Runaway global warming, what is the tipping point supposed to be?

[Beerina]

Yet Warmers feel the complete opposite and scream for "Urgent Action Now", since we "have already or are very close" to a "point of no return".

Curious, isn't it?


Well, "Point of no return" to...what? A somewhat warmer world with no ice caps? (Which may, by the way, be much better at supporting humanity's farming efforts, but that's a different issue.)


Suppose we already lived in such a thing, and some scientist came up with, "Hey, let's pull carbon out of the atmosphere so we can cool the planet, create cold winters and ice caps, and make it harder to grow things!"


Ya, his head would be on a pike in a heartbeat. And guess what faction would be leading the charge?

[mhaze]

I think this is where some would put out the laughing dog smiley. You may not fit the exact definition of an ad hom attack, but your posts are in the ad hom logical fallacy family. It is a style more common in politics. Let's see if you can try to discuss the issues without all the poisoning of the well. It truly marginalizes everything you post and all the global warming threads...and is definitely anti-science.

Anyhow, I am still waiting for your explaination of how CO2 can get the planet out of a snowball, but not heat it up now. It must have been the coolest..no wait...warmist tipping point. Please respond this time.

http://www.snowballearth.org/paleop.html

glenn:)
posts are in the ad hom logical fallacy family

You mean they may on ocassion be a parody of such, mirroring immediately preceeding ad hom logical fallacy family comments?

Now as for the snowball, the part that actually confuses me is the utter certainty with which some discuss this theory of what may have occurred in the past. Quoting Wikipedia, (http://en.wikipedia.org/wiki/Snowball_Earth)The existence of a Snowball Earth remains controversial, and is contested by various scientists who dispute the geophysical feasibility of a completely frozen ocean, or the geological evidence on which the hypothesis is based.
Your question is which of the deconstructed for clarity variants(bold section added by me)?


I am still waiting for your explaination of how CO2 can get the planet out of a snowball (and I am certain there was a snowball), but not heat it up now. It must have been the coolest..no wait...warmist tipping point.
I am still waiting for your explaination of how CO2 can get the planet out of a snowball (presuming there was a snowball or some partial variation thereof), but not heat it up now. It must have been the coolest..no wait...warmist tipping point.

Let's not engage in circular logic but instead actually consider the matter including the extent to which the historical -facts are unknown.

[mhaze]

Well, "Point of no return" to...what? A somewhat warmer world with no ice caps? (Which may, by the way, be much better at supporting humanity's farming efforts, but that's a different issue.)

Suppose we already lived in such a thing, and some scientist came up with, "Hey, let's pull carbon out of the atmosphere so we can cool the planet, create cold winters and ice caps, and make it harder to grow things!"

Ya, his head would be on a pike in a heartbeat. And guess what faction would be leading the charge?ChucKle Chuckle. Warmers heads on pikes?

Reposting from the past...

John Bailo's comment, from the message string following a section about melting sea ice at Gristmill - if I recall it was part of that "How to sound really dumb while debating a skeptic on climate science" section.

Yeah right.
Warmer..and Loving It !

I was channel surfing between breaks in football Sunday and caught a few minutes of a Global Warming scare flick (I mean, PBS documentary). This one was about arctic ice melting.

First the narrator says that the ice of some lake was frozen "year round". But then the guide for the explorers says it was free "a few months a year". Well, never mind, because now it's ice free almost all year round. And guess what -- the native people there love it! Now they have free passage and trade.

The funny part is the hapless "environmentalists" who go through the village trying to get someone to say what a bad thing it is...and yet, everyone of the Aleuts seems to be liking the warm weather and open water!

There's one fellow, who they really try to arm twist. He says how its getting warmer and warmer there every year.
"Well, how do you feel about that?" says the environmentalist, a foot from the guy's face, with his enviro-buddies right behind him...looking like a bunch of hoods asking "you want this loan, don't cha?".

The guy nonchalantly says "oh, I think it's good. We're poor and warm weather means we'll spend less on fuel".

"But, but" sputters the environmentalist, "what about the polar bear!?!"
"Oh", says the Aleut, "he can go North...to where it's colder".

See, this was the first time I ever had sympathy with a tunda person, because he reacted and spoke like every other person that I know -- he likes warm weather and he likes to save money. He didn't go into some epileptic fit about "Shamanadoda" and start decrying the spirit of the Polar Bear.

Nope. He wanted to sip pina coladas and watch the ice melt!

[Hindmost]

posts are in the ad hom logical fallacy family

You mean they may on ocassion be a parody of such, mirroring immediately preceeding ad hom logical fallacy family comments?

Now as for the snowball, the part that actually confuses me is the utter certainty with which some discuss this theory of what may have occurred in the past. Quoting Wikipedia, (http://en.wikipedia.org/wiki/Snowball_Earth)
The existence of a Snowball Earth remains controversial, and is contested by various scientists who dispute the geophysical feasibility of a completely frozen ocean, or the geological evidence on which the hypothesis is based.
Your question is which of the deconstructed for clarity variants(bold section added by me)?


I am still waiting for your explaination of how CO2 can get the planet out of a snowball (and I am certain there was a snowball), but not heat it up now. It must have been the coolest..no wait...warmist tipping point.
I am still waiting for your explaination of how CO2 can get the planet out of a snowball (presuming there was a snowball or some partial variation thereof), but not heat it up now. It must have been the coolest..no wait...warmist tipping point.
Let's not engage in circular logic but instead actually consider the matter including the extent to which the historical -facts are unknown.

I agree that the complete snowball is controversial. However, the near snowball earth is not as the evidence is clear through such things as drop stones in the tropics.

Now, how did we get out of a near snowball event if it wasn't CO2...I haven't found anything besides volcanic activity and the resultant CO2 release as the driving function that yielded an extreme positive feedback loop.

http://www.snowballearth.org/overview.html

glenn

[TrueSceptic]

ChucKle Chuckle. Warmers heads on pikes?

There have been societies where liars like you would be treated like that.

[CapelDodger]

Geophysical subsystems all have different instabilities and tipping points. Greenland will not stop melting now - it's irreversible unless we pump so much particulate that we cool the surface. That's a tipping point.

I don't think a tipping-point has been reached in Greenland because there's been no change in the basic nature of the process, only in the rate. Ocean water starting to penetrate far inland (much of central Greenland is below sea-level) will be a very definite tipping-point. It may not happen in our lifetimes, but with continued melting it will happen.

[CapelDodger]

Nope. He wanted to sip pina coladas and watch the ice melt!



You really believe all that crap, I'm sure. You are a walking embodiment of confirmation bias.

Melting permafrost is a tipping-point (regardless of how many tons of it there are) because it changes the nature of the warming process and is a self-reinforcing positive feedback. There is a lot of it - it is mostly deep and covers a vast area so do the math - so the melt will continue for a long time. Best you learn to live with it.

[mhaze]

.....Melting permafrost is a tipping-point (regardless of how many tons of it there are) because it changes the nature of the warming process and is a self-reinforcing positive feedback. There is a lot of it - it is mostly deep and covers a vast area so do the math - so the melt will continue for a long time. Best you learn to live with it.

No, melting permafrost does not seem to cause a tipping point. (http://forums.randi.org/showpost.php?p=4308182&postcount=223)

I don't think a tipping-point has been reached in Greenland because there's been no change in the basic nature of the process, only in the rate. Ocean water starting to penetrate far inland (much of central Greenland is below sea-level) will be a very definite tipping-point. It may not happen in our lifetimes, but with continued melting it will happen.So far in this thread I've seen no evidence presented for or against Greenland tipping over. Just by the book Warmer alarmism.

Well, after all, there is some sort of Warmer theory about Greenland having tipped or being about to - I've never seemed to be able to get the facts on this one.

How may it be pinned down to the dissection table?

[mhaze]

I agree that the complete snowball is controversial. However, the near snowball earth is not as the evidence is clear through such things as drop stones in the tropics.

