Holocene, historic and recent global temperatures from temperature proxies.
Guest post by: Frank Lansner, civil engineer, biotechnology
NOTE: Link to PDF of this article is HERE
In the climate debate, the temperatures of the past are used to determine if the present temperatures are unique and alarming. Any viewpoint can be supported by choosing specific science papers as reference
This paper is one of many attempts to give a realistic overview of the actual messages we get from the temperature proxies.
(“Temperature proxy”: Past temperatures reconstructed from samples using a row of techniques.
The “Spaghetti graphs” in the following gives an impression of the huge variability among the datasets. The essence of each graphic is the major trends. To enable display of multiple data series it was often necessary to interpolate temperature values to the specific years used in graphics.
To avoid most calibration problems, I have set specific years to zero for the different graphs I chose a year where practically all graphs has data, and no further calibration needed. In few cases I have calibrated from 1980-1990-2000 using UAH trend of approx. +0,1K/decade.)
Recent temperature proxies – 120 years
Fig 1: 10 multi proxies shown for the 20´th century. In addition 14 temperature proxy datasets. The black curve shows average of the 14 datasets as 1 multi proxy. This multi proxy + the 10 of the most used bigger multi-proxy series is the basis for the WHITE graph: “Average of 11 multi proxies”.
The temperature proxies does not show strong net warming since around 1940. In fact, proxy data does not show any warming since 1940. This is no news, it has been recognised for example here:
http://www.ldeo.columbia.edu/res/fac/trl/downloads/Publications/divergence2007.pdf
The authors call the missing global warming in proxies for “The Divergence problem”. And they try to give reasons for this problem using characteristics of trees. But since other proxies than using tree ring proxies also indicates no global warming after around 1940, the problem seems not related with tree rings measurements.
“The divergence problem”:
Fig 2: The “divergence problem”.
The “All China” multi proxy: A reliable work where 8 regions of China where studied and then yield the final China multi proxy temperature line. The “All USA”, NOAA raw, is the official measured USA temperatures minus the official correction, that is, the raw USA temperature dataset. I find it stunning how close All-China and All-USA matches each other, see fig 2! (- a dataset of measured temperature compared to a dataset of proxies). And unlike GISS 2009, the Northern Hemisphere temperature set of 1976 supports the raw trends of US and China. Several of the multi proxy series have been smoothed with a “50 year weighted Gaussian filter” etc. and therefore any bigger dive around 1970 could not be seen in the multi proxy graph.
We see a divergence after 1950 between:
- GISS 2009 vs. Average of the multi proxies, that is, the temperature evidence in the ground and trees.
- GISS 2009 vs. USA, CHINA and NH temperatures
- GISS 2009 vs. Solar activity.
So, at least when comparing with mostly raw datasets, the GISS 2009 dataset could seem to be the source of “the divergence problem” – “the outlier”. Problems for the GISS data set might be incorrect adjustments, problems with UHI and poor measuring sites, see www.surfacestations.org!!
The “divergence problem” also seems to vanish when using satellite data (UAH/RSS) in stead of GISS data:
Fig 3: A: Briffa´s 2001 illustration of tree ring proxies combined with the GISS dataset as “Observations” (as the adjusted GISS temperatures are called). B: Same, however this time “Observations” are raw satellite data UAH from 1980 – 2000 with a slope of 0,1K/decade.
There is no divergence problem when using satellite temperature data as “Observations”. We now have total compliance between proxy data and modern temperature measurements stating: No net warming since around 1940-50.
Historic temperature proxies – 1200 years
For this analysis 33 data sets was used. The first that strikes you when working with historic temperature proxies is the apparent chaos of data. However, after keying in 6-8 data sets the well known features “Middle age warm period” and “The little Ice Age” becomes clear. Keying in the rest of datasets doesn’t change much.
First, take a good look at the period 1900 to 2000..
