General Climate Change

[Yorkshiresnows]

http://www.livescien...ear-100510.html

Indeed! the warmest year on record!!!

Seeing as it is warming faster that the Arctic (well above the Surface in the middle atmosphere it is!) you have to wonder whether the closing of the Ozone hole will bring in the warming at ground level or whether it's own 'warming' will work down to ground level before then!!!

Of course the Southern oceans have already breached the circumpolar current and are lapping around areas of the coast as the Wilkins Ice sheet found to it's cost........

Maybe this year it might buck the trend then, otherwise, it at least looks as though its in pretty healthy state:

Antarctic Sea Ice Extent

Y.S

[laserguy]

I seem to remember back in 91' a U.S. fuel comp. putting out a vid, that told us all more CO2 was good for 'green things' (though most of us weren't fooled) and would 'green the globe'........

It seems they couldn't have been more wrong!

(Here we go! "the greening of planet Earth"!!!)

http://www.youtube.c...h?v=aUjnQT5fRdk

Cobbled together propaganda.

Check this out

http://wattsupwithth...threaten-crops/

Yeah I know - the struggling plant must have been denied essential nutrients or deprived of water etc,yawn. Why do commercial growers routinely pump CO2 into their greenhouses? Maybe it's because they actually prefer smaller,less healthy crops,or maybe they just get pleasure out of throwing money away. What are you CO2 bashers trying to do - starve us all to death or summink?

[Devonian]

Cobbled together propaganda.

Check this out

http://wattsupwithth...threaten-crops/

Yeah I know - the struggling plant must have been denied essential nutrients or deprived of water etc,yawn. Why do commercial growers routinely pump CO2 into their greenhouses? Maybe it's because they actually prefer smaller,less healthy crops,or maybe they just get pleasure out of throwing money away. What are you CO2 bashers trying to do - starve us all to death or summink?

No, just not play god.

Edited May 28, 2010 by Devonian

[laserguy]

No, just not play god.

Well maybe you think it's wrong to use fertilizers to increase crop yields. Next thing you'll be outside B&* with the sarnie board insisting that all fertilizers,weedkillers etc etc be banned,right? Shall we ban all medicines,too? I mean,that's every bit as much "playing God" as using CO2 to increase plant yields,no? The vilification of CO2 in the fallacious quest of "tackling climate change" knows no bounds. This is becoming truly incredible. In a weird way this sorta stuff helps soothe my summer blues - keep it up.

[Devonian]

Well maybe you think it's wrong to use fertilizers to increase crop yields. Next thing you'll be outside B&* with the sarnie board insisting that all fertilizers,weedkillers etc etc be banned,right? Shall we ban all medicines,too? I mean,that's every bit as much "playing God" as using CO2 to increase plant yields,no? The vilification of CO2 in the fallacious quest of "tackling climate change" knows no bounds. This is becoming truly incredible. In a weird way this sorta stuff helps soothe my summer blues - keep it up.

Did I say any of that? Why do you have to put words in my mouth? I dunno.

I think changes that play god and change the whole atmosphere to a marked and perhaps damaging extent aren't sensible. I don't, fwiw, think it's sensible to play god with fish stock to the extent you make them extinct, or forests to the extent you end up with none. Does that mean I don't eat fish? No. Or that I aviod using wood? No.

Please don't so misrepresent me.

Edited May 28, 2010 by Devonian

[Methuselah]

Cobbled together propaganda.

http://wattsupwithth...threaten-crops/

Cannae recall who it was (Tim Flannery's book has the appropriate citing) but somebody big in fossil fuels once looked forward to the day when the atmospheric CO₂ concentration is 1000ppm!

Anyhoo, the sceptics must be scraping the barrel if we're getting back to all that late-of-the-eighties 'CO₂ greening the planet' nonsense...

BTW, where are we on that other chestnut: as-yet undiscovered undersea volcanoes? Or did the truth that those would in no way exhonerate carbon dioxide finally dawn??

