Reference: 450 skeptical peer reviewed papers

15 11 2009

Andrew at Popular Technology has taken the time (quite a bit of it) to compile a list of papers that have skeptical views. It is reproduced in full here. My thanks to him for doing this. – Anthony

450 Peer-Reviewed Papers Supporting Skepticism of  AGW caused Global Warming

A 2000-year global temperature reconstruction based on non-treering proxies (PDF)
(Energy & Environment, Volume 18, Numbers 7-8, pp. 1049-1058, December 2007)
- Craig Loehle

- Reply To: Comments on Loehle, “correction To: A 2000-Year Global Temperature Reconstruction Based on Non-Tree Ring Proxies”
(Energy & Environment, Volume 19, Number 5, pp. 775-776, September 2008)
- Craig Loehle

A Climate of Doubt about Global Warming
(Environmental Geosciences, Volume 7 Issue 4, pp. 213, December 2000)
- Robert C. Balling Jr.

A comparison of tropical temperature trends with model predictions (PDF)
(International Journal of Climatology, Volume 28, Issue 13, pp. 1693-1701, December 2007)
- David H. Douglass, John R. Christy, Benjamin D. Pearson, S. Fred Singer

A critical review of the hypothesis that climate change is caused by carbon dioxide
(Energy & Environment, Volume 11, Number 6, pp. 631-638, November 2000)
- Heinz Hug Read the rest of this entry »


Comments : 318 Comments »

Categories : Science, climate_change

Another parallel with the Maunder Minimum

12 11 2009

Guest post by David Archibald

In a presentation dated 22nd September, 2009, Dr Svalgaard produced a graphic which can be interpreted to predict the timing of the Solar Cycle 24 maximum.

That presentation is available here: http://www.leif.org/research/Predicting%20the%20Solar%20Cycle.ppt

That graphic is reproduced with my annotation:

Altrock-2009

Dr Svalgaard annotated Altrock’s orgininal figure with the red and aqua arrows. What is significant is that the Solar Cycle 24 arrow is 15 years after the Solar Cycle 23 arrow.  With the maximum of Solar Cycle 23 in March 2000, that line suggests that the Solar Cycle 24 maximum will be in 2015. Read the rest of this entry »


Comments : 137 Comments »

Categories : Science, solar

Lightning: a new tool for accurately measuring the sun’s rotation when sunspots are not present

11 11 2009
Patterns of Lightning Activity

Patterns of Lightning Activity

This is one big surprise. Moments of serendipity are some of the best quotes of science: “Hmmm, that’s odd”. As an amateur radio operator myself, I find this study fascinating. If you want to know more about VLF radio, see the NASA online VLF radio receiver link below.

http://www.spaceweather.com/audio/inspire/spherics_big.jpg

Sferics, short for "atmospherics", are impulsive signals emitted by lightning. Sferics are caused by lightning strokes within a thousand kilometers or so of the receiver. The dynamic spectra of sferics are characterized by vertical lines indicating the simultaneous arrival of all audio frequencies.

Learn more (and listen to the signals) at NASA’s INSPIRE online VLF radio receiver. – Anthony

From Tel Aviv University: A Lightning Strike in Africa Helps Take the Pulse of the Sun

 

TAU discovers an accurate tool for tracking solar rotation

Sunspots, which rotate around the sun’s surface, tell us a great deal about our own planet. Scientists rely on them, for instance, to measure the sun’s rotation or to prepare long-range forecasts of the Earth’s health.

But there are some years, like this one, where it’s not possible to see sunspots clearly. When we’re at this “solar minimum,” very few, if any, sunspots are visible from Earth. That poses a problem for scientists in a new scientific field called “Space Weather,” which studies the interaction between the sun and the Earth’s environment.

