believe, it's near. Nearer, in fact, than any other year.

I think at the very least you're confused about the nature of trends. All you really need to do is look at the graph at the top of this post and see how there is a trend line and the data points exist on both sides of it. A single point above the trend line doesn't reverse its direction.

As I understand it extent is used rather than area as the record is longer. Ships on the edge can record extent, but for area you need over flights.
I guessing 15% was chosen as that was about as close a ship would want to get.
NSIDC has a nice graph back to 1953 here http://nsidc.org/sotc/sea_ice.html
Note the short term recovers..
A longer record is given in " Long Term Ice variability in Arctic Marginal Seas" (Ployakov 2002), based on ship measurements back to 1900. Basically it claims the current decline of extent is no worst than the 1920s.

Pretty much everyone thinks you need several years to see the real trend as several short "recovers" are clearly in the record.

If anyone has found anything longer than 1900, please post.

By sean egan (not verified) on 06 Sep 2008 #permalink

UNCONSCIOUS HEAD-FAKES AND SEEING THE BELT-BUCKLE

In high-school football, they used to tell us to ignore head-fakes in favor of watching belt-buckles.

When people look at NSIDC and worry about day-to-day jiggles, and whether or not one line will touch another for a day or two, I worry about something different. When I look at the NSIDC charts, what I think about is the difference in absorbed energy across the summer season between one decade and the next.

I know it's odd to believe in the Conservation of Energy, but some of us do, and albedo matters, as I pointed out over at RealClimate.

IF I could wish for *one* number per year, it would be an accurate measure of the global total Ocean Heat Content, for which most of our measurements are at best imperfect proxies. I.e., we can't quite see the belt-buckle.

In particular, notice the albedo difference there between:

.02-.35 water (depending on angle)

and

.75-.95 new snow

The NSIDC graph is not a head-fake, it's real, but it can distract people from the OHC belt-buckle.

By John Mashey (not verified) on 06 Sep 2008 #permalink

We get your point - you're about to make something up again.

Make something up? I am only curious. That data would be interesting to see.

bravo. sean egan was so far the denialist, making the most false claims on this topic. ben, you seriously need to get going!

Later we heard claims that the first year ice was thin and so the 2008 minimum would still be below 2007. Note the claim was WOULD not COULD.

i have been following this debate pretty close. i am unaware of anyone, making a "WOULD" claim, without any "could".

i am looking forward to your links on this subject...

for a start, all scientist cited in the original Goddard article include a very strong COULD...

http://tinyurl.com/5sma3z

The trend down did not continue in 2008.

you obviously have not the slightest understanding, on the meaning of the term "trend". a common problem among denialists. for a start, 1 year rarely makes or breaks a trend.

look at any ice time series:

http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.anom.jpg

A longer record is given in " Long Term Ice variability in Arctic Marginal Seas" (Ployakov 2002), based on ship measurements back to 1900. Basically it claims the current decline of extent is no worst than the 1920s.

how exactly will a paper from 2002 claim that ice extend this (or last..) year was similar to the 20s?

oh, your claim is simply false?!?

If anyone has found anything longer than 1900, please post.

Tamino has done an analysis of hadley data, reaching back to 1870.

beware, NOTHING similar to these years. you were wrong. again.

http://tamino.wordpress.com/2007/10/08/sea-ice-north-and-south-then-and…

"how exactly will a paper from 2002 claim that ice extend this (or last..) year was similar to the 20s?" - Its in the title, long term variability... Until you know the range of what is normal, it is hard to classify something as abnormal.

Any peer reviewed paper will lag the last measurement.

Thank-you sod for the reference. I am interested in looking at the Hadley data. It is not clear without further reading how it relates to Ployakov, which as I recall used Russian data. The bog post you indicate suggests the Hadley data appears to have large amounts of missing data filled with best guesses - So unless there a corresponding peer reviewed article, it is hard to see what is what.

By sean egan (not verified) on 06 Sep 2008 #permalink

It is not clear without further reading how it relates to Ployakov, which as I recall used Russian data.

In other words, doesn't cover the entire arctic.

Silly climatologists. Arctic ice melting stopped in 2007!

