Sunday, November 25, 2012

Has there been "Little change in global drought over the past 60 years"? - info links


I'm a regular visitor at the Climate Change board over at SkepticForum.com.  A recent post has inspired me to compile the following collection of links to recent articles since they examine a recent paper that "obfuscationists" are trumpeting as more proof that global warming is nothing to be concerned about.

The paper being:
"Little change in global drought over the past 60 years"
Nature 491, 435–438 (15 November 2012) doi:10.1038/nature11575
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So while denialists continue using every diversion in their drive to disregard the seriousness of our warming planet.  I believe we need to refocus on The Real Story.     

That is, the effort of working toward better understanding the physical dynamics of this one and only planet we inhabit.

More specifically our global heat distribution engine.

After all, science is a learning process and learning tends to be one lesson after another.

There are a handful of serious blogs looking at this.  Good places to continue the learning process.  For instance Nielsen-Gammon gives a nice thousand word description of the basic situation:

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"Counting Drought" by John Nielsen-Gammon 
Wednesday, November 21, 2012 
http://blog.chron.com/climateabyss/2012/11/counting-drought/  
The paper is called “Little Change in Global Drought Over the Past 60 Years”(Nature, doi:10.1038/nature11575), and it’s by a team led by Justin Sheffield,a research scientist at Princeton University.  When carefully parsed, the paper makes two arguments.  
First, it argues that previous analyses of increasing drought used a drought index that is artificially biased toward increasing drought in a warming climate.Second, it argues that when an appropriate drought index is used, one finds “little change” in drought.{...}...The trend in the old PDSI is twice the trend in the new PDSI, and the average area in drought is 25% of the globe with the old PDSI and only 15% of the globe with the new PDSI.So far, things seem straightforward.  But there’s the minor matter of two earlier studies that looked at the difference between old and new PDSI and, contrary to Sheffield et al., concluded that there was little practical difference. . .there's more

Then, there is this...
Tree rings and Drought IndicesKevin Anchukaitis ~ http://strangeweather.wordpress.com  
. . .  Sheffield et al. note that the bias they identify arises from ‘a simplified model of potential evaporation [Thornthwaite model] that responds only to changes in temperature’. Indeed, this is something that scientists in the drought community have been aware of — For example, Aiguo Dai published a paper last year in the Journal of Geophysical Research in which he noted that {link}

Trenberth has a few things to add...
By Joe Romm on Nov 20, 2012 ~ A “drought” in good science  http://thinkprogress.org/climate/2012/11/20/1194201/climate-change-droughts-nature/  
Kevin Trenberth:"The new paper recently published in Nature by Sheffield et al “Little change in global drought over the past 60 years” [Nature 491 15 Nov 2012 435-440] has done some impressive work. . . "

Here's another good one...
Drought area changed little over recent decades15 Nov 2012, Freya Robertshttp://www.carbonbrief.org/blog/2012/11/drought-area-little-changed-in-recent-decades  
What's changed?The Intergovernmental Panel on Climate Change (IPCC) concluded in its Fourth Assessment Report, published in 2007, that "Globally, the area affected by drought has likely increased since the 1970s". In its 2012 Special Report on Extreme Events (SREX), the IPCC was more cautious about past trends, concluding "there are large uncertainties regarding global-scale trends in drought".{and some say the IPCC is extreme and bias... nonsense !}{...}Newer models include more of these factors, giving a more accurate picture of drought. . .{...} 
Does this affect future predictions of drought?The finding that some models may have overestimated past drought is unlikely to affect predictions about future droughts. That's because working out how climate change might affect drought in the future is done using different - climate - models. These climate models are more sophisticated and operate in a different way than the simple models this study looked at to analyse past drought. . .
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SkepticalScience.com also has a good round up


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The thing that frustrated me the worst is how well the denialist camp manages to get everyone to focus on minute details.  
All intended to keep us from learning to appreciate what we do know.  
Our weather is the product of our planet's climate.   
GHGs are a central component of that global heat distribution engine.  
GHGs ARE sequestering more heat. 
Anthropogenic global warming will manifest itself in many ways, 
many of which we don't fully understand.  

