Reviews Paleofantasy? Maybe eating meat, nuts, fruit and vegetables is okay

Jason Collins has just written a review of Marlene Zuk’s book "Paleofantasy: What Evolution Really Tells Us about Sex, Diet, and How We Live". Having read several reviews of this book, this review sounds like the one I would have written, had I read the book. (I am not the only one; many reviews were written based upon previous articles by Zuk and not based on her book. Jason Collins did read the book.)

... Zuk parades a series of straw men rather than searching for the more sophisticated arguments of Paleo advocates. Many chapters begin with misspelled comments that Zuk found under blog posts. While Zuk shoots the fish in the barrel, the more interesting targets are not addressed.

I had almost chosen as title: debunking a book that promotes a diet full of processed "foods", grains and sugar and warns for a diet of meat, nuts, fruit and vegetables. Fortunately, that super straw man title was too long. This one, Maybe eating meat, nuts, fruit and vegetables is okay, is straw manly enough; it can be hard find a good concise title.

My paleofantasy

To me, paleo is not much more than a productive generator of hypothesis and a good story that helps to bundle several suggests for life-style changes.

Although you can say, that it would be very surprising that a diet humans were eating for a such long time, a time largely without chronic decease, would be unhealthy in this modern age. Not impossible, but you would expect very strong proof, much stronger as, for example, the epidemiological study promoted by T. Colin Campbell in his vegan bible: The China Study.

And the narrative is good enough to encourage people to try a range of different diets and life-style options to see on which one they feel best and not stick to the officially healthy one, if it is not working for them. Just play and experiment, that is what defines us as humans.

Review by Hunt Gather Love

You can go to Hunt Gather Love, for a more technical and intelligent review on Paleofantasy from someone who "wanted to like this book". Another good related post from the same blog: paleo fantasies: Debunking The Carnivore Ape Narrative, makes clear that paleo hypothesis does not prescribe a diet of only meat, nor a low-carb diet.

Christians on the climate consensus

Dan Kahan thinks that John Cook and colleagues should shut up about the climate consensus; the consensus among climatologists that the Earth is warming and human action is the main cause. Kahan claims that research shows that talking about consensus is:

a style of advocacy that is more likely to intensify opposition ... then [to] ameliorate it

It sounds as if his main argument is that Cook efforts are counter productive because Cook is not an American Republican, which is hard to fix.

Katryn Hayhoe

As an example of how you communicate climate science the right way, Kahan mentions Katryn Hayhoe as an example. Hayhoe is an evangelical climate change researcher and stars in three beautifully made videos where Hayhoe talks about God and climate change.

Except that she also talks about her religion, I personally see no difference with any other message for the general public on climate change. She also openly speaks about the disinformation campaign by the climate ostriches.

The most frustrating thing about her position, she says, is the amount of disinformation which is targeted at her very own Christian community.

Maybe naively, but I was surprised that the Christian community is a special target. While I am not a Christian myself, my mother was a wise environmentally concious woman and a devout Christian. Also when in comes to organized religion, I remember mainly expressions of concern about climate change. Thus I thought that Christians are a positive, maybe even activist, force with respect to climate change.

Thus let's have look what the Christian Churches think about climate change.

Evangelical Church in Germany

As I life in Germany, let's first have a look at the Evangelische Kirche in Deutschland (Evangelical Church in Germany), which is the democratic umbrella organisation of the non-catholic churches with 24 million members. They write in their annual book (link in German) titled "Justice V: People, Climate, Future. Roads to a just World, Social justice and climate justice belong together":

Climate change is the key environmental, social and peace-relevant challenge of the 21st Century - Justice, Peace and the Integrity of Creation will not be possible without limiting climate change.

German original:

Der Klimawandel ist die zentrale ökologische, soziale und friedenspolitische Herausforderung des 21. Jahrhunderts – Gerechtigkeit, Frieden und Bewahrung der Schöpfung werden ohne Begrenzung des Klimawandels nicht möglich sein.

In the clinical words of Cook et al. (2013) this would be an "implicit endorsement of human-caused global warming".

Dutch Counsel of Churches

I was born in The Netherlands. Most Dutch churches are organised in the Dutch Counsel of Churches (Raad van Kerken in Nederland). They have a subsidiary group on church and environment (in Dutch). In an official statement on climate change they write:

The climate change problem call for inventiveness, for radical proposals to change.

Dutch original:

Het probleem van de klimaatverandering vraagt om vindingrijkheid, om radicale voorstellen tot verandering.

Which I would judge to be "implicit endorsement".

Conference of European Churches

The Conference of European Churches is a fellowship of some 120 Orthodox, Protestant, Anglican and Old Catholic Churches from all countries of Europe, plus 40 associated organisations.
In a press release issued before their 13th Assembly in Lyon in 2009 they write jointly with the Catholic Commission of the Bishops’ Conferences of the European Community (COMECE):

Securing a stable climate is one of the most pressing moral and political challenges of the twenty-first century. Failure to address this challenge would amount to a moral failure on the part of humanity as a whole.

Which I would again judge to be implicit endorsement.

World Council of Churches

According to their homepage: "The World Council of Churches (WCC) brings together churches, denominations and church fellowships in more than 110 countries and territories throughout the world, representing over 500 million Christians and including most of the world's Orthodox churches, scores of Anglican, Baptist, Lutheran, Methodist and Reformed churches, as well as many United and Independent churches. At the end of 2012, there were 345 member churches."

One of their main activities is Care for Creation and Climate Justice.

Care for creation and justice are at the centre of WCC work on climate change. The Bible teaches the wholeness of creation and calls human beings to take care of the garden of Eden (Gen 2:15). ... When creation is threatened, churches and Christians are called to speak out and act as an expression of their commitment to life, justice and love.

I would say: "implicit endorsement".

Catholic Church

The position of the Catholic Church is made clear in the third encyclical of Pope Benedict XVI, Caritas in Veritate.

As an aside, in it Pope Benedict makes an unnecessary strange attack against atheists:

When nature, including the human being, is viewed as the result of mere chance or evolutionary determinism, our sense of responsibility wanes.

I would personally claim that from an evolutionary position nature is very precious. If a species goes extinct you are destroying billions of years of development and it is lost forever in the evolutionary view. In the creation view, you just destroy two days of work and God could recreate it any time.

On climate change he is clear. In paragraph 50, he writes about the obligation of international leaders to protect the climate.

the protection of the environment, of resources and of the climate obliges all international leaders to act jointly and to show a readiness to work in good faith, respecting the law and promoting solidarity with the weakest regions of the planet.

Implicit endorsement.

Climate consensus

If Dan Kahan is right, this post should be a convincing way to communicate the climate consensus. I am curious and would not mind seeing the number of readers to disinformation blogs such as WUWT going down further. It would be great if the word sceptic again stands for someone who is also critical about his own ideas. Without disinformation, the public debate about the pros and the cons of the various mitigation and adaptation measures will be much more productive.

The disparity of opinions between the American evangelical Christians and the rest of the Christian world, suggests that Christian exchange programs could be a good way to tackle climate change denial.