[laserguy]

Anyhoo, the sceptics must be scraping the barrel if we're getting back to all that late-of-the-eighties 'CO₂ greening the planet' nonsense...

Ha,wasn't me who instigated this particular exchange,Pete,but that's as relevant now as it was way back when - unlike the warmers' stance on everything which shifts by the minute!

Dev,sorry you feel that way but that's the way you came across . Love and peace an' all that....

[Devonian]

Ha,wasn't me who instigated this particular exchange,Pete,but that's as relevant now as it was way back when - unlike the warmers' stance on everything which shifts by the minute!

Dev,sorry you feel that way but that's the way you came across . Love and peace an' all that....

You read a hell of a lot into five words - words which were an answer to a question. I've explained why you were wrong.

Edited May 28, 2010 by Devonian

[sunny starry skies]

I disagree with the above being able to conclude your final point.

The water vapour feedback effect is exactly the point. It is assumed it is a positive one (for warming), yet there is satellite evidence that is has the exact opposite effect, thereby blunting the forcing. I've shown this in previous posts (publications by Wild et al, 2004 and 2005).

Even the IPCC discussed this in one of the 2007 (4th) working group summaries:

"The changes in both satellite derived and surface measured insolation data are in line with changes in global cloudiness .... which show an increase until the late 1980's and a decrease thereafter, on the order of 5% from the late 1980s to 2002",

This corresponds to a reported 6 watts per square metre in absorbed solar irradiation by the globe.

Y.S

Coincidence that these patterns fit with changing PDO cycles .... or not.

You're confusing water vapour (present in clear air and a powerful greenhouse gas, though a feedback not a forcing) with condensed water droplets (clouds). I'm amused that you give Wild as a reference for water vapour not being a greenhouse gas as the Wild papers deal with global dimming masking the enhanced greenhouse effect until the 1980s. Water vapour is not mentioned in Wild et al 2005, and Wild would certainly disagree with you on the presence of the enhanced greenhouse effect!

Wild is talking of how anthropogenic aerosols enhance cloudiness until the 1980s (and reduce transmissivity in clear skies), and the effect reversing after this time. The quote you have is from Wild et al (2005), but referring to data from Palle et al (2004). Palle et al's results are found to be erroneous by Wielicki et al (2005) who use CERES and MODIS results to show that Palle is in error. Consequently the variations seen by Palle are much too large, and in the wrong direction. There is no observed increase in cloudiness to account for the earthshine data used by Palle in the MODIS cloud data. Palle acknowledged that they were lacking alternative data than earthshine data. Wild acknowledges Wielicki's result when stating that the dramatic increase in albedo (the Palle result) is controversial, ie not verified and perhaps wrong.

What it goes to show is that you can't rely on a single paper to prove your point, unless that paper has been verified or accepted by subsequent literature. And still no evidence for PDO being effective at producing a secular trend in global climate (as if an internal oscillation could...)!

Your quote is from Wild et al (2005), not the IPCC, and does not include the context of Wild (and Wielicki), finding it unsupported by other data.

sss

[Yorkshiresnows]

You're confusing water vapour (present in clear air and a powerful greenhouse gas, though a feedback not a forcing) with condensed water droplets (clouds). I'm amused that you give Wild as a reference for water vapour not being a greenhouse gas as the Wild papers deal with global dimming masking the enhanced greenhouse effect until the 1980s. Water vapour is not mentioned in Wild et al 2005, and Wild would certainly disagree with you on the presence of the enhanced greenhouse effect!

Wild is talking of how anthropogenic aerosols enhance cloudiness until the 1980s (and reduce transmissivity in clear skies), and the effect reversing after this time. The quote you have is from Wild et al (2005), but referring to data from Palle et al (2004). Palle et al's results are found to be erroneous by Wielicki et al (2005) who use CERES and MODIS results to show that Palle is in error. Consequently the variations seen by Palle are much too large, and in the wrong direction. There is no observed increase in cloudiness to account for the earthshine data used by Palle in the MODIS cloud data. Palle acknowledged that they were lacking alternative data than earthshine data. Wild acknowledges Wielicki's result when stating that the dramatic increase in albedo (the Palle result) is controversial, ie not verified and perhaps wrong.