Notice how these 33 datasets confirms the trends from fig 1, the recent temperature proxies. We can conclude that we have a good ability to reproduce the result quite accurate with quite different datasets, and thus, neither of the graphs ( fig 1 and fig 4) are likely to reflect “random” results. All data evidence used in fig 1. + fig 4. actually suggests that today’s temperatures resemble the temperatures of 1940-50. Yes, a divergence problem for the temperature data from GISS and Hadcrut.
Fig 4: Historic temperature proxy data. Practically all methods and regions of the globe are represented.
6 of the data sets originate from tree ring data.
We see the Medieval Warm Period apparently ongoing already in year 800 and goes on for 5-600 years. First around year 1400 the Little Ice Age really takes over. It was around year 1400 the Vikings left the freezing Greenland.
From year 800 to year 1300 temperatures appears around 0,3 K higher than today. And from around year 1400 to 1900 temperatures appears to be are around 0,4 K lower than today. A difference from MWP to LIA of 0,7 K in average globally. (Max difference approx 1,1 K),
We will return to these historic data later, but lets first take a look even further back in time.
Holocene temperature proxies – 12000 years
For this analysis 29 long datasets where used. All graphs are calibrated to zero for year 1000.
First focus on years 800 to 2000…
Once again we see a reproduced trend between 2 different data sets. And again, the accuracy is nice. The MWP here appears almost 0,8 K degrees celcius warmer than the LIA, very close to what we saw it on fig 4, the historic data 0,7K. This once again confirms the impressing usefulness of data despite the chaotic and random appearance. There is however a tiny difference between the 2 graphs, around 0,1K. But it should be noted, that for the Holocene temperatures, no tree ring data was used. According to Loehle 2007, tree ring data tends to suppress the MWP somewhat. This we will return to.
Fig 5: Holocene temperature data.
The data point for year 2000 are based on too few datasets to be really trustworthy. Therefore I have inserted the red star where I use the value of todays temperature taken from fig 4, historic temperatures. By doing so, temperature for year 2000 got 0,2 K warmer than from Holocene data.
Fig 5 also shows that the whole debate about MWP is irrelevant. Imagine there was no MWP. Practically ALL of the Holocene period the eath appears to be between 0,5 and 1,5 K warmer than today. The little ice age does resemble a mini ice age or at least it appears to be the coldest period in over 10.000 years.
Finally, the overall picture from the graph is an almost perfect mathematical curve that tops around 5-6000 years ago. These Data tells the story quite clear: We are on a down trend in temperatures globally, we should not fear warmth by now. How much lower can the temperatures on earth go before we reach a tipping point to much colder temperatures at earth?
Medieval warm period
Arguments against the MWP often focus on the “fact” that the warmer temperatures from that period are a phenomenon exclusively to have appeared on the northern hemisphere.
Fortunately, the results from fig 4 and fig 5 shows an excellent match for the period year 800 to year 2000. It thus makes very good sense to combine the datasets and then obtain a better data foundation to analyse the MWP.
Datasets from fig 4 and fig 5 combined, a northern/southern hemisphere display of the Medieval Warm Period:
Fig 6: Historic temperatures, North and south hemispheres separated. Let’s first see what the graph actually says, very roughly:
NH MWP, 42 datasets:
Ongoing in year 800, temperatures mostly 0,3-0,4 K higher than today.
The temperature creeps below today’s level and ends around year 1300.
SH MWP, 13 datasets:
Ongoing in year 800, temperatures mostly 0,2-0,3 K higher than today.
The temperature creeps below today’s level and ends around year 1350.
Northern hemisphere is still much better represented than the southern hemisphere, so what can we conclude on this ground? Can we conclude anything?
On this ground I find it safe to accept the NH MWP approximately as described above.
To accept that globally there where no MWP, we will have to accept the following:
The 2 hemispheres have the ability to maintain a quite different temperature development for at least 500 years and did so from year 800 to year 1300.
What can we demand to accept this idea? We can demand solid evidence.
Anyone claiming the above must present solid evidence for a MEDIEVAL COLD PERIOD on the southern hemisphere.
IF data showed that the southern hemisphere had a MCP where temperatures for 500 years was 0,3-0,4 degrees colder than today, would this “kill” the MWP? Certainly not. Because, then we would have had 500 years with global temperatures just like today globally… – In that case, certainly no reason to be alarmed about the temperatures today.