But, the fact that we don't fully understand every aspect has nothing to do with the fact of the warming.  
How long will it take us to stop arguing about the scientific consensus and get on with the real work?


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The AGW consensus is NOT formed by scientists.
The AGW consensus IS compelled by the evidence.
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One Directional Skepticism Equals Denial

Monday, November 19, 2012

ChrisColose.wordpress.com... has moved to www.climatephys.org


Over at WUWTW I've reposted an article by Chris Colose "Judith Curry on 'dogma' and ideology."  I wasn't familiar with Chris until a couple days ago.  I was impressed with his clear writing style, balanced tone and most importantly the substance of his essay.

As I've had a chance to do more reading at Chris Colose's blog, it turns out he really does have a lot of interesting things to say.  Since sharing information is the main contribution I can hope to make I've included links to articles I found fascinating... that is educational.

Here is a list of worthy posts from Chris'  chriscolose.wordpress.com/livepage.apple.com
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PS. Chris has retired this blog and started a new one at http://www.climatephys.org
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Posted on August 27, 2010

"... there are still many popular misconceptions out there concerning the relative roles of individual greenhouse gases and the total mean climatology of the greenhouse effect, and some of these confusions have admittedly not been explicitly corrected in the literature very well..."
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Posted on May 12, 2010 |

"The blog Watts up with That is famous for its attempt to reinvent climate physics on Earth, and now they want to reinvent astrophysics as well..."
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Posted on May 8, 2010

"This is the first formal, peer-reviewed response paper to Gerhard Gerlich and Ralf Tscheuschner and their alleged greenhouse falsification..."
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Posted on March 2, 2010

"Two years ago I made a post that featured a dozen or so maps and graphs that lended insight into global warming... I now want to update that page with even better and a larger number images which are relevant to climate change.
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Posted on February 18, 2010
    
"Every once in a while it is worth reviewing the basic physics behind the greenhouse effect and global warming. Sometimes all the debate about global warming in the media loses focus of the fact that the world really is governed by the laws of physics..."
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Posted on December 18, 2009 |

"The webcast for Dr. Alley’s presentation is now up, so I recommend watching the video. It is concerning the role of CO2 on climate over geologic time..."
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Posted on December 8, 2009

"Professor Galen McKinley at the University of Wisconsin-Madison has recently put up a web page which discusses the global carbon cycle and its connection to climate change..."
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Posted on October 8, 2009
    
"... this post which outlines some of the basic radiative forcing and feedback physics which climatologists use to assess climate change. This is fairly standard material which should be understood by anyone with a deep interest in climate..." 
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Posted on August 12, 2009
    
"Hopefully people interested in the blog wars have been alerted to the ongoing climate change “debate” between George Monbiot and Ian Plimer. If not, the best place to start is probably Monbiot’s blog itself (with several posts on the topic already). Greenfrye and Tamino also have some ongoing commentary, so have fun catching up on what’s going on.

Unfortunately, round 1 consisted of Plimer dodging Monbiot’s questions which ask Plimer to defend certain indefensible statements in his book “Heaven and Earth.” Maybe Plimer just “wanted to go first” so I’ll give him the benefit of the doubt, but his own set of questions intended for Monbiot are quite revealing about his intentions.