What it goes to show is that you can't rely on a single paper to prove your point, unless that paper has been verified or accepted by subsequent literature. And still no evidence for PDO being effective at producing a secular trend in global climate (as if an internal oscillation could...)!

Your quote is from Wild et al (2005), not the IPCC, and does not include the context of Wild (and Wielicki), finding it unsupported by other data.

sss

My quote was from the IPCC summary actually .... so you clearly have not read either the paper or the summaries (available online) !!

Peter Taylor's book 'Chill' includes two chapters that review the entire satellite dataset ..... well up until 2009 and I've checked out most of them.

Think you need to do a little more uptodate research pal.

What I've highlighted above in your post is completley wrong (about feedback)..... but I'll let you figure that one out for yourself. I've read a load of papers ... not just the one.

With regards to the publication of papers, you need to not only submit your work, but have to have it independantly reviewed by two separate experts in the field who have nothing to do with your research (this is organised by the editorial staff of whichever Journal you are publishing in) .... if anything is total rubbish it gets rejected ...... these are facts I know well .... just had two papers accepted for publishing myself and I've had to go through hell and back to get them into a 'perfect state' for the publishers. So, don't so readily schoff at others work who have published ....... the data has already passed a lot of checks !!

Also the work carried out by Wild and others was done as part of a team .... not just one lone 'nut' with an agenda and nobody and I mean nobody will put their name to a piece of work they do not believe in.

Anyway, you are entitled to your view and good on you for sticking to yer guns !!

Off for the weekend now ... so will play later.

Y.S

P.S check this out: http://www.global-warming-and-the-climate.com/un-climate-change.htm

and this:

Edited May 28, 2010 by Yorkshiresnows

[Yorkshiresnows]

My quote was from the IPCC summary actually .... so you clearly have not read either the paper or the summaries (available online) !!

Peter Taylor's book 'Chill' includes two chapters that review the entire satellite dataset ..... well up until 2009 and I've checked out most of them.

Think you need to do a little more uptodate research pal.

What I've highlighted above in your post is completley wrong (about feedback)..... but I'll let you figure that one out for yourself. I've read a load of papers ... not just the one.

With regards to the publication of papers, you need to not only submit your work, but have to have it independantly reviewed by two separate experts in the field who have nothing to do with your research (this is organised by the editorial staff of whichever Journal you are publishing in) .... if anything is total rubbish it gets rejected ...... these are facts I know well .... just had two papers accepted for publishing myself and I've had to go through hell and back to get them into a 'perfect state' for the publishers. So, don't so readily schoff at others work who have published ....... the data has already passed a lot of checks !!

Also the work carried out by Wild and others was done as part of a team .... not just one lone 'nut' with an agenda and nobody and I mean nobody will put their name to a piece of work they do not believe in.

Anyway, you are entitled to your view and good on you for sticking to yer guns !!

Off for the weekend now ... so will play later.

Y.S

P.S check this out: http://www.global-wa...mate-change.htm

and this:

Highlighted text is not quite correct - really must take more care.

The quote comes from the expert working party (part of the IPCC process) that looked at clouds / satellite data and is re-printed in part in the book 'Chill' by Peter Taylor - it was the fact that these discussions never made it into the actual summary report which is controversial ..... I mean ...... why not when it formed part of that groups final minutes.

Anyway I do have the reference and a link somewhere so you can view this for yourself (on holiday at the minute, so no access to my files .... and missus not happy with my obsession at the moment .... hence the sneaky early morning post).