No, if today’s temperatures should be alarmingly warm, the S. hemisphere temperature should show a very strong MCP at least 0,4 degrees colder than today in the 500 year period.
Is there ANY indication of a 500-year strong MCP in the southern hemisphere indicated in the data above? No, certainly not. There are not that many SH data, but still, there is not the slightest indication of a strong MCP on the S. Hemisphere.
Until the strong 500 year long MCP on SH has been proven, there is nothing that shakes the acceptance of a global MWP with temperatures resembling or higher than today’s temperatures.
I believe a massive use of tree ring graphs exclusively might show a strong southern MCP. In this case, the idea that there is no MWP globally is dependent on only on one specific method of making temperature proxies, tree rings. Tree rings are 1 of at least 20 different methods to measure temperatures of the past. As such, they should never dominate the measurements.
The South pole and MWP:
While examining temperature proxies, I found some odd results:
Fig 7: -A stunning mismatch between 2 Antarctic data series.
Not only are they both from Antarctica, but they are both from near the south pole. The well known “MWP-signature” has found its way not only to the Southern hemisphere, but to the south pole. But in the near by Vostok location, for many centuries, there has been absolutely no sign of the MWP? Obviously this is absurd, so at least one of the two results is not accurate.
The black graph (from “Remote Plateau”) has a resolution of 1 – 3 years per sample, excellent. The blue graph (vostok) has approx 23 years between data points. Both series should be considered fine quality then.
How likely is it, that the “MWP/LIA-signature” has come up in “Remote plateau” (black graph) data by a coincidence? When it has also been spotted many other places on the SH? See fig 6: The Vostok data has a dotted red line. How well does vostok data then fit the rest of the Southern hemisphere data?
The use of vostok data also moves the SH temperature profile away from the NH average.
Tree rings
If the MWP only disappears using one a specific measuring method, the idea as well as the method is invalid.
Proxy temperature data from tree rings are easy to get, but the quality?
Craig Loehle: “There are reasons to believe that tree ring data may not capture long-term climate changes”.
Indeed. A good warm year will obviously help a tree growing, but decades of increasing temperatures could affect the whole area so for example more trees might be able to survive, the root nets would only be able to grow to some extend for other trees etc.
Example: Imagine that a warming after decades is accompanied by 10% more trees surviving in an area and eventually demands their “place in the sun”. By measuring tree rings for an individual tree you are not measuring the overall tree growth of the area. And measuring 10.000 trees does not change anything as all trees would have the same problem. Measuring tree pollen or isotopes etc in sediment cores avoids these problems and it makes me wonder how come so much energy has been used for tree ring analyses.
Selective adjustments?
Many kinds of adjustments are used in connection with climate results. But one adjustment I haven’t heard of is the down-adjustment of recent temperatures from temperature proxy data due to CO2-induced extra growth. If the CO2 level is indeed extraordinary high, then it is a fact that plants grow markedly more. And they grow at higher altitude etc.
Here is an impressing overview of plant response to extra CO2 in the atmosphere:
http://www.co2science.org/data/plant_growth/dry/dry_subject_p.php
I have chosen the letter P for the link since several tree ring analysis are made for pine trees. Check the responses for pine trees when adding extra CO2.
Therefore any temperature proxy based on plant growth should be adjusted down in times of high CO2. Otherwise you will measure CO2 and not heat. But this obvious kind of adjustment seems not to happen? Or? Can it really be, that the crew of alarmists so happy for adjusting for all kinds of tiny issues, simply don’t adjust when there is a really good reason to do so?
Fig 8: Historic temperature proxy data with focus on tree ring-method. In the analyses I have used, it turned out that 7 of 55 datasets where from tree rings. On this figure, these 7 datasets actually does seem to differ in trend from all the rest. The 7 tree ring datasets suggests no MWP, in fact, they suggest that the MWP was 0,3-0,4 K COLDER than today’s temperatures. Quite the opposite result than the majority of datasets concerning MWP.
