Tag Archives: Hockey Stick

The Hockey Stick and the Climate Wars:The Battle Continues

Climate Scientist Michael Mann, author of The Hockey Stick and the Climate Wars, gave a talk at Trinity College a couple of days ago on climate change and ethics. Just so you know, the Hockey Stick is a graph Mann and colleagues produced during the late 20th century showing how rapid recent global warming stands in stark contrast to previous centuries of climate change. The research itself has been repeatedly reconfirmed, refined, replicated, and verified, so it is for real. See, for example, this post by Stefan Rahmstorf.

Anyway, here’s the interview: Continue reading The Hockey Stick and the Climate Wars:The Battle Continues

Anti-Science NRO and CEI File New Briefs, Get It Wrong Again

This is about the law suit filed by Michael Mann against the Competitive Enterprise Institute, the National Review, Mark Steyn, and Rand Simberg because of accusations they made that were actionable. Michael Halpern summarized:

Competitive Enterprise Institute’s space technology and policy analyst, Rand Simberg, recently wrote a blog post in which he compared Penn State climate scientist Michael Mann to former university football coach and convicted child molester Jerry Sandusky. CEI published the post on its own blog, and the National Review decided it was appropriate to pass along. Michael Mann has rightly demanded that the National Review retract the blog post and issue a public apology.

The most offensive section of the CEI post, which has since been scrubbed:

“Mann could be said to be the Jerry Sandusky of climate science, except that instead of molesting children, he has molested and tortured data in the service of politicized science.”

There has been a lot of back and forth in the legal proceedings, and the latest is summarized by Aaron Huertas:

The latest round of legal briefs have been filed in climate scientist Michael Mann’s lawsuit against the National Review (NRO) and Competitive Enterprise Institute (CEI). …

NRO makes a distinction between calling Dr. Mann’s work “fraudulent” and alleging that he had, for instance, embezzled funds or fabricated raw data.

Indeed, there are gradations of accusations one can make against a researcher. Stating that a scientist is wrong in their analysis is a far cry from saying their work is shoddy, but both are normal parts of public discourse about science. It’s another thing entirely to accuse a scientist of manipulating data or knowingly using faulty methods to reach a pre-determined conclusion. …

The worst thing one can do to a scientist professionally is to accuse him or her of fraud. More commonly, scientists refer to fraud as “scientific misconduct” or “research misconduct.” …

While the original research Dr. Mann’s and his colleagues conducted 15 years ago was certainly subject to criticisms and scrutiny, it held up to that scrutiny, and nobody ever made the case that it was fraudulent.

CEI’s legal brief rehashes investigations of scientists after a hacker (or hackers) stole emails from them in 2009. …

Dr. Mann’s lawyers cite all the investigations in their brief. That makes sense since all the investigations are related and none found that Dr. Mann—or his colleagues—were guilty of scientific misconduct or fraud.

But CEI attempts to argue that these investigations were somehow insufficient. Regarding the two investigations that did focus specifically on Dr. Mann, CEI tries to downplay how serious they were. They write that Penn State’s committee looked at whether or not Dr. Mann “falsified data” and claimed that the “inquiry committee simply reviewed some of the [stolen] emails, spoke with Mann, and then dismissed it.” They also write the National Science Foundation “did not conduct an investigation of Mann’s data practices or research because it determined that ‘no direct evidence has been presented that indicates the Subject fabricated the raw data he used for his research or falsified his results.’”

…In reality, these investigations were far more thorough than CEI suggests. …These latest filings only reinforce my view that attacks against Dr. Mann are ideological and political in nature, not based on an actual assessment of his work.

You can read the rest, and more detail, here.