Now, how did we get out of a near snowball event if it wasn't CO2...I haven't found anything besides volcanic activity and the resultant CO2 release as the driving function that yielded an extreme positive feedback loop.

http://www.snowballearth.org/overview.html

glennI have trouble with the number of uncertainties, including the range of possibilities in solar and GHG forcing, combined with cloud cover and planetary albedo unknowns.

This is an if A-if B-if C-if D-if E then Z question.

Any way you splice a result the error will be orders of magnitude higher than the phenomena studied.

[BenBurch]

Just like the people who still say that tobacco smoke does not cause cancer.

Pathetic.

[CapelDodger]

No, melting permafrost does not seem to cause a tipping point. (http://forums.randi.org/showpost.php?p=4308182&postcount=223)

It doesn't cause a tipping-point : it is a tipping-point.

[macdoc]

I find it amusing that the ONE forcing that could account for a second La Nina event in the Pacific ( as opposed to the neutral phase it was more likely to maintain ) is entirely off the radar of the denier crowd.

Too busy circle jerking to notice what is actually happening on the planet.:rolleyes:

Why a real if short lived forcing ...imagine that...


http://graphics8.nytimes.com/images/2008/11/14/world/14cloud.600.jpg

Giant Asian smog cloud masks warming impact: U.N.
Thu Nov 13, 2008 7:30am EST

BEIJING (Reuters) - A three-kilometer thick cloud of brown soot and other pollutants hanging over Asia is darkening cities, killing thousands and damaging crops but may be holding off the worst effects of global warming, the U.N. said on Thursday.

http://www.undispatch.com/102695main_china_shenzhen.gif

The vast plume of contamination from factories, fires, cars and deforestation contains some particles that reflect sunlight away from the earth, cutting its ability to heat the earth.

"One of the impacts of this atmospheric brown cloud has been to mask the true nature of global warming on our planet," United Nations Environment Program head Achim Steiner said at the launch in Beijing of a new report on the phenomenon.

The amount of sunlight reaching earth through the murk has fallen by up to a quarter in the worst-affected areas and if the brown cloud disperses, global temperatures could rise by up to 2 degrees Celsius.

Giant Asian smog cloud masks warming impact: U.N. | Environment | Reuters (http://www.reuters.com/article/environmentNews/idUSTRE4AC3FG20081113)

This is a reprise of of the 70s global dimming.....an actual if temporary albedo change.

http://www.nytimes.com/2008/11/14/world/14cloud.html?_r=1&hp

[CapelDodger]

I find it amusing that the ONE forcing that could account for a second La Nina event in the Pacific ( as opposed to the neutral phase it was more likely to maintain ) is entirely off the radar of the denier crowd.

I very much doubt that solar dimming in China can cause a La Nina, since that depends on the strength of the trade-winds blowing from East to West across the Southern Pacific. No doubt it has a local impact, but ENSO is a far from local phaenomenon.

[mhaze]

Originally Posted by mhaze http://forums.randi.org/helloworld2/buttons/viewpost.gif (http://forums.randi.org/showthread.php?p=4312383#post4312383)
No, melting permafrost does not seem to cause a tipping point. (http://forums.randi.org/showpost.php?p=4308182&postcount=223)


It doesn't cause a tipping-point : it is a tipping-point.

I'll accept the inverse modification to my posted conclusion...

Permafrost neither causes a tipping-point : nor is it a tipping-point.

I very much doubt that solar dimming in China can cause a La Nina, since that depends on the strength of the trade-winds blowing from East to West across the Southern Pacific. No doubt it has a local impact, but ENSO is a far from local phaenomenon.Agreed, big local impact of course .

[mhaze]

I don't think a tipping-point has been reached in Greenland because there's been no change in the basic nature of the process, only in the rate. Ocean water starting to penetrate far inland (much of central Greenland is below sea-level) will be a very definite tipping-point. It may not happen in our lifetimes, but with continued melting it will happen.

Actually, you have a decrease in glacial movement in Greenland. So much for the Greenland tiping point theory.“The overall picture obtained by averaging all stake measurements at all sites for individual years indicates a small but significant (r=0.79, P < 0.05) decrease of 10% in the annual average velocity over 17 years”

van de Wal, R.S.W., et al., 2008. Large and Rapid Melt-Induced Velocity Changes in the Ablation Zone of the Greenland Ice Sheet. Science, 321, 111-113.
Now, where are those tipping points?

[a_unique_person]

Well, "Point of no return" to...what? A somewhat warmer world with no ice caps? (Which may, by the way, be much better at supporting humanity's farming efforts, but that's a different issue.)


Suppose we already lived in such a thing, and some scientist came up with, "Hey, let's pull carbon out of the atmosphere so we can cool the planet, create cold winters and ice caps, and make it harder to grow things!"


Ya, his head would be on a pike in a heartbeat. And guess what faction would be leading the charge?

I don't think you appreciate the changes that are going to be forced on the rest of the unsuspecting biological world, at a rate the evolution won't be able to cope. The change is going to be global, it will be to the climate, and just about everything biological depends on the climate.

[Pixel42]

Well, "Point of no return" to...what? A somewhat warmer world with no ice caps? (Which may, by the way, be much better at supporting humanity's farming efforts, but that's a different issue.)
A significant fraction of humanity already lives on the knife-edge where one bad harvest can make the difference between life and death. Yes global warming will have an up side in some places, but the down side in others scarcely bears thinking about.

[macdoc]

I don't think you appreciate the changes that are going to be forced on the rest of the unsuspecting biological world, at a rate the evolution won't be able to cope. The change is going to be global, it will be to the climate, and just about everything biological depends on the climate

gonna rephrase that slightly into the present tense. ;)

I don't think you appreciate the changes that ARE being forced on the rest of the unsuspecting biological world, at a rate the evolution IS NOT able to cope with. The change IS global, it IS to the climate, and just about everything biological depends on the climate.

Part of the reason we are into the 6th Great Extinction event.

Earth In Midst Of Sixth Mass Extinction: 50% Of All Species Disappearing

http://www.sciencedaily.com/images/2008/10/081020171454.jpg

Buttercups. Losing the buttercup, where it occurs in grasslands, would have a much bigger impact on the system than losing a daisy or a sunflower, for example. (Credit: iStockphoto/Mark Goddard)

ScienceDaily (Oct. 21, 2008) — The Earth is in the midst of the sixth mass extinction of both plants and animals, with nearly 50 percent of all species disappearing, scientists say.

Because of the current crisis, biologists at UC Santa Barbara are working day and night to determine which species must be saved. Their international study of grassland ecosystems, with flowering plants, is published in the Proceedings of the National Academy of Sciences.

"The current extinction event is due to human activity, paving the planet, creating pollution, many of the things that we are doing today," said co-author Bradley J. Cardinale, assistant professor of ecology, evolution and marine biology (EEMB) at UC Santa Barbara. "The Earth might well lose half of its species in our lifetime. We want to know which ones deserve the highest priority for conservation."

He explained that the last mass extinction near the current level was 65 million years ago, called the Cretaceous Tertiary extinction event, and was probably the result of a meteor hitting the Earth. It is best known for the extinction of non-avian dinosaurs, but massive amounts of plant species became extinct at that time as well.

According to the current study, the most genetically unique species are the ones that have the greatest importance in an ecosystem. These are the ones that the scientists recommend be listed as top priority for conservation.

http://www.sciencedaily.com/releases/2008/10/081020171454.htm

What's to come - when we stray out of the 1 degree +/- band and start getting into even wider and more frequent extremes excursions ( 1 meter of rain in one day in Bombay was a canary event )

It's the knock on consequences that deniers can't seem to see such as the buttercup noted above. Keystone species get threatened ( this is not just for AGW but also for land use and ocean acidification ) and entire ecosystems collapse.

It's similar to island biogeography in enhancing risk of extinction by narrowing ranges of tolerance for species and upping the frequency of excursion events.

It only takes one event ( the 1998 coral bleaching ) that might wipe out an eco system 10,000s of thousands of years in the making and just one event to cancel permanently ( dodos ) or damage severely ( tropical corals ).

