Continuing Problems with Paleoclimate Proxies

As has been pointed out often, the MBH98 hockey stick has been replicated because MBH98's errors were replicated. Here Steve McIntyre looked at updates to South American proxies, and found the errors sadly durable.

PAGES2K (2017) – South America Revisited Oct 7, 2018 – 4:54 PM
The most recent large-scale compilation of proxy records over the past two millennia is PAGES (2017). They made a concerted effort to archive data (to the credit of Julien Emile-Geay), archiving 692 series, but they perpetuated most other sins within the field. Rather than abjuring ex post screening, it carried ex post screening to extremes never previously contemplated: tree ring chronologies with negative correlations to temperature are now banished from view altogether. However, its self-professed quality control did not exclude stripbark bristlecone chronologies, which continue to populate the network.
In keeping with my preference to look at regions and proxy types before worrying too much about aggregates, I looked at their South American network, which is an update of the South American network of PAGES2K (2013), which I discussed a few days after publication here. There were major changes between 2013 and 2017 networks, which were not elucidated in the later study, but which will be discussed in today’s article. The changes illustrate the profound problems with the tree ring chronologies and lake sediment series which make up the vast majority of data in PAGES 2017 and similar studies. Continue reading →

. . . . Summary
The eight PAGES2017 series are summarized in a consistent panel plot below for the period 1000 on.


The tree ring component of this network is, more or less, a reductio ad absurdum of tree ring chronologies as useful temperature proxies: only four of 63 original tree chronologies have sufficient Hockey Stick-ness to be retained in the network, with even these poor remnants reverting to the mean in the 21st century updates. There is negligible similarity between the three lake sediment series, each of which uses a different indicator, though similar measurements appear to have been taken for all three sites. The only series with a meaningful HS (Chepical) appears to result from construction of a dam in 1885AD, rather than from increased temperature. This leaves the Quelccaya ice core series – which was a staple of temperature reconstructions as early as 1998 and, which, ironically, was used upside down in PAGES2K (2013), corrected in PAGES 2017 without disclosure/admission of the earlier error.
All in all, a rather pathetic show by PAGES2K.

 

Michael Mann’s 2008 Reconstruction
Andy May
By Andy May In my last post, it was suggested that Michael Mann’s 2008 reconstruction (Mann, et al., 200 was similar to Moberg’s 2005 (Moberg, Sonechkin, Holmgren, Datsenko, & Karlen,…

 

Admitting mistakes in a ‘hostile environment’

Posted on November 19, 2018 by curryja | 1 comment
by Judith Curry
Reflections on Nic Lewis’ audit of the Resplandy et al. paper.
Continue reading →

. . . While on the topic of ‘fixing it’, I must mention Steve McIntyre’s latest post PAGES2K: North American Tree Ring Proxies. I have long declared CE to be a tree-ring free zone, basically because I have not really delved into this topic and SM has done such a good job. But here is what caught my attention. PAGES is an international group of paleoclimatologists that is a partner of the World Climate Research Programme and funded by US National Science Foundation and the Swiss Academy of Science. The 2017 PAGES paper lists about 80 coauthors. After auditing this paper (and the 2013 PAGES paper) and the proxies used, McIntyre concludes the following

• PAGES 2013 and PAGES 2017 perpetuate the use of Graybill stripbark chronologies – despite the recommendation of the 2006 NAS Panel that these problematic series be “avoided” in future reconstructions.

There is no hockey stick without the Graybill stripbark chronologies. Without having the background or putting in the effort to personally evaluate any of this, I’m asking if can anyone explain how and why the PAGES team has justified using bristlecone strip bark chronologies, given the 2006 National Academies Panel recommendation that they not be used (not to mention MM criticisms)? If this problem is as bad as stated by SM, the whole field of tree ring paleoclimatology appears to be deluded (or worse). . . .

 

Here McIntyre goes into lengthy detail about problems in the paleoclimate field.

Again we see that the way to reproduce Mann's results is to reproduce his errors.