As most commenters have suspected, these questions are all ill-posed or have nothing to do with the attribution or prediction of future climate change..."
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Posted on June 27, 2009
    
"Many readers who keep up with the blogs will be aware of the recent post at RealClimate concerning a recent review by Alan Carlin and John Davidson on the EPA Endangerment Finding..."
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Posted on June 22, 2009
    
"... A hot topic this week has been the release of the Synthesis report from the discussions at the Copenhagen conference earlier this year..."
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Posted on April 21, 2009
    
"The EPA has recently announced a “Proposed Endangerment and Cause or Contribute Findings for Greenhouse Gases under the Clean Air Act.” It is summarized here for instance..."
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Posted on April 7, 2009
    
"Most people spending much time on the blogosphere are well aware of claims that “Global Warming stopped in 1998″ or similar-style remarks. Even though the 1998-2008 period contains most of the warmest years on the instrumental record (something that is very unusual), and all the years are well above the traditional 1951-1980 (or 1961-90) climatologies..."
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Posted on March 31, 2009
    
"... Richard Lindzen has made his presence felt at Anthony Watts blog in “Lindzen on Negative Climate Feedback”. Accuweather also has a recent blog post on it. In the comments, it is being hailed as the new found gospel truth of negative climate feedbacks and low sensitivity. Unfortunately, the problem with most skeptical arguments is not what we are told, but rather what we are not told. So what aren’t we told?..."

"... In short, Lindzen’s analysis is based on outdated data that has been revised since 2002, and these revisions are not exactly recent, so he should have been aware of them. Using the more recent data would not allow him to make his argument as presented as WUWT..."
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Posted on February 21, 2009
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Posted on January 23, 2009
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Posted on December 20, 2008

"In Part 1 I discussed the difference between skeptics and denialists. Not a few hours after I did that, I read a post over at Deltoid where Tim Lambert talks about a popular subject: Hotspots (no, nothing to do with geology)..."
"...As Tim Lambert has shown, David Evans is very confused, and now it appears he doesn’t even understand what his own argument was. I will copy David Evan’s reply to Tim Lambert with piece-by-piece clarifications..."
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Posted on December 20, 2008
    
"Chris wants to ask the age-old question: what separates denialists from skeptics?..."
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Posted on November 19, 2008
    
"The American Geophysical Union adopted a position statement concerning climate change in December 2007 which can be found here..."
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Posted on November 11, 2008

"Prof. Don Easterbrook has a piece Global Cooling is Here:Evidence for Predicting Global Cooling for the Next Three Decades that has been getting some attention in the blogosphere in which he claims that global warming has ended and that global cooling will occur over the next several decades.  

Easterbrook’s analysis is hopelessly flawed, and one is left to wonder just why he would intentionally shoot down his own credibility with such sloppiness. Any support of this work on internet sources is not a support of any actual science or data, but an appeal to authority.
Lets’ go point-by point..."
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"How to rank skeptical arguments..."
It's worth pointing out http://www.skepticalscience.com SkepticalScience.com has what may be the best collection of skeptical arguments and reviews:
Climate Myths sorted by taxonomy
Skeptic Arguments sorted by popularity
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Posted on September 9, 2008
    
"Sea ice extent in the Northern Hemisphere has exhibited large and anomalous declining trends over the last several decades. In particular, there has been over a 20% decline since 1979..."
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Posted on August 8, 2008
    
"Just one more to accompany Gerlich and Tscheuschner, Miskolczi, and other strange pieces on how an atmospheric greenhouse effect is supposed to operate.

Once again, like evolution, thermodynamics throws science out the window. Theories that don’t exist are refuted, and mysterious “natural variability” is thrown in the mix.

The first 6 pages of this paper involve..."
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Posted on May 22, 2008
    
"Same crap, different year, different number. Arthur Robinson and co. strike again. At first, it was the 19,000 signatories for the Oregon Institute of Science and Medicine (OISM), and now they’ve jacked the number up to over 31,000 “scientists” who signed a petition against the AGW consensus. 
The phone book is cute, but personally I’d prefer one person with real science and data, as opposed to 31,000 people supporting scientific hogwash

The science in their “peer-reviewed” publication is easy enough to invalidate, and carries its share of looking at regional temperature (as opposed to global), throwing up strawman attacks (no one expects global temperatures to follow hydrocarbon emissions), and refuting themselves in the process (like their solar radiative forcing graph, which would be converted into a temperature anomaly that is negligible). But, surely Chris doesn’t know more than all of these 31,000 scientists, right? Well I did a quick survery of these “scientists” and report as follows..."
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Posted on May 16, 2008
    
