Wednesday, 23 April 2014

Climate Change National Forum introduces the nonsense amplifier

The Climate Change National Forum now has a section called The Fact Checker. In it they will post the nonsense of pseudo-skeptics and they promise that the CCNF scientists will respond to it. I am glad not to be a CCNF scientist, having to jump up, drop everything I am working on, get myself into the topic and quickly write a response. Until that time, the nonsense is spread undisputed. And that happens every time the CCNF journalist think some pseudo-skeptical article is interesting. Poor scientists.

These "Fact Checker" articles have the highest prominence on the CCNF homepage, they are the first thing people will see and click on and are above the articles by CCNF scientists.

Or as the CCNF journalist Michael Quirke writes in his post explaining the carnage:
NOTE TO READER: This is the fact checker section, where the CCNF journalist impartially posts up outside material (the good, the bad, and the ugly), and the scientists fact check or comment on that material.
It has come to my attention that some readers don’t understand the function and purpose of this fact checker section. I have received some criticism that, by posting up an article for fact checking and commentary by the CCNF Scientist Community, I am somehow giving credence to the content being posted. Nothing could be further from the truth.
Naturally, you give credence to the posted content. Not only will it take time until the scientists can write their response and possibly with mistakes and only responding to parts of the story because of the haste. The article above the line automatically has more credibility as the response below the line. Simply by virtue of being above the line.

Until the scientists have responded the articles go undisputed. Without explaining why an idea is wrong, the idea will stick. Even as a scientist, I try to read WUWT and Co. as little as possible, because after some time you often do not know the source of an idea anymore and may falsely assume the source was reliable. That is why I prefer reading HotWhopper to hear what happens at WUWT.
As acting journalist, I am trying to provide a sampling of the coverage that I am finding in the greater media. You won’t like all material that is posted. I guarantee that. Heck, I don’t like it. But it is not my role, as acting journalist, to state what is credible and what is not in this Socratic forum of scientists. Not at this early stage at least. That is for the scientists in the Scientists’ Comment Thread under each post. The task of the journalist in this section is to post up the good, the bad, and the ugly — whatever is out there in the online space — in a strictly impartial manner.
And I was so naive to think that the role of an acting journalist was to help the reader interpret the news. I guess we can just remove journalists from the equation completely and read random bit of news, mostly nonsense, sometimes accidentally valuable. It is probably good for the click-rates, but I personally prefer quality journalism.


One of these "Fact checking" treasures has the "title": "YAHOO NEWS article “Global Cooling — The REAL Inconvenient Truth: Part 1″: Climate is cooling and will likely continue cooling for 20 years, sunspot cycles the “real culprit” of climate change, and new evidence of data manipulation by scientists; the world is cooling, bank on it." And started with snow in Egypt. In the comments written one day later the scientists explain that while the suns intensity has dropped since the beginning of the satellite record in 1979, the temperature has increased. Many other mistakes of the Yahoo post that is reposted fully, such as the camel in the Egyptian snow, are not commented on.

An older treasure has the "title": "Dr. Garth Paltridge on Reluctance of IPCC and others to reduce confidence levels in light of hiatus and misunderstood climate mechanisms shows a lack of scientific skepticism." It could be a stupid WUWT post pretending that global warming has stopped because the surface temperatures have not grown as fast as before, fully ignoring that the climate system as a whole keeps on warming and that only more of the warming went into the ocean rather than the atmosphere during the last decade. What makes this CCNF post even worse is that Judith Curry is defending it. Thus we have a confident wrong article above the line and little bickering scientists below the line. Great Fact Checking. That is science communication.


My suggestion would be to create a mailing list with the CCNF scientists. That way the journalist can propose articles for the Fact Checking section. This would allow CCNF to write articles where the science is presented above the line and immediately with the nonsense. For the scientists involved this is also much nicer as they will have some more time to prepare a quality reaction.

If the "Fact checker" stays this way, I would suggest all scientists to stop participating in CCNF. Let it succumb to another WUWT or Climate Etc. There are a lot of such homepages already; one more won't hurt. That is better as a homepage that has credibility due to the participation of scientists, but that is actually helping spread misinformation.