Any peer reviewed paper will lag the last measurement.

this is true.

and all denialist arguments are based on MISREPRESENTATIONS of peer reviewed papers!

the claim in the paper is fine. it is comparing ice data over the period that it does analyse. that is up to 2002.

your claim about the paper is FALSE. you make assumptions about a comparison between the 20s and THIS year, and this is not supported by the paper you linked in any way.

epic fail.

Well, the ice in my freezer is coming along just fine. Does this make me a "denialist?"

Only if you claim it is evidence that the whole world is cooling. This would be not far off the standard of denialist argument.

By Chris O'Neill (not verified) on 06 Sep 2008 #permalink

egan:

The trend down did not continue in 2008.

Others have said something about this but this is an absolutely incredible claim when looking at the graph trend line at the top of the page. 2008 is LOWER than the trend line. Therefore, if anything, 2008 has ACCELERATED the trend down, not discontinued it.

By Chris O'Neill (not verified) on 06 Sep 2008 #permalink

Drongo writes:

BPL, You can't have it both ways.
1998 is the standout, juiciest year in the true believers calendar.
10 years on and we are considerably cooler in spite of ever increasing ACO2.
Who are the deniers around here?

You and your pals. The World Meteorological Organization (WMO) defines climate as "mean regional or global weather over a period of thirty years or more." Ten years means nothing, especially when you choose your starting point. I demonstrated it statistically in the links which you apparently ignored.

Geezer writes:

In between the temperature was essentially flat.

So even if you discount these years as exceptional, surely increasing CO2 means temperatures should increase, not remain flat?

They didn't remain flat. Take out 1998 and 2007 and the period between is warming, not flat. Go look at it again:

Tilo Reber's error

In addition, CO2 isn't the only thing that affects global temperature, and no one is saying that it is. It's a denialist straw man.

Read reading the paper, the remark was - prior to the 1920s - So Sod got me on a technicality there.

By sean egan (not verified) on 07 Sep 2008 #permalink

The paper covers data up to 2000. This seems old until you see the data used in other recent papers, eg Rothrock2007.

Or until you look at the record of the last eight years ...

Dodgy Geezer:

When you look at the details, it seems that 1998 was particularly hot for El Nino reasons, and 2007 was particularly cold for La Nina reasons. In between the temperature was essentially flat.

So even if you discount these years as exceptional, surely increasing CO2 means temperatures should increase, not remain flat?

This would be true if you assumed that the world was incapable of cooling that could counteract CO2 warming temporarily. But we know from history that the world is capable of at least 0.1 deg C of cooling over a 10 year period even if you exclude El Niño/La Nina effects. This occurred over the period July 1958 to June 1968 (Hadcrut3).

Also, allowing El Niño-affected periods, it was possible to have 0.45 deg C of cooling over a 10 year period (April 1941 to March 1951). So we could actually pump CO2 into the atmosphere twice as fast as now and yet have no warming over a 10 year period.

By Chris O'Neill (not verified) on 07 Sep 2008 #permalink

Yes, I took one look at that graph, saw the end of the graph, and straight away knew what was coming. It's all rather sad really.

Plus I need to get off my arse and finish some of you know what.

dhogaza
There is I. V. Polyakov 2008 , "Arctic Ocean Freshwater Changes over the Past 100 Years and Their Causes." Journal of Climate 21/2.
In the abstract is the phase "the long-term variations of the freshwater content discussed here should be considered when assessing climate change and variability."
Saddly for me, this gives me the impression they now think there is some climate change and some variation.
I would buy the bl...dy thing to find out but the online vending service refuses to accept my French address.

By sean egan (not verified) on 08 Sep 2008 #permalink

Sean, having scanned the paper I would suggest that Oreskes would categorise it thus:

Agreement with scientific consensus on 'Global Climate Change'; implicit.

'Well, the ice in my freezer is coming along just fine. Does this make me a "denialist?" '

Replace "freezer" by "antarctica" then you tell us

I still can't quite figure out why the title is "Record ice loss in August". Congratulations to this first year ice that survived this record ice loss. Maybe it partly was first year ice that grew thicker than the multi year ice at its edge.
But look at the SST anomaly along the new ice edge compared to one year ago. SST anomaly August 2008 vs. August 2007.