"The IPCC AR4 report has concluded that atmospheric carbon dioxide has reached levels that are higher than anytime during the past 650,000 years. That was a recent update to the literature just several years ago which only went back 420,000 years. These results are supported by ice cores from Antarctica which trap bubbles of ancient atmosphere and allow for confident reconstructions of ancient climates. In the latest issue of Nature, members of the European Project for Ice Coring in Antarctica (EPICA) present the latest, and longest, record from ice cores which extend to 800,000 years..." 
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Posted on January 25, 2008
    
"... There is a lot of discussion about climate feedbacks in climate science, notably the role of water vapor. In short, the total amount of atmospheric water vapor should go up in a warmer climate under the assumption of approximately fixed relative humidity, at an increase of ~7% per degree Celsius warming, as per the Clausius-Clapeyron relationship. Water vapor is the strongest greenhouse gas, and so increases in water vapor will amplify any temperature changes from any initial forcing (e.g., CO2). However, many times the “water vapor feedback” being discussed on the internet is not the water vapor feedback at all. For example, in a recent web blog by Roger Pielke Sr., entitled Third Follow Up To Climate Metric Reality Check #3 – Evidence For A Lack Of Water Vapor Feedback On The Regional Scale or here, Dr. Pielke discusses how the WV feedback may not be showing up on the regional level and thereby questioning our understanding of how the climate reacts to temperature increase..."
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Posted on December, 2007 
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Thursday, November 15, 2012

YouTube - Peter Hadfield's educational "Climate Change" video series


"Skeptical" websites such as Curry's blog, or WUWT, or ClimateAudit, et al. spend endless hours side tracking the real issues.  And since I have some free time, I figured why not put together an index of Peter Hadfield's video series ~ it does an excellent job of reviewing what the scientific "consensus" on Climate Change is all about.

Grab the popcorn and sit down for some easy learning.   ;-)



Potholer Climate videos

Uploaded by potholer54 
Peter Hadfield 

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This has been all about Peter Hadfield but I shouldn't ignore Peter Sinclair, aka Greenman3610, and his top notch coverage of the AGW "debate"... story...

Greenman3610 ~ Climate Denial Crock of the Week 

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Peter Sinclair interviews Peter Hadfield
Potholer54/Greenman3610 - The Search for Lord Monckton






Wednesday, November 14, 2012

“Identifying human influences on atmospheric temperature”


Last night I emailed Ben Santer to let him know I was posting quotes 
from those dastardly climategate emails.  He sent me a nice reply 
and a pdf of the following study which is hot off the press, as they say.  
The embargo was lifted two days ago and I have permission to reprint it here.
I have taken the liberty to inject (to my thinking) appropriate links to sources for more background information... for those interested in learning.
The text has not been altered, though I have added highlights.

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Fact sheet for 
“Identifying human influences on atmospheric temperature”


by Benjamin D. Santer, 
Jeffrey F. Painter, 
Carl A. Mears,
Charles Doutriaux, 
Peter Caldwell, 
Julie M. Arblaster, 
Philip J. Cameron Smith, 
Nathan P. Gillett, 
Peter J. Gleckler, 
John Lanzante, 
Judith Perlwitz, 
Susan Solomon, 
Peter A. Stott, 
Karl E. Taylor, 
Laurent Terray, 
Peter W. Thorne, 
Michael F. Wehner, 
Frank J. Wentz, 
Tom M.L. Wigley, 
Laura J. Wilcox,
and Cheng-Zhi Zou

To be published in Proceedings of the U.S. National Academy of Sciences Online Early Edition

Embargoed until November 12, 2012, 3:00 p.m. U.S. Eastern Time


Summary: We find some of the clearest evidence to date of a discernible human influence on atmospheric temperature. 
Satellite data and computer model simulations of historical climate change show common patterns of pronounced warming of the troposphere and cooling of the lower stratosphere. In the model simulations, these changes are mainly caused by human factors. 
We show that sustained, global-scale tropospheric warming and lower stratospheric cooling cannot be explained by natural climate variability. Our results are robust to current uncertainties in models and satellite observations.