Y.S

For the full alternative view:

http://video.google.com/videoplay?docid=6613938246449800148#

Edited May 29, 2010 by Yorkshiresnows

[Gray-Wolf]

May 20, 2010

Ancient records confirm Arctic warming due to man

If Arctic warming continues at its current rate, the Arctic Ocean could have ice-free summers by 2040 or even earlier, modelling studies suggest. The last time the ocean may have had ice-free seasons was around 10,000 years ago, when the region was getting much more sunlight than today due to Earth's orbital fluctuations. By using geological records to piece together the history of Arctic sea ice over the last 50 million years, scientists have shown that the combined magnitude and abruptness of the recent ice loss is likely higher than ever before and can't be explained by any known natural variables.

Leonid Polyak, from the Byrd Polar Research Center of Ohio State University, US, and colleagues employed marine sediment cores and ice-core and terrestrial Arctic temperature records. Palaeoclimate proxies found in these sediments, such as ice-rafted debris, microscopic organisms, driftwood, whalebone, and plant material, indicate the presence or absence of sea ice in a particular region. Historical records and satellite data complete the picture for modern times.

The proxy records show that around 50 million years ago the Arctic was a balmy place, with summer temperatures as high as 24 °C and subtropical aquatic ferns basking in the warm waters. Then around 47 million years ago sea ice started to form, most probably encouraged by a fall in atmospheric carbon dioxide and an accompanying drop in temperatures.

Atmospheric carbon dioxide continued to decrease – caused in part by weathering of rocks as the Earth reorganised its continents – and temperatures fell. Then around 3 million years ago the carbon dioxide decline slowed and regular glacial cycles started to dominate temperature changes, driven by orbital variations which alter the amount of solar radiation reaching Earth. Since then the Earth has swung predictably from glacial to interglacial and back again, every few tens of thousands of years. Emerging data suggest that Arctic sea-ice was probably much reduced during the major interglacials.

For the last 11,000 years or so we have been enjoying a relatively warm, low-ice interglacial period, with a gentle cooling as we head towards the next glacial. "From orbital variations, we'd expect the Arctic to continue to slowly cool as it has done so for the past several thousand years, eventually slipping into a new ice age," said Mark Serreze director of the US National Snow and Ice Data Center at the University of Colorado.

But the last 100 years have bucked the trend in a big way. "We've lost about 30% of the summer ice extent and as much as 85% of the multi-year ice volume since the 1970s," Serreze told environmentalresearchweb. And this decrease can't be explained by natural variations alone. "If you ignored our recent atmospheric carbon dioxide rise, the recent reduction in sea ice in the Arctic would look highly anomalous, because it comes at a time when orbits favour extensive sea ice," said Richard Alley from Pennsylvania State University.

Publishing their findings in Quaternary Science Reviews, Polyak and his colleagues conclude that the recent decrease in Arctic sea ice doesn't fit any of the natural variabilities known from existing paleoclimatic data. This conclusion implies that the most plausible trigger for this warming is rising atmospheric carbon dioxide levels coming from human activities. "Orbital variations, which are currently slowly cooling the Arctic, are still there, it's just that climate warming due to human activities is now dominating and operating on a much shorter timescale – about 100 years – than orbital variations – [which operate over] thousands of years," explained Serreze.

The implications of ice-free summers in the Arctic within a few decades are of great concern. Coastal erosion will likely increase and many ice-adapted species will struggle, which will inevitably affect the human inhabitants of the Arctic. Out beyond the Arctic, weather systems will alter as atmospheric circulation patterns adjust to the effect of an ice-free Arctic Ocean.

As the geological record shows, the Arctic has occasionally been ice-free in the past. However, the current speed of on-going change is exceptional. "In the past, one went from heavier ice to milder, or ice-free, conditions over the span of thousands of years," said Serreze. "Now we are talking about doing it in 100 years, or less. Can species like polar bears adapt to such rapid change? We'll see."

==========================================================================

I thought that a couple of our regular posters might profit from a look at this.