As you may know, we have been having a lengthy discussion here about the original work done by Mann and his colleagues. Feel free to join in! Regarding the research itself, this is very simple. Mann and his colleagues attempted to look simultaneously at some “paleorecords” … indications from ancient sources of temperature … and the modern “instrumental record” (i.e., from thermometers) to see if the already observed increase in temperatures thought to be linked to anthropogenic global warming really does stick out like a sore thumb among temperatures going back longer in time. The result of that study was, essentially, a graph combining ancient data and modern data that looked like a hockey stick laying on its back:

The original northern hemisphere hockey stick graph of Mann, Bradley & Hughes 1999, smoothed curve shown in blue with its uncertainty range in light blue, overlaid with green dots showing the 30-year global average of the PAGES 2k Consortium 2013 reconstruction. The red curve shows measured global mean temperature, according to HadCRUT4 data from 1850 to 2013. From Wikipedia.
The original northern hemisphere hockey stick graph of Mann, Bradley & Hughes 1999, smoothed curve shown in blue with its uncertainty range in light blue, overlaid with green dots showing the 30-year global average of the PAGES 2k Consortium 2013 reconstruction. The red curve shows measured global mean temperature, according to HadCRUT4 data from 1850 to 2013. From Wikipedia.

There are three ways in which this research could be questioned. First, it was only of the Northern Hemisphere, not global. Second, it is possible that the particular observations of modern temperature, the instrumental record, was somehow incorrect or biased. Third, it is possible that even though this graph shows the modern increase in temperatures as extreme, maybe the older data is bad, or maybe if you went back further in time (and globally) you’d find pre-industrial (prior to the release of so much carbon dioxide into the atmosphere) periods that are warmer than today, suggesting that the underlying assumption of how greenhouse gases might be wrong.

Even at the time, though, these objections were weak. While the Norther and Southern Hemispheres may (and do) act somewhat differently from each other, they are not as out of sync as they would have to be for the basic hockey stick graph to be wrong. The instrumental data was certainly not as perfect as one might like, but it was pretty darn good data. For the last few million years, during the course of human evolution and the evolution of our current ecology, there was no reason to believe that there were periods much warmer than today, if at all.

But subsequent research was done, of course, and several findings support, refine, and expand on the hockey stick model. Additional studies of modern temperatures showed results very similar to the data used by Mann and colleagues. At least two studies look at biases (one looked at the possibility of false warming caused by urban heat island effects, another looked at areas of the Earth that are under-sampled by direct observation). Both found that the hockey stick curve was either pretty much correct for instrumental data, or actually possibly a bit lower in temperature than reality.

Of course, the entire study was extended globally, confirming this as a global pattern.

Work on paleo information extended the range of the hockey stick graph way back in time, and showed that during the Holocene (last 10,000 years) there was not a period warmer than today. Further work seems to indicate that even during among interglacial periods (we are in an interglacial now) things are warmer now than usual. It turns out that you almost certaily have to go back in time several hundred thousand years, possibly several million years, to get a time period as warm as today.

Most importantly, per has, as time has passed since the original hockey stick curve was produced, the globe has gotten warmer. The air and sea surface are warmer, though the amount of warming has been modest compared to what we would expect for a simple model where greenhouse gasses only warm the atmosphere. But a lot of heat is being absorbed by the ocean, it turns out. The true surface temperature of the planet has to include both the atmosphere and the ocean (both surface and at depth) and we think over 95% of the extra heat from global warming goes into the deep ocean, but it is not well measured.

Meanwhile the whole “Hockey Stick” controversy continued and developed. This isn’t just a couple of people and a major conservative publication falsely accusing Michael Mann of fraudulent behavior (scientific misconduct). Anti-science forces have spent millions of dollars attempting, usually very clumsily, climate science, and one or more individuals went so far as to steal emails among climate scientist, falsifying using cherry picking what was said in those emails. It is an all out war between anti-science and anti-environment groups and individuals on one hand vs. scientists and rightfully concerned citizens on the other. A great description of how these “Hockey Stick Wars” played out can be found in this book.

Steve McIntyre Misrepresents Climate Research History

Who is Steve McIntyre?

From DeSmogBlog.com:

Stephen McIntyre has been a long-time mining industry executive, mostly working on the “stock market side” of mining exploration deals. He published a blog called Climate Audit where he attempts to analyse in sometimes long and extensive detail the work of climate change scientists where he documents “statistical mistakes” in peer-reviewed scientific literature. …

McIntyre has been described as a “persistent amateur who had no credentials in applied science before stepping into the global warming debate in 2003” and has been a prominent critic of temperature records that suggest increasing global temperatures over the past 1000 years.