When you get swings like the +80 degree excursion in Baffin Island last year - fragile local ecosystems simply vanish.

The headache of course as with loss of rain forest sometimes we don't even know what's been lost.:(

Even deep ocean biota are impacted

http://www.independent.co.uk/environment/climate-change/climate-change-will-harm-life-on-the-deep-ocean-floor-study-finds-401874.html

as well as perimeter and shallow ocean
http://www.sciencedaily.com/releases/2008/12/081211141832.htm

[macdoc]

mHaze
Actually, you have a decrease in glacial movement in Greenland. So much for the Greenland tiping point theory.
“The overall picture obtained by averaging all stake measurements at all sites for individual years indicates a small but significant (r=0.79, P < 0.05) decrease of 10% in the annual average velocity over 17 years”

van de Wal, R.S.W., et al., 2008. Large and Rapid Melt-Induced Velocity Changes in the Ablation Zone of the Greenland Ice Sheet. Science, 321, 111-113.
Now, where are those tipping points?

Classic http://tbn2.google.com/images?q=tbn:8PWanPS9RXDapM::http://www.ryanbraman.com/blogging%2520images/Ron-01.1_flat.jpg doesn't quite get the picture denier interpretation.

Glacial acceleration depends on any number of factors and is no indicator of mass loss beyond the faster it thins and dumps into the ocean the greater the loss - but there are many factors affecting acceleration - as before it's like a slide slope moving then hitting a new equilibrium.

When the net mass loss reverses globally OR in Greenland ( there are a few pockets of positive gain thanks to more moisture in the air ) let us know.:rolleyes:

Permafrost melting in itself is not a tipping point - it can however lead and already is, into a positive feedback phase for methane release - which because of it's potency magnifies warming 25x over carbon.

It IS a positive feedback which reinforces the massive changes in the north already observed. This is why the changes are skewed heavily to the north.

http://i106.photobucket.com/albums/m269/macdoc/Fig2_lanina_s.gif

...which you would know if you actually followed science journals instead of denier trash.

Read it yet??
http://www.arctic.noaa.gov/reportcard/

[Geckko]

As a Mercator projection I think that temperature anomolly image is potentialy misleading for the purposes of the point you are trying to make here.

[macdoc]

Argue with NOAA :rolleyes: - for the purposed of showing the asymmetrical heating in the north lateral expansion is rather immaterial- if you have to have help with interpretating that aspect the image is effectively meaningless to you anyway.

•••

Further to methane......

As NOAA reported, levels of methane rose sharply in 2007 for the first time since 1998. Methane is a far more potent greenhouse gas than carbon dioxide, especially over the near term. And the tundra has as much carbon locked away in it as the atmosphere contains today.

Scientific analysis suggests the rise in 2007 methane levels came from Arctic wetlands. The tundra melting is probably the most worrisome of all the climate-carbon-cycle amplifying feedbacks — and it could easily take us to the unmitigated catastrophe of 1000 ppm.

Though you should also worry that the methane might be coming the underwater permafrost, which is also thawing and releasing methane. Or from the drying of the Northern peatlands (bogs, moors, and mires). If methane rises again in 2008 — and NASA reported another brutally hot year for the Siberian tundra — then that will probably be among the top three global warming stories of 2008.



Polemic but not far off the mark for the one climate gorilla that has near term potential for running amok.

This doesn't improve the outlook

ublished online 3 December 2008 | Nature | doi:10.1038/news.2008.1275

News
Methane bursts from frozen tundra

Ice build-up may squeeze greenhouse gas from cold soil.

http://www.nature.com/news/2008/081203/full/news.2008.1275.html

[mhaze]

mHaze
.....Permafrost melting in itself is not a tipping point - it can however lead and already is, into a positive feedback phase for methane release - which because of it's potency magnifies warming 25x over carbon.

It IS a positive feedback which reinforces the massive changes in the north already observed. This is why the changes are skewed heavily to the north.

Shurr included methane and the 25x multiplier for it in his findings. However, a simple look at the relation of northward isotherm creep and its relation to inceasing temperature shows that methane release from permafrost could not comprise a positive feedback.

"Changes are skewed north" due to global weather circulation equator --> poles low then returning air streams higher.

Therefore, my prior conclusion holds:
Permafrost is not Tipping Points you can believe in.

Now, where are the tipping points? If you've got them, let's see them. Get to the point please.


Greenland?
Thermohaline circulation ?
Ocean acidification - debunked, no tipping point, skipped to tipping points for Fish, apparently
Permafrost - debunked, no tipping point

Reciting the OP, I've only invited you to show a reasonable proof of a tipping point. You've neither done that or connected causation to man.

Just noting that the world has been warming does not connect causation to man. For example:

the long-term variations in global temperature are compared to the long-term variations in geomagnetic activity as expressed by the ak-index (Nevanlinna and Kataja 2003). The correlation between the two quantities is 0.85 with p<0.01 for the whole period studied.It could therefore be concluded that both the decreasing correlation between sunspot number and geomagnetic activity, and the deviation of the global temperature long-term trend from solar activity as expressed by sunspot index are due to the increased number of high-speed streams of solar wind on the declining phase and in the minimum of sunspot cycle in the last decades. BODY { FONT-FAMILY:Tahoma; FONT-SIZE:10pt } P { FONT-FAMILY:Tahoma; FONT-SIZE:10pt } DIV { FONT-FAMILY:Tahoma; FONT-SIZE:10pt } TD { FONT-FAMILY:Tahoma; FONT-SIZE:10pt }

http://forums.randi.org/imagehosting/thum_14224495e34e0a9922.png (http://forums.randi.org/vbimghost.php?do=displayimg&imgid=14754)

So the sunspot number is not a good indicator of solar activity, and using the sunspot number leads to the under-estimation of the role of solar activity in the global warming.


BODY { FONT-FAMILY:Tahoma; FONT-SIZE:10pt } P { FONT-FAMILY:Tahoma; FONT-SIZE:10pt } DIV { FONT-FAMILY:Tahoma; FONT-SIZE:10pt } TD { FONT-FAMILY:Tahoma; FONT-SIZE:10pt } Georgieva, Bianchi, and Kirov.
http://sait.oat.ts.astro.it/MSAIt760405/PDF/2005MmSAI..76..969G.pdf

[BenBurch]

... the image is effectively meaningless to you anyway...

As usual, I have to use software to make contrast because of my color-blindness, but... ;-)

[mhaze]

As usual, I have to use software to make contrast because of my color-blindness, but... ;-)

This issue of distorsion using the Mercator projection is described here, along with the alternatives. Ben, don't worry about it, you are only missing out on the Alarming Stuff.:)

Distorsion is equal to the secant of longitude:

http://www.climateaudit.org/?p=2721

[Geckko]

Argue with NOAA :rolleyes: - for the purposed of showing the asymmetrical heating in the north lateral expansion is rather immaterial- if you have to have help with interpretating that aspect the image is effectively meaningless to you anyway.

I need help dealing with ill mannered posters only.

I also need trouble interpreting that loose jumble of words that you fail to combine into a comprehensible sentance.

In you haste to lampoon somone else you clearly forgot to recognise that the "assymetric heating in the north lateral expansion" (gag), grossly exapnds the apparent magnitude of the relative asymmetry you opine about due to the scale distortions inherent in the projection.

Here's one back at you. ****wit. :rolleyes:

[macdoc]

:rolleyes: as I said argue with NOAA. You clearly had no problem understanding the image nor do I suspect others would. Most even semi-intelligent posters comprehend that a mercator has a built in distortion - I suspect NOAA felt the same.

Now, anything cogent to add to the conversation??

A bit of verbal reinforcement for the concept...

12/04/2008

FAST-FORWARD WARMING
Point of No Return for the Arctic Climate?

By Volker Mrasek

Temperatures in the Arctic are rising much faster than elsewhere in the world. Researchers now say it may be the result of a dramatic shift in global climate patterns. If they are right, ice at the North Pole may soon be a thing of the past.