It would be highly appreciated if you could add the positions of your national Churches below.

Further reading

Pale Blue Dot

A Baptist describes how a change in perspective can make you see how precious and valuable the Earth is.

The Guardian: Just what is it with evangelical Christians and global warming?

Discussion of the Pew Forum on Religion & Public Life, the need for "creation care" and speculative global warming.

Reddit, Christianity: Why are conservative evangelicals against climate change?

Interesting discussion among Christians.

On consensus and dissent in science - consensus signals credibility

Since Skeptical Science published the Pac Man of The Consensus Project, the benign word consensus has stirred a surprising amount of controversy. I had already started drafting this post before, as I had noticed that consensus is an abomination to the true climate ostrich. Consensus in this case means that almost all scientists agree that the global temperature is increasing and that human action is the main cause. That the climate ostriches do not like this fact, I can imagine, but acting as if consensus in itself is in bad thing in itself sounds weird to me. Who would be against the consensus that all men have to die?

Also the Greek hydrology professor Demetris Koutsoyiannis echoes this idea and seems to think that consensus is a bad thing (my emphasis):

I also fully agree with your statement. "This [disagreement] is what drives science forward." The latter is an important agreement, given a recent opposite trend, i.e. towards consensus building, which unfortunately has affected climate science (and not only).

So, what is the role of consensus in science? Is it good or bad is it helpful or destructive, should we care at all?

Credibility

In a recent post on the value of peer review for science and the press, I have argued that one should not dramatize the importance of peer review, but that it is a helpful filter to determine which ideas are likely worth studying. A paper which has passed peer review, has some a-priory credibility.

In my view, consensus is very similar, consensus lends an idea credibility. It does not say that an idea is true; if formulating carefully a scientist will never state that something is true, not even about the basics of statistical mechanics or evolution, which are nearly truisms and have been confirmed via many different lines of research.

You could thus say that peer review of an article, is a first step on the credibility ladder. The longer an idea holds, the more people have invested more time in studied it from many different angles, the more credibility an idea gains. A consensus among the people that actually studied the problem is stronger than a consensus among people that did not. In this respect, I value the IPCC reports, where groups of experts described our current understanding, a better information source on the consensus as the counting of scientific articles performed in The Consensus Project. Most of the scientists acknowledging the climate consensus, will not have studied the problem in much detail.

Credibility, makes the probability that a theory is wrong smaller. Consequently, it also makes the honour of finding a problem larger. There is nothing more beautiful for a scientist as to destroy a consensus, no better way to show that you are a good scientist. In principle, the bigger the consensus, the better. However, the bigger the consensus, the more difficult is will also likely be to find a problem with it. Thus you need some confidence if you go after a big one. It is likely smart to build your scientific career on a mixture of problems with varying degrees of difficulty, only trying to destroy century old theories is a high-risk strategy. Often it is possible to first build up evidence for a smaller question, before you go for the big kill.

Just as an expert can ignore peer-review and simply judge ideas from the non-reviewed literature himself, there is no reason whatsoever to respect the consensus opinion in the field you are working in. If you have a good idea and strong arguments why the consensus is wrong, go for it! If a new idea requires the consensus of one or even neighbouring fields to be wrong as well, the situation becomes complicated. That would require a lot of study to become expert in those other fields and quite likely in the end you will not find the hole you need in their consensus. If you have nothing else to work on or the consequences would be enormous, by all means try it, but I would not prioritize pursuing such an idea.

Dikran Marsupial summarises this section very well:

... the existence of a consensus is not scientific evidence of anthropogenic climate change (and nobody is claiming it is), the consensus is a result of the scientific evidence of anthropogenic climate change.

Standing on the shoulders of giants

It is a bon mot that we can only see so far because we are standing on the shoulders of giants. This foundation, an indispensable network of interlinked ideas, is the consensus of the preceding research. Not all of it is right, it does not have to, it should help in finding new fruitful questions that in the end help us understanding the world a little better.

If you want to add a new piece to this network, you may have to destroy a piece of the old network because it does not fit. The more "consensus" you would have to destroy, the less likely it is that your new idea will turn out to be an improvement. By the way, often you can also do something completely new, improve methodologies, find interesting consequences of known theories, etc. Thus often there need be no conflict whatsoever.

I have always wondered why the climate "sceptics" often claim that CO₂ is of minor importance as a greenhouse gas. That would mean that either quantum mechanics or the radiative transfer (RT) equation should be wrong. The RT equation is so basic, that it if were wrong, also much of astronomy, remote sensing by satellites and many laboratory experiments would be have been based on the wrong equations. That is quite a consensus the destroy. Not impossible, but highly unlikely, especially by someone with almost no expertise in any of the fields.

It may take a bit more thinking to realise their importance, but my advice to the ostriches would thus be to look at climatic feedbacks, they are unique to climate science and thus have much less consensus behind them and are consequently much more likely to be wrong. Strong negative feedbacks have the potential to make the global temperature increase due to CO₂ very small, which is all a climate ostrich needs. My personal favourite feedback would be the cloud feedback, Roger Pielke Sr. would probably mention land-surface feedbacks.

Encouraging dissent

Obey, photo by Peat Bakke, CC2.0 license.

Dissent in itself is neither good nor bad. Ideally a scientific paper should be so strong that even if someone initially held the opposite opinion, he can only agree that the article is right. In this respect, you should strive for consensus. In praxis, you will often need multiple papers to build up a case and answer criticisms you did not think of in the first paper. Thus in praxis there may be a phase with dissent, but I do not see it as something to strive for as a scientist.

Still, humans have a tendency to seek consensus and to copy opinions of high-status individuals. To counter this tendency, the scientific community should explicitly encourage dissent, naturally without relaxing our quality standards. Dissent, just for the fun of it, with unfounded arguments and rookie errors only hinders science.

Science and society are two very different realms. In a democracy it is much more important to encourage dissent. In a democracy there is not just one truth, different people have different interests. Even if the interests of everyone would be the same, the kind of questions that need to be negotiated are too complex to be proven optimal. Science done right, on the other hand, splits up problems in sufficiently small questions that have a clear answer. (This is also why governments by experts are bad, experts are not able to deal with this ambiguity, think in terms of one right answer and not experienced in building coalitions with groups of different interests.)

In science dissent is a sign that there is work to do. In a democracy it is the natural state.

Climate ostriches

Interesting is that that consensus is not opposite of dissent. As HotWopper noticed the climate ostriches do not agree about much:

WUWT deniers can't agree about what is happening to the climate (it's the sun, it's natural, it's not warming, it's cooling, we're heading for an ice age, it's thunderstorms, there is no greenhouse effect, it's cosmic rays, it's warming, it's not warming, it's ENSO, it's an ice age) - but when it comes to conspiracies they all agree that climate science is a hoax! A conspiracy! A scam! A SECRET scam!

While every ostrich seems to have its own alternative hypothesis, that is there is no consensus, there is also no dissent. Like a pack of wolfs the regulars at WUWT attack people who dare to claim that the global temperature is increasing and that humans are the main cause. However, if one of pseudoskeptics makes an obvious mistake, e.g. a clear misquotation, no one will criticise this, there is no sign of dissent.