As of 2003, McIntyre had worked in the mineral business for 30 years and he has been an officer or director of small public mineral exploration companies for over 16 years…

In February, 2014, he put up four blog posts attacking Dr. Michael Mann in relation to Mann’s defamation suit against Mark Steyn et al, claiming in those posts that Mann had “misrepresented the findings of reports and inquiries into his work and the work of other climate scientists in relation to the so-called “climategate” affair, when the emails of scientists at the Climatic Research Unit at the University of East Anglia were illegally hacked and then published.” (desmogblog.com)

Today, McIntyre’s blog posted a lengthy “fisking” (sort of) written by Jean S, of the climategate emails. The focus is on the famous “Hockey Stick” curve produced by Mann and others just prior to 2000. This graph is an assembly of carefully vetted climate records including proxies and the modern instrumental record. The different sources of information used to show dramatic 20th century warming are well documented in Mann’s publications and further documented in freely distributed supplementary information. Two objections seem to have been raised by climate science denialists such as McIntyre and others. One is that one of the proxies, certain tree ring data, show cooling or at least a lack of warming. The other is that the graphic representation of 20th century warming uncritically combined proxy data and instrumental data.

Denier Complaints About Climate Proxies Are Based On Ignorance Of The Science

A proxy, or proxyindicator, is a natural system that leaves a recoverable residue that varies in some measurable or observable way, such that the variation may correspond to a natural variation happening in the world at the time the proxy was being formed. For example, the ratio of Oxygen-16 and Oxygen-18, two stable isotopes of that element, in Oxygen incorporated in stable form (in biogenic tissues, for example) indicates the ratio of these isotopes in the ambient environment, which in turn, indicates the amount of each element available at the time, which in turn, indicates how much of each type of oxygen is trapped in glacial ice (which tends to have more Oxygen-16 because glaciers are ultimately made of vapor, which is isotopically light). Oxygen isotope ratios of materials recovered from deep sea cores indicate the march of glacial formation and melting over long periods of time.
The first of these two objections to Mann’s work, and other work, relies on naiveté among potential readers about proxyindicators. As is the case with all scientific data, all proxies are suspect, and all proxies have the potential of varying in sensitivity over time. Scientists must always evaluate the quality of the data they use, and not accept it uncritically.

For example, say you wanted to estimate the flow of a major river over time. You could measure how much silt is deposited on the river’s flood plain by taking Carbon-14 samples at numerous depths in the floodplain. A greater depth between samples separated by similar amounts of time might mean more flooding. But, as the flood plain matures and raises in elevation, the frequency of floods year to year may decrease, causing a decline in the rate of siltation, and thus, apparent water flow in relation to the actual water flow. Furthermore, at some point, the flood plain is essentially filled up, and flooding overbank happens elsewhere along the river, and no longer (or infrequently) at your sample site. This is a decline in the usefulness of the proxy to the point that you have to simply stop using it.

Another example. Say you want to use pollen counts form layers found in mud at the bottom of a lake, the layers having been recovered from cores sunk in the lake. Assume your lake is in a region that started out as grassland but slowly became more forested. Trees act as pollen filters. Pollen wafting across the landscape is caught in the trees. In the early part of the lake core data, pollen may be introduced from many kilometers away from wind blown plants (grasses, some trees) and from similar distances from plants that do not distribute pollen via wind, but in small quantities (such plants produce way less pollen than wind pollenated plants) via streams that enter the lake. Over time, however, trees will grow up first around the lake, then over a larger area of the landscape. Windblown pollen from grasses is less likely to get into the pond, and there may be less of that pollen because trees are replacing grassland. Meanwhile, the longer distance stream carried pollen may continue to represent the original catchment of pollen. But, if there are changes in rainfall patterns, that could change too. People looking at pollen in lake cores may use an independent measure, such as the amount of iron in the sediment, to indicate how much water comes in from longer distances via streams vs. how much comes in from groundwater and as direct rain. They will use studies of pollen taphonomy, which look at changes in “pollen rain” as forests develop, to calibrate the effects of trees on the wind blown grass pollen representation. At some point, near the top of the core, the tree pollen may be suddenly and dramatically reduced and the wind blown grass pollen may switch to mostly corn or wheat. This is farmers coming in and completely changing the environment. The core from that point on up may become useless. In sum, the entire core has to be analyzed as a dynamic, changing proxy where some of the changes are important information about the changing environment, while other changes are indicative of an increase or a decline in sensitivity of the proxy as an indicator of what is being studied.