The heat is off. But this is just weather.

So many earth scientists, climate modellers and other statisticians among you will agree with me that this "record ice loss" in August is just as little an indicator of global warming as the record ice gain of last winter was an indicator of global cooling.

Climatepatroll.

Since you seem to have your finger on the statistical button, perhaps you could tell us what the ice extent would need to be this year to be significantly below the 1979-2000 average, irrespective of what the record loss was last year.

One simply number will do, and you can even leave showing your working until later.

By Bernard J. (not verified) on 11 Sep 2008 #permalink

So many earth scientists, climate modellers and other statisticians among you will agree with me that this "record ice loss" in August is just as little an indicator of global warming as the record ice gain of last winter was an indicator of global cooling.

the difference is simple to explain:

pointing at a single year (or season) uptick, claiming a "change in trend" is STUPID.

pointing out that another record is CONFIRMING THE TREND is a useful thing to do.

@Bernard J.
About 7 million square kilometers. Why, if I may ask?

@sod
No need to shout. It's the impact that changes a trend, not the statistical proof of it a few years later. So if there is a change in ocean circulation or any other impact, this may be the change of the trend. I simply don't know. It is too early to tell. So who is the stupid guy who claimed a change in trend?

Climatepatrol.

Erm, "[a]bout 7 million square kilometers" is the mean summer minimum ice extent for 1979-2000.

I was wondering what deviation from this would be required to signify to you that the melt is below the 1979-2000 average.

By Goldenwood (not verified) on 16 Sep 2008 #permalink

Climatepatrol.

Erm, "[a]bout 7 million square kilometers" is the mean summer minimum ice extent for 1979-2000.

I was wondering what deviation from this would be required to signify to you that the melt is below the 1979-2000 average.

By Goldenwood (not verified) on 16 Sep 2008 #permalink

Climatepatrol.

The post at #54 was actually from me - I had some friends over for dinner and in the ensuing tussle to each get a post in near 1^6 I didn't change his user details.

My question still stands though.

By Bernard J. (not verified) on 16 Sep 2008 #permalink

@Bernard
4.5 million square kilometers is below 7 million square kilometers. 2008 is below the 1979-2000 average. Wow. What a revelation! Is it really? "North west passage open for ships".
Time Magazine September 13, 1937. 1937!

climatepatrol:

The "NW passage open in 1937' thing is the newest denialist meme. If you actually read the story, though, and cut through the hype, what it reports is that two Canadian ships managed to meet in mid=passage in that one year, and that Time hyped it as a new shipping route. There is nothing in that article detailing the conditions they encountered. One would also note that its now 70 years later, and no such shipping route materialized.

Two ice-prepared ships slipping through - despite the Time hype - is not in itself evidence that 1937 was anything like the last two years.

i think it's pretty clear. the northwest passage opened in 1937, but the incredibly wealthy and powerful climatologist cartel has kept the knowledge suppressed in order not to damage their plan to tout "global warming" at the end of the 20th century. think of the savings that could have been attained had ships been allowed to use that route. damn you, Al Gore!!!!

Climatepatrol.

Yes, 4.5 million km2 is 'below' 7 million km2, and thus 2008 is 'below' the 1979-2000 mean.

Back at #50, and several times since, I asked you what you thought the number would need to be in order to be considered sifnificantly below the mean. And by extension, whether the 2008 value is above or below this figure.

You are dancing around and doing your best to avoid ansering this simple question. Is this because answering it might actually be a 'revelation'? is it because answering it might have more bearing on the future of the Northwest passage than does your magazine reference from 1937?

Since this question seems to have stumped you I will rephrase it: is there any significant trend in the summer minimum Arctic sea ice extent since 1979? And a suplementary: how does the 2008 value relate to any trend since 1979?

Come on, show us your analytical skills.

By Bernard J. (not verified) on 17 Sep 2008 #permalink

Bernard
With all due respect, but I knew all along what the motive of your questions are. So why not ask directly? What are your credentials? How many peer reviewed papers have you written and published in Science, Nature, etc.? Do you qualify to debate with the pharizees of the holy community here? Are you qualified to ask critical questions like a journalist to the royal community here?