PAGES2K: North American Tree Ring Proxies Oct 24, 2018 – 1:57 PM
The PAGES (2017) North American network consists entirely of tree rings. Climate Audit readers will recall the unique role of North American stripbark bristlecone chronologies in Mann et al 1998 and Mann et al 2008 (and in the majority of IPCC multiproxy reconstructions). In today’s post, I’ll parse the PAGES2K North American tree ring networks in both PAGES (2013) and PAGES (2017) from two aspects:

• even though PAGES (2013) was held out as the product of superb quality control, more than 80% of the North American tree ring proxies of PAGES (2013) were rejected in 2017, replaced by an almost exactly equal number of tree ring series, the majority of which date back to the early 1990s and which would have been available not just to PAGES (2013), but Mann et al 2008 and even Mann et al 1998;
• the one constant in these large networks are the stripbark bristlecone/foxtail chronologies criticized at Climate Audit since its inception. All 20(!) stripbark chronologies isolated by Mann’s CENSORED directory re-appear not only in Mann et al (200, but in PAGES (2013). In effect, the paleoclimate community, in apparent solidarity with Mann, ostentatiously flouted the 2006 NAS Panel recommendation to “avoid” stripbark chronologies in temperature reconstructions. In both PAGES (2013) and PAGES (2017), despite ferocious data mining, just as in Mann et al 1998, there is no Hockey Stick shape without the series in Mann’s CENSORED directory.

PAGES2K references: PAGES (2013) 2013 article and PAGES (2017) url; (Supplementary Information).
Continue reading →

 

Science can be tricky.

The CO2 Kink; Firn to Ice Transition
Andy May
Guest Post by Renee Hannon Introduction This post examines CO2 data collected in Antarctic firn and its journey as firn transitions to ice where CO2 is eventually trapped in bubbles.…

. . . Many authors have documented gas smoothing in the firn layer due to vertical gas diffusion and gradual bubble close-off during the transition from firn to ice (Trudinger, 2002; Spahni, 2003; MacFarling, 2006; Joos and Spahni, 2008; Ahn, 2012; Fourteau, 2019; Rubino, 2019). Gas concentrations measured during firn densification are an average of atmospheric concentrations that range from 10 years at high accumulation sites like DE08-2 to hundreds of years at low accumulation sites such as Dome C and Vostok. Fourteau shows the measured rate of change of CO2 in ice bubbles can be three times lower than the actual atmospheric rate of change. Even though firn models can reproduce the measured gas profiles, the gas age distributions can differ substantially according to Buizert, 2012. He discovers that the mean age and distribution width of gases in the firn were found to differ among the models by up to 25% in low accumulation sites.

As atmospheric CO2 passes from firn to ice, it is altered due to gas mixing processes and compaction as discussed above. Most CO2 graphs are presented using a simple splice of modern atmospheric CO2 measurements onto Antarctic ice CO2 data. The necessary corrections for attenuation of CO2 in ice due to gas mixing and depth of burial are not applied or even noted. By neglecting these corrections, resulting plots are misleading and amplify the difference between modern and older ice core CO2 measurements such as this one on Scripps’ website. Beware of the CO2 Kink, it is not a real atmospheric signal, it is an artifact.

 

A tree under the ice.
Proof Of Warmer Earlier Climate! Swiss Geologist Studies 10,800-Year Old Tree Trunk Under Alps Glacier
By P Gosselin on 17. January 2021

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Previously hidden under a Swiss glacier, a 10,800-year old tree trunk was discovered and tells us the Alps were much warmer in the early Holocene than today.

Online SRF Swiss Broadccasting recently reported on a fascinating find in the Swiss Alps: a more than 10,000 year old tree trunk that had been until recently buried under the Morteratsch Glacier. . . .

 

Woolly mammoths may have lived thousands of years after supposed extinction
Charles Rotter
Scientists have discovered the DNA of some 2,100 kinds of plants and 180 animals — including American horses and woolly mammoths – dating to thousands of years after their supposed…

". . . Paleontologists have been arguing for decades what may have caused these species to vanish. For much of the second half of the 20th century the ‘overkill hypothesis’ dominated the scientific debate, claiming that the post-glacial expansion of human populations into their habitats led to the overhunting and gradual destruction of these species.

With the rise of climate catastrophism, a growing number of studies attempted to show that global warming rather than humans were primarily responsible for the disappearance of these Pleistocene species.

Now, a team of paleogeneticists have discovered DNA of “about 2,100 kinds of plants and 180 animals—including American horses and woolly mammoths, in samples from soil dated to thousands of years after their supposed extinction.”

Once this new discovery can be confirmed, the whole idea of an abrupt climate catastrophe wiping out the wholly mammoth and other Pleistocene species in one fell swoop is likely to go the way of the Dodo. . . . "

 

Claim: Climate and carbon cycle trends of the past 50 million years reconciled
Charles Rotter
Predictions of future climate change require a clear and nuanced understanding of Earth’s past climate. In a study published today in Science Advances, University of Hawai’i (UH) at Mānoa oceanographers…

 

Steve McIntyre once again causing good trouble.

Milankovitch Forcing and Tree Ring Proxies
Mar 2, 2021 – 5:05 PM
Mar 2, 2021. This post was written in 2015 but, for some reason, I didn’t publish it at the time. Seems just as valid today as when it was written.