Something similar is going on with the tree ring data Mann used. At around 1960 the ability of the tree ring data to represent regional temperature declines and the tree rings become useless. Prior to that time the data should be used. After that time the data should be discarded.

A proxy is not a pre-calibrated consistent source of information. It is a method that uses measurements of recovered material that allow the reconstruction of an ancient process. But that requires understanding the process well enough to develop a way of determining when the proxy is being helpful and when it is providing noise. A good amount of the research on ancient paleoclimate and paleoecology is about how the proxies work. With this research it is possible in many cases to evaluate the utility of a proxy at a given location, and furthermore, to assess which parts of the proxy can be used, which parts need to be further calibrated, and which parts need to be ignored because of a decline in their usefulness.

We see climate science deniers claiming, for example, that the tree ring proxy used by Mann needs to be used “all or nothing.” This is nothing more than ignorance of how paleoclimatology works.

(See also: Clearing up misconceptions regarding ‘hide the decline’)

Complaints About The Hockey Stick Graph Are Not Valid

McIntyre’s arguments (along with others) about the graph are middle-school level obfuscation of the point. The scientists who published the original Hockey Stick graph went through pains to be clear about what information was going into which part of the overall curve. Subsequent renditions of the same data, or similar sets of data with new information added, range across the board from highly complex constructs showing the different sources of the data, error ranges, etc. to those that simplify by drawing a simple curve of combined information. I wrote about this here, showing how this practice, of sometimes making a very complex thing simpler in a way that makes the point accurately, is done all the time.

The latest post on McIntyre’s site, completely misrepresented what happened with the Hockey Stick curve. Nowhere in the quoted emails is there any suggestion or approval or any indication by Michael Mann of seamlessly merging proxyindicator data and instrumental data. The original documents clearly show that this is not what happened at any stage.

Why Do McIntyre And Others Fabricate These Objections?

If you read JeanS’s post closely, s/he seems to be simultaneously implying that Mann created a falsified representation of how the data come together, while at the same time admitting he did not. This is an increasingly common tactic among climate science denialists. They can no longer totally make up what they are saying because they are too easily called on it, yet want to provide other denialists with fodder, and confuse anyone involved in policy, or who just wants to learn, with more confusion and less clarity.

The only way to accept or even seriously consider the arguments that climate scientists developing the Hockey Stick curve or similar research were involved in inappropriate shenanigans is to anchor oneself deeply in a mire of intentional ignorance. There seems to be only one reason to do that (other than simply being very, very ignorant): a commitment to anti-science activism, with the likely intention of damaging the translation of good science into useful policy.

This is something a mining industry executive might do out of self interest and to represent the interests of that industry. Is that the case here? There is a trick to help determine if that is the case. Follow the money.

The graphic depicted above is from here. It is a 2007 version o the often replicated and used “Hockey Stick.”

There is now a Tumblr for stuff like this.

More on Steve McIntyre:

RealClimate on McIntyre
Skeptical Science on McIntyre
Rational Wiki on McIntyre

The Hockey Stick and the Climate Wars: Dispatches from the Front Lines

51c9ZYOtkvL._SY344_PJlook-inside-v2,TopRight,1,0_SH20_BO1,204,203,200_You probably already know about Michael Mann’s book, “The Hockey Stick and the Climate Wars: Dispatches from the Front Lines.”

The ongoing assault on climate science in the United States has never been more aggressive, more blatant, or more widely publicized than in the case of the Hockey Stick graph — a clear and compelling visual presentation of scientific data, put together by MichaelE. Mann and his colleagues, demonstrating that global temperatures have risen in conjunction with the increase in industrialization and the use of fossil fuels. Here was an easy-to-understand graph that, in a glance, posed a threat to major corporate energy interests and those who do their political bidding. The stakes were simply too high to ignore the Hockey Stick — and so began a relentless attack on a body of science and on the investigators whose work formed its scientific basis.