If the climate ostriches would like to develop a better alternative hypothesis, which I doubt after reading WUWT for over a year, it is time the ostriches allow for dissent and start discussing the strengths and weaknesses of their ideas and not just the stupidity of scientists and scientific ideas.

Further reading

• The value of peer review for science and the press
• The Consensus Project of Skeptical Science

Readership of all major "sceptic" blogs is going down

In my first post of this series I showed that the readership of WUWT and Climate Audit has gone down considerably according to social bookmarking site Alexa; see below. (It also showed that the number of comments at WUWT is down by 100 comments a day since beginning 2012.)


I looked a bit further on Alexa and this good news is not limited to these two. All the "sceptics" blogs I knew and had statistics are going down. Bishop Hill, Climate Depot, Global Warming, Judith Curry, Junk Science, Motls, and The Blackboard (Rank exploits) are all going down. Interestingly the curves look very different for every site and unfortunately they show some artificial spikes. Did I miss a well known blog?


As I showed in my second post in this series, this decline is not due to a decline in interest in the general public. The climate science blogs and Google searches are stable. See below for Real Climate and Skeptical Science.

Four independent lines of evidence

We now have four lines of evidence for a decline of the "sceptic" community: the decreasing number of readers of all major climate sceptic blogs according to Alexa, the reduction in the number of comments at WUWT and the number of Google searches for "global warming" and other climate sceptic terms and opinion polls on climate change that show that even in the USA an increasing majority accepts the basic science.

The evidence starts to look pretty convincing. Maybe we can soon talk about the science without being distracted by noise and deliberate misinformation. Who said climatologists do not like decreasing trends?

Previous posts

The age of Climategate is almost over

Shows that the number of readers of WUWT and climate audit is going down and that the number of comments at WUWT is down by 100 comments a day.

Decline in the number of climate "sceptics", reactions and new evidence

Shows that climate science blogs have a stable readership, that the number of Google searches for climate sceptics terms is down and for climate science terms is stable and finally that opinion polls show that more and more people accept the basic science.

Decline in the number of climate "sceptics", reactions and new evidence

My last post showing that the number of readers of Watts Up With That and Climate Audit are declining according to Alexa (social bookmarking) has provoked some interesting reactions. A little research suggests that the response post by Tom Nelson: Too funny: As global warming and Al Gore fall off the general public's radar, cherry-pickin' warmist David Appell argues that WUWT is "Going Gently Into That Good Night", could be a boomerang and another sign of the decline. More on that and two more indications that climate change ostriches are on their way back.

Public interest in climate change

An anonymous reader had the same idea as Tom Nelson, but did not write a mocking post, but politely asked:

"how do you know it is not a general diminution of interest in climate change?".

That is naturally possible and hard to check without access to the statistics of all climate related blogs and news pages. However, as you can see below, the number of readers of SkepticalScience and RealClimate seem to be stable according to Alexa. This suggests that the decline is not general, but specific to the "sceptic" community.

Dana1981 (a nick often used by Dana Nuccitelli of Skeptical Science) responded to the stable readership of SkS and RC: "I have a hunch that Skeptical Science is going to have a big jump in traffic in the near future." My first guess was that Skeptical Science is negotiating a merger with WUWT. Another guess could be that Skeptical Science has hacked the computer of Anthony Watts and stole his correspondence with all the other main "sceptic" bloggers, where they make fun of their gullible readers. Does anyone have a better idea? I will be waiting for the day that Skeptical Science will halt their blog for two days before they reveal the big surprise.

Tom Nelson attributed the decline to a decrease of interest in climate by the general public. Too funny: As global warming and Al Gore fall off the general public's radar, cherry-pickin' warmist David Appell argues that WUWT is "Going Gently Into That Good Night"

The title and the figure below are basically Nelson's entire post. The figure shows how often a search term is typed into Google globally over the last few years. The big peak in 2007 is likely due to the publication of the last IPCC report. The upcoming IPCC report this autumn could thus be the reason, why Dana1981 expects more readers soon; see sidebar.

UPDATE: Dana1981 was probably talking about Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature, which is generating a lot of press attention.



Interesting what the first two terms are, a climate "sceptic" is thinking of with respect to climate. Out of curiosity, I also looked at the Google trend for "climate change", see below. Looks as if the interest in "climate change" is as stable as the readership of SkS and RC.



Thus I asked Tom Nelson why he preferred the term "global warming" over "climate change", but that comment made 3 days ago did not yet pass moderation.

After visiting the Web of Science (a database with scientific articles), it became clear why my first intuition was to try "climate change". There are 325,829 articles with this term, whereas there are "only" 71,052 articles on "global warming". The same numbers for Google Scholar are: 1,560,000 (climate change) and 914,000 (global warming). Scientists seem to prefer climate change nowadays. (I would personally probably use "global warming" when I want to emphasis that a statement is mainly about temperature and otherwise use the more encompassing term "climate change".)

A web search using Google for these terms restricted to the main blogs shows a similar pattern, that the climate "sceptics" use the term "global warming" more and the science blogs the term "climate change". The difference is not large, though.

Interesting is that Google trends shows that searches with "global warming" and the terms more typical for "sceptics" such as conspiracy, controversy, doesn't exist, fake, is fake, myth, natural, skeptics, is not real, junk science, lies, not real, are going down. Whereas searches for "climate change" and more science oriented key words such as, articles, causes, adaptation, and agriculture, data, education, effects, for kids, health, impacts, jobs, journal, lesson plans middle school mitigation, predictions, research, science, statistics, vulnerability are either stable or are even going up.

In the light of all the other evidence, the decline in the "global warming" searches could thus be interpreted as another indication that it is the interest in the "sceptics" that is dwindling and not the interest in climate change in general.

The minute peak for "climategate" is also interesting. The "sceptics" seem to be isolated in their view that this was an enormous scandal.

Thank you, Tom Nelson, for reminding me of this great information resource!

Big is beautiful?

On Quark Soup by David Appell, Les Johnson notes that my blog and Quark Soup are read less than WUWT. As if that would change the argument.

Not only our little blogs, also Skeptical Science and RealClimate are read much less than WUWT. The simple explanation is likely that for non-libertarians there is no special need to read "climate" blogs, they have no problems with cognitive dissonance, they can just read the newspaper without getting high blood pressure.

My main reason to blog is that it help me order my thoughts. Before blogging, I would write the occasional essay for my homepage, but never got much feedback from that. The nice thing of blogging is that it is easy to comment and in this way you get more feedback, some of which is helpful in developing your thoughts.

Now that I do have more readers than I ever expected, I once in a while also write a post because I think others may be interested, such as the post on the time of observation bias and its correction in homogenization. I could not find good free information on that topic. The post statistical homogenization for dummies also falls in this category. And I have started writing posts to make my articles more visible.

If I were interested in getting as much readers as possible, I would not blog about arcane topics such as future research on the homogenization of daily datasets (post1, post2), which only a minimal number of people will appreciate.

