AGW Update: AGW on Ellesmere Island (far Arctic Canada)- 2 Million Years Ago

[JBG]

Two million years ago, Al Gore would have had a field day. Apparently, at some point, the climate warmed enough to allow foresting of Ellesmere Island.

2-Million-Year-Old 'Mummy Trees' Reveal Harsh Climate

(link)

SAN FRANCISCO - When rangers came across mummified wood uncovered by a melting glacier in the northernmost Arctic reaches of Canada, they had no idea they were staring at an ancient forest dating back millions of years. Researchers eventually found a twisted tangle of preserved trees that reflects a harsh struggle to survive during an ancient global cooling period.

The spindly trees would have barely hung on during a time when the Arctic climate changed from greenhouse to icehouse, on top of enduring darkness for half of each year. Signs of stress are evident in narrow tree rings and undersized leaves that were preserved at the time of death - when a landslide may have buried the trees alive. [image of mummy leaf]

"We know the climate was really hitting the fan for these guys," said Joel Barker, a biogeochemist at the Byrd Polar Research Center of Ohio State University.

Barker discussed the find here at the 2010 fall meeting of the American Geophysical Union. His group's discovery in Ellesmere Island National Park represents the northernmost mummified forest site in Canada.

In other alarming climate news, both Heathrow and Gatwick Airports are closed for heavy snow.

Snow brings travel gridlock on busiest weekend before Christmas

(link)

Blizzard conditions brought large parts of Britain to a standstill on Saturday as major airports closed their runways and roads became impassable during the busiest weekend before Christmas.

Millions of people hoping to make an early getaway faced travel misery as the big freeze brought renewed chaos.

All planes were grounded at London's Heathrow and Gatwick airports.

Forecasters warned that Britain was heading for the coldest December on record, with a current average temperature of minus 0.7C five degrees below the long-term average.

Blizzards and plummeting temperatures on Friday night, coupled with heavy snow on Saturday, crippled a huge section of the nation's road, air and rail networks, with little sign of the situation improving.

[Hambone]

Two million years ago, Al Gore would have had a field day. Apparently, at some point, the climate warmed enough to allow foresting of Ellesmere Island.

2-Million-Year-Old 'Mummy Trees' Reveal Harsh Climate

(link)

SAN FRANCISCO - When rangers came across mummified wood uncovered by a melting glacier in the northernmost Arctic reaches of Canada, they had no idea they were staring at an ancient forest dating back millions of years. Researchers eventually found a twisted tangle of preserved trees that reflects a harsh struggle to survive during an ancient global cooling period.

The spindly trees would have barely hung on during a time when the Arctic climate changed from greenhouse to icehouse, on top of enduring darkness for half of each year. Signs of stress are evident in narrow tree rings and undersized leaves that were preserved at the time of death - when a landslide may have buried the trees alive. [image of mummy leaf]

"We know the climate was really hitting the fan for these guys," said Joel Barker, a biogeochemist at the Byrd Polar Research Center of Ohio State University.

Barker discussed the find here at the 2010 fall meeting of the American Geophysical Union. His group's discovery in Ellesmere Island National Park represents the northernmost mummified forest site in Canada.

In other alarming climate news, both Heathrow and Gatwick Airports are closed for heavy snow.

Snow brings travel gridlock on busiest weekend before Christmas

(link)

Blizzard conditions brought large parts of Britain to a standstill on Saturday as major airports closed their runways and roads became impassable during the busiest weekend before Christmas.

Millions of people hoping to make an early getaway faced travel misery as the big freeze brought renewed chaos.

All planes were grounded at London's Heathrow and Gatwick airports.

Forecasters warned that Britain was heading for the coldest December on record, with a current average temperature of minus 0.7C five degrees below the long-term average.

Blizzards and plummeting temperatures on Friday night, coupled with heavy snow on Saturday, crippled a huge section of the nation's road, air and rail networks, with little sign of the situation improving.

Both of these events are consistent with the AGW models......

[BethesdaWX]

While this doesn't disprove AGW, it certainly does show that our warming right now is NOT unprecedented by any means, and that natural forces are dominant over our climate.

[ineedsnow]

started reading some threads and came upon this kind of interesting

[The_Global_Warmer]

While this doesn't disprove AGW, it certainly does show that our warming right now is NOT unprecedented by any means, and that natural forces are dominant over our climate.

