Bishop Hill A Tibetan temperature reconstruction
Dec 7, 2011 Climate: MWP H/T to Scientist for Truth for this paper from the Chinese Science Bulletin, which incorporates a reconstruction of temperatures from tree rings in Tibet.
Amplitudes, rates, periodicities, causes and future trends of temperature variations based on tree rings for the past 2485 years on the central-eastern Tibetan Plateau were analyzed. The results showed that extreme climatic events on the Plateau, such as the Medieval Warm Period, Little Ice Age and 20th Century Warming appeared synchronously with those in other places worldwide. The largest amplitude and rate of temperature change occurred during the Eastern Jin Event (343-425 AD), and not in the late 20th century. There were significant cycles of 1324 a, 800 a, 199 a, 110 a and 2-3 a in the 2485-year temperature series. The 1324 a, 800 a, 199 a and 110 a cycles are associated with solar activity, which greatly affects the Earth surface temperature. The long-term trends (>1000 a) of temperature were controlled by the millennium-scale cycle, and amplitudes were dominated by multi-century cycles. Moreover, cold intervals corresponded to sunspot minimums. The prediction indicated that the temperature will decrease in the future until to 2068 AD and then increase again.
;)
Reader Comments (55)
The last two numbers of the current volume of the journal were dedicated to climate change.
http://www.springerlink.com/content/1001-6538/56/28-29/
Well, Bishop, using the figures given in the paper for the cycles of the climate in Tibet we can be sure that the climate there will repeat every ~672 billion years (there are 2, 2.1, 2.3, 3, 110, 199, 800 and 1324 year cycles in the data). Even if you ignore the short period cycles it will still only repeat every ~23 billion years.
No danger of climate déjà vu.
They looked pretty relaxed about that warming from contemporary art in the Eastern Jin Event (343-425 AD),
http://upload.wikimedia.org/wikipedia/commons/b/bb/Seven_Sages_of_the_Bamboo_Grove.jpg
"Seven Sages of the Bamboo Grove. Several tombs near the Eastern Jin capital at modern Nanjing have pictures of the eccentric 'seven sages' depicted in the brick walls. In the example shown here, each of the figures is labeled and shown drinking, writing, or playing a musical instrument (Shaanxi Provincial Museum, Shaanxi, China)."
From page 75 of East Asia: A Cultural, Social, and Political History (2006) by Patricia Ebrey, Anne Walthall, and James Palais.
So that's a temperature, and not an anomaly. Quite brisk in those parts.
I still don't see what magic is used to convert tree rings into a tremperature proxy. Surely a tree ring is a very blunt instrument: it tells you what growing conditions were like, but only in the broadest sense.
So a period of heavy growth "suggests" warm and wet conditions but a narrow ring might mean hot and dry or cold and dry. Either way, surely it tells us more about precipitation than temperature ?
Predicting decreasing temperatures until 2068! That'll upset a few people in Durban.
Why do they think this tells us anything about temperature? Surely treemometers should have been abandoned by now as a lost cause.
Hardly - it will just give 'em something to claim credit for!
"Why do they think this tells us anything about temperature? Surely treemometers should have been abandoned by now as a lost cause."
That these proxies more or less match up with the by now much agrees upon "extremes" a la MWP, LIA, etc, make them pretty compelling. This was pretty much the view of even the IPCC before Michael Mann and his merry band of tricksters stole the show. That the colder periods match up the solar inactivity if also very powerful.
Sorry for the poor syntax above. That's what I get for trying to type with 3 dogs in my lap.
Off topic, but has anyone seen tonight's Frozen Planet?
Attenborough just said polar bear populations are declining because sea ice is becoming scarcer in summer months.
I thought polar bear populations were increasing? Has Attenborough just lied?
If you cherry-pick your polar bear population, you can easily demonstrate their numbers as increasing, decreasing, remaining the same, or even increasing-but-it-ain't-fair-they-would-be-decreasing-without-us claims in case of bears fattened up by hanging around anthropogenic rubbish.
I can easily see a hockey stick shape...can't you? Just linearly extend to the right by 100 years and you'll have it.
The U.S. Fish and Wildlife Service estimates that the polar bear population is currently at 20,000 to 25,000 bears, up from as low as 5,000-10,000 bears in the 1950s and 1960s.
Environment Canada - 2009
In 2008, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assessed the Polar Bear as a single overall population in accordance with established criteria. In its report, COSEWIC also reported trends by subpopulation. Population models project that 4 of 13 subpopulations (27% of Canada's 15 500 polar bears) have a high risk of declining by 30% or more over the next three bear generations (36 years). Declines are partly attributed to climate change for western Hudson Bay (Nunavut and Manitoba) and the southern Beaufort Sea (Northwest Territories), but are mostly due to unsustainable harvesting in Kane Basin and Baffin Bay (Nunavut). Seven subpopulations (43% of the total population) are projected to be stable or increasing. Trends currently cannot be projected for two subpopulations (Davis Strait, Foxe Basin - Nunavut - 29% of the total population).