So the saceond version of your question is asked in laymans terms without implying any nitty gritty technical mathematicial details. Here is the simple answer. Yes, there is a significant trend in the Arctic Sea ice extend since 1979. 2008 confirms any trend that implies a continued decline in Arctic Sea ice extend.

Now you may read again my other comments and see how consistent this answer is with them. But you need to take off your glasses of prejudice beforehand please Sir.

Sorry to all readers of #60 for my typos in #60 done in a hurry.

Bernard:

After your two-faced attempt of marginalization, lets get back to the title of this post:

Record ice loss in August.

Following a record rate of ice loss through the month of August, Arctic sea ice extent already stands as the second-lowest on record...

My finger still remains on this "record rate of ice loss through the month of August". Since nobody took the chance to support this claim scientifically after my questioning in #49, I assume that there is no scientific basis for such a claim, and thus conclude that it is a sort of deception to make it look more dramatic.

@Lee

Two ice-prepared ships slipping through - despite the Time hype - is not in itself evidence that 1937 was anything like the last two years.

I agree with you. The satellites scan the Arctic ice since 1979 only. We don't have accurate data from what happened before. And this was just at the beginning of an accelerated global warming trend, triggered partly by a change of ocean weather.

To all:
There is indeed evidence that part of the melting of the Arctic sea ice was caused by human activities (CO2, ground level ozone, black soot) and another part by natural variability.

@Tim Lambert

Now, if you are into global warming denial, you might decide that it's time to stop talking about Arctic sea ice and start calling Al Gore fat.

I know, Tim. Yet a real skeptic doesn't fit into your box of denialist trolls. To the contrary: Is there an expert in the field who could be as kind as to name a paper dealing with the question what portion of the melting of the Arctic sea ice between 1979 and 2008 can be attributed to human activities?

climatepatrol asks:
"Yet a real skeptic doesn't fit into your box of denialist trolls. To the contrary: Is there an expert in the field who could be as kind as to name a paper dealing with the question what portion of the melting of the Arctic sea ice between 1979 and 2008 can be attributed to human activities?"

Climatepatrol, a REAL skeptic has some clue how to go find information on his own. But since you asked:

Rigor er al, 2000; Deser et al 2000; Zhang et al 2000; Tucker et al 2001; Koberle and Gerdes 2003; Rothrock and Zhang 2005; Law and Stohl 2007; Min et al 2008

Since nobody took the chance to support this claim scientifically after my questioning in #49, I assume that there is no scientific basis for such a claim, and thus conclude that it is a sort of deception to make it look more dramatic.

What an incredibly stupid assumption, as though we're all your personal secretary-scientists yet at the same time out to get you. Look at mr big shot with his tinfoil hat.

Are you asking for something other than the obvious? What kind of "scientific basis" are you looking for? I added up some numbers. Is that scientific enough? Can I take the rest of the day off to get my hair done?

Loss of sea ice for the 3 record years:

2005: 1,395,000

2007: 1,768,282

2008: 2,173,750

Number added up from the data linked to at http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

It's possible some of the years with less sea ice loss actually had a more rapid rate of loss during August, but I'm a lazy secretary-scientist and I'm also out to get you.

Notes:

1. That's loss of sea ice during the month of August for those three years.

2. Numbers added up... I added more than one number.

3. The last number is the biggest one, in case your finger gets stuck again.

4. Next time maybe take your finger off the thing you're not sure about and try sticking it in your Google or something.

What an incredibly stupid assumption, as though we're all your personal secretary-scientists yet at the same time out to get you. Look at mr big shot with his tinfoil hat.

Not to mention he's on [killfile] by likely 1/4 of the readers here (incl me). Talk about desperate to win points!

Best,

D

"Since nobody took the chance to support this claim scientifically after my questioning in #49"

I.e. "PAY ATTENTION TO MEEEEEEEEEEEE!"

Looking at the data pough linked to at #63, I notice a little spike seems to occur at the same time in June for all of the annual trajectories illustrated.

Anyone know what's happening here?