The Hockey Stick achieved prominence in a 2001 UN report on climate change and quickly became a central icon in the “climate wars.” The real issue has never been the graph’s data but rather its implied threat to those who oppose governmental regulation and other restraints to protect the environment and planet. Mann, lead author of the original paper in which the Hockey Stick first appeared, shares the story of the science and politics behind this controversy. He reveals key figures in the oil and energy industries and the media frontgroups who do their bidding in sometimes slick, sometimes bare-knuckled ways. Mann concludes with the real story of the 2009 “Climategate” scandal, in which climate scientists’ emails were hacked. This is essential reading for all who care about our planet’s health and our own well-being.

The book is now available in paper back, and as a reader of Greg Laden’s blog I’m happy to give you a way to get it at 30% off.

Just go to the Columbia University Press site for the book and use the promotional code HOCMAN. It is an important book, if you don’t have it, go get it!

Treatment of Climate Change and Hockey Stick Controversy in Wikipedia

The current Wikipedia entry for Climate Change has about 7000 words on that one page (including notes, all the other words that show up on Wikipedia pages). The current Wikipedia entry for the Hockey Stick Controversy has about 25,000 words in all.

The controversy over one aspect of climate change, the basic observation of temperature change known as the hockey stick graph, is certainly not more complex than, more important than, or harder to explain than climate change as a whole. Is this a failing of Wikipedia? A success for the Climate Science Deniers who are also hoping to have the conversation about “the controversy” be an order of magnitude lengthier in our schools than any discussion of climate change? A random occurrence? I’m thinking a little of all three.

25,000 vs 7,000. Holy crap. Would someone who works with Wikipedia please see to this? Thank you.

The Climate Hockey Stick is Wrong!

This is a hockey stick:


This is the Grim Reaper’s Scythe:


This is global temperature over the last 10,000 years projected into the immediate future using good scientific estimates:


You decide. Should the Hockey Stick be replaced with the Grim Reaper’s Scythe?

More information on the climate change graphic HERE.

See more climate change graphics HERE.

If you are not sure what any of this is about, you can read about the Hockey Stick thing here.

Michael Mann on Climate Scientists and Smear Campaigns

Climate scientist Michael Mann is no stranger to smear campaigns. Man has the distinction of having made important contributions to climate science, for which he shared the Nobel Peace Prize. He is famous to many of you for having come up with the “hockey stick” metaphor.

Michael Mann is a good scientist who has done honest, important, and high quality work, but there are those who don’t want to hear about the results he and other climate scientists have come up with. So, they hate him. And by “hate” I don’t mean that they sit there not liking him. I mean, they actively hate him. They wake up every morning and try to think of things to do to ruin his life, and they conspire with each other to carry out these nefarious acts, and in some cases, they are paid by special interests to do these things.

We all get this hate, to one level or another. I was amused the other day when one of the haters, someone who had made death threats against me, had apparently pressed the button on his Linked In account to “find people to link to” and thus accidentally sent me an invitation to “Link In.” I get an email that says “I want to kill you” then I get an invitation to link up. Made me laugh.

But in reality this is no laughing matter. Even though we all take a certain amount of crap for either being a climate scientist or a person who teaches about climate change or a blogger or journalist who covers these issues honestly and critically, no one has taken the crap that Michael Mann has had to take. I don’t know how he does it.

Anyway, Michael has written a commentary for CNN that covers not so much the attacks on him, but rather, the attacks on climate science more generally. He talks about the theft of emails and subsequent dissemination and misuse of their contents and related events:

In the most infamous episode, somebody stole thousands of e-mails and documents from leading climate researchers, including me. They cherry picked key phrases from the e-mails and published them out of context, like a black-and-white political attack ad with ominous music. Fossil fuel industry-funded groups gleefully spread the e-mails online and badgered the mainstream media into covering the “controversy” they had manufactured.

It was no accident that this happened on the eve of a major international climate change meeting. … The dozen independent investigations that did follow — all of which exonerated the scientists — got much less media coverage than the original nonscandal.

Go read his essay. Also, please, please check out the comment section and say something not horrible there to help diffuse the crap that I’m sure is going to appear there over the next few days!

Michael Mann is the author of The Hockey Stick and the Climate Wars: Dispatches from the Front Lines.