For years, scientists have been watching the Arctic Ocean with a mounting sense of unease. Sea ice on the very northern tip of our planet is melting -- and it has been doing so much more quickly than expected.

By September 2007, in fact, the area in the Arctic covered by sea ice was only half as big as Europe, a 40 percent reduction from the mid-1990s, as calculated by the National Snow and Ice Data Center in the US. Glaciers on Greenland are likewise disappearing at an alarming rate. And the Arctic Ocean itself has been warming up since 1995, a trend that has only accelerated since the beginning of this decade. In the summer of 2007, water temperatures in the Bering Sea between Alaska and eastern Siberia were 5 degrees Celsius (9 degrees Fahrenheit) higher than average -- warmer than ever before.

continues

http://www.spiegel.de/international/world/0,1518,594461,00.html

[TrueSceptic]

As a Mercator projection I think that temperature anomolly image is potentialy misleading for the purposes of the point you are trying to make here.
Clearly not Mercator. As we all know, Mercator makes areas at high latitudes huge in order to maintain shape, not area, with the result that Greenland looks as large as S America or Africa.

This appears to be Equirectangular (plate carrée). Much less misleading than Mercator but still not ideal. I prefer Mollweide.

[macdoc]

Thanks for that correction ....drop NOAA a note ;)

Maybe I shall chase down a 3d model.

[CapelDodger]

Shurr included methane and the 25x multiplier for it in his findings. However, a simple look at the relation of northward isotherm creep and its relation to inceasing temperature shows that methane release from permafrost could not comprise a positive feedback.

That makes no sense at all. Relate isotherms to temperature? What do you think isotherms are, FCOL?

Methane release is inevitably a positive feedback to warming because it's a greenhouse gas and greenhouse gases cause warming. No amount of gibberish is going to change that fact.

Nor will it change the fact that melting permafrost represents a tipping-point. There were decades of Arctic warming without permafrost melt because it was still too cold, but ten years or so ago Arctic temperatures reached the point - the tipping-point - when permafrost did start to melt. It is continuing to melt, and will do for a considerable time absent a cooling forcing that outweighs the AGW forcing plus the permafrost forcing. Learn to live with it is my advice.

[CapelDodger]

"the long-term variations in global temperature are compared to the long-term variations in geomagnetic activity as expressed by the ak-index (Nevanlinna and Kataja 2003). The correlation between the two quantities is 0.85 with p<0.01 for the whole period studied."I

They're just saying that to keep the funding flowing. Irony

So where does this leave the PDO explanation you were espousing so recently? Or the 60-80 year Arctic sea-ice cycle you used to be so into?

[CapelDodger]

This issue of distorsion using the Mercator projection is described here, along with the alternatives. Ben, don't worry about it, you are only missing out on the Alarming Stuff.:)

Distorsion is equal to the secant of longitude

So what? macdoc posted the image to illustrate the longitudinal variation in warming - nothing to do with areas. Something which you and Geckko obviously missed.

[Hindmost]

I have trouble with the number of uncertainties, including the range of possibilities in solar and GHG forcing, combined with cloud cover and planetary albedo unknowns.

This is an if A-if B-if C-if D-if E then Z question.

Any way you splice a result the error will be orders of magnitude higher than the phenomena studied.

I would expect a near snowball to be a simpler model. The solar forcings are not that variable. The sun was radiating 30% less energy 4 billion years ago and has been increasing steadily since then..in about a billion years, it will most likely be too hot for life here. the surface albedo would be more uniform...etc. The calcuations from the site seem very straight forward--it points to CO2 being a major factor in stopping the snowball.

http://www.snowballearth.org/end.html

If there were too many variables for the snowball, then certainly there are too many to draw any conclusions about recent climate.

glenn

[mhaze]

Now, where are the tipping points? If you've got them, let's see them. Get to the point please.


Greenland? (he he he he...)
Coral bleaching ? (yum yummie chomp chomp)
Thermohaline circulation ?
Ocean acidification - debunked, no tipping point, skipped to tipping points for Fish, apparently
Permafrost - debunked, no tipping point

Bring'em out.

Let 's pin them down in harsh lights on the dissection tables and check their numerical numbers...

[mhaze]

That makes no sense at all. Relate isotherms to temperature? What do you think isotherms are, FCOL?

Methane release is inevitably a positive feedback to warming because it's a greenhouse gas and greenhouse gases cause warming. No amount of gibberish is going to change that fact.

Nor will it change the fact that melting permafrost represents a tipping-point. There were decades of Arctic warming without permafrost melt because it was still too cold, but ten years or so ago Arctic temperatures reached the point - the tipping-point - when permafrost did start to melt. It is continuing to melt, and will do for a considerable time absent a cooling forcing that outweighs the AGW forcing plus the permafrost forcing. Learn to live with it is my advice.Isotherm refers to a line of constant temperature, so the northward creep of isotherms would be what occurs say during summer compared to winter in Greenland.

We've shown that greenhouse gas release from permafrost only causes a "new equilibrium" to be reached a few miles farther north, 3.3 miles, in the example analysed. Assume that all the carbon output was methane with a 25x multiplier, you get a northward movement of the constant temperature link about equal to 82.5 miles. But that is impossible, only a small fraction of the carbon will be released as methane. So this is the range to the "new equilibrium point". There is no further effect with this phenomena. The reason is that the carbon released by permafrost is distributed on a global scale, and simply does not influence the total greenhouse gas balance much.

I think I've used all the standard Warmer presumptions to reach these conclusions, including temporarily for the sake of the argument, ignoring contrary evidence and dozens of scientific papers, etc.

Not sure what else needs to be said...

[Hindmost]

Now, where are the tipping points? If you've got them, let's see them. Get to the point please.


Greenland? (he he he he...)
Coral bleaching ? (yum yummie chomp chomp)
Thermohaline circulation ?
Ocean acidification - debunked, no tipping point, skipped to tipping points for Fish, apparently
Permafrost - debunked, no tipping point
Bring'em out.

Let 's pin them down in harsh lights on the dissection tables and check their numerical numbers...

snowball earth.

glenn

[macdoc]

Denier crowd chowing down....:rolleyes:

http://www.hawkeye.ca/images/raccoon_commercial_garbage.jpg

Getting near the scrapings at the bottom. I'm sure they are equally "happy"

on the other hand

Real world science......

http://www.arctic.noaa.gov/reportcard/

••

a little tipping point for the topic....

Canada's vast forests, once huge absorbers of greenhouse gases, now add to problem

By Howard Witt (http://www.chicagotribune.com/howardwitt) |Tribune correspondent January 2, 2009 http://www.chicagotribune.com/media/photo/2009-01/44313602.jpg
Forestry officials in British Colombia used a controlled fire to check the spread of a devastating infestation by the mountain pine beetle. (Reuters photo by Andy Clark / August 8, 2005)


VANCOUVER — As relentlessly bad as the news about global warming seems to be, with ice at the poles melting faster than scientists had predicted and world temperatures rising higher than expected, there was at least a reservoir of hope stored here in Canada's vast forests.

The country's 1.2 million square miles of trees have been dubbed the "lungs of the planet" by ecologists because they account for more than 7 percent of Earth's total forest lands. They could always be depended upon to suck in vast quantities of carbon dioxide, naturally cleansing the world of much of the harmful heat-trapping gas.

But not anymore.

In an alarming yet little-noticed series of recent studies, scientists have concluded that Canada's precious forests, stressed from damage caused by global warming, insect infestations and persistent fires, have crossed an ominous line and are now pumping out more climate-changing carbon dioxide than they are sequestering.


more
http://www.chicagotribune.com/news/nationworld/chi-canada-trees_wittjan02,0,539661.story

[CapelDodger]

Isotherm refers to a line of constant temperature, so the northward creep of isotherms would be what occurs say during summer compared to winter in Greenland.

We've shown that greenhouse gas release from permafrost only causes a "new equilibrium" to be reached a few miles farther north, 3.3 miles, in the example analysed. Assume that all the carbon output was methane with a 25x multiplier, you get a northward movement of the constant temperature link about equal to 82.5 miles. But that is impossible, only a small fraction of the carbon will be released as methane. So this is the range to the "new equilibrium point".