 

 

what happen to the geomag cooling that was supposed to grip 2011 then 2012 then 2013?

[The_Global_Warmer]

started reading some threads and came upon this kind of interesting

 

 

What is so interesting about it?

[AvantHiatus]

What is so interesting about it?

Perhaps the behavior of the trees implies some rapid shift, until recently climate change was viewed as a very slow process requiring thousands of years to evolve.

[skierinvermont]

This warming period has been known about for a long time. There have been massive variations in the earth's climate throughout the earth's history. Frequently these past periods of warming, when there is enough data to form a conclusion, demonstrate that the earth's climate is very sensitive to small fluctuations in radiative forcing. Doubling CO2 concentration causes 3.7W/m2 of radiative forcing. 

 

 

Also a weather event in London is not climate news. 

[PhillipS]

Perhaps the behavior of the trees implies some rapid shift, until recently climate change was viewed as a very slow process requiring thousands of years to evolve.

 

A rapid climate shift can't happen if the climate sensitivity is low unless the triggering perturbation is massive - along the lines of a large asteroid impact.  So if you are hypothesizing that the fossil forest on Ellesmere Island resulted from a rapid shift, you are arguing against climate sensitivity being near the lower end of possible values.  Just sayin'.

[AvantHiatus]

A rapid climate shift can't happen if the climate sensitivity is low unless the triggering perturbation is massive - along the lines of a large asteroid impact.  So if you are hypothesizing that the fossil forest on Ellesmere Island resulted from a rapid shift, you are arguing against climate sensitivity being near the lower end of possible values.  Just sayin'.

The key take away point is that if rapid shifts can occur that severely impact the environment without anthropogenic warming, then one should probably raise the bar a bit and be more cautious about how much ecosystem damage AGW can cause.(It is magnitudes faster than natural processes)

 

We know that the mindset of viewing GW as a long-term problem way down the road is not realistic as feedbacks take great amounts of time to respond but will have been initiated in our lifetimes. Earth's climate sensitivity was found to be greater than expected for a doubling of Co2 or radiative forcing.

 

http://www.climatecentral.org/news/new-climate-records-focus-on-earths-sensitivity-16834

 

 

 

Since this article never comes right out and says it, I would just like to be clear: The new finding suggests that climate sensitivity to doubling of CO2, rather than being 3 degrees C (+/- 1.5), is in fact more like 6 degrees C??

[ineedsnow]

dont bite my head off for saying this but maybe the same thing is happening now?

What is so interesting about it?

[Jonger]

A rapid climate shift can't happen if the climate sensitivity is low unless the triggering perturbation is massive - along the lines of a large asteroid impact.  So if you are hypothesizing that the fossil forest on Ellesmere Island resulted from a rapid shift, you are arguing against climate sensitivity being near the lower end of possible values.  Just sayin'.

The key take away point is that if rapid shifts can occur that severely impact the environment without anthropogenic warming, then one should probably raise the bar a bit and be more cautious about how much ecosystem damage AGW can cause.(It is magnitudes faster than natural processes)

 

We know that the mindset of viewing GW as a long-term problem way down the road is not realistic as feedbacks take great amounts of time to respond but will have been initiated in our lifetimes. Earth's climate sensitivity was found to be greater than expected for a doubling of Co2 or radiative forcing.

 

http://www.climatecentral.org/news/new-climate-records-focus-on-earths-sensitivity-16834

 

 

 

Since this article never comes right out and says it, I would just like to be clear: The new finding suggests that climate sensitivity to doubling of CO2, rather than being 3 degrees C (+/- 1.5), is in fact more like 6 degrees C??

Interesting.... I thought the meme of the day was that co2 sensitivity has been overestimated.

[AvantHiatus]

Interesting.... I thought the meme of the day was that co2 sensitivity has been overestimated.

Yeah, one has to also consider non-human sources of greenhouse gases, such as permafrost and methane hydrates which could double the CO2 before 2100 when combined with human emissions.

 

The current estimate is only based on human CO2 emissions alone, same with the climate models which do not factor in certain key feedbacks that occur in the arctic. At bare minimum at least a 3.5c rise is guaranteed by 2100 and probably much more.