That may happen automatically. Michael Tobis of Planet 3.0 writes:
I have been trying to convince scientists that this site presents a level playing field where the true balance of science can emerge, and I’ve been rebuffed with the idea that this site is another example of “false balance”, wherein the politically structured arguments will again take precedence. That argument is being bolstered by this article...
Scott Mandia writes below the hiatus article:
"Michael, I know your heart is in the right place but posting this piece really damages the credibility of CCNF. There is no place for the "It's not happening" argument. ... You have just elevated Dr. Paltridge to the status of the other experts who write here. You also run the risk of deterring real experts from future posts because they do not wish to be associated with this National Enquirer-type nonsense. Keep the discussion where it belongs. ... Michael Quirke Please do a search for "Familiarity Backfire Effect" and you will see why this post is not helpful."
And Bart Verheggen writes:
"Also, I’d be [in] favor of setting a higher bar for articles to be posted in that section. Most scientists are growing tired of the same old “global warming stopped” type memes and have no interest and no time to engage in a game of whack-a-mole. Plus there are excellent myth-busting websites out there already. If there’s an intelligent argument brought forward that shines a new light on something, now that’s different. Bring it on!"
And CCNF scientist Scott Denning writes:
I agree with Bart that the first impression of the CCNF forum is visually dominated by sometimes-bizarre and inflammatory posts that are not even remotely credible, and that this detracts from the quality of the forum.

It’s just not feasible to “fact-check” all these articles. Most of them are not fact-oriented in the first place. Propagandist rhetoric dripping with contempt for science has worse problems than can be addressed by simply “fact checking.”
It seems like Michael Quirke did notice the discontent among the scientists:
Will post up less of the inflammatory and complete B.S. for a while. Don’t want it to become whack a mole or lose the scientists’ participation. That being said, it is important to show readers what “the mole” looks like.
But I have the feeling, he does not really understand why. "Less of the inflammatory and complete B.S. for a while" sounds more like pacifying of the flaring protests than like a long-term solution.

I have wondered whether I should add NoFollow tags to the links to CCNF.

Related information

I have the feeling the Skeptical Science understands debunking climate myths at lot better; see their Myth Debunking One-Pager.

Saturday, 12 April 2014

Planning for the next Sandy: no relative suffering would be socialist

The river Waal at Nijmegen, The Netherlands. The original river is to the left, which was a bottleneck and extra dangerous due to the curve. This problem has been resolved by a bypass (right), which has made part of the old dike into an island. In this way the river got more space and flood risks are reduced.

The New York Times Magazine has a beautiful article on a Dutch water manager, Henk Ovink. He enrolled with Shaun Donovan, the United States Secretary of Housing and Urban Development, serving in the cabinet of President Barack Obama to make the USA fit for the next Sandy.

The Dutch approach to water management is very different and looks for inexpensive regional collaborative solutions. Whereas the Americans prefer expensive local isolated solutions, because solutions that would help everyone would be "socialist".

I do not know about socialism, but the American solution sure reminds one of the relative suffering mechanism, I recently proposed to understand the climate "debate" in the post: "Do climate dissenters like climate change?"

Relative suffering is an evolutionary mechanism where you do not optimize your own absolute fitness, but rather how well you and your kin are doing relative to outsiders. It can be an evolutionary stable strategy suffer more yourself, as long as others suffer more.

Some excerpts from the article.

The funniest quote is:
Beyond that, Ovink feared that politics might undermine any chance to encourage new thinking about water management. “When I mentioned climate change to one official,” he said, “she almost hit me.”
The irrational response to climate change of some Americans is really unbelievable. Is there a smiley for someone shacking his head?
For all the unexpected support Ovink and his ideas have received, some observers still maintain skepticism about how much change can be effected here, and how fast. “When I heard about Room for the River, and that Dutch farmers said, ‘O.K., we’ll allow our fields to be flooded in order to protect the city,’ I thought, you’re going to have a harder time with that kind of thing in the U.S.,” said Armando Carbonell, a senior fellow at the Lincoln Institute of Land Policy. (My link)
I wonder whether Carbonell realises that the farmer will naturally be compensated for his "socialist" behaviour. In that case the behaviour would be economically rational as it would maximise wealth. Sounds like being a good capitalist is socialist in the USA.