Thanks to a serendipitous discovery by Tel Aviv University’s Prof. Colin Price, head of TAU’s Department of Geophysics and Planetary Science, and his graduate student Yuval Reuveni, science now has a more definitive and reliable tool for measuring the sun’s rotation when sunspots aren’t visible — and even when they are. The research, published in the Journal of Geophysical Research – Space Physics, could have important implications for understanding the interactions between the sun and the Earth. Best of all, it’s based on observations of common, garden-variety lightning strikes here on Earth. Read the rest of this entry »


Comments : 114 Comments »

Categories : Science, lightning, solar

Jan Janssen’s presentation on Solar Cycle 24 hints at Dalton or Maunder type minimum ahead

8 11 2009

David Archibald forwarded me this PowerPoint presentation from Jan Janssens which he presented on October 22nd. It has some very interesting slides and is a good summary of the current debate over solar cycle 24.

I’ve put the entire slide show online in the post below at 50% size, as the PDF download of the PowerPoint document is quite large. For those that want it, you’ll find it at the end of the post mirrored on WUWT’s file system so that better bandwidth can help out.

Janssens1

Read the rest of this entry »


Comments : 152 Comments »

Categories : Science, solar

Antimatter signature spotted in Earth’s lightning

8 11 2009

Personally, I think this has to do with thunderstorms being essentially linear accelerators, vertical SLAC’s if you will. Huge charge differentials from top of cloud to bottom makes for a nice particle slingshot. There’s plenty of opportunity for antimatter (positrons) to be created in energetic collisions from particles coming out of the tops of thunderstorms. Sprites and blue jets for example, may be indicators for energetic particles.

It could also be very energetic photons from lightning as seen in the diagram below. At the high photon energies (twice the rest energy of electrons at 511 keV) and above 1.022 MeV positron-electron pair production may take place. Getting energies of 1.022 million electron volts certainly seems easy enough in thunderstorms. – Anthony

File:Pairproduction.png

From Sciencenews.org: Signature of antimatter detected in lightning

Fermi telescope finds evidence that positrons, not just electrons, are in storms on Earth

By Ron Cowen

 

http://www.sciencenews.org/view/download/id/49330/name/Antimatter_lightning.jpg

During two recent lightning storms, the Fermi telescope found evidence that positrons, not just electrons, are in storms on Earth.Axel Rouvin/Flickr

Washington — Designed to scan the heavens thousands to billions of light-years beyond the solar system for gamma rays, the Fermi Gamma-ray Space Telescope has also picked up a shocking vibe from Earth. During its first 14 months of operation, the flying observatory has detected 17 gamma-ray flashes associated with terrestrial storms — and some of those flashes have contained a surprising signature of antimatter. Read the rest of this entry »


Comments : 66 Comments »

Categories : Science

The Sun’s magnetic funk continues

4 11 2009

I’ve looked at the Ap Index on a regular basis, as it is an indicator of how active the solar dynamo is. When we had sunspot 1029 recently, the largest in months, it gave hope to many that Solar cycle 24 had finally started to ramp up.

From the data provided by NOAA’s Space Weather Prediction Center (SWPC) on November 2nd, you can see that October 2009 had little Ap magnetic activity. The value is now 3 for the month. Here’s my graph from October 2009 SWPC Ap data:

Ap_index_Oct09

Click to enlarge

Leif Svalgaard points out to me another indicator of low solar magnetic activity. Bill Livingston was able to observe sunspot group 1029, and measure its magnetic field and contrast. Leif’s graph with my annotation for group 1029 is below. By itself, this one sunspot group isn’t significant, but it does fit into a prediction made by Livingston and Penn. Read the rest of this entry »


Comments : 164 Comments »

Categories : Science, solar

Spencer on Lindzen and Choi climate feedback paper

3 11 2009

Some Comments on the Lindzen and Choi (2009) Feedback Study

by Roy W. Spencer, Ph. D.

http://asd-www.larc.nasa.gov/erbe/erbssat.gif

The ERBE satellite

I keep getting requests to comment on the recent GRL paper by Lindzen and Choi (2009), who computed how satellite-measured net (solar + infrared) radiation in the tropics varied with surface temperature changes over the 15 year period of record of the Earth Radiation Budget Satellite (ERBS, 1985-1999).