[skierinvermont]

dont bite my head off for saying this but maybe the same thing is happening now?

 

Various orbital parameters are responsible for many previous climate changes and they occurred over longer periods than our current warming. These same causes are not at play and cannot be causing our current warming. The earth doesn't simply gain and lose massive amounts of heat for no reason. 

[The_Global_Warmer]

dont bite my head off for saying this but maybe the same thing is happening now?

 

 

well we are rapidly warming.  probably much faster than the Earth cooled then. 

 

Our biggest nemesis with AGW in terms of absolute devastation will be the rate of methane being released.  We are playing with armed nuclear warheads by the way we treat the potential catastrophe. 

 

Our arrogance to to dismiss the methane possibility could end up being our downfall. 

 

the other major disaster that is getting out of control right now is Land ice loss.  996 of every 1000 glaciers on Earth is losing mass. 

 

The land ice in the 35S to 35N zones are being totally devastated by AGW.  In spite of a total slow down in OHC uptake 0-700M from 2003-2012 and global surface temps essentially flat-lining since the early 2000s we have seen land ice loss continue to rapidly accelerate.

 

 

well before it makes any meaningful inroads into Sea Level Rise.  it will cause massive issues wit drinking water.

 

so no the same thing isn't happening now.

 

To many folks don't give Man proper credit for our ascension to global dominance.  We could probably start the foundation for Primates evolutionary ascension to Mankind.  So the seeds for primates to evolve enough to be ripe to begin bipedalism is  huge part of the ascension story. 

 

3.5 MYA or so we are a semi  upright chimp-like primate. 

 

 

 

 

 

 

2.2 MYA we have already dramatically evolved.  In less than 1.5 MYA or so we went from tree dwellers to essentially bipedal chimps.  For multiple reasons these first species evolved to survive on foot. The only possible way is for our brains to grow and our bodies to grow so we can fight the apex predators.

 

Since we were still to small and weak to survive long term vs the predators more brain and dexterity enhancement were needed as well as the ability to strategically communicate hunting strategy and short term planning.

 

 

 

 

In less than 200K years or so after H. habilis above showed up. H. Erectus below shows up.  Larger cranial capacity.  much more modern human like everything while still retaining many primate characteristics.

 

So in 1.5-2 million years we went from swinging with the monkeys to Erectus who

 

 

 

 

 

 

Then this cave man looking hominid shows up.  While his brain was about as large as the ones we have. it probably had far less neural connections and much less surface space from folding. 

 

We can call Heidelberg Man the first Prototype of H. Sapein. 

 

 

Homo heidelbergensis (sometimes called Homo rhodesiensis) is an extinct species of the genus Homo which lived in Africa, Europe and western Asia from at least 600,000 years ago, and may date back 1,300,000 years. It survived until 200,000 to 250,000 years ago. Its brain was nearly as large as a modern human's. It is very likely the direct ancestor of Homo sapiens in Africa and the Neanderthals in Europe, and perhaps also the Denisovans in Asia.

 

 

 

 

Then Prototype 2.0 showed up around 400K years ago.  Homo-Neanderthalis 1.0.  Like it's cousin H. Sapien it had a very large brain, even bigger ours.  Also like modern Man we have found two nearly identical but definitely separate species of Neanderthal.  it is very likely Neanderthal 2.0 was just a neanderthal line with Homo Sapien mixed.

 

In spite of a large cranium these humans

 

 

 

 

 

Then around 120K to 80K years ago homo sapiens encountered Neanderthals.  How they mingled is unknown.  Maybe Neanderthal Men did the work or the other way or both.  But it was only a partial mingle to get Cro-Magnon to appear as another evolutionary step.  We can call this guy "Almost Human."

 

 

 

 

So after 50-70K years of the 4-5 top hominids co-existing to some extent.  Only one is left standing and yes that one carries DNA from all of it's contemporaries but in the end a combo of Cro-Magnon + archaic homo sapiens.  Then + Neanderthal eventually paved the way for an intelligence ascension that is so profound it's nearly impossible to gauge the concious human who can visually see "the entire" universe and comprehend the vastness and grandness of it VS what Chimps?  Elephants? Dolphins?  They can't even give those hairy ass humans above a run for their money. 