Sunday, 30 March 2014

The BBC will continue fake debates on climate science

Nigel Lawson
Nigel Lawson, not a scientist, but confuses public about science helped by the BBC.
David Rose wrote in The Daily Mail that Mr MacLeod, head of editorial standards and compliance for BBC Scotland, sent an email to his colleagues:
"When covering climate change stories, we should not run debates / discussions directly between scientists and sceptics. If a programme does run such a discussion, it will... be in breach of the editorial guidelines on impartiality."
Anthony Watts wrote a response in his usual elderly statesman manner; it was titled: "Climate change campaigners fear debate, can’t face climate skeptics anymore, so they rig TV news shows". No link, you can find the cesspit yourself. Note the word fear that is so important to the conservatives and the concealed message that climate scientists are climate change campaigners.

The Daily Mail is not the most reliable source around. The only article missing in the side bar is "Britney beheaded two-headed baby in satanic ritual". Thus I have asked the BBC for confirmation. They replied:
[I]t is not the case that “the new policy of the BBC is to no longer have debates between climate scientists & climate "sceptics"” as you state – our policy is and remains that all views are given due weight in BBC coverage of the issue.
Sounds like the bad news for Watts' blood pressure and the good news for science and democracy is wrong. The BBC will continue having fake debates on climate science. Or at least there does not seem to be a BBC-wide consensus opinion yet. What I found especially worrying is that the BBC does not distinguish between false balance ("due weight") and fake public debates. They are related, but separate problems.

What is wrong with the media?

Why is this a problem for democracy? I would like to explain the importance of accurate media reporting on climate science using a great new video that was just released called Can we trust scientists? h/t The New Anthropocene.

It reminds us of the huge trust the public has in science and contrasts it to the large percentage of people holding opinions that deviate from the scientific consensus. Not only when it comes to climate change, but also evolution and vaccination.

It argues that people who know of the consensus generally accept it. This makes sense because a consensus opinion is much more reliable as the opinion of single persons. However, many people have the wrong impression that scientists are not sure yet whether climate change is a problem. Also the climate dissenters often claim there is no consensus.

As a consequence climate scientists are forced to state that there is a consensus on the basics. A somewhat awkward position as the job of a scientist is to refute existing hypothesis and there is nothing more beautiful for a scientist to refute a consensus idea. That means you are better than all the others. Or more modestly, that you were lucky and had a better idea. :-)

The video argues that vocal individual dissenters and the press are responsible for the misperception of how sure scientists are that climate change is real. The problem with the press is that they like controversy and that they present both sides as equal.

I think that the press is just part of the problem. Some people seem really determined not to understand what science has found. And I am not so sure whether the solution presented in the video, reading and watching bloggers and YouTube v-bloggers, will help. But maybe WUWT and Co. have damaged my trust in blogging. Apart from that, this is a video well worth watching and sharing.

False balance

I have this vision of a few theoretical physicists leaving the Large Hadron Collider after a long night of experiments, and stopping in at the local pub for a drink, where a few of the rowdier locals decide to challenge them on the fundamentals of quantum chromodynamics and a nonsense argument (debate) ensues.
David Sanger

Saturday, 15 March 2014

Do climate dissenters like climate change?

Ronald McDonald enjoying himself after Hurricane Katrina.

The kind of "conversations" I am having in the so-called climate "debate" made no sense to me until I asked myself the question whether climate dissenters might like climate change? Maybe a strange question, but it would explain a lot about the debate.

Take Watts Up With That (WUWT), the largest climate dissenter blog. The mainstream opposition of the IPCC. Every post I have read there on a topic where I am knowledgeable contains serious errors. The other posts are likely not better. HotWhopper finds errors on WUWT that make one cringe every single day.