As is highlighted we've had the best of our 'interglacial' and should be on a 'cooldown' and proxy records show it's at least 10,000yrs since we last had so little ice up there.

Edited May 29, 2010 by Gray-Wolf

[Solar Cycles]

May 20, 2010

Ancient records confirm Arctic warming due to man

If Arctic warming continues at its current rate, the Arctic Ocean could have ice-free summers by 2040 or even earlier, modelling studies suggest. The last time the ocean may have had ice-free seasons was around 10,000 years ago, when the region was getting much more sunlight than today due to Earth's orbital fluctuations. By using geological records to piece together the history of Arctic sea ice over the last 50 million years, scientists have shown that the combined magnitude and abruptness of the recent ice loss is likely higher than ever before and can't be explained by any known natural variables.

Leonid Polyak, from the Byrd Polar Research Center of Ohio State University, US, and colleagues employed marine sediment cores and ice-core and terrestrial Arctic temperature records. Palaeoclimate proxies found in these sediments, such as ice-rafted debris, microscopic organisms, driftwood, whalebone, and plant material, indicate the presence or absence of sea ice in a particular region. Historical records and satellite data complete the picture for modern times.

The proxy records show that around 50 million years ago the Arctic was a balmy place, with summer temperatures as high as 24 °C and subtropical aquatic ferns basking in the warm waters. Then around 47 million years ago sea ice started to form, most probably encouraged by a fall in atmospheric carbon dioxide and an accompanying drop in temperatures.

Atmospheric carbon dioxide continued to decrease – caused in part by weathering of rocks as the Earth reorganised its continents – and temperatures fell. Then around 3 million years ago the carbon dioxide decline slowed and regular glacial cycles started to dominate temperature changes, driven by orbital variations which alter the amount of solar radiation reaching Earth. Since then the Earth has swung predictably from glacial to interglacial and back again, every few tens of thousands of years. Emerging data suggest that Arctic sea-ice was probably much reduced during the major interglacials.

For the last 11,000 years or so we have been enjoying a relatively warm, low-ice interglacial period, with a gentle cooling as we head towards the next glacial. "From orbital variations, we'd expect the Arctic to continue to slowly cool as it has done so for the past several thousand years, eventually slipping into a new ice age," said Mark Serreze director of the US National Snow and Ice Data Center at the University of Colorado.

But the last 100 years have bucked the trend in a big way. "We've lost about 30% of the summer ice extent and as much as 85% of the multi-year ice volume since the 1970s," Serreze told environmentalresearchweb. And this decrease can't be explained by natural variations alone. "If you ignored our recent atmospheric carbon dioxide rise, the recent reduction in sea ice in the Arctic would look highly anomalous, because it comes at a time when orbits favour extensive sea ice," said Richard Alley from Pennsylvania State University.

Publishing their findings in Quaternary Science Reviews, Polyak and his colleagues conclude that the recent decrease in Arctic sea ice doesn't fit any of the natural variabilities known from existing paleoclimatic data. This conclusion implies that the most plausible trigger for this warming is rising atmospheric carbon dioxide levels coming from human activities. "Orbital variations, which are currently slowly cooling the Arctic, are still there, it's just that climate warming due to human activities is now dominating and operating on a much shorter timescale – about 100 years – than orbital variations – [which operate over] thousands of years," explained Serreze.

The implications of ice-free summers in the Arctic within a few decades are of great concern. Coastal erosion will likely increase and many ice-adapted species will struggle, which will inevitably affect the human inhabitants of the Arctic. Out beyond the Arctic, weather systems will alter as atmospheric circulation patterns adjust to the effect of an ice-free Arctic Ocean.

As the geological record shows, the Arctic has occasionally been ice-free in the past. However, the current speed of on-going change is exceptional. "In the past, one went from heavier ice to milder, or ice-free, conditions over the span of thousands of years," said Serreze. "Now we are talking about doing it in 100 years, or less. Can species like polar bears adapt to such rapid change? We'll see."