Signal-to-noise analysis: A brief introduction
Our PNAS paper describes results from a climate change detection and attribution (“D&A”) study, in which we investigate the causes of temperature changes in Earth’s atmosphere. The focus of our study is on geographical patterns of temperature change in the troposphere and the stratosphere (see below):

pastedGraphic.pdf   {source}

Figure 1: This Figure is from Synthesis and Assessment Product 1.1 of the U.S. Climate Change b Program (Karl et al., 20061). It shows the approximate pressure and altitude boundaries of the troposphere and the stratosphere. The multi- colored line indicates the average dependence of temperature on altitude.
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We rely on estimates of atmospheric temperature change from satellites and computer models of the climate system (“climate models”). The satellite observations are made available by three different research groups; the simulation output is from 20 individual models participating in phase 5 of the Coupled Model Intercomparison Project (CMIP-5).

The climate model results provide estimates of the atmospheric temperature changes expected to occur in response to a combination of human and natural factors (such as changes in greenhouse gases, aerosol particles, the Sun’s energy output, and volcanic activity). These expected changes are typically called the “fingerprint”. From a large number of previous studies, we know that human-caused changes in well-mixed greenhouse gases and stratospheric ozone are the most important influences on tropospheric and stratospheric temperature fingerprints.

The model simulation output also gives us estimates of the year-to-year and decade-to-decade “noise” of internal climate variability, arising from such natural phenomena as the El Niño/Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO).

We use a standard fingerprint method2 to search for the model signal pattern3 in the satellite observations. Our method quantifies the strength of the signal in observations, relative to the strength of the signal in natural climate noise. This yields so-called signal-to-noise (S/N) ratios. 

If the observed patterns of atmospheric temperature change are becoming increasingly similar to the model fingerprint pattern, and if the natural noise patterns are dissimilar to the fingerprint, the S/N ratios will be large. S/N ratios larger than 3 indicate that there is highly significant correspondence between the model fingerprint and satellite data, and that climate noise is unlikely to explain this pattern matching.
{speaking of observed changes, here's a talk by Jennifer Francis, where you can get some insights into the dynamic atmospheric flows happening ~ including how melting arctic ocean is impacting the jet stream. . .  the cascading consequences of warming our global heat distribution engine . . .
Weather and Climate Summit, Day 5, Jennifer Francis }


The S/N ratios we report on are given as a function of the length of the temperature record. Our primary focus is on S/N ratios over the full, 33-year period of the satellite data (1979 to 2011). Looking at longer periods of record helps to reduce the impact of large, year-to-year “noise”, and more clearly reveals any underlying signal. S/N ratios for relatively short periods of record (10 to 15 years) are typically smaller, and are dominated by interannual noise. Our summary of results (see below) is for the longest, 33-year temperature records.