Esper et al 2012, Orbital Forcing of Tree Ring Data pdf SI, is one of the few paleoclimate articles in past decade which really made me stop and think. It connected two obvious points:

• high-latitude tree ring proxies are sensitive to summer (JJA, even JJ) temperature, not annual temperature.
• high-latitude NH summer insolation, which has long had special interest as the “prime forcing” of Milankovitch theory of ice ages, had declined by ~6 w m-2 over the past 2000 years, the period covered by many popular IPCC temperature reconstructions. An amount that is approximately four times larger than anthropogenic forcing from CO2 since 1750 AD (~1.5 w m-2).

From these two points, they made plausible and compelling observation that the very large changes in high-latitude Holocene summer insolation should be visible in long high-latitude tree ring chronologies, especially those chronologies reaching back to the Roman period and earlier.

But it isn’t, as they demonstrated in an important graphic, which, unfortunately, was buried in the SI where it passed unnoticed. (One of the authors drew my attention to it several years ago or I too would have missed it.) Long tree ring chronologies have negligible millennial-scale variance – one more reason to distrust the temperature reconstructions of PAGES2K and IPCC. . . .

 

The work continues.
Improving access to paleoclimate data [link]

 

PAGES 12K… A funny thing happened on the way to the Anthropocene!
David Middleton
Guest “A funny thing happened on the way to the Anthropocene” by David Middleton I’ve been studying a recent Holocene climate reconstruction (Kaufman, D., McKay, N., Routson, C. et al., 2020)……

 

PAGES 12K: The Ice Age Goeth
David Middleton
Guest “damning with faint praise” by David Middleton Kaufman, Mckay, Routson, et al., 2020 In my previous post, I noted a “funny pattern” in the latest Holocene climate reconstruction (Kaufman,…

In my previous post, I noted a “funny pattern” in the latest Holocene climate reconstruction (Kaufman, McKay, Routson, et al., 2020). In this post, I will go into more detail as to why I chose the composite plus scale (CPS) method rather than the other four methods employed by the authors.

I think the paper represents a good faith effort to reconstruct global climate change over the past 12,000 years. The authors were very transparent about data and methods, even noting that no one really knows how to reconstruct climate at this sort of scale. While not a Mannian hockey stick or a Marcottian mess, they sill insisted on muting the low frequency component of the climate signal and directly comparing the high resolution instrumental record to the very low frequency, heavily smoothed multi-proxy reconstruction. That said, one of their five reconstruction methods did preserve the low frequency climate signal (yes, I am using the word “signal” correctly). This post will point out two things:

1. Direct comparisons of the instrumental data to the reconstruction violate the basic principals of signal theory.
2. Only the composite plus scale (CPS) method is consistent with the observations. . . .

 

New York Times 1992 – MWP And LIA Were Global
Posted on April 8, 2021 by tonyheller
In 1992, the New York Times said there was no indication of global warming and that the MWP and LIA were global.

Warming? Tree Rings Say Not Yet

Lisa J. Graumlich, who examines the ring patterns of foxtail pine trees and western junipers in the Sierra Nevada, has compiled a detailed record of the year-to-year variation in temperature and precipitation over the last thousand years.

She has seen in the North American trees the feathery but unmistakable signatures of the Medieval Warm Period, a era from 1100 to 1375 A.D. when, according to European writers of the time and other sources, the climate was so balmy that wine grapes flourished in Britain and the Vikings farmed the now-frozen expanse of Greenland; and the Little Ice Age, a stretch of abnormally frigid weather lasting roughly from 1450 to 1850. A Crucial Question

“We can now see that these were global climate phenomena, not regional temperature variations,” she said. “The question is, how did we get those warmer temperatures during pre-industrial times, and what can we learn from those conditions about what is going on today?”. . . .

 

The beat goes on . . . .

• Tree Rings Crack’d?

 

Uncovered: CO2 In Modern Ice Reaches 900 – 70,000 ppm – Wildly Incompatible With Atmospheric Levels
By Kenneth Richard on 6. May 2021

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It’s considered canonical that global-scale atmospheric levels of CO2 from thousands of years ago can be precisely discerned just by examining air bubbles in ancient snow and ice from Antarctica. But an examination of the CO2 levels in modern snow and ice shows there are gigantic discrepancies between the measurements of CO2 in ice versus the atmosphere. . . .