 

 

 

 

So now the table is set.  We have many large cranial capacity species(and sub species) coming into conflict mostly being pressured by outside forces or population growth.

 

When these species mingled it was like the Gods of the Animal Kingdom had the most magnificent biological orgy ever.  The first species to go was Cro-Magnon.  Since they lived mostly between us and neanderthals they were probably pinched from both sides and were absorbed by sapiens. 

 

 

 

 

 

 

 

 

 

This list is in chronological order across the page by genus.

• Sahelanthropus
  • Sahelanthropus tchadensis
• Orrorin
  • Orrorin tugenensis
• Ardipithecus
  • Ardipithecus kadabba
  • Ardipithecus ramidus

• Australopithecus
  • Australopithecus anamensis
  • Australopithecus afarensis
  • Australopithecus bahrelghazali
  • Australopithecus africanus
  • Australopithecus garhi
  • Australopithecus sediba
• Paranthropus
  • Paranthropus aethiopicus
  • Paranthropus boisei
  • Paranthropus robustus
• Kenyanthropus
  • Kenyanthropus platyops

• Homo
  • Homo gautengensis
  • Homo habilis
  • Homo rudolfensis
  • Homo ergaster
  • Homo georgicus
  • Homo erectus
  • Homo cepranensis
  • Homo antecessor
  • Homo heidelbergensis
  • Homo rhodesiensis
  • Homo neanderthalensis
  • Homo sapiens idaltu
  • Homo sapiens (Cro-Magnon)
  • Homo sapiens sapiens
  • Homo floresiensis
  • Denisova hominin
  • Red Deer Cave people

 

 

 

5-7 Million years of the primate to Human evolutionary convergence.  Our Brains tripled in size and they were already 300-350CC back then.  One of the most advanced on Earth.  Our bodies went from disjointed bent over chimp like bodies(but feeble) to human like in 2 million years or so.

 

How many other species had incredible wholesale evolutionary changes that fast?  Obviously no animal has ever come close in any way that is close to Erectus.

 

Comparing Modern Homo Sapiens to other land mammals would be like comparing Gods to Dogs.  it's that unfair we are that far beyond all other animal live and almost any life that ever existed on Earth except our most near ancestors. 

 

 

 

My point is we have to start looking at ourselves for what we good or bad. While all of our remarkable achievements show off only a bit of what seems like a bottomless pit of capability.

 

It also shows us that we are truly an unstoppable force on this planet.

 

In spite of everything we are and have accomplished. We have one very fatal flaw.  In the land mammal kingdom only one other species carry's this gift and yet most likely downfall.

 

 

We are hopeless opportunists.  We can't help but walk the path of least resistance.  

 

 

We build a chemical that can give us never before seen crop yields.  But it can at times be poisonous to humans and other animals.  What do we do?  We use it anyways.

 

 

how many people die in cars?  Drunk drive? Play around with a gun like its a toy and hurt or kill someone on accident.

 

how many species go to war over metals like gold, silver, copper. 

 

 

When opportunity comes good or bad we take it.  Thats how we end up in freaking world wars slaughtering each other by the tens of millions.

 

 

Splitting the God damn atom wasn't enough we had to nuke someone at least once.  We took that opportunity.  That wasn't enough to show ourselves our prowess.  We built a mechanical fuel powered machine that took us to other planetoids.

 

 

60-70 years before that the airplane was just a pipe-dream on napkin.

 

 

global landlines phone wasn't enough.  So we started electronically faxing then we went Gangsta and created the internet. 

 

 

Now 20 something years into that 4-5 billion of 7 billion humans are connected through information sharing everyday.

 

If we can do all of that.  The idea that we can't be responsible for a climate catastrophe is nothing but fear and denial of what we are truly capable of good or bad.

 

 

Oh and the other ultimate opportunist is the feline.  Felines are so good at it they have us working for them.