On might say that these 7 datasets are too little a basis for any conclusion, and therefore I have included a bigger tree ring multi proxi, “Esper et al 2002” and the trend from the 7 tree ring datasets are confirmed:
Unlike all other methods, tree rings shows no warm MWP.
Example, the European Alps:
Fig 9: Here from fig 4, we have 2 different temperatures in the same area, the European Alps.
Quite like Antarctica, we have 2 datasets, one showing the well known “MWP/LIA-signature” and one not showing this. Both cannot be correct, so we know that at least one of the datasets is faulty.
In addition, these measurements where taken in the middle of Europe where we have an overwhelming amount of non-tree temperature proxy datasets confirming a very warm MWP.
Therefore, if the tree ring method was useful, we definitely should see a warm MWP from tree ring data in Europe. But we don’t. And unless all the other temperature proxy methods just shows a very warm MWP in Europe by coincidence, the tree ring method does appear to be the faulty method.
The tree graph appears flat compared to the other methods (- a “yummy” to use if you want to produce a hockey stick), but we are not here to produce a hockey stick, we seek the temperatures of the past.
Now it becomes relevant to examine jus non-tree temperature proxies (As Loehle concluded) for better accuracy:
Fig 10: The Historic temperature proxy trend based on 27 non tree ring proxies show a slightly warmer MWP than when including tree rings, fig 4. The average temperature for year 800-1400 is approx 0,4 K warmer than today, and the years 1400-1900 is around 0,4 K colder than today. So the non tree historic temperatures now gives a MWP/LIA difference of 0,8 K like the (non tree) Holocene temperatures, fig 5.
We even see “peaks” in the MWP up to 0,6K warmer than today, and now 1950 actually appears slightly warmer than today.
Fig 11: Briffa’s 2001 all tree ring proxy data, compared with non tree ring data.
First of all, I have every respect for the huge work done using tree rings. There are indeed many sources to errors (like the idea about different SH/NH temperature development etc.) – but despite all, this graph speaks a very clear language.
Here we see the 27 datasets of non-tree rings, together with the well known tree ring graphs.
It becomes clear, that the non tree rings world wide – THICK BLUE CURVE – matches extremely well in the 20’th century and all the way back to year 1450. Then exactly as the MWP starts, the tree rings and the non
tree rings simply “looses contact”.
What ever the reason for the differences between tree ring or non tree ring temperature proxies,
it becomes evident, that choosing tree rings or not is the same as choosing a MWP or not.
.
One partly explanation for this huge mismatch could be CO2. If indeed the CO2 concentration today is a lot higher in the atmosphere than it was in the MWP, then trees simply grows faster than in the MWP, apparently even though temperatures are not higher.
S
Conclusion:
– Its way too early to consider the MWP gone. There is a lot of scientific work to be done before any such conclusion has any weight. MWP disappears when using tree ring data.
– In this writing we see that 48 non tree ring temperature proxies combined shows a MWP around 0,4 K warmer than today, lasting at least 500 years.
– Besides the MWP discussion: 80-90% of the Holocene period (last 10-12.000 years) has been warmer than today. The last 6000 years, the general temperature trend has been steady cooling. The temperature levels in the Little Ice Age were the lowest in the Holocene period.
I find it relevant to study the consequences of further cooling.
– Except for strongly adjusted temperature data, there is compliance between recent temperatures measured from satellites, evidence from tree-proxies, evidence from non-tree-proxies and more showing that: It does not appear warmer today than around 1940-50.
This is in compliance with solar activity in the 20’th century.
This does not suggest a warming effect of CO2 in the atmosphere.
ome of the non-tree-ring measurement methods includes Be, O and C isotopes etc, that in some cases are more independent of changing tree growth or the like. These methods would be preferable if we wanted to clear CO2-induced errors on temperature measurements.
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Nasif Nahle (20:37:37) :
Interesting.
I acquired new words : “poikilothermic”, in greek,even modern greek, poikilia means diversity. And “homothermic”, omoios means the “same”. I am amazed at the ingenuity of current researchers in constructing new terminology from ancient greek and latin roots.