Equilibrium of what? Atmospheric methane?

There is no further effect with this phenomena.

You assume that all the methane is produced instantaneously. Think again.

The reason is that the carbon released by permafrost is distributed on a global scale, and simply does not influence the total greenhouse gas balance much.

You originally claimed it would not be a positive feedback at all, now you say it's a small one. And even that's without any good reason as far as I can unravel.

In one paragraph you have a "new equilibrium" (whatever that is) locally, then in the next you say the methane is globally distributed. Which is it to be?

I think I've used all the standard Warmer presumptions to reach these conclusions, including temporarily for the sake of the argument, ignoring contrary evidence and dozens of scientific papers, etc.

What contrary evidence? (We're all used to you ignoring scientific papers that don't confirm your bias.) If you have evidence that methane isn't a greenhouse gas pony it up, there's a good chap.

Not sure what else needs to be said...

What you're not sure about is not my concern. I want to hear more about this instantaneous methane release.

[CapelDodger]

Denier crowd chowing down....:rolleyes:

http://www.hawkeye.ca/images/raccoon_commercial_garbage.jpg

Getting near the scrapings at the bottom. I'm sure they are equally "happy"

Not nearly so cute, though.

Real world science......

http://www.arctic.noaa.gov/reportcard/

Very interesting. I take particular note of the Arctic river discharge figures (which include run-off from melting permafrost, of course). Also permafrost temperatures, which are apparently increasing at up to 20m depth. (I'm not fixated on permafrost, by the way, I just like to focus. And there's plenty of interest to be found in permafrost.)

"Observations show a general increase in permafrost temperatures during the last several decades in Alaska (Osterkamp and Romanovsky 1999; Romanovsky et al. 2002; Osterkamp 2003; Romanovsky et al. 2007a), northwest Canada (Couture et al. 2003; Smith et al. 2005), Siberia (Pavlov 1994; Oberman and Mazhitova 2001; Romanovsky et al. 2007b; Pavlov and Moskalenko 2002), and northern Europe (Isaksen et al. 2000; Harris and Haeberli 2003). Permafrost temperature records uninterrupted for more than 25 yr have been obtained by the University of Alaska Fairbanks along the International Geosphere-Biosphere Programme Alaskan transect, which spans the entire continuous permafrost zone in the Alaskan Arctic. All of the observatories show a substantial warming during the last 20 yr (Fig. L3). The detailed characteristic of the warming varies between locations, but is typically from 0.5° to 2°C at the depth of zero seasonal temperature variations in permafrost (Osterkamp 2005). These data also indicate that the increase in permafrost temperatures is not monotonic. During the observational period, relative cooling has occurred in the mid-1980s, in the early 1990s, and then again in the early 2000s. As a result, permafrost temperatures at 20-m depth experienced stabilization and even a slight cooling during these periods. Permafrost temperature was relatively stable on the North Slope of Alaska during 2000–07. However, 2007 data show a noticeable increase in the temperature at 20-m depth by 0.2°C at the two northernmost sites of Deadhorse and West Dock. Permafrost temperature did not change significantly at the other North Slope sites. This may indicate a new wave of permafrost warming similar to the warming that started in 1994 (Fig.L2), which also started at the Deadhorse and West Dock sites and only later appeared at the interior sites."


Insects are a whole other ball of string. There are masses of them, of all sorts of types, and they do get around a lot. I think we'll see insects featuring quite a lot in the next few decades.

[mhaze]

Equilibrium of what? Atmospheric methane?
You assume that all the methane is produced instantaneously. Think again.
You originally claimed it would not be a positive feedback at all, now you say it's a small one. And even that's without any good reason as far as I can unravel.

In one paragraph you have a "new equilibrium" (whatever that is) locally, then in the next you say the methane is globally distributed. Which is it to be?....What you're not sure about is not my concern. I want to hear more about this instantaneous methane release.No, I never laid the steps out instantaneous. Rather the complete opposite, wasn't it? Seems to indicate did not understand the method? Clearly taking more interim data points won't change the reaching of the limit. "Equilibrium" was used to imply "radiative balance" using the standard Warmer Religion values.

Positive feedback? Not sure what you are talking about there, exactly. Wasn't the issue tipping points and runaway conditions? Those would be positive feedbacks that led to actual real world results of the "Alarmist" variety.

Technically something that caused a feedback of 3, then 1/3, then 1/30 could be called a positive feedback, I suppose. But not a positive feedback that would cause a tipping point, rather one that dies out rapidly due to the weakness of it's effect.

A tipping point would be when the feedback of 3 (miles) released sufficient GHG that in the next sequential increments of time, the feedback was 4, 5, 6 or 6, 9, 12, etc....a self propagating process of additional GHG added to the atmosphere, causing additional permafrost melt, la de da de da...

It does not seem that is possible with permafrost melt.

[macdoc]

More crunchy bits for denier rats...hard on their teeth after such soft wattsy mush.

Tipping elements in the Earth's climate system

http://i106.photobucket.com/albums/m269/macdoc/Picture23.jpg

1. *School of Environmental Sciences, University of East Anglia, and Tyndall Centre for Climate Change Research, Norwich NR4 7TJ, United Kingdom;
2. ‡Potsdam Institute for Climate Impact Research, P.O. Box 60 12 03, 14412 Potsdam, Germany;
3. §Department of Engineering and Public Policy, Carnegie Mellon University, Pittsburgh, PA 15213-3890;
4. ¶School of Civil Engineering and Geosciences, Newcastle University, and Tyndall Centre for Climate Change Research, Newcastle NE1 7RU, United Kingdom; and
5. ‖Environmental Change Institute, Oxford University, and Tyndall Centre for Climate Change Research, Oxford OX1 3QY, United Kingdom

1. Edited by William C. Clark, Harvard University, Cambridge, MA, and approved November 21, 2007 (received for review June 8, 2007)

Abstract

The term “tipping point” commonly refers to a critical threshold at which a tiny perturbation can qualitatively alter the state or development of a system. Here we introduce the term “tipping element” to describe large-scale components of the Earth system that may pass a tipping point. We critically evaluate potential policy-relevant tipping elements in the climate system under anthropogenic forcing, drawing on the pertinent literature and a recent international workshop to compile a short list, and we assess where their tipping points lie. An expert elicitation is used to help rank their sensitivity to global warming and the uncertainty about the underlying physical mechanisms. Then we explain how, in principle, early warning systems could be established to detect the proximity of some tipping points.

* Earth system
* tipping points
* climate change
* large-scale impacts
* climate policy

Footnotes

* †To whom correspondence may be addressed. E-mail: t.lenton@uea.ac.uk or john@pik-potsdam.de

http://www.pnas.org/content/105/6/1786

download the paper here for your edification.....:garfield:

http://www.pnas.org/content/105/6/1786/suppl/DC1

[Beausoleil]

No, because there's a maximum amount of heat that can be absorbed in the CO2 absorption bands, period, the end. The earth only emits a certain amount of light on those frequencies, and CO2 does NOT absorb outside those bands.



The atmosphere absorbs then re-emits the radiation. The crucial question is, in simple terms, how high in the atmosphere do you have to go before IR is radiated away to space rather than re-adsorbed. Heat has to be transported to this level to be lost, the more CO2 there is in the atmosphere the higher this level is. To transport the heat you need a given thermal gradient, so the surface temperature has to be higher if higher levels are to be reached.

Same on Venus as on Earth.

[mhaze]

MacDoc -

That is indeed a useful reference, unlike a number that you have posted which link to popular newspapers and magazines. Now, is there any phenomena mentioned there that you feel you can support the claim of tipping point on? (I'm not interested particularly in the arguments from the scientists. Those are for you to use, if you think you can support your claim with them).

Obviously, you believe in biggie tipping points. Now, where are they? Let's see them. Are we still discussing any of these subjects or have you moved on yet again to something else?