The ERBS satellite carried the Earth Radiation Budget Experiment (ERBE) which provided our first decadal-time scale record of quasi-global changes in absorbed solar and emitted infrared energy. Such measurements are critical to our understanding of feedbacks in the climate system, and thus to any estimates of how the climate system responds to anthropogenic greenhouse gas emissions.

The authors showed that satellite-observed radiation loss by the Earth increased dramatically with warming, often in excess of 6 Watts per sq. meter per degree (6 W m-2 K-1). In stark contrast, all of the computerized climate models they examined did just the opposite, with the atmosphere trapping more radiation with warming rather than releasing more. Read the rest of this entry »


Comments : 238 Comments »

Categories : Science, climate data

Physicists send letter to Senate — Cite 160 scientists protest regarding APS climate position

2 11 2009

Since I’m not legally allowed to show the American Physical Society logo (they complained last time) this will have to do:

consensus

A GAGGLE IS NOT A CONSENSUS

You have recently received a letter from the American Association for the Advancement of Science (AAAS), purporting to convey a “consensus” of the scientific community that immediate and drastic action is needed to avert a climatic catastrophe.

We do not seek to make the scientific arguments here (we did that in an earlier letter, sent a couple of months ago), but simply to note that the claim of consensus is fake, designed to stampede you into actions that will cripple our economy, and which you will regret for many years. There is no consensus, and even if there were, consensus is not the test of scientific validity. Theories that disagree with the facts are wrong, consensus or no.

We know of no evidence that any of the “leaders” of the scientific community who signed the letter to you ever asked their memberships for their opinions, before claiming to represent them on this important matter. Read the rest of this entry »


Comments : 168 Comments »

Categories : Science, politics

Spot the science error

1 11 2009

Guest post by Dr. Leif Svalgaard

The following abstract of a poster to be presented next month at the Fall Meeting of the American Geophysical Union caught my eye:

Session Title: GC11A. Diverse Views From Galileo’s Window: Solar Forcing of Climate Change Posters Chair: Willie Soon, Nicola Scafetta, Richard C Willson

ID# GC11A-0685: Dec 14 8:00 AM – 12:20 PM
Revised Assumptions and a Multidiscipline Approach to a Solar/Climate Connection

C. A. Perry (US Geological Survey, Lawrence, KS, USA).

Click to enlarge

Abstract: Read the rest of this entry »


Comments : 214 Comments »

Categories : Science, solar

The Sun Defines the Climate – an essay from Russia

28 10 2009

Habibullo Abdussamatov, Dr. Sc. – Head of Space research laboratory of the Pulkovo Observatory, Head of the Russian/Ukrainian joint project Astrometria – has a few things to say about solar activity and climate. Thanks to Russ Steele of NCWatch

Russ1__550x348

Total Solar Irradiance over time in watts per square Variation in the TSI during the period 1978 to 2008 (heavy line) and its bicentennial component (dash line), revealed by us. Distinct short-term upward excursions are caused by the passage of faculae on the solar disk, and downward excursions by the passage of sunspot groups.

Key Excerpts:

Observations of the Sun show that as for the increase in temperature, carbon dioxide is “not guilty” and as for what lies ahead in the upcoming decades, it is not catastrophic warming, but a global, and very prolonged, temperature drop.

[...] Over the past decade, global temperature on the Earth has not increased; global warming has ceased, and already there are signs of the future deep temperature drop. Read the rest of this entry »


Comments : 209 Comments »

Categories : Science, solar

Extremists More Willing To Share Their Opinions, Study Finds

21 10 2009

From Ohio State University, an explanation for the existence of bloggers like Joe Romm and why many moderate scientists don’t speak out. There’s even “fake data” involved.