The excerpt above, “The assumption in all of these studies was that tree leaf temperatures were equal to ambient temperatures.” in conjunction with the poikilotherm’s behavior ( 😉 ) clarifies for me why the tree ring temperatures are flat. They are temperatures of the leaves of the tree and not of the environment.
I just find it hard to understand why glaciers all over the world keep melting if the world is actually getting colder; why the permafrost in the Arctic keeps right on melting if the world is actually getting colder; why spring in the northern hemisphere arrives earlier with every decade if the world is actually getting colder. I do not believe that tree ring proxies tell us anything about the impact of a global industrial high-tech civilisation (which is transferring more than one hundred billions tonnes of pure carbon from the ground to the atmosphere every decade), and the effects of this on the world’s climate and ecosystems. And that is what we are dealing with right now. Just as you cannot infer anything about the nature of a nuclear war by studying the Napoleonic wars, you cannot infer anything about future climate change by looking at preindustrial climate change. Nothing like this has ever happened to this planet before.
Wow that was a lot of spagetti:) Seems to me the problem for the most part (short of those we think are cookin the books) is the predictions of the future by models, not the actual temps themselves. Lets face it given the seasonal noise, ie temp variations from summer to winter, around here its about 80 – 90 degrees.. is two degrees either way really going to be a disaster? We already get that sort of range from summer to summer depending on weather.
I agree too that trees are a poor indicator of temp. I should think that they would be more accurate in determining seasonal growth, the the variables are insane. Too hot, too cold, too much water, too little water, too much sun, too little sun, co2 content, fertilization, air quality..
Awesome, Frank, you killed several birds with one stone. Medieval Warm Period vindicated. Global with South Pole; but Vostok doubted. Dendrochronology displaced. UAH vindicated over GISS. Holocene far warmer. Solar correlation demonstrated.
You must get this published because I think people will read it. Your methodology looks pretty unassailable. But offer it to Climate Audit first, for an audit, like Craig Loehle did. It will toughen it up. With a bit of luck you’ll draw useful rude comments from RC too.
One interesting thought “under our noses”: lower CO2 in MWP?? Could this be because there was a rather woodier NH biosphere to instantly sequestrate any spare CO2? Therefore ALL plants register lower CO2 and their growth is less luxuriant, although as much CO2 as now was produced by the warming sea? Think about it. Forests across the whole Northern Hemisphere… a lot. If you look at the seasonal fluctuation of NH CO2 vs SH CO2 you can see my point.
Thank you Mr. Lansner; very interesting work.
Do you suppose Mr. Hansen is squirming in his chair as he reads this?
“They are temperatures of the leaves of the tree and not of the environment.”
Who says tree rings are related to temperatures? Maybe and elk died next to that tree and for nearly 50 years its soil was much more fertile than it had been. Maybe it warmed up but the storm track moved a little so it became dry and the rings didn’t change at all. There are too many things that impact ring widths with temperature being only one of them. And when temperature changes, maybe other things change, too, such as precipitation patterns or animal habitation (or the lack thereof).
That tree rings are a thermometer is a figment of someone’s imagination. They are an indication fo the whole environment around the tree with temperature being only one part of it. Where it gets most arrogant is where they attempt to find trees where temperature is the primary constraint. That might be true for the climate right now, but if you shift that climate, maybe rainfall changes. Maybe animals forage elsewhere and don’t leave droppings. There are any number of things that impact ring width and to assume that nothing else changes when temperature changes is actually quite knuckle-headed in my opinion.
Richard M
“One last comment on my CO2-ice age hypothesis. If true it means both the skeptics and the climate scientists are right.”
What is a climate scientist? What are the required qualifications? Why should Mr Lansner be considered less of a “climate scientist” than astronomer Hansen?
Great work, Mr Lansner – it will take some time to absorb.
Incidentally – in response to another commenter: Denmark has also given us Dr Svensmark and the skeptical enviro guy.
Anders L. (22:28:43)
Glaciers started melting long before industrial processes began. The changes – growth and decrease – are not new and it is not up to the UN to decide what comes next.