Hard evidence?

keihard cijfermatig bewijs: klimaatontkenning is op z'n retour, de onzinblogs verliezen terrein variable-variability.blogspot.nl/2013/05/the-ag… via @janpaulvansoest

— Carl Königel (@CarlKonigel) May 7, 2013

Freely translated: Hard numerical evidence: climate denial is on its way back, the bosh blogs are loosing ground.

As a scientist I am probably indoctrinated to use the term "hard evidence" a bit more carefully as the general public. It is possible that the community using Alexa is more turned off by "sceptical" nonsense as the general public. Thus there could be a bias in the Alexa data. And there is conflicting evidence in the number of readers WUWT itself reports. I have noticed for my own blog that almost half of the "readers" come in spikes and often seem to visit only to leave the URL in the statistics, hoping that I will click on the link to see who is linking to me. This seems to be getting worse as my blog gets better known. The number of readers WUWT itself reports are thus likely not very reliable.

It is a pity we cannot harass the climate sceptics blogs back with Freedom of Information Act requests for their data.

Further indications

Anthony Watts himself provides a fourth tentative indication that the activism is declining. He wrote this week:

I don’t normally do mid week open threads, but I’ve not found much of interest to write about tonight, and story submissions have been a dry hole lately.

UPDATE: Watts now wrote that the contributions were not low, but had landed in his SPAM folder. Very fitting.

More on the opinion poll To anticipate a "sceptic" objection: "Hey man, you cannot read, the PEW poll clearly states the the public does not see climate change as a priority for this year." That is the main problem of gradual global phenomena such as climate change. Because the problem builds up slowly and every country contributes only a small part, it is never a short term priority for a nation. That is also why politicians came up with the arbitrary 2°C limit. That helps to build up political pressure to do something on the "shorter term". It would still be smart to do something about climate change in the long term; if you average over a longer period and all nations, those short term local priorities become a lot less important. As another aside. While the "sceptics" have problem with scientists broadly agreeing on basic facts such as that the Earth is warming, I found the percentage of the public without opinion surprisingly low. Whereas opinions are very mixed: 87% of the Democrats see solid evidence for warming, and 50% of the Republicans see no evidence, almost no one sees mixed evidence or doesn't know (Rep: 7%, Dem: 3%). It is strange that ideology determines the strength of the evidence, but if that happens you would expect to see such differences for difficult topics where many people have no idea what is right, wouldn't you?

All the evidence also fits to the general change in the public opinion in the USA. In the latest PEW poll of March 2013, nearly seven-in-ten Americans say they believe there is solid evidence of global warming. This number is increasing since 2009.

You could also see the reduction in the number of readers and especially of the number of people commenting as a sign of a diminishing morale among climate science deniers? I think that the opinion polls are an indication that the reason is more like a change in public opinion.

FiveFour independent lines of evidence

We now have five four lines of evidence for a decline of the "sceptic" community: the number of readers according to Alexa, the number of comments at WUWT and, thanks to Tom Nelson, the number of Google searches for "global warming", Anthony Watts himself and opinion polls on climate change. Combined all the evidence is quite persuasive.

I am looking forward to a more fruitful and mature climate debate in future.

Further reading

• An interesting Gallup poll: Americans' Concerns About Global Warming on the Rise. Majority believe global warming is happening, but many still say it's exaggerated.

My previous posts about misinformation on WUWT are:

• The age of Climategate is almost over
• Blog review of the Watts et al. (2012) manuscript on surface temperature trends
• No trend in global water vapor, another WUWT fail
• Investigation of methods for hydroclimatic data homogenization

With 5 posts a day, it is impossible to discover the errors in every post, not even Anthony Watts can. Still if you doubt about some aspect of a WUWT post, here are some resources where you get inspiration for finding the problem. Currently, Hotwhopper is very active. Other sites specialising on WUWT are: Wott's Up With That?, Whats Up With That Blog, VVatts Up With That and What's Up With That Watts? General climate sites that are regularly have to correct WUWT madness are: Open Mind, RealClimate and SkepticalScience.

The age of Climategate is almost over

It seems as if the age of Climategate is over (soon). Below you can see the number of Alexa (social bookmarking) users that visited What Up With That? At the end of 2009 you see a jump upwards. That is where Anthony Watts made his claim to fame by violating the privacy of climate scientist Phil Jones of the Climate Research Unit (CRU) and some of his colleagues.

Criminals broke into the CRU backup servers and stole and published their email correspondence. What was Phil Jones' crime? The reason why manners and constitutional rights are not important? The reason to damage his professional network? He is a climate scientist!

According to Watts and co the emails showed deliberate deception. However, there have been several investigations into Climategate, none of which found evidence of fraud or scientific misconduct. It would thus be appropriate to rename the Climategate to Scepticgate. And it is a good sign that this post-normal age is (almost) over and the number of visitors to WUWT is going back to the level before Climategate.

Since the beginning of 2012, the number of readers of WUWT is in a steady decline. It is interesting coincidence that I started commenting once in a while since February 2012. Unfortunately for the narcissistic part of my personality: correlation is not causation.

The peak in mid 2012 is Anthony Watts first failed attempt in writing a scientific study.

According to WUWT Year in review (Wordpress statistics), WUWT was viewed about 31,000,000 times in 2011 and 36,000,000 times in 2012. However, a large part of the visitors of my blog are robots and that problem is worse here as for my little read German language blog. Alexa more likely only counts real visitors.



Anthony Watts is not the only one feeding on the criminals that broken in the the email servers. As you can see below, also Climate Audit, the blog of Steve McIntyre gained a lot of attention after the theft. Attention that had fortunately disappeared almost completely. No wonder his motivation is dwindling.

One can see that McIntyre really needed the fabricated scandal this March on the Marcott et al. (2013) paper with a multi-proxy global temperature reconstruction for the entire Holocene. Marcott et al. had written in their paper that the results for the 20th century were not robust. Thus McIntryre made a "scandal" out of a tick in the 20th century caused by edge effects and proxy dropout (less data for recent times). (For those interested, the answer of the authors can be found at RealClimate.)

Native sceptics

The data from Alexa tells us something about the readers. What about the native sceptics? The ones writing thank-yous to Watts for posting about another "nail in the coffin of catastrophic anthropogenic climate change". (With all that metal, you probably need a forklift for the burial by now.)

As far as I remember, I have never seen a climate "sceptic" that admitted having made an error or that a WUWT post was wrong. When I am commenting on WUWT I have to remind myself that it is not futile. That while you will never convince the regulars no matter how clearly the post misinforms (such as clear cases of misquotations). My comments are aimed at new and casual readers, the ones Alexa shows are leaving.

Below you can find a graph with the number of comments. To my surprise, even the number of comments is decreasing. Over the period of interest by about 100 comments a day. Thus apparently, while they will not admit being wrong in a discussion, it is actually possible to convince these people that WUWT lacks credibility.

I have the feeling that the tone on WUWT is getting more and more grim and I am not the only one. Maybe the moderates are leaving. Are there automatic text analysis tools with which you could study this change of atmosphere?