[StudentOfClimatology]

As skierinvermont stated, ice core records suggest that the climate system is highly sensitive to fluctuations in radiative forcing. So, it's very hard to physically deny a fairly high climate sensitivity (> 3K for a doubling of CO2 concentration), and the peer reviewed literature recognizes this: http://www.atmos.washington.edu/2006Q2/211/articles_required/Lorius90_ice-core.pdf

In fact, looking at abrupt climate change of the past, we really need to watch what we put in the atmosphere, because tipping points do exist:

I found these to be great reads:

http://www.liv.ac.uk/~jan/teaching/References/Taylor,%20Lamorey,%20Doyle%20et%20al.%201993.pdf

http://epic.awi.de/17919/1/Ste2007b.pdf

Ice core proxies are fantastic, not only due to their high resolution, but also because the variations in the isotopes examined are driven by global scale processes. The H^2-16/O isotope is lighter than the H^2-18/O isotope, so it requires less energy to evaporate from the subtropical oceans and be carried poleward via the Hadley Cells. When we see a greater ratio of the heavier H^2-18/O isotope in the ice cores, we know that time period likely featured warmer subtropical SSTs and broader Hadley Cells, implying a warmer climate. The Greenland ice cores do not just depict arctic climate, but rather the climate of the majority of the Northern Hemisphere, making it key to determining climate sensitivity: http://www.gisp2.sr.unh.edu/DATA/Obrien.html

So as a result it is fairly easy to determine climate sensitivity to variations in radiative forcing, as the peer reviewed literature confirms:

https://notendur.hi.is/~oi/AG-326%202006%20readings/Ice%20sheets%20and%20glacial%20cycles/Grootes_NATURE93.pdf

http://journals.ametsoc.org/doi/pdf/10.1175/2011JCLI4078.1

http://m.pnas.org/content/109/28/11101.short

The data suggests that the rate of warming over the past few centuries is unprecedented in the context of at least the past 1200 years. The rate of warming is the smoking gun here, rather than our temperature relative to previous warm periods, as is depicted by the peer reviewed literature:

http://journals.ametsoc.org/doi/abs/10.1175/2009JCLI2816.1

Jason E. Box

[...]

Lei Yang

[...]

David H. Bromwich

[...]

Le-Sheng Bai

[...]

Journal of Climate

Vol. 22: 4029-4049 (Volume publication date: July 2009)

DOI: 10.1175/2009JCLI2816.1

F. C. Ljungqvist, P. J. Krusic, G. Brattström, and H. S. Sundqvist: http://www.clim-past.net/8/227/2012/cp-8-227-2012.html

Contributions: Department of History, Stockholm University, 10691 Stockholm, Sweden

2Centre for Medieval Studies, Stockholm University, 10691 Stockholm, Sweden

3Bert Bolin Centre for Climate Research, Stockholm University, 10691 Stockholm, Sweden

4Department of Physical Geography and Quaternary Geology, Stockholm University, 10691 Stockholm, Sweden 5Department of Mathematics, Stockholm University, 10691 Stockholm, Sweden

Abstract. We analyse the spatio-temporal patterns of temperature variability over Northern Hemisphere land areas, on centennial time-scales, for the last 12 centuries using an unprecedentedly large network of temperature-sensitive proxy records. Geographically widespread positive temperature anomalies are observed from the 9th to 11th centuries, similar in extent and magnitude to the 20th century mean. A dominance of widespread negative anomalies is observed from the 16th to 18th centuries. Though we find the amplitude and spatial extent of the 20th century warming is within the range of natural variability over the last 12 centuries, we also find that the rate of warming from the 19th to the 20th century is unprecedented in the context of the last 1200 yr. The positive Northern Hemisphere temperature change from the 19th to the 20th century is clearly the largest between any two consecutive centuries in the past 12 centuries. These results remain robust even after removing a significant number of proxies in various tests of robustness showing that the choice of proxies has no particular influence on the overall conclusions of this study.

Broad results will vary depending on the underlying resolution you apply, but the underlying conclusion remains the same. The recent warming has occurred extraordinarily fast , suggesting a system well out of equilibrium.

[sokolow]

Our biggest nemesis with AGW in terms of absolute devastation will be the rate of methane being released. We are playing with armed nuclear warheads by the way we treat the potential catastrophe.

More prosaically and literally, as you mentioned in re land ice, we're playing with nuclear arsenals because three major nuclear powers are immediately vulnerable to freshwater availability issues.

[Jonger]

What just happened in this thread?

Sent from my HTC6435LVW using Tapatalk

[SVT450R]

What just happened in this thread?