==========================================================================

I thought that a couple of our regular posters might profit from a look at this.

As is highlighted we've had the best of our 'interglacial' and should be on a 'cooldown' and proxy records show it's at least 10,000yrs since we last had so little ice up there.

Yes but if that was the case, it still wouldn't be proof that AGW was responsible. Also the blog which this is taken from, is a well known extremists site.

[jethro]

GW, does that report put any kind of figure on how much ice loss can be attributed to being above natural variation and therefore likely due to AGW, or is that the entire report above?

[osmposm]

You're confusing water vapour (present in clear air and a powerful greenhouse gas, though a feedback not a forcing) with condensed water droplets (clouds).......

Your quote is from Wild et al (2005), not the IPCC, and does not include the context of Wild (and Wielicki), finding it unsupported by other data.

sss

My quote was from the IPCC summary actually .... so you clearly have not read either the paper or the summaries (available online) !!...........

.......What I've highlighted above in your post is completely wrong (about feedback)..... but I'll let you figure that one out for yourself......

Highlighted text is not quite correct - really must take more care.....

YS, this is not a private conversation between you and SSS. Many others read your and others' posts, with interest and a desire to learn. Please, therefore, avoid such phrases as "I'll let you figure that one out for yourself" - if you think his statement is wrong, we would like to know why, and see your evidence. If you don't show us, we may tend not to believe you.

Oh, and while I genuinely appreciate your willingness to correct yourself, it would be preferable if you checked before, not after making such forceful and contradictory assertions - otherwise some of us may begin to doubt what you say before we start reading it, not after!

Edited May 30, 2010 by osmposm

[Gray-Wolf]

Sorry Jethro ,S.C. I came across the piece on the NSIDC web site

http://nsidc.org/news/inthenews/

and no nothing more about the research. It just caught my eye with it's bold title!!!

S'funny to see all the 'right wing' sites up there with tales of ice recovery etc. (any time NSIDC is mentioned in an article it is reproduced in the 'NSIDC in the news' section) with this type of article sat atop of them............though I said it at the time some folk will need to do a lot of explaining come sept! )

http://www.firstthin...back-to-normal/

http://www.prisonpla...e-news-say.html

http://despardes.com/?p=15357

http://www.dailymail...doomsayers.html

http://www.timesonli...icle7086746.ece

http://www.coastrepo...&template=cpArt

http://www.americant..._adjuste_1.html

http://www.cejournal.net/?p=3029

http://www.examiner....-how-you-say-it

Edited May 30, 2010 by Gray-Wolf

[jethro]

Thanks GW.

I do find it rather odd that no quantifying statements are made in this (and many other) papers/reports. Surely if you are able to say the melt is above natural variation, then you must have a figure for the natural and therefore the unnatural too - how could you possibly make such statements without those figures?

Personally speaking, given so much time, money and media space is expended on this subject, I'd like to know is it 2% above natural variation, 10%, 20%?????? The cynic in me thinks the reason for the absence of this information is perhaps the percentage figures are not nearly as alarming as the picture being painted. The story that the ice is melting at an alarming rate is not nearly as alarming as the ice is melting at 5% above natural variation, especially when you have to factor in a margin of error.

Perhaps I'm just too cynical.

[Solar Cycles]

Thanks GW.

I do find it rather odd that no quantifying statements are made in this (and many other) papers/reports. Surely if you are able to say the melt is above natural variation, then you must have a figure for the natural and therefore the unnatural too - how could you possibly make such statements without those figures?

Personally speaking, given so much time, money and media space is expended on this subject, I'd like to know is it 2% above natural variation, 10%, 20%?????? The cynic in me thinks the reason for the absence of this information is perhaps the percentage figures are not nearly as alarming as the picture being painted. The story that the ice is melting at an alarming rate is not nearly as alarming as the ice is melting at 5% above natural variation, especially when you have to factor in a margin of error.

Perhaps I'm just too cynical.