Climate discussions

Scientist, normal citizen and real climate sceptics, the ones without the scare quotes, should welcome the disappearance of WUWT. With all the nonsense and misinformation published there, it is hard to find the valid points of criticism. I have said more often that if someone will find a problem in climate science, it will be a scientist and not this hopeless bunch. Without WUWT and co, it would become more likely that the blogosphere will contribute.

For example, in all the commotion around the game-changing manuscript of Anthony Watts, the second game-changing study of the month was not discussed as much as would have been warranted. This smart study by McNider and colleagues suggested that the observed trend in the minimum temperature at night could also partially be due to a change in the temperature profile of the nocturnal stable boundary layer. I would love to see more research in this direction. The paper is based on boundary layer theory. My master supervisor was fond of saying that this theory can only be tested accurately in three places in the world as it is only valid for flat and uniform terrain. Thus it would be great to see some empirical studies into this matter, to see whether the idea also holds for more realistic measuring conditions.

Another question where we can have a productive scientific debate is around climatic changes in weather variability. It is often claimed that the weather variability is increasing and that consequently what used to be extreme weather will become common. In as far as extreme weather is influence by the mean temperature, I expect very hot weather to become more common. However, I am not yet convinced that we can state this because the variability around the mean is becoming larger and that we can thus also attribute cold extremes to global warming. In my opinion, the quality of daily data has not been sufficiently studied for robust statements.

A considerable part of the budget for climate research goes to climate change impact studies, because governments need advice to protect the population. For many impacts you need spatially (and temporally) highly resolved data and I personally only trust global climate models with respect to global mean and maybe continental mean properties. To increase the spatial and temporal resolution of the data, various so-called downscaling techniques are used. Scientists use statistical downscaling methods by comparing global model runs with observed data or drive higher resolution local climate models by the global models. This makes the data more useful, but if the large-scale circulation in the global climate model is wrong, for example because the ice cover of the Arctic is not modelled right, you cannot solve this by adding more detail.

While I have no doubt the people working on this are doing their best, I worry that many impact studies have larger (structural) uncertainties as expected by the users of the information. On the other hand, I understand the need of the governments for some guidance for adaptation policies and these studies are likely more predictive as throwing a dice and in this sense valuable. Thus not working on climate impacts is also no option.

Many I should add for the "sceptics", the ones which need the scare quotes: uncertainty does not mean that there will be no impacts, uncertainties goes both ways. Furthermore, more uncertainty means that adaptation is more difficult and more costly (you have to prepare for more possibilities) and large uncertainty is thus an argument for not messing with the climate in the first place (mitigation).

Above I was only discussing the natural science part of climate impact studies. However, the changing climate only adds an additional stressor to a system. Whether this leads to a catastrophe, will depend on interactions with other stressors, how well we prepared for the problem and how we respond. Maybe it is my bias as a natural scientist, but I feel that the latter human part of the predicting the impacts is nearly impossible to solve.

And those were just three topics that jumped to mind. There are many, many more problems we could hold civilized discussions about. The demise of WUWT and co would make these discussions more intelligent and fruitful. Some time ago, I was discussing homogenization (as always) with the people at The Blackboard. A totally different atmosphere, while some of the regulars of WUWT were also there, many people at The Blackboard were interested in understanding the problems. If you are a real sceptic and you are looking for a new home, why not have a look. I love real sceptics and hope that soon that word regains its original meaning again.

UPDATE, 20th May 2013: Isn't is ironic? Or maybe convenient? WUWT now has a toolbar with a little help from Alexa. Let's see if that increases the counts. Anthony Watts writes:

The other value to this toolbar is that it helps Alexa get accurate data on WUWT traffic and reach, so you’d be helping WUWT by installing it and using it.

Further reading

My next post, Decline of the climate "sceptical" community, reactions and new evidence, discusses some of the reactions to this post and provides several new lines of evidence that more and more people are fed up with Anthony Watts lying circus.

My previous posts about misinformation on WUWT are:

• Blog review of the Watts et al. (2012) manuscript on surface temperature trends
• No trend in global water vapor, another WUWT fail
• Investigation of methods for hydroclimatic data homogenization

With 5 posts a day, it is impossible to discover the errors in every post, not even Anthony Watts can. Still if you doubt about some aspect of a WUWT post, here are some resources where you get inspiration for finding the problem. Currently, Hotwhopper is very active. Other sites specialising on WUWT are: Wott's Up With That? and What's Up With That Watts? General climate sites that are regularly have to correct WUWT madness are: Open Mind, RealClimate and SkepticalScience.

The value of peer review for science and the press

The value of peer review keeps on producing heated debates. An interesting example was the weekend that physics professor Richard Muller wrote an op-ed in the New York Times. Some claim that Anthony Watts halted his blog for 2 days and released a scientific manuscript and an accompanying press release on the same weekend to steal attention away from Mullers op-ed. Both the op-ed and the press release were about scientific claims that had not passed peer review. Thus the Washington Post asked: Is it okay to seek publicity for a work that is not peer reviewed?

Watts et al. manuscript The eventful weekend at end of July 2012, resulted in two worthwhile blog post in the New York Times (Andrew C. Revkin at dotEarth) and the Washington Post (Jason Samenow). The manuscript was clearly released prematurely and had serious methodological problems. A few days after the press release and the blog reviews, Anthony Watts still wrote: "I’m hoping to post up a revised draft, addressing many of those comments and corrections in the next day or two." And he opened a "work page" for the manuscript, which is so quiet you can hear crickets. Just when no one expected it any more, the zombie manuscript came back from the undead; this March Watts wrote about this manuscript: "we are preparing a paper for submission". I am not a native speaking. May I ask, if you write "we are preparing", that indicates an ongoing action, right? Is there any lower limit on the intensity of this action?

The other side of the question about seeking the press before peer review is should a journalist only write about peer-reviewed studies? Further questions that came up since are: Is it unscientific to cite non-reviewed studies? Should the IPCC limit itself to reviewing only the peer-reviewed literature? Is peer review gate keeping? Is peer review necessary?

As often the context is important. What the value of peer review is, depends on who you are? An expert or not, a journalist or a newspaper reader? Another important part of the context is how controversial the finding is.

The Value of Peer Review for Science

Peer review gives an article credibility. As such peer review is "just" a filter, it does not guarantee that an article is right. Many peer-reviewed articles contain errors, many ideas outside of the peer-reviewed literature are worthwhile. However, on average the quality of peer-reviewed work is better. Thus peer-reviewed work is more likely worthy of your attention.

If you are a scientist and an idea/study is about something you are knowledgeable about there is no reason to limit yourself exclusively to peer-reviewed articles, but it is smart to prefer them. A scientist will only use peer review to preselect, because you simply cannot read and check everything. Life is short and attention a very limited resource. I also see no problem in citing studies that are not peer-reviewed, whether scientific reports or conference contributions. I do feel that by citing such studies, you give them some of your reputation, you become partially a reviewer and should read them as careful as a reviewer would.