By Bernard J. (not verified) on 18 Sep 2008 #permalink

@Lee
"a REAL skeptic has some clue how to go find information on his own."
Whatever. ...or if he doesn't quite qualify, he has the choice to either put his finger into an open den of lions and little roaring and screeming copycats - or - to stick to the "comfort zone" of real denialists. (Food for thought for those of you who care...).

Thank you very much, lion Lee and lion Pough!

This is how I would rephrase the sentence where I put my finger on: "Following the record rate of ice loss for a month of August..."

Other than that and scoffing aside: Great info with great links. Thanks, Tim!

Lee
Unlike dhogaza , you do not seem bothered by the data being a bit old.

Rigor Colony Martin 2000
Variations in surface air temperature observations
http://iabp.apl.washington.edu/AirT/RigorEtal-SAT.pdf

Deser C Walsh J Timlin M 2000;
Artic Sea Ice Variability in the context of the recent atmosperic Circulation Trends
http://ams.allenpress.com/perlserv/?request=get-document&issn=1520-0442…
or was it
Deser C 2000
On the teleconnectivity of the Arctic Oscillation
Not found online

Zhang, J., D.A. Rothrock, and M. Steele (2000)
Recent changes in arctic sea ice: The interplay between ice dynamics and thermodynamics
J Clim 13, 3099-3144
http://psc.apl.washington.edu/zhang/Pubs/ zhang_etal2000.pdf

Rothrock and Zhang 2005;
Arctic Ocean sea ice volume: What explains its recent depletion
http://psc.apl.washington.edu/zhang/Pubs/ rothrock_zhang_2004JC002282.pdf
Do not tell dhogaza it appears to only have data up to 2000.

After reading the two Zhangs above, you might want to read
Zhang 2008
Ensemble 1-Year prediction of Arctic sea ice for spring and summer 2008
http://psc.apl.washington.edu/zhang/Pubs/ Zhang_etal2008GL033244.pdf
then look up the current sea ice extent - less than impressive

Law and Stohl 2007;
Arctic Air Pollution: Origins and Impacts
Science 16 March 2007
Cost 10 dollars

Min et al 2008
« Human-Induced Arctic Moistening »
Science 25 April 2008
costs 10 dollars

"what portion of the melting of the Arctic sea ice between 1979 and 2008 can be attributed to human activities?"
I did not find a simple answer in the above, but I think the question is ill formed. All that is not natural variation is us, or God. So the trick is to see what is natural variation. God seems to have been inactive in this areas since genesis 7.

By sean egan (not verified) on 20 Sep 2008 #permalink

Thanks to Sean for this comprehensive addition. It seems like you are one of the few posters in this or any scientific blog that recognizes the big picture. Yet it is too delicate for me to answer the part where you mention God and apparently the big flood. Let's stick to scientific language. I in fact did find some answers regarding human impact through Arctic air pollution in Law and Stohl 2007 (as previously suggested by Lee). My point is, if we don't know the portion of human impact, let alone the portion of the role of long lived greenhouse gases, it seems to me that we should tackle first what is an obvious impact, like Arctic air pollution according to the Law n Stohl paper. We should still be good stewards of the planet God entrusted us, if I may say so. If Kyoto is the right solution? Well, I still don't know if doing nothing about long lived greenhouse gases is better. Off topic closed.

The reason why I put my finger on this "record loss of ice throughout the month of August" was my concern of a possible exaggeration. It turned out - well - it is the official press release of the NSIDC website. I have to acknowledge that in fairness to Tim Lambert. To me as a layman it sounded like a record rate of ice loss throughout August PUNKT. July 2007 stands out as the record ice loss, that was my first thought. In August, the ice usely melts more slowly than in July which is surely clear to the majority of the commenters here.

For me, the rate of ice loss in August was not impressive because I assume there is less ice volume than last year (less thick multi-year ice). So it is only natural that the ice continued to brake up an melt a lot throughout August. It is by no means an indication of a high climate sensitivity of the Arctic towards human activities as long as there are no data that suggest the human portion. So thank you again for skimming through the above papers.

Wow,
the sea ice extent is taking off like a rocket.
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
Its still looks good for 2008 being a recovery year.
It would have been very spectacular if all the hugh loss in 2007 over 2006 was made up in one year. It is all so much better than with post 2007 predictions.