 

The paleoclimate claims of AGW advocates continue to unravel.
The temperature–CO2 climate connection: an epistemological reappraisal of ice-core messages
Charles Rotter
From History of Geo-and Space Sciences Hist. Geo Space. Sci., 12, 97–110, 2021https://doi.org/10.5194/hgss-12-97-2021© Author(s) 2021. This work is distributed underthe Creative Commons Attribution 4.0 License. The temperature–CO2 climate connection: an epistemological…

The temperature–CO2 climate connection: an epistemological reappraisal of ice-core messages

Pascal Richet
Institut de Physique du Globe de Paris, 1 Rue Jussieu, 75005 Paris, France

Correspondence: Pascal Richet Received: 24 Jan 2021 – Revised: 21 Mar 2021 – Accepted: 11 Apr 2021 – Published: 26 May 2021

Abstract
As simply based on fundamental logic and on the concepts of cause and effect, an epistemological examination of the geochemical analyses performed on the Vostok ice cores invalidates the marked greenhouse effect on past climate usually assigned to CO2 and CH4. In agreement with the determining role assigned to Milankovitch cycles, temperature has, instead, constantly remained the long-term controlling parameter during the past 423 kyr, which, in turn, determined both CO2 and CH4 concentrations, whose variations exerted, at most, a minor feedback on temperature itself. If not refuted, the demonstration indicates that the greenhouse effect of CO2 on 20th century and today’s climate remains to be documented, as already concluded from other evidence. The epistemological weakness of current simulations originates from the fact that they do not rely on any independent evidence for the influence of greenhouse gases on climate over long enough periods of time. The validity of models will, in particular, not be demonstrated as long as at least the most important features of climate changes, namely the glacial–interglacial transitions and the differing durations of interglacial periods, remain unaccounted for. Similarly, the constant 7 kyr time lag between temperature and CO2 decreases following deglaciation is another important feature that needs to be understood. Considered in this light, the current climate debate should be considered as being the latest of the great controversies that have punctuated the march of the Earth sciences, although its markedly differs from the preceding ones by its most varied social, environmental, economical and political ramifications.

How to cite. Richet, P.: The temperature–CO2 climate connection: an epistemological reappraisal of ice-core messages, Hist. Geo Space. Sci., 12, 97–110, https://doi.org/10.5194/hgss-12-97-2021, 2021. . . .

 

A better understanding of paleoclimate suggests less need to worry about the present.
A fiery past sheds new light on the future of global climate change
Charles Rotter
Many of today’s climate models rely on past levels of greenhouse gasses and aerosols to validate their predictions for the future. But there’s a problem: While pre-industrial levels of greenhouse…

 

Paleoclimate malpractice has metastasized to the IPCC.
The IPCC AR6 Hockeystick
Aug 11, 2021 – 3:14 PM
Although climate scientists keep telling that defects in their “hockey stick” proxy reconstructions don’t matter – that it doesn’t matter whether they use data upside down, that it doesn’t matter if they cherry pick individual series depending on whether they go up in the 20th century, that it doesn’t matter if they discard series that don’t go the “right” way (“hide the decline”), that it doesn’t matter if they used contaminated data or stripbark bristlecones, that such errors don’t matter because the hockey stick itself doesn’t matter – the IPCC remains addicted to hockey sticks: lo and behold, Figure 1a of its newly minted Summary for Policy-makers contains what else – a hockey stick diagram. If you thought Michael Mann’s hockey stick was bad, imagine a woke hockey stick by woke climate scientists. As the climate scientists say, it’s even worse that we thought. . . .

 

The problem with lying is that your memory has to be perfect.
The IPCC’s Latest PAGES 2k (2019) Temperature Hockey Stick Is Contradicted By . . . PAGES 2k (2015)
By Kenneth Richard on 16. August 2021

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The IPCC’s latest report uses a hockey stick-shaped reconstruction of global temperatures that wholly contradicts previous records produced by the same PAGES 2k and Oceans 2k consortiums from 4 years earlier. . . .

 

When I was both in High school and later college, I took a lot of math. Including Calculus.
I know the way the Hockey stick graph was made. It was a political graph.

So small were the changes that were it a graph of the impressions made by ants feet, it would amaze you how it looked terrible, but the impressions very tiny.

 

Another blog

BTW no one argues that paleoclimate is 100%

 

I will believe climate causes forest fires when they prove to me that lugging in fire wood is set on fire by bringing it in from the cold into the area where the fireplace is.

 

Another visit from a blogger who thinks Democrats can control Global climate by wishing and hoping.

I have watched our Democrats now for over 25 years promise they can control climate. They are still harping that they can control climate. Why are they holding back then?

 

I have been to see the Bristle Cone pines. I know the mountains they are in are high mountains. It is colder there, not warmer.

 

Hyperbole and blame shifting

I can play that game too but why bother? All it does is focus on one country one one continent

But you keep forgetting that this is a global problem, that is why the IPCC was originally formed - so as to get the global view