Sent from my HTC6435LVW

Just another Friv rant about mankind.

[sokolow]

I went browsing to see what had come of this since the press release / poster presentation in 2010 and apparently the lab is awaiting funding for further research.

Here's some of the photies they put up and a lo-res snap of the poster:

JD Barker, Y Chin, and DH Elliott of the OSU Byrd Polar Research Center

http://bprc.osu.edu/~barker.246/BARKER_website/Ancient_Organic_Matter.html

http://bprc.osu.edu/~barker.246/BARKER_website/Barker_Lab.html

And well, Ok, mummy trees are all right, I guess but for mid-pliocene Ellesmere Island findings how about some giant arctic camels

Image from the Canadian Museum of Nature

http://nature.ca/en/about-us/museum-news/news/press-releases/remains-extinct-giant-camel-discovered-high-arctic-canadian

The whole paper by Rybczynski et. al is here and its bizzarely fascinating, probably displacing giant swans as my favorite prehistoric megafauna:

http://www.nature.com/ncomms/journal/v4/n3/full/ncomms2516.html

The discovery of giant camel remains on Ellesmere Island extends the range of North-American camels northward by ~1,200 km. The Ellesmere camel is the first evidence that camels inhabited the High Arctic at a time when global temperatures were ~2 to 3 °C greater than modern. Palaeoenvironmental reconstruction of the upper portions of the FLB and BP fossil sites suggests that during relatively warmer times in the mid-Pliocene the Strathcona Fiord area of Ellesmere Island supported a larch dominated forest habitat, with a slightly below freezing mean annual temperature. Yet, cooler mid-Pliocene conditions allowed for thermal contraction cracking (ice wedges). Thus, it is likely that the Ellesmere camels survived winters with very low temperatures and ~6 months of 24-h darkness, perhaps inhabiting the forest-tundra ecotone.

Although their localities are over 2,000 km apart, the Ellesmere Island and Yukon camels show nearly identical collagen fingerprints (shared also with the modern dromedary). The similarities are striking when compared with the differences observed between the two living camel species (Fig. 4), and suggest that the Arctic fossils represent closely related populations, possibly the same species. The North-American Arctic cameline shows morphological affinities with Paracamelus, but lived long after the appearance of Paracamelus in the mid-latitudes of Eurasia, 6–7 Ma.

[blizzard1024]

As skierinvermont stated, ice core records suggest that the climate system is highly sensitive to fluctuations in radiative forcing. So, it's very hard to physically deny a fairly high climate sensitivity (> 3K for a doubling of CO2 concentration), and the peer reviewed literature recognizes this: http://www.atmos.washington.edu/2006Q2/211/articles_required/Lorius90_ice-core.pdf

In fact, looking at abrupt climate change of the past, we really need to watch what we put in the atmosphere, because tipping points do exist:

I found these to be great reads:

http://www.liv.ac.uk/~jan/teaching/References/Taylor,%20Lamorey,%20Doyle%20et%20al.%201993.pdf

http://epic.awi.de/17919/1/Ste2007b.pdf

Ice core proxies are fantastic, not only due to their high resolution, but also because the variations in the isotopes examined are driven by global scale processes. The H^2-16/O isotope is lighter than the H^2-18/O isotope, so it requires less energy to evaporate from the subtropical oceans and be carried poleward via the Hadley Cells. When we see a greater ratio of the heavier H^2-18/O isotope in the ice cores, we know that time period likely featured warmer subtropical SSTs and broader Hadley Cells, implying a warmer climate. The Greenland ice cores do not just depict arctic climate, but rather the climate of the majority of the Northern Hemisphere, making it key to determining climate sensitivity: http://www.gisp2.sr.unh.edu/DATA/Obrien.html

So as a result it is fairly easy to determine climate sensitivity to variations in radiative forcing, as the peer reviewed literature confirms:

https://notendur.hi.is/~oi/AG-326%202006%20readings/Ice%20sheets%20and%20glacial%20cycles/Grootes_NATURE93.pdf

http://journals.ametsoc.org/doi/pdf/10.1175/2011JCLI4078.1

http://m.pnas.org/content/109/28/11101.short

The data suggests that the rate of warming over the past few centuries is unprecedented in the context of at least the past 1200 years. The rate of warming is the smoking gun here, rather than our temperature relative to previous warm periods, as is depicted by the peer reviewed literature:

http://journals.ametsoc.org/doi/abs/10.1175/2009JCLI2816.1

Jason E. Box

[...]