Permafrost has apparently defrosted in a few places but this doesn’t seem to be a major issue and certainly not a catastrophic one. Read this:
http://www.nytimes.com/2008/09/23/science/23obsperm.html?ref=science
Early spring seems to have passed many folks by the last couple of years. Take a look at the Yakima, WA 2009 temperatures.
http://www.wrh.noaa.gov/climate/temp_graphs.php?stn=KYKM&submit=Change+Station&wfo=pdt
Locally, April has seen a couple of nice days but the next few days are going to be below normal. The charts at the above link will show that spring has had a real hard time getting started. I know, just one place and one year but do some checking and you will find there is not much to the early spring reports. I haven’t saved the recent items — too non-issue.
And about global industrial high-tech civilization and carbon: Because CO2 as an agent of change doesn’t withstand scrutiny, I guess the new phrase is made to sound scarier. Still, it is hard to make a catastrophe where there isn’t one. Well, unless you do a trek in the Arctic ill prepared for cold and ice.
Zebra’s would do just fine in southern Europe.
i spoke of “middle europe” on purpose.
the MWP ideas had a massive problem: different studies found two different periods. a late and an early period.
linking the two of them removes an internal contradiction in sceptical writing, but produces a massive problem: a 500 year period warmer than modern times, would have lead to a massive effect on fauna and flora.
i haven t seen any discussion of this, beyond the incredibly weak “wine in england” meme.
Bateman
“Seriously, does a tree know the difference for the most part between warm & dry vs cool & dry?”
Bery pertinent question. and I imagine you will be surprised with the answer. Carbon starvation, which apparently sometimes occurs during glacial periods due to the low levels of CO2 that are reached, has the same effect on C3 plants *trees, shrubs, and such) as do warm, dry conditions when the warm is excesaive. In both cases, plant growth slows greatly or ceases. I can’t give you a reference because I am not that well organized. But it seems obvious that hot and dry conditions would certainly affect tree ring data quite differently than would hot and wet conditions.
Lucy Skywalker (22:41:12) :
Awesome, Frank, you killed several birds with one stone. Medieval Warm Period vindicated. Global with South Pole; but Vostok doubted. Dendrochronology displaced. UAH vindicated over GISS. Holocene far warmer. Solar correlation demonstrated.
I think it is important enough to be broken into the individual refutations in different publications. This will allow the focusing of the criticism on one subject. For example I would see Figure 11 as the basis for one letter, with clear reference to the results given in :
From Canada to the Caribbean: Tree leaves control their own temperature, Penn study reveals http://www.eurekalert.org/pub_releases/2008-06/uop-fct061108.php .
A straight logical proposition: tree temperature measurements measure leaf temperatures which have been shown by measurements to be stable within a certain range and not correlated strongly with ambient temperature.
This would impose limits to criticism that would come when the total information is included and make the point clearer. Nothing like giving handles for the ones who want to obfuscate.
One interesting thought “under our noses”: lower CO2 in MWP?? Could this be because there was a rather woodier NH biosphere to instantly sequestrate any spare CO2? Therefore ALL plants register lower CO2 and their growth is less luxuriant, although as much CO2 as now was produced by the warming sea? Think about it. Forests across the whole Northern Hemisphere… a lot. If you look at the seasonal fluctuation of NH CO2 vs SH CO2 you can see my point.
I agree with this proposition. When Greece came out of the Ottoman empire in 1821 it was 80% forests while now it is 20%. Same must be true everywhere because the populations were much less and less land was needed to be cleared for cultivation.
Anders L.
“Nothing like this has ever happened to this planet before.”
Why bother posting this rubbish!!!!!!, you just look silly
Anders L. (22:28:43) wrote:
“I just find it hard to understand why glaciers all over the world keep melting if the world is actually getting colder …”
Regarding glacial retreat, see section 2.2 (pages 28-32), “Glaciers,” of Dr. Syun-Ichi Akasofu’s paper, “Two Natural Components of Recent Climate Change,” here (as a 50-Mb PDF):
http://people.iarc.uaf.edu/~sakasofu/little_ice_age.php
He writes, on p. 28: ” Figures 9a-9f show records of glaciers in Alaska, New Zealand, the European Alps, and the Himalayas, respectively, which have been receding from the time of the earliest records, about 1800. … It is clear that the retreat is not a phenomenon that began only in recent years, or after CO2 emission increase in1946.”