Results of our S/N analysis: A brief summary

The lower stratosphere
In both satellite observations and the CMIP-5 simulations of historical climate change, the lower stratosphere cools markedly over the past 33 years. This cooling is primarily a response to the human-caused depletion of stratospheric ozone. Depending on the observational data set we use in our analysis, the S/N ratios for lower stratospheric temperature range from 26 to 36. To the best of our knowledge, these values are substantially higher than the S/N ratios reported in any previous climate change detection and attribution study. 
The lower troposphere
The observations and model simulations show a common pattern of large-scale warming of the lower troposphere, with largest warming over the Arctic, and muted warming (or even cooling) over Antarctica. Tropospheric warming is mainly driven by human-caused increases in well- mixed greenhouse gases. The lower tropospheric S/N ratios range from 3 to 8, depending on which satellite data set we use. While these S/N ratios are smaller than for stratospheric temperature changes, they are still highly significant. 
Why do we obtain these large S/N ratios?
The large S/N ratios tell us that the observed atmospheric temperature changes over the satellite era are becoming increasingly similar to model fingerprints, and are dissimilar to the main patterns of internal climate noise. In other words, the observations and fingerprint patterns show global-scale cooling of the lower stratosphere and global-scale warming of the lower troposphere, while the dominant patterns of climate noise do not show such large-scale temperature changes. 
Are our S/N ratios biased by model errors in estimates of climate noise?
If the CMIP-5 models analyzed here systematically underestimated the size of observed climate noise, our S/N ratios would be spuriously inflated. We find no evidence that this is the case. To test the fidelity with which models simulate observed variability, we compared modeled and observed temperature fluctuations on decadal timescales.
4 On average, the CMIP-5 models substantially overestimate the size of observed tropospheric temperature variability, suggesting that our tropospheric S/N ratios are probably too conservative. In the lower stratosphere, the size of modeled and observed decadal variability is (on average) very similar. 
Are these results driven solely by large global-mean changes?
We addressed this possibility by removing the global-mean temperature change from each data set before performing the S/N analysis. In the troposphere, in over 50% of the cases we considered, S/N ratios remain highly significant. This shows that correspondence between the model fingerprint and observations is not solely due to a common global-mean warming signal, but also to common patterns of temperature change. In the lower stratosphere, however, S/N ratios are not significant when global-mean information is removed. 
The Higgs boson, and the meaning of a “five sigma” result
In recent news coverage of the discovery of the Higgs boson, there has been considerable public discussion of the significance of a “five-sigma” result.
5 In our PNAS paper, the lower stratospheric temperature changes over 1979 to 2011 yield results at the 26 to 36 sigma level. These values are surprisingly large – as is our estimated 5.5 sigma result for the strength of the model-predicted fingerprint in the two publicly-available satellite records of lower tropospheric temperature changes. In terms of identifying a human-caused fingerprint in satellite records of atmospheric temperature change, our findings suggest that we are already beyond the “five- sigma” threshold
Are there still unresolved issues?
Yes. Although we found a “pattern match” between modeled and observed atmospheric temperature changes, most models have problems capturing the size of the observed changes. On average, the CMIP-5 models underestimate the observed cooling of the lower stratosphere, and overestimate the warming of the troposphere. Some scientists have claimed that there is only one possible interpretation of such differences – that models are too sensitive to greenhouse gas increases. Such claims are incorrect. There are multiple interpretations of differences between modeled and observed temperature changes. Other possible explanations include: A) residual errors in the observations; B) an unusual sequence of natural climate fluctuations in the observations; and C) the neglect or inaccurate specification of key “forcings” in model simulations of historical climate change. Results presented here and elsewhere suggest that forcing errors make an important contribution to the biases in model temperature trends.


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Karl, T.R., S.J. Hassol, C.D. Miller, and W.L. Murray (eds.), 2006: Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences. A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. National Oceanic and Atmospheric Administration, National Climatic Data Center, Asheville, NC, USA, 164 pp.

Our fingerprint method has been successfully employed for the identification of human effects on surface and atmospheric temperature, upper ocean heat content, the height of the tropopause (the boundary between the troposphere and stratosphere), and atmospheric moisture over oc.eans.

Here, the signal is a geographical pattern of atmospheric temperature change.

 4 This analysis used digitally-filtered temperature data; the filtering highlighted temperature variability on timescales ranging from 5 to 20 years.

 
See, for example, http://physicsbuzz.physicscentral.com/2012/07/does-5-sigma-discovery.html

Note that these biases have relatively small impact on the “model-versus-observed” S/N results presented here (see discussion on lines 825-832). This is because the searched-for fingerprint patterns are normalized – thus reducing the effect of biases in the size of modeled temperature changes. 
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I've added a few more links, the first two are listings of data sources.



Multi-fingerprint detection and attribution analysis of greenhouse gas, 
greenhouse gas-plus-aerosol and solar forced climate change