I’ve seen this phenomenon of extreme views being the most vocal in my own hometown of Chico, where a small vocal group of people often hold sway of the city council because they are the ones that show up up regularly to protest, well, just about anything. The council, seeing this regular vocal feedback, erroneously concludes that the view accurately represents the majority of city residents. The result is a train wreck, and the council sits there scratching their heads wondering why after making such decisions, they get their ears burned off by people unhappy with the decision. Bottom line, we all need to be more active in the public input process if we want decisions to be accurately reflected.

COLUMBUS, Ohio – People with relatively extreme opinions may be more willing to publicly share their views than those with more moderate views, according to a new study.

The key is that the extremists have to believe that more people share their views than actually do, the research found.

Kimberly Rios Morrison

The results may offer one possible explanation for our fractured political climate in the United States, where extreme liberal and conservative opinions often seem to dominate.

“When people with extreme views have this false sense that they are in the majority, they are more willing to express themselves,” said Kimberly Rios Morrison, co-author of the study and assistant professor of communication at Ohio State University.

How do people with extreme views believe they are in the majority?  This can happen in groups that tend to lean moderately in one direction on an issue.  Those that take the extreme version of their group’s viewpoint may believe that they actually represent the true views of their group, Morrison said. Read the rest of this entry »


Comments : 399 Comments »

Categories : Science, politics

Discoveries from the IBEX satellite show we still don’t know quite a few things about the heliosphere and solar system

17 10 2009

Voyagers 1 and 2 reached the termination shock in 2005 and 2007, respectively, taking point measurements as they left the solar system. Before IBEX, there was only data from these two points at the edge of the solar system. While exciting and valuable, the data they provided about this region raised more questions than they resolved. IBEX has filled in the entire interaction region, revealing surprising details completely unpredicted by any theories. IBEX completes one all-sky map every six months. IBEX completed the first map of the complex interactions occurring at the edge of the solar system (shown) this summer. (Credit: SwRI via Science Daily)

From the University of Chicago

Satellite reveals surprising cosmic ‘weather’ at edge of solar system


IMAGE: Image from one of the IBEX papers published in the Oct. 16, 2009, issue of Science showing a map of the ribbon of energetic neutral atoms (in green and yellow)…

The first solar system energetic particle maps show an unexpected landmark occurring at the outer edge of the solar wind bubble surrounding the solar system. Scientists published these maps, based mostly on data collected from NASA’s Interstellar Boundary Explorer satellite, in the Oct. 15 issue of Science Express, the advance online version of the journal Science.

“Nature is full of surprises, and IBEX has been lucky to discover one of those surprises,” said Priscilla Frisch, a senior scientist in astronomy & astrophysics at the University of Chicago. “The sky maps are dominated by a giant ribbon of energetic neutral atoms extending throughout the sky in an arc that is 300 degrees long.” Energetic neutral atoms form when hot solar wind ions (charged particles) steal electrons from cool interstellar neutral atoms. Read the rest of this entry »


Comments : 221 Comments »

Categories : Science, solar, space

New paper: Barents Sea Temperature correlated to the AMO as much as 4C – potential for sea ice effect

8 10 2009

A new paper just published in the Geophysical Review Letters finds a significant correlation between the Atlantic Multidecadal Oscillation (AMO) and the water temperature of the Barents Sea.

Barents_sea_map

Barents Sea - click for larger map

This was made possible by a significant network of hydrographical stations in the Barents Sea which resulted in a 230,000 temperature profiles used in this analysis. The hint in the conclusion (which the authors stop short of defining)  is that the pattern of data, seen below, might be linked to the recent pattern of Arctic sea ice melt and some partial recovery seen in the last two years. Their figure 2 below, certainly seems to suggest a strong correlation between water temperature in the Barents Sea and the AMO index.

Monthly temperature (°C) in the Barents Sea for the 100–150 m layer, from 1900 to 2006. Years without all 12 months of data are not plotted. The red line is the Atlantic Multidecadal Oscillation Index.

Monthly temperature (°C) in the Barents Sea for the 100–150 m layer, from 1900 to 2006. Years without all 12 months of data are not plotted. The red line is the Atlantic Multidecadal Oscillation Index.