By sean egan (not verified) on 01 Oct 2008 #permalink

sean egan, you should apply the same method of 'analysis' to the American economy, which is full of short-term 'recoveries'. That'll work.

Sean Egan at #72.

Can you explain exactly how 'Its (sic) still look[ing] good for 2008 being a recovery year'?

Statistical working would be good, but mere scientific logic will suffice.

C'mon, put up.

By Bernard J. (not verified) on 02 Oct 2008 #permalink

Several competing popular arguments about arctic ice have been made.

The first is that temperature gives you a 3% to 4% per decade. Wind / currents gives you large variations between years. Look at the period 1998,1990, 1991 and 1992 in the graph at the start of this. There was a big dip, followed by a recovery over two years. The downward trend continued, but continued from the decade line, not from the 1990 dip.

The second widely published argument was that with more open water and less ice, more heat will be taken up. Therefore one really bad year would be enough to push us off the gentle 3% - 4% decade decline, into a « rapid » decline. The most extreme variation of this is the « tipping point « argument.
Now there are variations, like measuring extent hides that the ice is much thinner now than before. Thick ice can weather bad years, but the now, as it is thinner, we are heading for a rapid lose. Not the same tipping point as above but complimentary, and the outcome is the same.

A third argument, which is much less popular, is that is hugh natural variability in ice extent. 50 years is too short to be sure there is any significant global warming ice extent loss. So I look at the early 20th Century. However, as we know the quality of competing series is much more disputed here. We know in winter 2007 it became very much harder to make this argument as the 2007 winter pushed the trend a long way down. If 2009 is better than 2005, then this argument may be easier to make as we would be closer the decade trend. 2007 becomes a blip. The amount of lose natural multidecade cycles would need to explain becomes much reduced. Currently 2009 is getting a much better start than 2008 did. If October has the fastest build up on record , will we have the same fanfare as we had for August being the fastest lose ?

The rapid lose in August helped argument 2 over argument 1. The failure of the minimum to be lower than 2007, helps 1 over 2. My view is that if the decadal trend is temp drive, now that the world temp has been stable for 10 years, we could hope for the world Ice extent lose to stabilise also. Possibly with a bit more ice in the Antarctic making up for a bit less ice in the north. If this were the case, it could start with what we have seen 2008. The key point being without any catastrophic consequences through of ice loss. Implicit in this is that the 10 year world temp record is stable and that up to now we have not paid a heavy price for ice loss up to now, and it is not a big problem if there is more or less ice in itself provided we do not pay a heavy price in sea level rise/ rainfall/current changes or the like.

Stabilisation at the current lower ice extent is not compatible with 2. If 3 is correct, AGW is not the largest key facture driving the extent lose. Hence, I keenly look for elements against 2 -"tipping points".

For those objecting to the term recovery, it depends on context. If you are in a head on road crash, go to hospital, but come out with a limp, did you recover? If you were expecting to die, yes, I would say you recovered. 2007 was a hugh crash.

By sean egan (not verified) on 03 Oct 2008 #permalink

It is all so much better than with post 2007 predictions.

Arctic Sea Ice ... Likely Record-Low Volume meaning Arctic Ocean heat content was likely at a record high in 2008, "despite cooler temperatures and ice-favoring conditions".

Yes, it's all so much better than with post 2007 predictions. Sure.

By Chris O'Neill (not verified) on 04 Oct 2008 #permalink

Thanks Chris for the link, but contrast these two pages on the same site, the same day, today.

« Thus warming conditions and wind patterns have been the main drivers of the steeper decline since the late 1990s. Sea ice may not be able to recover under the current persistently warm conditions, and a tipping point may have been passed where the Arctic will eventually be ice-free during at least part of the summer (Lindsay and Zhang 2005). «
http://nsidc.org/sotc/sea_ice.html

to

« This summer's weather did not provide the "perfect storm" for ice loss seen in 2007: temperatures were lower than 2007, although still higher than average (Figure 5); »

« Simply put, the natural variability of short-term weather patterns provided enough of a brake to prevent a new record-low ice extent from occurring. »

http://nsidc.org/news/press/20081002_seaice_pressrelease.html

Now clearly I am cherry picking their words to make a point, and you should look at original texts. But, we got « recovery » in a year with warmer than « average » temp. We have been consistently warmer than average over the last decades and are unlikely to be average any time soon, so that's good news not bad news. Now as indicated above, world temp appear more or less stable over the last 10 years. Looks like this may be enough for the ice extent to stabilise. This is less obvious than it sounds, as if we have tipped, it is just too late... Also if the driver is soot/aerosols/ humidity the actions to take are not the same, and stabilised temp may not be enough.