And on page 32: ” Altogether, long-term glacier data presented here show that glaciers advanced from about 1400 and began to retreat after 1800 (cf. Akasofu, 2008). These facts confirm that the Earth experienced the LIA.”
******
“why the permafrost in the Arctic keeps right on melting if the world is actually getting colder; …”
Akasofu writes, on p. 45 (section 3.4, Summary): “Permafrost temperatures have stopped rising during the last several years (Richter-Menge et al., 2006); see Figure 17. It is puzzling why permafrost temperatures do not show an accelerated increase after 2000 if the increase from 1986 to 2000 was due to the greenhouse effect. It seems that snow depth has the most important effect on permafrost temperature (Osterkamp, 2007a, b).”
****
“why spring in the northern hemisphere arrives earlier with every decade if the world is actually getting colder.”
In one recent thread a commenter here contested that assertion, or at least the degree to which it’s true. (I.e., spring’s not coming two weeks earlier, as some have claimed.) I hope he/she will re-post his comment.
However, Akasofu doesn’t dispute that there has been a warming trend in recent decades since 1970 (except since 2000). His contention is that this is due to a natural multi-decadal oceanic oscillation that is in its warming phase, superposed on a natural 200-year warming trend-rebound since the end of the Little Ice Age. See the Abstract on p. 1 of Akasofu’s paper for his summary, and pages 2-27 for his detailed discussion of the matter. See also a recent WUWT thread on one of Akasofu’s diagrams, here:
http://wattsupwiththat.com/2009/03/20/dr-syun-akasofu-on-ipccs-forecast-accuracy/
****
“I do not believe that tree ring proxies tell us anything about the impact of a global industrial high-tech civilisation (which is transferring more than one hundred billions tonnes of pure carbon from the ground to the atmosphere every decade), and the effects of this on the world’s climate and ecosystems. And that is what we are dealing with right now. Just as you cannot infer anything about the nature of a nuclear war by studying the Napoleonic wars, you cannot infer anything about future climate change by looking at preindustrial climate change. Nothing like this has ever happened to this planet before.”
Browse this site for rebuttals to this. Or maybe someone will kindly point him/her to a spot that specifically discusses this contention.
Anders L. (22:28:43) is concerned that “….more than one hundred billions tonnes of pure carbon from the ground to the atmosphere every decade…”
As an ameliorative may I suggest Dr. Spencer’s vision test:
http://www.drroyspencer.com/2009/01/50-years-of-co2-time-for-a-vision-test/
UPDATE:
Check out this updated fig 2 with Raobcare tropical measurement nicely free of UHI etc:
http://www.nofeestamps.net/climate/Fig%202.gif
Hmm, 10 billion tons of carbon shoved into the atmosphere ‘by Man’.
Where does that guess come from?
What are the current guesses for annual increase of Amazon jungle biomass over the last 20 years?
Roger Knights posted:
“In one recent thread a commenter here contested that assertion, or at least the degree to which it’s true. (I.e., spring’s not coming two weeks earlier, as some have claimed.) I hope he/she will re-post his comment”.
I was not the original poster but if I may observe.
The Director of Kew Gardens said in the last few months that spring is coming about two weeks early. I live two miles away from Kew and as I write this I look out of my window at the London Plane trees in the street which still show no signs of buds breaking into leaves. A few hundred yards further down the road, whole swathes of Richmond Park yesterday still had trees with no leaves.
This is one of the latest springs that we can remember. Perhaps because, in January/February, London had its heavieast and most prolonged cold spell for twenty years and since then we have had several nights of bitter frosts Less than a fortnight ago I had to break the ice which had formed in the birdbath and was still there three hours after sunrise.
And thank you to all for such nice feedback!!!
It took the evenings of 2 months to create this monster.