The paper is:

Levitus, S., G. Matishov, D. Seidov, and I. Smolyar (2009), Barents Sea multidecadal variability, Geophys. Res. Lett., 36, L19604, doi:10.1029/2009GL039847.

We present area-averaged time series of temperature for the 100–150 m depth layer of the Barents Sea from 1900 through 2006. This record is dominated by multidecadal variability on the order of 4C which is correlated with the Atlantic Multidecadal Oscillation Index. Read the rest of this entry »


Comments : 102 Comments »

Categories : Arctic, Science, oceans, sea ice

What climate news you aren’t seeing in the American press but can in Iran

8 10 2009

It’s really rather sad that you can read about Svensmark’s climate research in an Iranian news outlet (FARS) but you won’t see any mention of it in American press, such as in the NYT. A search for Svensmark (and also cosmic rays) yields nothing. Maybe Andy Revkin just hasn’t gotten around to it yet, but if I were in his shoes, I wouldn’t enjoy being scooped by Iran. WUWT covered this story, complete with comments direct from Dr. Svensmark, nearly one month ago. See here.

NYT-svensmark-search

FARS-iran

Here’s the story from FARS:

===

TEHRAN (FNA)- New research by the National Space Institute in the Technical University of Denmark (DTU) validated 13 years of discoveries that point to a key role for cosmic rays in climate change.

Billions of tons of water droplets vanish from the atmosphere in events that reveal in detail how the Sun and the stars control our everyday clouds.

DTU Researchers have traced the consequences of eruptions on the Sun that screen the Earth from some of the cosmic rays – the energetic particles raining down on our planet from exploded stars.

“The Sun makes fantastic natural experiments that allow us to test our ideas about its effects on the climate,” lead author of a report newly published in Geophysical Research Letters Prof. Henrik Svensmark said.

When solar explosions interfere with the cosmic rays there is a temporary shortage of small aerosols, chemical specks in the air that normally grow until water vapor can condense on them, so seeding the liquid water droplets of low-level clouds.

Because of the shortage, clouds over the ocean can lose as much as 7 per cent of their liquid water within seven or eight days of the cosmic-ray minimum.

“A link between the Sun, cosmic rays, aerosols, and liquid-water clouds appears to exist on a global scale,” the report concludes. Read the rest of this entry »


Comments : 106 Comments »

Categories : Science, climate_change, clouds, space

New Svalgaard paper – reconstructing the heliospheric magnetic field since 1835 – with insight into the peer review process

6 10 2009

Leif Svalgaard writes in comments:

We plan to submit tomorrow to JGR the following…

http://www.leif.org/research/IDV09.pdf (preprint)

…showing the run of the heliospheric magnetic field since 1835 [not a typo]. I plan to discuss the whole peer-review process here on WUWT, complete with nasty comments by the reviewers and our responses. This will be an illustration of the peer-review process as it unfolds. Should be interesting.

I’ll say. I’ve taken some of the most interesting graphics and put them up for WUWT readers, along with the abstract.

http://www.leif.org/research/Heliospheric-Magnetic-Field-Since-1900.png

Leif's plot for the last century to present is now extended back to 1835

IDV09 and Heliospheric Magnetic field 1835-2009
Leif Svalgaard1 and Edward W. Cliver2
Stanford University, HEPL, Cedar Hall, Via Ortega, Stanford, CA 94305-4085
Space Vehicles Directorate, Air Force Research Laboratory, Hanscom AFB, MA 01731-3010

Abstract.

We use recently acquired archival data to substantiate and extend the IDV index of long-term geomagnetic activity, particularly for years from 1872-1902 for which the initial version of the index (IDV05) was based on observations from very few stations. The new IDV series (IDV09) now includes the interval from 1835-2009, vs. 1872-2004 for IDV05. The HMF strength derived from IDV09 agrees closely with that based on IDV05 over the period of overlap. Comparison of the IDV09-based HMF strength with other recent reconstructions of solar wind B yields a strong consensus between the series based on geomagnetic data, but significant lack of support for a series based on the 10Be cosmic ray radionuclide.