Peer review is far from perfect. It is not intended to and cannot prevent fraud. Some bad papers will get through and some good ones will be rejected. This can be annoying for the scientists involved, but given that peer review is just a filter, it is not that bad for science in general. It is only since the second world war that peer review has become the standard. We also had scientific progress before that time.

Having to read a few bad papers is no tragedy and will not slow scientific progress much. Recently, Hans-Joachim Lüdecke, the press officer of EIKE, a German blog that tries to challenge the quality of WUWT, published a paper in Climate of the Past. If after reading the abstract, you do not google the title to learn about the mistakes, you can only blame yourself. A special recent case is the paper written by Alan Carlin (Wikipedia | his blog) for a special Issue with guest editor Alan Carlin(!). It is a special case, because by hiding the paper in the International Journal of Environmental Research and Public Health, (almost) no climate economist will have to waste his time reading it. Thus the peer review filter did do his job, albeit indirectly.

Also scientists manage to get bad studies published. I would say that it is noticeable that articles by well-known scientists more often contain little errors. And one famous scientist proudly told me that when one of his articles was rejected, he just called the editor to ask whether his journal would like to receive future well-cited manuscripts from him or not? The rejected paper was published without any changes. In case of well-known scientists you could even argue that this is okay; reviews do not always improve papers and if the articles are really bad, they mainly hurt their own reputations. The little errors are probably not always due to power abuse. I have the impression that stylistically well-written articles also contain more errors. The good name or the good prose may simply make the reviewer less critical.

The reverse, good studies that are not published, is more problematic. One problem is that if you criticise a previous study, some editors send the manuscript to the author of the criticised study and treat the reviewers recommendations to completely revise the manuscript or reject it as if it came from a neutral, disinterested person. Fortunately not all journals do. In the end, a good study will find its place in the literature. There are so many journals and editors that "gate keeping" of good articles is impossible, such problems mainly cause delays. For the scientists involved this is very annoying and may slow down their career. Thus this is something that should not happen and something we should fight, but it is no foundation for the conspiracy theories of the climate "sceptics".

Concluding, bad papers in the scientific literature are a minor problem for science as long as their number is limited (and people still take the time to blog about them or write a formal comment). Whereas, a good idea that is not published is a big loss to science.

The main effect of bad papers is outside of science, if they confuse the population about the current state of science. Politicians like immutable truths and sometimes call for water-tight review systems. That is impossible, would add so much overhead that it would slow down scientific progress and make it very difficult to publish unorthodox ideas, which are typically weak in the beginning. As a scientist, I would thus prefer to have a peer review filter that errs on the side of publishing a few articles too much.

Donna LaFramboise, thinks that a study that is not peer-reviewed should be disregarded by the Intergovernmental Panel on Climate Change, IPCC. After the previous discussion, I hope it is clear that I could not care less whether they cite peer-reviewed literature or non-reviewed works. Every IPCC author writes about those topics where he is knowledgeable and should be able to judge what is worth citing. The citation policy of IPCC sounds fine to me.

Peer Review & Publicity

If you are not knowledgeable and have little time it is best to limit yourself to peer-reviewed studies. As journalists are interested in spectacular new ideas, the scientific articles headlining the science sections are already very likely to be found to be (partially) wrong later on. (As an aside, I would advocate journalists not to write about single articles, but about new ideas that are supported by a number of articles, as this reduces the likelihood of reporting erroneous ideas.) Furthermore, as the general public is not in the position to judge the value of a new paper, also scientists should show restrained in seeking publicity for non-reviewed studies.

Because it is a matter of credibility, not only peer review is important. Also the reputation of the scientist and how controversial the matter determine whether the time is ripe for publicity. I do not think that many people would object to the press conferences on the discovery of the Higgs boson, although these results were not published yet. However, the group is highly reputable in this field, the finding is a confirmation of an well-established theory and the experimental set-up has been vetted before building the enormously expensive instruments. Furthermore, the topic is of high public interest. Trying to delay its publication in the mass media while waiting for a peer-reviewed article would have been impossible.

In the same vein as the Higgs story, I see no problem with the op-ed of Richard Muller, mentioned in the introduction. Yes, it was before peer review. But if a physics professor confirms what climatology already knows for decades, you cannot see such a story as especially controversial. The press attention was consequently also not really about the science, but a human interest story of a self-proclaimed climate-sceptic, funded by the libertarian Koch brothers, being convinced by the data that global warming is real.

From private to public communication

A modern "problem" is that the distinction between communication between colleagues and the public is becoming less clear. From a private mail to one or multiple colleagues, to a small or large e-mail distribution list, from your personal homepage, to a blog post or a guest post at a well-known blog and from a working group seminar to a conference presentation. Where does publicity start?

As a consequence it can be impossible to control an interesting story and stories about non-reviewed studies are likely to become more common. Our Italian colleagues that had measured speeds faster than the speed of light had no other option as going to the press after all the attention their results got in the blog-o-sphere. And at least to me as a scientist, they communicated very clearly that they expected the reason to be the measurement error that it turned out to be. The press articles, I read about it could have been toned down a little more, but given that newspapers are competing for readers, I guess these articles were okay.

If the blogosphere starts zooming or journalists ask questions, you cannot expect scientists to keep silent. Similarly, if a scientist makes publicity, you cannot expect a journalist to ignore it. But you can expect from both groups to show restraint on studies that are not reviewed.

I often put my submitted manuscripts on my homepage, so that my colleagues can read them early and possibly give valuable feedback. (In economics it is even tradition to circulate a manuscript for over a year before submitting it to a journal. In physics the manuscript is often submitted to a public database before submitting it to a journal.) In my case, that is still pretty private, in case of Richard Muller of BEST that is equivalent to going to the press. I will not refrain from using my homepage for communication just because a blogger or journalist may read a manuscript. When I am blogging about an article, I prefer to wait until it is accepted. However, some posts contain ideas that may become part of an article later.

Let's close with the Watts et al. (2012) manuscript, this post started with. I would say that Anthony Watts naturally had the right to publish the manuscript on his blog and ask his readers for feedback. Given the large readership of WUWT this is already seeking publicity, but you cannot expect the blogger Watts not to use his blog for feedback. Immediately making a press release out of the manuscript is not especially elegant, rather one would expect a scientist to emphasis the preliminary nature of the work and state that it is not yet ready for publicity. But then, Watts is clearly not a scientist.

UPDATE I : Michael Tobis at Planet 3.0 blogged about this post and added the wise comment:

I would add: take the true skeptic’s path. The first thing to do is neither to doubt the publication nor to accept it. The first thing to do is doubt your own understanding of it.

UPDATE II: As a sequel, my latest post discusses the value of consensus in science, which is also a matter of credibility.

Further reading

• The Washington Post, Wonkblog: Two climate papers get hyped first, reviewed later. Is that a bad idea?
• Richard Black of the BBC on the same incidents
• Nature, editorial: Coping with peer rejection
• Organizers have only two options for their meetings: open or closed
• The IPCC citation policy
• Problems with and alternatives for peer review
• Blog review of Watts et al. (2012)

Special issue on homogenisation of climate series

The open access Quarterly Journal of the Hungarian Meteorological Service "Időjárás" has just published a special issue on homogenization of climate records. This special issue contains eight research papers. It is an offspring of the COST Action HOME: Advances in homogenization methods of climate series: an integrated approach (COST-ES0601).