With your nice feedback, perhaps my wife can forgive me?
My biggest hope is, that this exercise will keep the investigations on the area going.
Its simply not acceptable with a totaly tree-ring /Giss based conclusion of anything. I may be an amateur (!) but i comparison with the tree ring / giss based “science”, things can only get better, even with me contributing.
About calibration etc: I made an historical graph where i fixed all data to year 1800 in stead of year 2000. Nothing changed in the appearence of the graph trend. I used year 2000 so that we could have todays temperatures as the zero line for comparison. In some cases there can be doubts about the year 2000 point. But the 1940,50,60,70,80, 90 and 2000 are fairly matching the trend showed in fig 1 from recent times with a huge data foiundation(!!)
Therefore, if there are any adjustments to be made to the year 2000 of the historical graph, its tiny and cannot change anything.
In some cases the year 2000 compared to year 1990 had to be calibrated, and i used either UAH trend.
There are some datasets with no points around the peak in 1950. These datasets then just (wrongly?) show one big rise of temperatures through the 20’th century. But I used that data anyway, so i am STRONGLY convinced that my use of data did not promote my personal views.
And as i said: Remeber that the outcome happened to match very fine the well founded data of recent data, fig one. This graph could be used for future calibrations.
Calibration issue about MWP?
For those who thinks that the MWP here is caused by my calibrations, take a gooood look at fig 11.
Im waiting…
Good. The curves are following each other VERY nice 1450-2000. How could I calibrate so that the MWP just came out of the graphs??
It is 100% impossible that the MWP of fir 11 comes from my calibrations..!
Please think about this.
K.R. Frank
Steve Keohane (14:10:19)… Try:
Tree leaves control their own temperature Science Centric
The D’Arrigo paper cited above is well worth reading. The article refers to quite a number of truncations, such as this one:
“The reconstruction was truncated after 1970 due to the weakened recent signal (D’Arrigo et al., 2004b)”
Is that telling us that the researcher’s response to “bad data” (that is, going against the presumed correct shape of the reconstruction) is simply amputated?
There are many other things I could comment on, although this also raised an eyebrow at the start of section 3:
“The principal difficulty is that the divergence disallows the direct calibration of tree growth indices with instrumental temperature data over recent decades (the period of greatest warmth over the last 150 years), impeding the use of such data in climatic reconstructions.”
Disallows the direct calibration? Is that not just saying that the data doesn’t calibrate to temperature? If there is no calibration in recent decades, what does Occams Razor tell us about the whole data series?
So much data, so little time. Thanks Frank, for your hard work in bringing all this data together.
Although it is almost impossible for a layman to peer-review the outcome, I trust that the general trends are represented truthfully.
So many thoughts have come into my mind while reading and rereading this that I can hardly capture them.
Frank, what you have done is just* to compare data, but reading your paper it feels like reading a set of runaway conclusions (I mean no sleight against it, far from it). What I mean is that the implications of your comparisons are almost lost by you having done so much work and presenting it all together.
(*using the word ‘just’ sounds dismissive, but I mean to convey simple elegance – what you have achieved is simple and beautiful but took a lot of work)
This needs to be published, however I agree with anna v that this needs to be broken down, not just just for maximum impact. As the paper stands it has probably less chance of being published (again anna v is right about chance for criticism). In more digestible chunks it will be easier to publish, partly for reasons of space, allowing an introduction/critique of the proxies used as source data etc.
You describe yourself as an amateur, but I am sure you can get help from scientists (if you feel you need it) to ease the path to journal publication. This is a science blog so perhaps some of the scientists here can help… I for one would be willing, but probably not the best person.
Zebras crossing the Sahara is no big deal, they could easily go by truck. However they are notoriously bad sea-farers so would run into trouble at the Straights of Gibraltar. I suppose they could work their way round to Istanbul but that could take years. 🙁
Frank, Thanks for a great presentation. I have borrowed just a very, very small portion of it for my blog and directed readers to this page to read the full content.
I also want to thank you for this inclusion:
That fact is not mentioned enough in the AGW debate.