For most subpopulations, population counts over time suggest a slight increase in the last 10-25 years. At the same time, bears in some subpopulations show declining health and changes in habitat location linked to decreased sea ice. The Polar Bear cannot persist without seasonal sea ice.
Polar bear population:
1945 - 5000
2011 - 25000
They're not increasing but they have.
Wouldn't mind citation for the decreasing comment.
Ice cores from Greenland suggest that the world was warmer than it is today during the Medieval Warm Period, the Roman Warm Period, the Minoan Warm Period, most of the Holocene from 4000 - 8000 years ago and the last interglacial period. And yet the polar bear is still with us. If the polar bear becomes extinct it will not be because of global warming.
Cue post from Zed expressing outrage that we're looking at tree rings..!
The latest Private Eye has a cartoon of Attenborough as a polar bear, wrestling with a Lawson bear. There is also a poke at Huhne and his windmills (which will boil the staffroom kettle on windy days). I wonder if they're listening to Booker for once?
Don't forget the missing caribou.
"A herd that once numbered 276,000 animals seemed to have completely disappeared, the most dramatic and chilling example of a general decline in barren-ground caribou."
http://blogs.dailymail.com/donsurber/archives/46673
First read the caribou story over at Kate's place.
http://www.smalldeadanimals.com/archives/018444.html
Science schmience. Here's the public message in time for Durban:
"XINING - Glaciers in Southwest China's Qinghai-Tibetan Plateau, the major source of the country's largest rivers, are melting faster than ever under the influence of global warming, researchers said.
Experts... An expert with Qinghai's Three-River Headwaters Office said the cluster of some 80 glaciers around the Aemye Ma-chhen Range, the source of the Yellow River headwaters, is shrinking especially fast.
"I can sometimes see the Ameye Ma-chhen Range on the plane. But I worry that we are not likely to see the glaciers there in ten years or more," Li Xiaonan, deputy head of the office, said...
Xin Yuanhong, a senior engineer with the Qinghai Hydrography and Geology Study Center, said the melting of the glaciers could lead to a water shortage and even a dry-up of rivers in the long run, and consequent ecological disasters like wetland retreat and desertification.
"The Qinghai-Tibetan Plateau is among the regions worst hit by global warming. Consequently, this will have a deleterious effect on the global climate as well as the livelihood of Asian people," said Qin Dahe, a researcher with the Chinese Academy of Sciences."
http://www.chinadaily.com.cn/china/2011-10/21/content_13953136.htm
In related news, experts have confirmed that everything the government is doing is doublegood.
Experts called for intensified efforts in conducting further studies on glaciers, and setting up a database to monitor glacier change in the three-river headwaters region.
http://www.chinadaily.com.cn/china/2011-10/21/content_13953136.htm
Whether tree rings record temperature or not doesn't really matter since this paper uses the same methods as those of the Hockey Team but arrives at a different conclusion. It is likely just one more nail in the coffin of CAGW and apparently published in time to qualify for AR5. Will they pick it up, or find some way to ignore it?
Oops. Pardon that redundant link and hanging sentence (from the same article). Didn't think I needed to add the standard 'we need more funding for research' line.
Interesting citation on page 2988 -
No doubt [26] will be delighted for his citation to be quoted in relation to the MWP and LIA.
[26] Mann M E. Little Ice Age. In: Munn T, ed. Encyclopedia of Global Environmental Change. London: John Wiley and Sons Ltd, 2002. 504–509
As most polar bears must have been photographed by now, I did a search on google images: there are 6,900,000 of them!
"XINING - Glaciers in Southwest China's Qinghai-Tibetan Plateau, the major source of the country's largest rivers, are melting faster than ever under the influence of global warming, researchers said.
Xin Yuanhong, a senior engineer with the Qinghai Hydrography and Geology Study Center, said the melting of the glaciers could lead to a water shortage and even a dry-up of rivers in the long run, and consequent ecological disasters like wetland retreat and desertification."
Duh and double Duh. Go look at the rivers. What is the distance from the glaciers to the mouths of the rivers? Do the rivers flow through a desert? I didn't think so. What is the volume of water at the head of the river and what is the volume at the mouth? Probably a ratio of 1000 to 1, like the Mississippi. If the Mississippi were damned at St. Paul, the effect on St. Louis would be undetectable.
Theo Goodwin
Actually, it is dammed at St. Paul Ford Dam
When I lived in St. Paul, we threatened to close the dam spillway and dry up the river. Happened on Saint Patrick's day. You have to know about St. Paul and Saint Patrick's day to understand that one. :-)
At times like this when you are faced with more NGOs than you can shake a stick, all out in sunny Durban, this BH Tibetan post might be just the place to take solace from Dalai Lama XIV:-
“If you think you are too small to make a difference, try sleeping with a mosquito.”
Now is not the time to stop biting!
Theo Goodwin
Ahem. Are you daring to question the Chinese state authorized message? Hope so. Because as you have explained, it is laughable.
I'm still trying to unravel their pretzel logic on how "melting of the glaciers could lead to a water shortage and even a dry-up of rivers in the long run, and...desertification."
Apparently these rivers must now run through areas which would otherwise be desert. Or something.