To be able to discuss eight papers, this post does not contain as much background information as usual and is aimed at people already knowledgeable about homogenization of climate networks.

Contents

Mónika Lakatos and Tamás Szentimrey: Editorial.

The editorial explains the background of this special issue: the importance of homogenisation and the COST Action HOME. Mónika and Tamás thank you very much for your efforts to organise this special issue. I think every reader will agree that it has become a valuable journal issue.

Monthly data

Ralf Lindau and Victor Venema: On the multiple breakpoint problem and the number of significant breaks in homogenization of climate records.

My article with Ralf Lindau is already discussed in a previous post on the multiple breakpoint problem.

José A. Guijarro: Climatological series shift test comparison on running windows.

Longer time series typically contain more than one inhomogeneity, but statistical tests are mostly designed to detect one break. One way to resolve this conflict is by applying these tests on short moving windows. José compares six statistical detection methods (t-test, Standard Normal Homogeneity Test (SNHT), two-phase regression (TPR), Wilcoxon-Mann-Whithney test, Durbin-Watson test and SRMD: squared relative mean difference), which are applied on running windows with a length between 1 and 5 years (12 to 60 values (months) on either side of the potential break). The smart trick of the article is that all methods are calibrated to a false alarm rate of 1% for better comparison. In this way, he can show that the t-test, SNHT and SRMD are best for this problem and almost identical. To get good detection rates, the window needs to be at least 2*3 years. As this harbours the risk of having two breaks in one window, José has decided to change his homogenization method CLIMATOL to using the semi-hierarchical scheme of SNHT instead of using windows. The methods are tested on data with just one break; it would have been interesting to also simulate the more realistic case with multiple independent breaks.

Olivier Mestre, Peter Domonkos, Franck Picard, Ingeborg Auer, Stéphane Robin, Emilie Lebarbier, Reinhard Böhm, Enric Aguilar, Jose Guijarro, Gregor Vertachnik, Matija Klan-car, Brigitte Dubuisson, and Petr Stepanek: HOMER: a homogenization software – methods and applications.

HOMER is a new homogenization method and is developed using the best methods tested on the HOME benchmark. Thus theoretically, this should be the best method currently available. Still, sometimes interactions between parts of an algorithm can lead to unexpected results. It would be great if someone would test HOMER on the HOME benchmark dataset, so that we can compare its performance with the other algorithms.

Luís Freitas, Mário Gonzalez Pereira, Liliana Caramelo, Manuel Mendes, and Luís Filipe Nunes: Homogeneity of monthly air temperature in Portugal with HOMER and MASH.

Our Portuguese colleagues compare the new homogenization package HOMER with MASH. MASH is the homogenization method developed by the Hungarian Meteorological Service. They do so by homogenizing monthly temperature data for the north of Portugal. The main comparison statistic is the Spearman correlation coefficient, which is computed between one stations and all the others and between a station and a composite reference of neighbouring stations. In general HOMER increases the correlations more than MASH, this could indicate that HOMER performs better, but could also be overcorrection. This type of study cannot make that distinction. Somewhat a sign of overcorrection is that for some stations the minimum temperature is less well correlated with its direct neighbours after homogenization with HOMER. This could be because the correction method of HOMER assumes that the entire network has the same regional climate signal. This assumption may not be optimal for this large region with coastal and mountainous stations. I do not understand the results for the station Dunas de Mira (DM), here HOMER increases the correlations with all stations a lot, while MASH does not change these correlations much (Figure 2). However, the correlations with the direct neighbours are high and similar for both methods (Figure 3).

Peter Domonkos: Measuring performances of homogenisation methods.

Naturally, I loved reading Peters review on benchmarking homogenization algorithms. If only because I kinda like the topic after coordinating the HOME benchmarking and being member of the benchmarking group of the International Surface Temperature Initiative. The main message is briefly summarised in the abstract: "The principles of reliable efficiency evaluations are: (i) Efficiency tests need the use of simulated test datasets with similar properties to real observational datasets; (ii) The use of root mean square error (RMSE) and the accuracy of trend estimation must be preferred instead of the skill in detecting change-points; (iii) The evaluation of the detection of inhomogeneities must be clearly distinguished from the evaluation of whole homogenization procedures; (iv) Evaluation of homogenization methods including subjective steps needs blind tests." I do hold the opinion that the HOME benchmarking paper showed that it is more likely that the HOME benchmark had too much rather than too little platform-type break-point pairs, as this article claims, but that is a long, long quarrel between the two of us.

Daily data

Tamás Szentimrey: Theoretical questions of daily data homogenization.

Tamás wrote a thought provoking article on the correction of daily data. It contains some valuable points, which are actually worth an entire post of its own. The paper would, however, have been stronger if his strong words would have been limited to what he actually mathematically proved. He discusses the daily correction method for parallel measurements of Trewin and Trevitt (1996), which is used if you have overlapping data with the old and the new measurement set-up standing next to each other. Tamás shows that this method is biased due to the decorrelation between the two parallel measurements. In case of parallel measurements the correlations are normally very high and this bias term will thus be very small. Likely the inhomogeneity in the distribution is larger and the correction still improves the data; this can be tested by bootstrapping (Nemec et al., 2012). The paper unfortunately lacks a proof that decorrelation is also a problem for the correction method HOM (Della-Marta and Wanner, 2006), which uses a neighbouring station that is thus more decorrelated, but this method is smarter as just computing one regression. HOM and its variants are used a lot nowadays to correct daily temperature data. A better understanding that could lead to better method would thus be very valuable.

Petr Štěpánek, Pavel Zahradníček and Aleš Farda: Experiences with data quality control and homogenization of daily records of various meteorological elements in the Czech Republic in the period 1961–2010.

Our colleagues from Middle Europe describe how they generated their high-quality daily dataset for the last 50 years. The dataset (62 million values) contains temperature (minimum and maximum and temperature at 7, 14, and 21 hours and daily average), water vapour pressure (again at three fixed hours and average), wind speed (again at three fixed hours and average), maximum daily wind gust, daily precipitation totals, and daily sunshine duration. The article describes the quality control, homogenization with AnClim, the filling of missing data and gridding. It shows the number of detected breaks and their sizes for the different climate variables and time of year. The article also gives a short description of their daily correction method, which extents HOM in interesting ways by adjusting the percentiles, smoothing the corrections and correcting the distribution for every month using also data from the adjacent months. The automation of the measurements had a very strong influence on the homogeneity of the data and on the number of outliers.

Mónika Lakatos, Tamás Szentimrey, Zita Bihari, and Sándor Szalai: Creation of a homogenized climate database for the Carpathian region by applying the MASH procedure and the preliminary analysis of the data.