But almost no one at WUWT seems to care about these errors. If anything they cheer the loudest when Lord Monckton has a guest post. These posts probably deserve the prize for the highest error density. Or as Barry Bickmore eloquently writes:
Lord Monckton is a living symbol of the fact that many climate change contrarians will believe anything that seems to support their case, even if it’s coming from the most ridiculous source.
And it is not just that science is overtaxing these people, also very simple to check cases of misquotations of a paper on global water vapor or misleading statements about the web traffic of WUWT are accepted without critique. I informed the WUWT audience of the misquotation, but no one cared. If I may quote one of my last comments:
[N]o one here complained about being misinformed. No one said, I do not believe in climate change, but Forest Mims misinformed me and that is wrong. I do not like being misinformed and I feel that this gives our community a bad reputation.
They were happy to discuss any other typical climate ostrich meme or ask: "Do you feel any amount of shame for helping promote death?" The clear misquotation was not interesting, however. That is not what one would expect from a group that wants to develop an alternative to mainstream science.

In discussions with dissenters I get the impression that they make a determined effort not to understand what the others write. This is especially visible on twitter where you only have 140 characters and cannot be very precise. With colleagues and people that accept the science, this imprecision is no problem, they make an effort to understand you and normally manage to interpret the text in the intended way. I try to avoid such "discussions" on twitter, but see others try and end up in endless twitter streams that go nowhere. As an example, see this post by AndThenTheresPhysics about a discussion on twitter and elsewhere on whether greenhouse gases warm or cool :-) the Earth surface temperature.

Such unproductive discussions are unlike anything I know and especially unlike anything I am used to among scientists. Climate dissenters, for example, often dodge the discussion by moving to new topics before agreement on first topic is made. That does not give the impression that the dissenter wants to understand the reason for the difference of opinion. And it does not show much confidence that one's opinion holds up to scrutiny. In the scientific community, you stay at one topic, try to find out where you agree, where you do not agree and why you do not agree. Until you arrive at statements that are so simple that rational persons can agree upon whether it is true or not or what research would need to be done to verify them.

This part of the rant is getting too long. Let me just state that I do not have the impression that the climate dissenters want to understand the climate better. They mainly seem to want to have some fake "arguments" for discussions, to have some fodder to annoy greenies.

This impression fits to the large differences in acceptance of the science between political groups, which suggests that people arrive at their opinion about climate science based on their political positions and not based on arguments. It could be that the dissenters just find science largely irrelevant compared to their political views and good relations with peers who hold similar views. However, it may go beyond that, I have the impression that the climate dissenters do accept the science and are just mocking opposition, because they do not trust themselves to say that they like climate change. Partially their liking may also be subconscious. Humans are complex.

Salmonella infection

Before I explain why climate dissenters may like climate change, I have to make a detour and explain how a Salmonella infection works. I do not want to compare climate dissenters with a disease, but I need the mechanism. If someone knows a similar evolutionary mechanism for cute fluffy animals with big eyes, please tell me so in the comments, then I will replace this part.

Evolution is a beautiful topic. Many people just think of survival of the fittest and in the worst case think that this fitness has to do with building as much muscle as possible in the fitness studio. The intricacies of evolution are well illustrated by the famous creed: "Evolution is cleverer than you are." Also the evolved behavior of Salmonella about with I learned a year ago via a Nature article (pay-walled, press release) is full of beautiful surprises.

Salmonella attacks the intestinal lining of the gut and thus provokes an immune response. What I had not realized is that this immune response actually helps Salmonella to reproduce. While the immune response also hurts Salmonella, it hurts the other bacteria much more and thus makes the niche for Salmonella larger. They are suffering, but the others suffer more. Relative suffering is their survival strategy. That is the mechanism that is important for this post.

Producing the proteins that provoking the immune system comes at a cost. Thus Salmonella bacteria that do not produce them can reproduce faster. Mutant Salmonella bacteria that are just as good in withstanding the immune system, but do not help in provoking it, thus have a fitness advantage. From the perspective of a sick human it is somewhat strange, but from the Salmonella perspective the active bacteria are altruists that help the other Salmonella and the passive mutant Salmonella are the parasitic free-riders.