Greenland?
Thermohaline circulation ?
Ocean acidification - debunked, no tipping point, skipped to tipping points for Fish, apparently
Permafrost - debunked, no tipping point

Just to be clear - shouting about the Alarming Possibility of a Tipping Point is not the same as supporting the claim of a tipping point.

[mhaze]

snowball earth.

glennIt is impossible to disprove snowball earth as a tipping point due in large part to CO2 concept - for these purposes , it is an irrefutable hypothesis. Too many things varied and in ways that are unknowable.

Neither is it provable.

What was cloud cover?

[TrueSceptic]

For anyone wondering what had happened to GMB (http://forums.randi.org/showthread.php?t=131300)!

[Hindmost]

It is impossible to disprove snowball earth as a tipping point due in large part to CO2 concept - for these purposes , it is an irrefutable hypothesis. Too many things varied and in ways that are unknowable.

Neither is it provable.

What was cloud cover?

Impossible is a very strong word. The snowball earth gives a unique opportunity to study extreme conditions and relate them back to less extreme. (when I was teaching, it was easier to understand General relativity under the "extreme" black hole scenarios and then relate it back to such things as the global positioning system)

The link in my other posts showed the water cycle essentially shut down during snowball earth, so cloud cover would have been very little. However, there is reasonable mechanisms to show CO2 clouds--depending on concentration in the atmosphere. As the earth warmed, water vapor clouds formed a positive feedback and to cause rapid warming.

I see no other mechanism for removing the snowball than CO2 from volcanic and tectonic activity. Methane could be a contributer if it was released in some mechanism, but that seems implausible until a fair amount of the snowball was removed. The near snowball has adquate data...CO2 has an adequate mechanism to absorb and reradiate photons to raise the temperature of the snowball. These are reasonable hypotheses.

glenn

[bobdroege7]

Permafrost - debunked, no tipping point




Not with your use of 10 years as the atmospheric stay time for CO2, you don't

[macdoc]

10 years....!!!?? :eusa_doh:

Published online: 20 November 2008 | doi:10.1038/climate.2008.122

Carbon is forever

Carbon dioxide emissions and their associated warming could linger for millennia, according to some climate scientists. Mason Inman looks at why the fallout from burning fossil fuels could last far longer than expected.

http://www.nature.com/climate/2008/0812/images/climate.2008.122-i1.jpg
Distant future: our continued use of fossil fuels could leave a CO2legacy that lasts millennia, says climatologist David Archer

After our fossil fuel blow-out, how long will the CO2 hangover last? And what about the global fever that comes along with it? These sound like simple questions, but the answers are complex — and not well understood or appreciated outside a small group of climate scientists. Popular books on climate change — even those written by scientists — if they mention the lifetime of CO2 at all, typically say it lasts "a century or more"1 or "more than a hundred years".

"That's complete nonsense," says Ken Caldeira of the Carnegie Institution for Science in Stanford, California. It doesn't help that the summaries in the Intergovernmental Panel on Climate Change (IPCC) reports have confused the issue, allege Caldeira and colleagues in an upcoming paper in Annual Reviews of Earth and Planetary Sciences2. Now he and a few other climate scientists are trying to spread the word that human-generated CO2, and the warming it brings, will linger far into the future — unless we take heroic measures to pull the gas out of the air.

University of Chicago oceanographer David Archer, who led the study with Caldeira and others, is credited with doing more than anyone to show how long CO2 from fossil fuels will last in the atmosphere. As he puts it in his new book The Long Thaw, "The lifetime of fossil fuel CO2 in the atmosphere is a few centuries, plus 25 percent that lasts essentially forever. The next time you fill your tank, reflect upon this"3.

"The climatic impacts of releasing fossil fuel CO2 to the atmosphere will last longer than Stonehenge," Archer writes. "Longer than time capsules, longer than nuclear waste, far longer than the age of human civilization so far."

http://www.nature.com/climate/2008/0812/full/climate.2008.122.html

[CapelDodger]

No, I never laid the steps out instantaneous. Rather the complete opposite, wasn't it? Seems to indicate did not understand the method?

If you tidied up your grammer that might not happen so much. Try explaining it again.

Clearly taking more interim data points won't change the reaching of the limit. "Equilibrium" was used to imply "radiative balance" using the standard Warmer Religion values.

That's still not exactly clear.

Positive feedback? Not sure what you are talking about there, exactly.

I'm referring to a positive feedback. Something which you claimed methane release due to warming isn't.

Wasn't the issue tipping points and runaway conditions? Those would be positive feedbacks that led to actual real world results of the "Alarmist" variety.

I'm only referring to a tipping-point. When warming reaches a point where a new feedback kicks in, a tipping-point has been reached and passed. Plain and simple.

Technically something that caused a feedback of 3, then 1/3, then 1/30 could be called a positive feedback, I suppose.

It simply is a positive feedback. You seem a little confused as to what a positive feedback is.

But not a positive feedback that would cause a tipping point, rather one that dies out rapidly due to the weakness of it's [sic] effect.

It isn't going to die out rapidly because more warming will lead to more methane release for a long time. Said methane hangs around for a few years and then oxidises to CO2 (which hangs around for a great deal longer).

A tipping point would be when the feedback of 3 (miles) released sufficient GHG that in the next sequential increments of time, the feedback was 4, 5, 6 or 6, 9, 12, etc....a self propagating process of additional GHG added to the atmosphere, causing additional permafrost melt, la de da de da...

See above for what a tipping-point is.

It does not seem that is possible with permafrost melt.

The onset of permafrost-melt clearly is a tipping-point and has happened, so it's not only a possibility, it's a certainty.

[CapelDodger]

Not with your use of 10 years as the atmospheric stay time for CO2, you don't

mhaze did that? Oh dear ...

[applecorped]

http://www.dailytech.com/Article.aspx?newsid=13834

"Ice levels had been tracking lower throughout much of 2008, but rapidly recovered in the last quarter. In fact, the rate of increase from September onward is the fastest rate of change on record, either upwards or downwards."

[mhaze]

Not with your use of 10 years as the atmospheric stay time for CO2, you don'tYou are most welcome to run the numbers with a different atmospheric stay time, though, and state your results and why you think they are more accurate.

Simply insinuating that the result will be different (and conducive to production of "tipping points") by way of changing this or other parameters doesn't fly. That's what I've been trying to illustrate, that the verbal assertion of a "tipping point" really is not only unscientific, but often flat wrong, even though it may sound scientific and perfectly logical.

My selection of parameters would be 0.5C climate sensitivity and 10 years for the stay time, but what I used was 3.0 and 10. To affect global climate whatever that comes out of the ground in the latitudes of melt zone must be sufficient to have an effect after the distribution of the outgassing world wide, resulting in a northward creep of the isotherm lines.

(crude guess) Increasing the stay time to 50 years would likely cause the melt zone creep to 15 miles for the first decade, then 1.5 miles, then 0.15 miles and then your limit or (Warmer phrase) "new equilibrium".

No tipping point or runaway climate.

If you tidied up your grammer that might not happen so much. Try explaining it again.....That's still not exactly clear.....See above for what a tipping-point is.....The onset of permafrost-melt clearly is a tipping-point and has happened, so it's not only a possibility, it's a certainty.I'm not really sure what you are trying to say at this point. Maybe you don't understand the method I used?

It is straight forward. By looking at the (tiny) additional melt zone caused by release of GHG from permafrost melt zone it is clear there is nothing to be alarmed about from permafrost melt.

[mhaze]

Impossible is a very strong word. The snowball earth gives a unique opportunity to study extreme conditions and relate them back to less extreme. (when I was teaching, it was easier to understand General relativity under the "extreme" black hole scenarios and then relate it back to such things as the global positioning system)

The link in my other posts showed the water cycle essentially shut down during snowball earth, so cloud cover would have been very little. However, there is reasonable mechanisms to show CO2 clouds--depending on concentration in the atmosphere. As the earth warmed, water vapor clouds formed a positive feedback and to cause rapid warming.