And, of course, the same old implied canard about glacier melt being THE or the primary source of most river and other water. So, if this bad glacier melt was halted by the UN Climate Magicians, I guess that would mean "a dry-up of rivers in the long run, and...desertification."
2 + 2 = 5.
Green Sand
“If you think you are too small to make a difference, try sleeping with a mosquito.”
I must assume that by "sleeping" the DL actually did mean sleeping. Otherwise this quote takes on a whole new meaning.
edward getty
Sure, O yes, the quote has been used both ways, but any who have like me, once shared a sleeping bag with a mossie can and will only have one interpretation.
The b***ards bite and bite and bite and so should we!
Green Sand
I have spent much of life in the great outdoors, often in areas with zillions of them, and have contributed who knows how much of my blood to their reproductive cycle - only females 'bite' - so I sure get your point.
But I will say, from personal experience, that you can and do become more oblivious to them with time and the 'right' attitude - to a point. Sometimes it is just toooo much. But the actual effect of their 'bite' is so irrelevant - even the itching gets less problematic after enough bites - that one can choose to ignore them. The worst part is their incessant whining, which brings us back to the topic of NGOs.
edward getty
"The worst part is their incessant whining, which brings us back to the topic of NGOs. "
LOL, comment of the night!
But whilst I get your "getting used to" my good lady never can! Many times in places where the mossie is never ever expected or even known to be viable they find her, they are truly vindictive.
my favourite part of the paper -
{The 2485-year temperature data used in this study are taken
from reference [13]. This temperature series is not only
representative of the central-eastern Tibetan Plateau, but
also the vast area of central-northern China. It is also significantly
correlated with seven other temperature series of
the Northern Hemisphere [13]. It even has a teleconnection
with series for middle-low latitudes in the Southern Hemisphere
[15]. Therefore, the spatial representative of this
temperature series is quite clear. Since a conservative negative
exponential or linear regression is employed in the
detrending process, most low-frequency signals are preserved
in the chronology and can be used to detect the
low-frequency components of climate change.}
Get her to take up smoking a pipe filled with Black Irish Twist baccy, that'll keep them away. ;)
The tree ring sites are from near Dulan, a location that has been discussed from time to time at CA see climateaudit.org/tag/dulan. Measurement data for trees used in Sheppard et al 2004 have been archived. A DUlan version was used in Yang et al 2002 and also shows a MWP.
"but are mostly due to unsustainable harvesting"
Over 1,000 a year are "harvested" by natives (mostly) and other hunters.
Stop shooting them and all will be well. Sea ice is irrelevant.
Its been well established within the scientific literature that trees growing within the territorial boundaries of Tibet (unlike those growing in the Pacific North West) do not teleconnect. Therefore, this new study should be viewed simply as a regional chronology with no bearing on global temperature reconstructions.
The results showed that extreme climatic events on the Plateau, such as the Medieval Warm Period, Little Ice Age and 20th Century Warming appeared synchronously with those in other places worldwide.
Really?
There are huge spikes at 400AD and 600AD plus their MWP ends dramatically just before 1000AD. Should have gone to Specsavers!
What caught my eye was the Fourier analysis and its attempt to detect cycles in the estimated temperature. If this series truly is a representation of temperature (we don’t know that for certain yet), then the paper may give some insights into the real drivers of the planet’s temperature. Setting aside the science, the political ramifications are unclear, but it’s unlikely that The Team can get the journal editor to resign. The Team may have to respond in the more traditional way by publishing a paper. It will also provide unwelcome reading for the BBC and Chris Huhne, but will doubtless be dismissed by them under some sort of ‘weight of evidence’ argument espoused by Paul Nurse.
Might we finally be seeing proper science creeping back into favour as the machinations and the misdeeds of the high priests of the global warming religion are exposed to public gaze? As a scientist, I certainly hope so.
I'm as fond of polar bears as the next man, but the implicit idea that we should switch off the global economy in order to preserve their numbers seems preposterous to me.
Well I'm the next man and I'm not fond of them at all. There is a good reason why we no longer have bears, wild boar and wolves running round in England.
Actually we do have wild boar. They are running around Sussex. I believe they staged a great escape from farms down there.
Happily the findings of this trash are not contrary to my own views but it is trash none the less. Trees are not thermometers; not for anyone.
Plenty of wild boar' in the Forest of Dean, Monbbiot is very excited about it, he's even being paid to write a book on 'Rewilding'.
If he has his way any 'lost' mammal could be re-introduced.
George claims that we are the most 'ZOOPHOBIC' people in Europe.
Apparently though, a Zoophobe is not the opposite of a Zoophile !
I can see it now, Dr Rajendra Pachauri, standing up at the Durban conference and assuring the faithful that this work was fudged by the Chinese government to back up their case against Kyoto 2. Unlike, of course, the honest efforts of Mann et al.
I wonder which of these has been anaesthetised?
Link
The question still remains do trees make good thermometers?
Toad
You have conjured up a pleasing image of Monbiot encountering a wild pig with a grudge, and wondering if saving them was such a good idea.
Exit, pursued by a boar, as it were...