I don't think you are Jethro, too me it looks like more manipulated data tweaked here and there! I for one get sick and tired of reading these cherry picked reports, which have no raw data for you to access and draw your own conclusions. Anyway I'm off camping for a few days, no doubt when I return there will be more doom and gloom stories to catch up on!

[jethro]

I don't think it's manipulated, I just wonder why such important information always seems to be excluded.

[sunny starry skies]

Highlighted text is not quite correct - really must take more care.

The quote comes from the expert working party (part of the IPCC process) that looked at clouds / satellite data and is re-printed in part in the book 'Chill' by Peter Taylor - it was the fact that these discussions never made it into the actual summary report which is controversial ..... I mean ...... why not when it formed part of that groups final minutes.

Anyway I do have the reference and a link somewhere so you can view this for yourself (on holiday at the minute, so no access to my files .... and missus not happy with my obsession at the moment .... hence the sneaky early morning post).

Y.S

For the full alternative view:

http://video.google....938246449800148#

YS, I've been through the review process myself and so you're teaching a grannie to suck eggs on the review process. And seeing as you were incorrect about the quote, best to check your sources before mocking my reading of the literature! If you're so interested in reviewed literature, why do you spend so much time being concerned about one book by a climate skeptic (Taylor's Chill)? You, I'm sure, are aware that books do not go through the same review process as academic papers and so the information in them reflects the author's personal opinion, whether he believes in aliens, a flat earth, perpetual motion, or CO2 not being an effective greenhouse gas! I'm not interested in Peter Taylor's opinion, but am more interested in the peer-reviewed research.

If you follow up the papers I referred to in my last post you'll see that Wild does not agree with your opinion on water vapour or on the climate sensitivity of clouds. It makes a lot more sense that the quote from Wild (which made it sound like he saw a large sensitivity due to clouds, contrary to his other research), was actually taken out of context by Peter Taylor in his book. When you look at the literature you see that the large cloud-induced forcing is not supported by observational evidence, hence why it did not make it into the AR4 summary. Wild states exactly that in the subsequent sentence in his 2005 paper, referring to literature that seriously cast the finding of a large cloud forcing in doubt. Y.S., by all means, defend Wild, research I agree with him, perhaps rather more than you think you do! Read the other references in my last post if you don't believe me. Apologies to others that the references are not, I think, free to view.

As always in this debate, the most useful thing is to identify the originl sources, identify clearly the context in which a quote originates, and identify how this has survived in the literature subsequently. It's not an easy job, which is why so many lay climate scientists get it wrong (BTW, I'm not being personal here).

sss

Edit: SC, why do you always have to believe that data must be 'manipulated'? Implying dishonesty amongst a staggering range of researchers! Do you doubt that the Arctic has rather less ice than in recorded history? And in a related comment to above, if you doubt G-W's information because of the website it was on, then go to the source - find where the data originated, then identify problems with it.

Edited May 31, 2010 by sunny starry skies

[Gray-Wolf]

http://bprc.osu.edu/

I've looked through the Uni and the institute and can find nothing 'iffy' about it or it's research/findings?

The fact we are slowly mapping the basin wide history of the Arctic will enable us to dismiss claims that this is a 'cyclical' event that we are witnessing today.

I know we'll still have the odd person throwing in spurious anecdotal remarks about how all of science is 'bent' or just plain wrong but ,like me, most will be satisfied with the evidence and therefore pay more attention to the seriousness of the changes we see across the basin.

This will not be the last major change that we have to link in with man's activities but ,it being the first, I hope it will help add weight to the impacts we are flirting with and the need to plan for such.

[jethro]

GW, do you know of any research which puts a figure on how much is natural variation, and how much is AGW?

[Gray-Wolf]

I'd imagine the 'bit' that has pushed it beyond 'natural variation'. I don't really understand the thrust of your question though Jethro as ,to me, the fact that it has upset the balance is surely enough?