While you are at it look for the word « recovery » in the web page and see if you think they have used it in the same sense I have? Note the web page and the pdf version of the same article are not the same.

Naturally web pages are not the same as peer reviewed papers - so it is likely to be several months or even a couple of years before we understand 2007/2008.

By sean egan (not verified) on 04 Oct 2008 #permalink

Sean, your arguments lose credibility when you write: "Now as indicated above, world temp appear more or less stable over the last 10 years". How many times does this outright distortion of empirical science have to be promulgated? For the billionth time, 1998 was an extreme outlier: it was profoundly warmer than any year had been to that date, and for this to happen in a largely deterministic system (global climate control) suggests that it must have been caused by a massive forcing: in that year, the largest (by far) El Nino on record occurred. This amplified the anthropogenic forcing and resulted in a spike in temperature. Check the NASA data for years immediately preceding 1998, and the magnitude of that year becomes clear.

The other thing is that changes in global temperture regimes precede actual changes in the way systems function by years, perhaps decades. The effects we are witnessing on ice-retreat now were probably the result of temperature increases well before 1998. Complex adaptive biotic systems exhibit temporal lags in cause and effect relationships that may take decades or even centuries to be manifested, as Tilman and May wrote in their seminal 1994 Nature paper. Thus, losses in biomes or even ecosystems at smaller scales may not ripple through ecological communities, generating population declines or even extinction, by a long, long time. One cannot say that we lose habitat 'x' on day one that will result in extinctions of species 'y and z' on day two; instead, these demographic changes occur over a long time span that eventually result in stable equilibria being reached at lower population densities, or the passing of thresholds that precipitate eventual extinctions, at least at the level of populations. There is no reason to believe that abiotic systems work any differently. You appear to be suggesting that temperatures over the past couple of years determine the extent of ice loss in 2008/9. If this is actually what you are saying, then you are gravely mistaken. Moreover, as I said above, its utter nonsense to say that temepratures have stablized over the past ten years. They HAVE NOT. And to reiterate, the current climate change patterns must take into account the preceding decades. The sceptics are really clutching at straws when they have to invoke their little chestnut: warming stopped in 1998".

By Jeff Harvey (not verified) on 05 Oct 2008 #permalink

Sean Egan said:

we got « recovery » in a year with warmer than « average » temp.

and Jeff Harvey responded with better clarity than I could have mustered.

Nevertheless, I think that it bears repeating - the surface temperatures this year do not instantaneously translate into oceanic (and especially polar ice) responses in the same year. Think mass (and lots of it), think heat capacity, and think of 'inertia', and you might actually understand Jeff's point.

What's next? A claim that the Tooth Fairy does exist because you left a molar under your pillow, and the next morning there was a dollar in its place?

Science please; not pretend-science.

By Bernard J. (not verified) on 05 Oct 2008 #permalink

Jeffy
I am not looking at 1998 nor 1999 which as you say are exceptional. I am more looking at 1997 to now and 2000 to now. But anyone can easily compare the three major series NCDC HadCRUT3 and GIST here http://junkscience.com/MSU_Temps/Warming_Look.html and form their own opinion. Remember no major volcano to cool us and hide the trend. Also Gist = NASA = Hansen's and he very actively announces his political opinions which probably do not add credibility when comparing his to the other two.

The remark about a missing « not » - you did see it was « may not » and you understood the difference between may not be able to recover and won't be able to recover?