This article is also presents the quality control, homogenization and gridding of multiple daily variables (mean, minimum and maximum temperature, precipitation totals, wind direction and speed, sunshine duration, cloud cover, global radiation, relative humidity, surface vapour pressure and surface air pressure). For quality control and automatic homogenization, the MASH package was used, for gridding MISH, both developed by the Hungarian Meteorological Service. Special about this project is that the Carpathian region contains many countries and that therefore data of stations near the border needed to be exchanged. The gridded dataset has a resolution of 10 km and was produced using kriging (optimal estimation). The article shows the gridded maps of two indices computed from the daily data. It is a pity that such projects are so complicated to organise because of the data policy of the weather services. I am hopeful though that things are improving and that in a few years the situation will become better. Finland, for instance, has opened its climatological datasets beginning this year.

More posts on homogenisation

Statistical homogenisation for dummies

A primer on statistical homogenisation with many pictures.

Homogenisation of monthly and annual data from surface stations

A short description of the causes of inhomogeneities in climate data (non-climatic variability) and how to remove it using the relative homogenisation approach.

New article: Benchmarking homogenisation algorithms for monthly data

Raw climate records contain changes due to non-climatic factors, such as relocations of stations or changes in instrumentation. This post introduces an article that tested how well such non-climatic factors can be removed.

HUME: Homogenisation, Uncertainty Measures and Extreme weather

Proposal for future research in homogenisation of climate network data.

A short introduction to the time of observation bias and its correction

The time of observation bias is an important cause of inhomogeneities in temperature data.

Future research in homogenisation of climate data – EMS 2012 in Poland

Some ideas for future research as discussed during a side meeting at EMS2012.

References

Della-Marta, P. M. and H. Wanner. A method of homogenizing the extremes and mean of daily temperature measurements. J. Climate, 19, pp. 4179–4197, doi: 10.1175/JCLI3855.1, 2006.
Nemec, J., Ch. Gruber, B. Chimani, I. Auer. Trends in extreme temperature indices in Austria based on a new homogenised dataset. Int. J. Climatol., doi: 10.1002/joc.3532, 2012.
Venema, V., O. Mestre, E. Aguilar, I. Auer, J.A. Guijarro, P. Domonkos, G. Vertacnik, T. Szentimrey, P. Stepanek, P. Zahradnicek, J. Viarre, G. Müller-Westermeier, M. Lakatos, C.N. Williams,
M.J. Menne, R. Lindau, D. Rasol, E. Rustemeier, K. Kolokythas, T. Marinova, L. Andresen, F. Acquaotta, S. Fratianni, S. Cheval, M. Klancar, M. Brunetti, Ch. Gruber, M. Prohom Duran, T. Likso,
P. Esteban, Th. Brandsma. Benchmarking homogenization algorithms for monthly data. Climate of the Past, 8, pp. 89-115, doi: 10.5194/cp-8-89-2012, 2012.

New article on the multiple breakpoint problem in homogenization

An interesting paper by Ralf Lindau and me on the multiple breakpoint problem has just appeared in a Special issue on homogenization of the open access Quarterly Journal of the Hungarian Meteorological Service "Időjárás".

Multiple break point problem

Long instrumental time series contain non-climatological changes, called inhomogeneities. For example because of relocations or due to changes in the instrumentation. To study real changes in the climate more accurately these inhomogeneities need to be detected and removed in a data processing step called homogenization; also called segmentation in statistics.

Statisticians have worked a lot on the detection of a single break point in data. However, unfortunately, long climate time series typically contain more than just one break point. There are two ad hoc methods to deal with this.

The most used method is the hierarchical one: to first detect the largest break and then to redo the detection on the two subsections, and so on until no more breaks are found or the segments become too short. A variant is the semi-hierachical method in which old detected breaks are retested and removed if no longer significant. For example, SNHT uses a semi-hierachical scheme and thus also the pairwise homogenization algorithm of NOAA, which uses SNHT for detection.

The second ad hoc method is to detect the breaks on a moving window. This window should be long enough for sensitivity, but should not be too long because that increases the chance of two breaks in the window. In the Special issue there is an article by José A. Guijarro on this method, which is used for his homogenization method CLIMATOL.

While these two ad hoc methods work reasonably, detecting all breaks simultaneously is more powerful. This can be performed as an exhaustive search of all possible combinations (used by the homogenization method MASH). With on average one break per 15 to 20 years, the number of breaks and thus combinations can get very large. Modern homogenization methods consequently use an optimization method called dynamic programming (used by the homogenization methods PRODIGE, ACMANT and HOMER).

All the mentioned homogenization methods have been compared with each other on a realistic benchmark dataset by the COST Action HOME. In the corresponding article (Venema et al., 2012) you can find references to all the mentioned methods. The results of this benchmarking showed that multiple breakpoint methods were clearly the best. However, this is not only because of the elegant solution to the multiple breakpoint problem, these methods also had other advantages.

Could we get more Earthquakes due to global warming and thermal expansion of the Earth's crust?

Thermal expansion can release quite some force as is seen in bridges and railroad tracks that are deformed due to hot weather. I am wondering whether thermal expansion of the Earth's crust due to global warming can similarly lead to seismic activity, especially at subduction zones where one crustal plate slides under another one.

I have searched the scientific literature, but was unable to find any articles on the topic, while it sounds quite straight forward to me. Did really no one have this idea before, or was it already debunked in 1960?

Dear journalists, This is not a press release; I do not like science by press release. While I am a scientist, I have no special expertise in geology. Please only write about this if the standards of your publisher are so low that you would also write about it if you next-door neighbour would have this idea. In other words, please wait until there is a scientific publication on this. Even better would be to wait until there are several papers, but I realise that that is illusory. Dear "skeptics", I did not write that your SUV is responsible for the seismic atomic genocide of the the Japanese population. This post is only written to bring the idea under the attention of the right scientists. At this stage, it is very likely that the idea is wrong and that nothing will happen. Dear colleagues, the reason to write this post is to attend someone with the skills to investigate it. It is thus highly appreciated if you could forward it to someone who may have the right skills. I guess two skills are needed: 1) modelling of the warming of the crust and 2) dynamical modelling of the crust expansion. If you have one of these skills, please contact me, maybe someone with the second skill also responded. If you have both skills or know someone, feel free to act as if it is your own idea. Ideas are cheap and this back-of-the-envelope computation was quickly made. The real innovative step is deciding which idea is worth spending a year of your time on to make it into science. It would be nice if after publication you could act as if a colleague attended you to this post and send me a copy of the article. I am curious.

Back-of-the-envelope computation

The length of the Equator is roughly 40x10⁶ metres. And my high-school tables book gives thermal expansion coefficients for various stone types between 4 and 12x10^-6 K^-1. So for a one degree temperature change one would expect that the Earth's crust would expand by 160 to 480 metre. (More accurately, one would use the size of a plate not the circumference of the Earth. On the other hand, the projected temperature change is larger than one degree.) For the sake of the argument, let's say that it is about 100m. One thing I do not know is whether the crust is sufficiently brittle/solid (like a railway track or bridge that deforms by heat) or whether there are air and liquid pockets and cracks which could absorb the expansion. Furthermore, maybe the additional pressure would mainly increase the width of the crust not its length or the crust would just crumple a little more.