I think we''l find that the fact it is 'basin wide' and that we have lost all the perennial means we are beyond the point of return (as Mr Serezze points out).

I know this is very sad news for us all but it is where we find ourselves.

On another tack the first T.D. on the Atlantic side seems to have slipped in under the wire by crossing the isthmus and into the Caribbean heading north into the Gulf. If it develops further then I have a lot of concerns about the oil slick and any attempts to cap the leak. This season is being touted as a busy one so you'd hope they can get the leak plugged before the 'train' of T.D.s/'canes sets off!!!

[jethro]

I'd imagine the 'bit' that has pushed it beyond 'natural variation'. I don't really understand the thrust of your question though Jethro as ,to me, the fact that it has upset the balance is surely enough?

I think we''l find that the fact it is 'basin wide' and that we have lost all the perennial means we are beyond the point of return (as Mr Serezze points out).

I'm afraid it's not enough for me.

My question is simple - if as stated, the loss is beyond natural variation, I'd like to know how much above and beyond natural variation?

To state that the ice loss is now greater than at any other time, in however many thousand years, they must have an idea of how much ice there would be without AGW. It's simple maths surely? You cannot have one answer without the other.

Simply saying we've looked at sediment cores (or any other means of determining historical levels) and there's now less than at any other point, in however many years, only tells us there's less ice. It makes no judgement upon why, or validation of AGW unless there is an explanation together with calculations of how much ice there should be if natural variation alone were to blame.

I want to know how much of the ice loss is due to AGW.

Also how do we know we've not been in this position before regarding the perennial ice or that recovery will not happen? Isn't that just a "not in recorded history" statement and therefore fairly meaningless given the time period of recorded history we're talking about is so short?

[sunny starry skies]

I'm afraid it's not enough for me.

My question is simple - if as stated, the loss is beyond natural variation, I'd like to know how much above and beyond natural variation?

To state that the ice loss is now greater than at any other time, in however many thousand years, they must have an idea of how much ice there would be without AGW. It's simple maths surely? You cannot have one answer without the other.

Simply saying we've looked at sediment cores (or any other means of determining historical levels) and there's now less than at any other point, in however many years, only tells us there's less ice. It makes no judgement upon why, or validation of AGW unless there is an explanation together with calculations of how much ice there should be if natural variation alone were to blame.

I want to know how much of the ice loss is due to AGW.

Also how do we know we've not been in this position before regarding the perennial ice or that recovery will not happen? Isn't that just a "not in recorded history" statement and therefore fairly meaningless given the time period of recorded history we're talking about is so short?

I'm not quite sure what you're driving at there Jethro, and I'm not sure an answer exists that would satisfy you! We only have a few decades of sea ice extent data for the whole basin. There are longer historical records from specific locations (Newfoundland, Iceland etc), but not within the ocean itself. Your question relies heavily on what you term 'natural variation', and how long you are considering. Additionally, the long-term timeseies from sediment cores are most likely (I've not checked this btw) to record presence/absence of ice, and not thickness, probably due to variations in planktic foraminifera? If that's the case we'll never know what the palaeo-record of Arctic sea ice thickness is, though we might find more about the extent.

So far, the reductions in both volume and extent are clearly unprecedented and have a direction (they are not apparently random variations, and not clearly tied to any other mechanism than AGW). Had, a mechanism such as the PDO been dominant, we should have seen at least one, probably two similar minima in thickness/extent in the last 100-150 years. We haven't. The decline of Arctic sea ice is one of the predictions of our theory of climate, but does not, by itself, confirm warming due to anthropogenic GHGs. When taken with the other evidence - direct observations of the enhanced greenhouse effect, specific spatial and temporal patterns of warming that confirm it's the GHGs doing it and not anything else, then the fact that we observe polar amplification as predicted means it's (in true IPCC-speak) very likely that the sea ice reduction is a consequence of AGW. In fact, it would be very remarkable if sea ice reduction was not occurring!

sss