The reconstructed data in the graphic below, from the paper, is quite interesting. Currently, we appear to be at the lowest point in the record. Read the rest of this entry »


Comments : 248 Comments »

Categories : Science, solar

A borehole in Antarctica produces evidence of sudden warming

4 10 2009

From a Louisiana State University Press Release Oct 1, 2009

Algae and Pollen Grains Provide Evidence of Remarkably Warm Period in Antarctica’s History

Palynomorphs from sediment core give proof to sudden warming in mid-Miocene era


The ANDRILL drilling rig in Antarctica

For Sophie Warny, LSU assistant professor of geology and geophysics and curator at the LSU Museum of Natural Science, years of patience in analyzing Antarctic samples with low fossil recovery finally led to a scientific breakthrough. She and colleagues from around the world now have proof of a sudden, remarkably warm period in Antarctica that occurred about 15.7 million years ago and lasted for a few thousand years.

Last year, as Warny was studying samples sent to her from the latest Antarctic Geologic Drilling Program, or ANDRILL AND-2A, a multinational collaboration between the Antarctic Programs of the United States (funded by the National Science Foundation), New Zealand, Italy and Germany, one sample stood out as a complete anomaly. Read the rest of this entry »


Comments : 317 Comments »

Categories : Antarctic, Science, paleoclimatology

Cycle 24 spotless days keeps moving up the hill – now “competitive with the Baby Grand minimum”

3 10 2009

After an exciting encounter last week with some genuine sunspots that weren’t arguable as specks, pores, or pixels, the sun resumes its quiet state this week.

SOHO_MDI_100309

Todays SOHO MDI image: back to cueball

People send me things. Here’s the latest email from Paul Stanko, who has been following the solar cycle progression in comparison to previous ones.

Hi Anthony,

Out of the numbered solar cycles, #24 is now in 7th place. Only 5, 6, and 7 of the Dalton Minimum and cycles 12, 14, and 15 of the Baby Grand Minimum had more spotless days.  Since we’ve now beaten cycle #13, we are clearly now competitive with the Baby Grand minimum.

Here’s a table of how the NOAA panel’s new SC#24 prediction is doing:

November 2008:  predicted = 1.80, actual = 1.67 (predicted peak of 90 suggests an actual peak of 83.7)
December 2008:  predicted = 1.80, actual = 1.69 (predicted peak of 90 suggests an actual peak of 84.7)
January 2009:  predicted = 2.10, actual = 1.71 (predicted peak of 90 suggests an actual peak of 73.2)
February 2009: predicted = 2.70, actual = 1.67 (predicted peak of 90 suggests an actual peak of 55.6)
March 2009: predicted = 3.30, actual = 1.97 (predicted peak of 90 suggests an actual peak of 53.8)

April would require the October data which is still very incomplete.  If this analysis intrigues you, I’d be happy to keep you updated on it.  Please also find a couple of  interesting graphs attached as images.

Paul Stanko

Here’s the graphs, the current cycle 24 and years  of interest are marked with a red arrow: Read the rest of this entry »


Comments : 374 Comments »

Categories : Science, solar

Wheel! – - Of! – - Silly!

2 10 2009

I thought I’d seen the end of this after we first saw it back on May 26th of this year. I wrote then:

How not to make a climate photo op

You have to wonder- what were these guys thinking? The only media visual they could have chosen that would send a worse message of forecast certainty was a dart board…or maybe something else?

MIT’s “wheel of climate” – image courtesy Donna Coveney/MIT

But no, they apparently didn’t get enough press the first time around. I mean, come on, it’s a table top roulette wheel in a science press release. Today we were treated to yet another new press release on the press mailing list I get. It is recycled science news right down to the same photo series above which you can see again in the press link below. The guy on the left looks slightly less irritated in the new photo at the link. Next, to get more mileage, I think we’ll see the online game version.