Lei Yang

[...]

David H. Bromwich

[...]

Le-Sheng Bai

[...]

Journal of Climate

Vol. 22: 4029-4049 (Volume publication date: July 2009)

DOI: 10.1175/2009JCLI2816.1

F. C. Ljungqvist, P. J. Krusic, G. Brattström, and H. S. Sundqvist: http://www.clim-past.net/8/227/2012/cp-8-227-2012.html

Contributions: Department of History, Stockholm University, 10691 Stockholm, Sweden

2Centre for Medieval Studies, Stockholm University, 10691 Stockholm, Sweden

3Bert Bolin Centre for Climate Research, Stockholm University, 10691 Stockholm, Sweden

4Department of Physical Geography and Quaternary Geology, Stockholm University, 10691 Stockholm, Sweden 5Department of Mathematics, Stockholm University, 10691 Stockholm, Sweden

Broad results will vary depending on the underlying resolution you apply, but the underlying conclusion remains the same. The recent warming has occurred extraordinarily fast , suggesting a system well out of equilibrium.

 

This is a basic question as I am not a statistician. How do they thread proxy data to observed data like the two graphs above? You have a course data-set that only is

a proxy for temperature whether it be oxygen isotope ratios, tree rings or ocean foram shells etc and you have direct temperatures measurements. The direct measurements are more dense in coverage worldwide and an actual measurement vs a proxy which is just that...a proxy. I have never been able to get a good understanding of this. I know there are "transfer" functions at least for tree rings but you get different results based on the function used. Oxygen isotope ratios depend on whether you are looking at an ice core or a deep sea or near surface ocean dwelling foram. Both ocean and ice core isotope ratios are based on the current ratios as a proxy for establishing a normal for recent temperatures.  But these recent temperatures are very coarse at least temporally and even spatially. How do you thread such a coarse data set temporally and spatially to a much finer and accurate temperature measurement dataset like HADCRUT?  This is very important and when reading the above papers it is not clear to me. I could have missed it or misunderstood it too. thanks. 

[sokolow]

There was a rather long series of posts by (statistician) Tamino @ Open Mind on this, discussing the so-called "wheelchair" graph

...that joins Marcott, Shakun and HadCRUT, with particular attention to how things get difficult near the endpoints. The post on the "tick" which goes into the process of a record with proxy drop-out over time being matched to denser insumental data might be what you're looking for. The comments are also informative, and if you have questions you might get an answer by posting in the comments of his latest entry, or emailing him.

http://tamino.wordpress.com/2013/03/22/global-temperature-change-the-big-picture/

http://tamino.wordpress.com/2013/03/22/the-tick/

http://tamino.wordpress.com/2013/03/23/regional-marcott/

http://tamino.wordpress.com/2013/03/29/easy-question/

[blizzard1024]

There was a rather long series of posts by (statistician) Tamino @ Open Mind on this, discussing the so-called "wheelchair" graph

...that joins Marcott, Shakun and HadCRUT, with particular attention to how things get difficult near the endpoints. The post on the "tick" which goes into the process of a record with proxy drop-out over time being matched to denser insumental data might be what you're looking for. The comments are also informative, and if you have questions you might get an answer by posting in the comments of his latest entry, or emailing him.

http://tamino.wordpress.com/2013/03/22/global-temperature-change-the-big-picture/

http://tamino.wordpress.com/2013/03/22/the-tick/

http://tamino.wordpress.com/2013/03/23/regional-marcott/

http://tamino.wordpress.com/2013/03/29/easy-question/

There are some real issues with this graph. Take a coarse dataset of proxies and compare it to a finer resolution actual measurement. Basically, they are trying to validate what the GCMs are saying. This study is seriously flawed after reading this and the actual paper. You are comparing apples to oranges here. Bad science IMO. The Earth's climate is much more stable during interglacials like today than when we had ice sheets in the NH. that is what the ice core data shows. 

[sokolow]

Yes there are issues with the graph(s), and with matching proxy derived temperature and the historical instrumenetal record . That's what the blog posts are about.