Clearly in ice there is some memory year to year. However you cut it, thick ice is more likely to last difficult weather than thin ice. Thin ice is likely to reflect heat better than no ice. But stabilising effects have also been suggested. For example a smaller ice extent implies less drifting into warmer waters. More open water warming suggest more evaporation and more snow. There are paper given above which go into various ice production/export and mass balance arguments. However if it is still possible for weather to make 2008 better than 2007 - we are probably in a period were feedback effects are not so overwhelming to prevent improvement or at least stabilisation around the current ice extent. Anything which has survived other warm periods is likely to be robust with limiting effects both for maximum and minimum.

As indicated above I am not even sure we are outside natural variation as the quality records are so short compared to the claimed cycles. If we are outside natural variation, I would expect just to see an under damped response with a new extent balance point a bit further North offseting any temp rise. Yes I expect this could take years or decades, and I do not know how many so I am watching out for it now.
Note, I suspect this but I do not claim to know this.

As for the tooth fairy, I am a believer. WE have had recent visits from La Petite souris.

By sean egan (not verified) on 05 Oct 2008 #permalink

Sean, You obviously must know that there are problems with drawing conclusions on a year-to-year basis. Short time scales = stochastic, long time scales = deterministic. As Bernard also said, you have to gauge effects from the perspective of the forcing it takes to influenbce the properties of a large mass. Time lags may be close to instantaneous at very small spatial and/or temporal scales, but these lags become pronounced at very large scales.

Moreover, with respect to determinstic systems, it is wrong to gauge trends on the basis of 10 year extrapolations. As I said yesterday, it was argued by Tilman and May (1994) that current demographic changes in the populations of some organisms over large portions of their ranges may be the consequence of changes to their habitats that occurred perhaps three centuries ago. One of the major problems with humans that is evolutionarily programmed into our genomes is that we equate change with time scales that represent the evolutionary blink of an eye in natural systems. Typically this is a single human lifetime. For that reason, we do not seem well adapted to respond to what we perceive as gradual, incipient changes that in a geological context are exceedingly rapid. Consequently, we are programmed to respond to what we perceive as relatively instantaneous threats: the dammage wrought by a hurricane or a volcanic eruption, a black mamba on the path in fron of us, a bear at the mouth of a cave. But we appear less adapted to changes that we interpret as being slow and gradual, but which in complex adaptive ecological systems are in fact rather unprecedented in terms of rate for many tens of thousands of years - and when they did occur in the past they did not so so in the face of a biosphere that has been greatly simplified (indeed stressed) by a suite of human activities.

By Jeff Harvey (not verified) on 05 Oct 2008 #permalink

Yes,Jeff. Timescales are a problematic.
There is also the role of the observer. It is only since we have the technology to measure extent, do we worry about ice extent. Plus seeing anything on the TV distorts priorities. Marine litter in the high seas has much impact than the polar bears as polar bears on pack ice look better in a 20 second film clip on the news.

The remark about "greatly simplified" is true. However, I would suggest human pressure on other species is largely not through warming, but by directly occupying the living space, pollution particulary water born, and over hunting/fishing.

By sean egan (not verified) on 06 Oct 2008 #permalink

Sean, Good points. The only thing I would caution is to downplay the effects of climate change on population declines in natural communities. Given that the planet's surface has been greatly simplified by humans, AGW may be colloquially "the straw the breaks the camel's back", thus playing a profoundly important role in driving the current extinction episode. When responding to rapid warming, species must now cross human created barriers - urban landscapes, agricultural expanses, other altered habitats - that they never faced in previous warming/cooling episodes. The lack of dispersal corridors, especially for species with poor dispersal capabilities, consign them to an uncertain fate. And as biological systems become simpler, the effects rebound on human civilization, through a breakdown in ecosystem services. Effectively, simplified systems become more prone to collapse, with concomitant economic costs. The prognosis is not good.

By Jeff Harvey (not verified) on 06 Oct 2008 #permalink

Yes Jeff,
I am 100% with you on that.

By sean egan (not verified) on 07 Oct 2008 #permalink

Anyone surprised that the long-term trend for Arctic ice area and thickness is way down, and declining?

Best,

D

"Anyone surprised?"

That folks with an agenda would summarize this graph
as "Sea Ice Growing at Fastest Pace on Record"? No, i gave up being surprised at wilful collective stupidity decades ago.