So what I think we need now is  a caption contest for the photo above. Readers, start your word skills. I’ll post the best three captions from comments in a  new post later.

Oh and if you want to read about the press release, here it is below:

From MIT Public Release: 2-Oct-2009
There’s still time to cut the risk of climate catastrophe, MIT study shows

A new analysis of climate risk, published by researchers at MIT and elsewhere, shows that even moderate carbon-reduction policies now can substantially lower the risk of future climate change. It also shows that quick, global emissions reductions would be required in order to provide a good chance of avoiding a temperature increase of more than 2 degrees Celsius above the pre-industrial level — a widely discussed target.

Read the rest of this entry »


Comments : 312 Comments »

Categories : Science, ridiculae

NASA Goddard climate scientist charged in nepotism money scheme

1 10 2009

h/t to WUWT reader Keith.  Excerpts from:

Government Executive

NASA scientist pleads guilty to directing contracts to wife’s firm

By Robert Brodsky rbrodsky@govexec.com September 30, 2009

An award-winning NASA scientist has admitted to directing thousands of dollars in sole-source agency contracts to his wife’s firm and failing to report the income on a financial disclosure form.

Mark Schoeberl, 60, of Silver Spring, Md., a senior manager and scientist at the Goddard Space Flight Center, pleaded guilty on Tuesday in the U.S. District Court in Greenbelt, Md., to one count of felony conflict of interest.

Schoeberl, who has worked at NASA since the early 1980s, was charged last week after authorities completed an investigation run out of NASA inspector general’s office.

“When government officials direct business to themselves or their family members, other people are deprived of a fair chance to compete,” said U.S. Attorney Rod Rosenstein. “It is illegal for any federal employee to make an official decision that directly affects their financial interest, unless they disclose that conflict of interest and get approval from the government.” Read the rest of this entry »


Comments : 39 Comments »

Categories : Science, ridiculae

Response from Briffa on the Yamal tree ring affair – plus rebuttal

1 10 2009

First here is Dr. Keith Briffa’s response in entirety direct from his CRU web page:

Dr_Keith_Briffa

Dr. Keith Briffa of the Hadley Climate Research Unit - early undated photo from CRU web page

My attention has been drawn to a comment by Steve McIntyre on the Climate Audit website relating to the pattern of radial tree growth displayed in the ring-width chronology “Yamal” that I first published in Briffa (2000). The substantive implication of McIntyre’s comment (made explicitly in subsequent postings by others) is that the recent data that make up this chronology (i.e. the ring-width measurements from living trees) were purposely selected by me from among a larger available data set, specifically because they exhibited recent growth increases.

This is not the case. The Yamal tree-ring chronology (see also Briffa and Osborn 2002, Briffa et al. 2008) was based on the application of a tree-ring processing method applied to the same set of composite sub-fossil and living-tree ring-width measurements provided to me by Rashit Hantemirov and Stepan Shiyatov which forms the basis of a chronology they published (Hantemirov and Shiyatov 2002). In their work they traditionally applied a data processing method (corridor standardisation) that does not preserve evidence of long timescale growth changes. My application of the Regional Curve Standardisation method to these same data was intended to better represent the multi-decadal to centennial growth variations necessary to infer the longer-term variability in average summer temperatures in the Yamal region: to provide a direct comparison with the chronology produced by Hantemirov and Shiyatov.

These authors state that their data (derived mainly from measurements of relic wood dating back over more than 2,000 years) included 17 ring-width series derived from living trees that were between 200-400 years old. These recent data included measurements from at least 3 different locations in the Yamal region. In his piece, McIntyre replaces a number (12) of these original measurement series with more data (34 series) from a single location (not one of the above) within the Yamal region, at which the trees apparently do not show the same overall growth increase registered in our data. Read the rest of this entry »


Comments : 366 Comments »

Categories : Science, paleoclimatology

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