I see no other mechanism for removing the snowball than CO2 from volcanic and tectonic activity. Methane could be a contributer if it was released in some mechanism, but that seems implausible until a fair amount of the snowball was removed. The near snowball has adquate data...CO2 has an adequate mechanism to absorb and reradiate photons to raise the temperature of the snowball. These are reasonable hypotheses.

glennThey are reasonable speculative hypotheses, and they are very speculative. Given that, I can't see any reason not to consider them, why should we not speculate about what happened 600+ million years ago?

I'm reminded of Hoyle's speculation about viruses being basically carted around the solar system by comets, which had substantial evidence backing it but he clearly stated it was speculative. Very interesting book there, ultimately proven false if I recall correctly.

What I'd object to (not saying you said or implied this) is some kind of twisted logic like this....


I believe CO2 warms the planet blah blah blah (A causes B)
A snowball melted 600 million years ago. (Event C)
CO2 is most likely what melted the snowball. (A may have caused Event C)
Look at what CO2 did 600 million years ago!(A caused Event C)
CO2 could cause drastic changes today. (A causes B)

This is circular reasoning, obviously.

[macdoc]

Sure :rolleyes: a million sq km of ice film. When this reverses let us know.

Ice thickness is intrinsically more difficult to monitor. With satellite-based techniques (Laxon et al. 2003; Kwok et al. 2004, 2007) only recently introduced, observations have been spatially and temporally limited. This said available data from a variety of sources consistently indicate a net thinning of the Arctic sea ice cover. Data from submarine-based observations indicate that over the period of available records, 1975 to 2000, the annual mean thickness of the ice cover declined from a peak of 3.71 m in 1980 to a minimum of 2.46 m in 2000, a decrease of 1.25 m (Rothrock et al. 2008). Satellite-derived estimates of sea-ice age and thickness, combined to produce a proxy ice thickness record for 1982–2007, also indicate the ice has thinned significantly between 1982 and 2007 (Maslanik et al. 2007). Helicopter-borne and ice-based electromagnetic measurements indicate a reduction of modal and mean sea ice thicknesses in the region of the North Pole of up to 53 and 44%, respectively, between 2001 and 2007 (Haas et al., 2008). In contrast to the central Arctic, measurements of the seasonal and coastal ice cover do not indicate any statistically significant change in thickness in recent decades (Melling et al. 2005; Haas 2004; Polyakov et al. 2003). This observation indicates that the thinning of the ice cover is primarily the result of changes in the characteristics of the perennial ice.

Seasonal versus perennial ice

http://www.arctic.noaa.gov/reportcard/images/essays/seaice/s4.jpg

Figure S4. Time series of area of perennial sea ice extent in March of each year estimated by the Drift-Age Model and observed by QuikSCAT satellite scatterometer within the model domain. In each year, the model result was an average over March, and the satellite observation was on the spring equinox (21 Mar). (Adapted from Nghiem et al. 2007)

The Arctic sea ice cover is composed of perennial ice (the ice that survives year-round) and seasonal ice (the ice that melts during the summer).

Consistent with the diminishing trends in the extent and thickness of the cover is a significant loss of the older, thicker perennial ice in the Arctic (Fig. S4). Data from the NASA QuikSCAT launched in 1999 (Nghiem et al., 2007) and a buoy-based Drift-Age Model (Rigor and Wallace, 2004) indicate that the amount of perennial ice in the March ice cover has decreased from approximately 5.5 to 3.0 million km2 over the period 1958–2007. While there is considerable interannual variability, an overall downward trend in the amount of perennial ice began in the early 1970s. This trend appears to coincide with a general increase in the Arctic-wide, annually averaged surface air temperature, which also begins around 1970 (see Fig. A1). In recent years, the rate of reduction in the amount of older, thicker perennial ice has been increasing, and now very little ice older than 5 yr remains (Maslanik et al. 2007).

Many authors have recently acknowledged that a relatively younger, thinner ice cover is more susceptible to the effects of atmospheric and oceanic forcing (e.g. Gascard et al., 2008; Stroeve et al., 2008; Kwok, 2007; Ogi and Wallace, 2007; Maslanik et al., 2007; Serreze et al., 2007; Shimada et al., 2006). In the face of the predictions for continued warming temperatures (Christensen et al., 2007), the persistence of recent atmospheric (Comiso et al., 2008; Kwok, 2008) and oceanic circulation patterns (Steele et al. 2008; Polyakov et al. 2007), and the amplification of these effects through the ice albedo feedback mechanism (Perovich et al., 2008), it is becoming increasingly likely that the Arctic will change from a perennially ice-covered to an ice-free ocean in the summer.

http://nsidc.com/arcticseaicenews/

Ice extent without taking into account thickness in the Arctic is just about meaningless...

A cold Pacific circulation and a record amount of open ocean to skim over....what do you think is going to happen.....

There is very little variation at a January time point in ANY year....but keep swallowing the denier Koolaid.

When you start chattering about global dimming V2.0 you might actually get some respect.
Talking about the extent of single year ice in January, after two record years of open water shows astounding lack of comprehension.....and basic physics.

[lomiller]

applecorped, the Arctic basin, Hudson bay, Canadian archipelago, and Bering sea freeze solid by December ever year and are expected to continue to do so for the foreseeable future. This means the more ice that melts in summer the “faster the recovery” but it isn’t a real recovery it’s simply a side effect of more summer melting recovering to the same point by December.

Once these freeze the “fast recovery” stops in it’s tracks because from winter to winter the only place sea ice can change is a little in the pacific and the Atlantic around Norway. See how this “fast recovery stopped” in November and has lined up with last years almost exactly since.

http://www.nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png

[macdoc]

There was actually a record low extent a month or so back where more ocen stayed open

right here

http://2.bp.blogspot.com/_7pPdnIdJ3DE/SU-99JBQQ-I/AAAAAAAAAQc/FB4B4rxIOas/s400/N_timeseries122008.png

But there has a wicked stationary set of highs in Siberia and the Canadian Arctic with some record lows associated ( these usually form with light winds which is also ice film friendly. )

Together with a cold Pacific cycle some fast growth of single year ice can be expected - those are monstrously cold temps when those highs persist for a period.

The air over the ocean is actually above normal warm but freezing ice can cause that.

Believe it or not, freezing actually slows down dropping temperatures. As water gets colder, its temperature drops lower and lower, until it begins to freeze. Then, during freezing, the temperature stays the same. The rise in ice extent over the past three weeks has been much slower, and should continue to slow until the expected seasonal ice extent maximum is reached sometime in March. Air temperatures over the Arctic Ocean stayed well above average during November, partly because of continued heat release from the ocean to the atmosphere and partly because of a pattern of atmospheric circulation transporting warm air into the region.http://apollo.lsc.vsc.edu/classes/met130/notes/chapter2/graphics/latent_heat_schem.jpg

[macdoc]

There was actually a record low extent a month or so back where more ocen stayed open

right here

http://2.bp.blogspot.com/_7pPdnIdJ3DE/SU-99JBQQ-I/AAAAAAAAAQc/FB4B4rxIOas/s400/N_timeseries122008.png

But there has a wicked stationary set of highs in Siberia and the Canadian Arctic with some record lows associated ( these usually form with light winds which is also ice film friendly. )

Together with a cold Pacific cycle some fast growth of single year ice can be expected - those are monstrously cold temps when those highs persist for a period.

The air over the ocean is actually above normal warm but freezing ice can cause that.

Believe it or not, freezing actually slows down dropping temperatures. As water gets colder, its temperature drops lower and lower, until it begins to freeze. Then, during freezing, the temperature stays the same. The rise in ice extent over the past three weeks has been much slower, and should continue to slow until the expected seasonal ice extent maximum is reached sometime in March. Air temperatures over the Arctic Ocean stayed well above average during November, partly because of continued heat release from the ocean to the atmosphere and partly because of a pattern of atmospheric circulation transporting warm air into the region.http://apollo.lsc.vsc.edu/classes/met130/notes/chapter2/graphics/latent_heat_schem.jpg

[macdoc]

There was actually a record low extent a month or so back where more ocen stayed open

right here

http://2.bp.blogspot.com/_7pPdnIdJ3DE/SU-99JBQQ-I/AAAAAAAAAQc/FB4B4rxIOas/s400/N_timeseries122008.png

But there has a wicked stationary set of highs in Siberia and the Canadian Arctic with some record lows associated ( these usually form with light winds which is also ice film friendly. )

Together with a cold Pacific cycle some fast growth of single year ice can be expected - those are monstrously cold temps when those highs persist for a period.

The air over the ocean is actually above normal warm but freezing ice can cause that.

Believe it or not, freezing actually slows down dropping temperatures. As water gets colder, its temperature drops lower and lower, until it begins to freeze. Then, during freezing, the temperature stays the same. The rise in ice extent over the past three weeks has been much slower, and should continue to slow until the expected seasonal ice extent maximum is reached sometime in March. Air temperatures over the Arctic Ocean stayed well above average during November, partly because of continued heat release from the ocean to the atmosphere and partly because of a pattern of atmospheric circulation transporting warm air into the region.http://apollo.lsc.vsc.edu/classes/met130/notes/chapter2/graphics/latent_heat_schem.jpg

[macdoc]

There was actually a record low extent a month or so back where more ocen stayed open

right here

http://2.bp.blogspot.com/_7pPdnIdJ3DE/SU-99JBQQ-I/AAAAAAAAAQc/FB4B4rxIOas/s400/N_timeseries122008.png

But there has a wicked stationary set of highs in Siberia and the Canadian Arctic with some record lows associated ( these usually form with light winds which is also ice film friendly. )

Together with a cold Pacific cycle some fast growth of single year ice can be expected - those are monstrously cold temps when those highs persist for a period.

The air over the ocean is actually above normal warm but freezing ice can cause that.

Believe it or not, freezing actually slows down dropping temperatures. As water gets colder, its temperature drops lower and lower, until it begins to freeze. Then, during freezing, the temperature stays the same. The rise in ice extent over the past three weeks has been much slower, and should continue to slow until the expected seasonal ice extent maximum is reached sometime in March. Air temperatures over the Arctic Ocean stayed well above average during November, partly because of continued heat release from the ocean to the atmosphere and partly because of a pattern of atmospheric circulation transporting warm air into the region.

http://i106.photobucket.com/albums/m269/macdoc/Picture34.jpg

[mhaze]

applecorped, the Arctic basin, Hudson bay, Canadian archipelago, and Bering sea freeze solid by December ever year and are expected to continue to do so for the foreseeable future. This means the more ice that melts in summer the “faster the recovery” but it isn’t a real recovery it’s simply a side effect of more summer melting recovering to the same point by December.

Once these freeze the “fast recovery” stops in it’s tracks because from winter to winter the only place sea ice can change is a little in the pacific and the Atlantic around Norway. See how this “fast recovery stopped” in November and has lined up with last years almost exactly since.

http://www.nsidc.org/data/seaice_index/images/daily_images/N_timeseries.pngAs far as climate , sea ice affects albedo regionally. Now you have produced a reference showing "area of ocean at least 15 % covered by sea ice".

From this we do not know albedo or change of it. There have been studies showing various drift patterns that change from year to year - ice gets jammed up in bunches, at other times it is sparse. Now, is it reasonable to assume -


from a year of thick ice, to a year of thin ice
from a year of various weather patterns, to a year when unusual winds blow ice a certain way

that the "area of ocean at least 15% covered by sea ice" has a constant average albedo? That seems an impossible stretch - of course it might still be a reasonable assumption, but I would not accept it a priori. No reasonable person would.

Yet Warmers always point to these sea ice data sets. Do they not have a straight out data set of arctic and antarctic albedo?

Let's have some data to support the claims regarding sea ice.

[Hindmost]

They are reasonable speculative hypotheses, and they are very speculative. Given that, I can't see any reason not to consider them, why should we not speculate about what happened 600+ million years ago?

I'm reminded of Hoyle's speculation about viruses being basically carted around the solar system by comets, which had substantial evidence backing it but he clearly stated it was speculative. Very interesting book there, ultimately proven false if I recall correctly.

What I'd object to (not saying you said or implied this) is some kind of twisted logic like this....


I believe CO2 warms the planet blah blah blah (A causes B)
A snowball melted 600 million years ago. (Event C)
CO2 is most likely what melted the snowball. (A may have caused Event C)
Look at what CO2 did 600 million years ago!(A caused Event C)
CO2 could cause drastic changes today. (A causes B)
This is circular reasoning, obviously.

That is not the logic that should be applied.

The greenhouse effect keeps the surface of the planet warm to a large extent. Depending on the variation of the content of the atmosphere as far as dust, GHG, etc..the temperature is going to vary--along with orbital considerations and ocean currents. The change from the snowball had to be caused by some mechanism and due to the time table in which it occurred, increasing greenhouse gases and CO2 provides the plausible mechanism. Nothing circular about it.

glenn

[macdoc]

Put him on ignore.

It's just a cover for

"Well GHG warm the planet to be habitable but then it stops warming due to some yet unspecified negative feedback."

:eusa_doh:

Tuneable laws of physics. :eusa_boohoo:

[CapelDodger]

"Ice levels had been tracking lower throughout much of 2008, but rapidly recovered in the last quarter. In fact, the rate of increase from September onward is the fastest rate of change on record, either upwards or downwards."

Daily Tech seem to be getting their retaliation in first (as they say in Wales). Summer ice minimum is rather more relevant. After all, when the Sun sets over ocean for months at a time sea-ice will follow.

I don't know Daily Tech, but from a search for "climate change" on the site
http://www.dailytech.com/searchresults.aspx?keyword=climate%20change
they don't seem to take a very balanced view of the matter.

[CapelDodger]

Tuneable laws of physics. :eusa_boohoo:

If that's what it takes to keep the fat lady singing that's what'll be drummed up.

[lomiller]

mhaze I have no idea what you are trying to say or why you want to bring up albedo since. It’s the middle of winter, it’s dark 24 hours a day in the Artic. When there is no sunlight to reflect, there is no sunlight reflected so artic ice albedo this time of year is a complete non-issue.

[macdoc]

oops http://i106.photobucket.com/albums/m269/macdoc/Picture37.jpg

[CapelDodger]

As far as climate , sea ice affects albedo regionally. Now you have produced a reference showing "area of ocean at least 15 % covered by sea ice".

It's a rough measure of sea-ice volume, no doubt, but does have the advantage of being easy to determine accurately.

From this we do not know albedo or change of it.

We know that ice albedo is 0.7 and open-water albedo is effectively zero.

There have been studies showing various drift patterns that change from year to year - ice gets jammed up in bunches, at other times it is sparse. Now, is it reasonable to assume -


from a year of thick ice, to a year of thin ice
from a year of various weather patterns, to a year when unusual winds blow ice a certain way
that the "area of ocean at least 15% covered by sea ice" has a constant average albedo?

Not at all. It has a maximum of 0.7 (100% ice) and a minimum of 0.105 (15% ice). The oceaan around it has albedo from 0.1 to zero.


Yet Warmers always point to these sea ice data sets. Do they not have a straight out data set of arctic and antarctic albedo?

I don't think the instruments exist to measure that directly. What all reasonable people can infer is that lower sea-ice extent means lower albedo.

Let's have some data to support the claims regarding sea ice.

Sea-ice extent can be found at http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png, updated daily. That's a direct measure by satellite-borne instruments. Sea-ice volume is more difficult to measure, but seems to be on a downward trajectory. The next couple of summers should reveal more about that.

[a_unique_person]

Put him on ignore.

It's just a cover for

"Well GHG warm the planet to be habitable but then it stops warming due to some yet unspecified negative feedback."

:eusa_doh:

Tuneable laws of physics. :eusa_boohoo:

How about "Intelligent Climate"?

[macdoc]

:thumbsup::garfield: puuuuurfect.