Once the mutant Salmonella gain the overhand, the immune system goes down and the other bacteria again grow strong and remove the mutant Salmonella, which is the end of the infection.

Relative suffering

This mechanism was what made me wonder whether some people might like climate change. Yes, it will bring suffering over everyone, but they may think that others will suffer more than they will (and their children) and that climate change thus improves their relative fitness.

Thursday, 13 March 2014

Why doesn't Big Oil fund alternative climate research?

A short post. Asking the question is answering the question.

Jo Nova, an Australian climate ostrich, is begging for money to keep blogging. Anthony Watts helped her with an appeal to his readers. Below his post "ClimateReason" complains:
"We are woefully underfunded and under resourced. Every sceptic I know of has to fund their own projects and have jobs unrelated to their interest in climate.

It takes me a year to research my large articles. Who funds me? No-one. Can I afford the time and money? No. Could I do more if Big Oil funded me? Of course. But they don’t, because money from this source for sceptics is completely imaginary. "
Big Oil prefer to give their money to politicians and PR firms, not to research. That Big Oil does not fund research suggests that even they think mainstream science is solid.

Very solid. If they had just the smallest bit of doubt, it would pay off for them to fund studies on climate change big time. They have so much to lose that money would be largely irrelevant. They already do much research themselves and also fund much external research. Universities get funding from oil companies for a large range of other research topics. Thus the structures are in place, the money is there.

If I had a good idea and could not get funding from national funding agencies, I would have no problem with accepting money from companies. My university certainly would not.

Not that I not expect to have problems with a research proposal because it would challenge the mainstream. On the contrary, I expect that a proposal that challenges the mainstream would have more chances of being funded. Is anything more beautiful fundamental research? Another rhetorical question. However, maybe for more speculative ideas, that are likely to fail, the profit motive of an oil company could improve my funding opportunities. Most scientists would be happy to use such an opportunity.

Poor climate ostriches, not even their oil companies believe in them.

Sunday, 9 March 2014

The ultimatum game, a key experiment showing intrinsic fairness and altruism among strangers

Knowledge will come only if economics can be reoriented to the study of man as he is and the economic system as it actually exists.
Ronald Coase

There is a line of economic research on altruism that get only little attention in the media, which is why I want to report on it here. There is by now solid evidence that humans can behave altruistically towards strangers. This is surprising because a naive version of evolutionary theory would expect that altruism is only possible among kin. It also goes against the basic assumptions of economics, game theory and public choice theory, which all assume that humans only have an eye for their self-interest. These assumptions are often defended referring to evolution by stating that you need to be an unapologetic egoist for optimal reproduction. I mention this, because non-academics may think it is natural to assume humans can be altruistic and wonder why one would research something that trivial.

It is not controversial science. There are hundreds of scientists working on it. Almost every month Nature or Science publishes an article on altruism. And at the University of Bonn, where I work, Reinhard Selten is emeritus professor and got his Nobel price for experimental research on the ultimatum game. That is also how I heard about it, our University Magazine had an article on Selten and this beautiful experiments.

In a social setting, where there is an opportunity to build up a reputation, altruism can be explained. In this case, altruism may lead to future benefits and one may even argue that it is thus not real altruism. However, this type of altruism is expected to break down when a group is under pressure and may soon dissolve, but humans also collaborate under such difficult circumstances. Furthermore, reputation-building naturally does not work under conditions of anonymity, while experiments show that humans also collaborate with strangers they will never see again. Our ability to collaborate with non-kin is an important innovation that contributes much to our success as dominant animals.

Ultimatum game

A very simple and pure economic game, which thus shows the problem very clearly, is the ultimatum game (Güth et al., 1982). In the ultimatum game, two players must divide a sum of money. The first player has to propose a certain division. The second player (responder) can accept this division or reject it; in the latter case both players do not receive any money. In its purest form, the experiment is played only once and anonymously with players that do not know each other.

When the article described the experiment, I wondered what was interesting about that. Naturally people offer 50% and the responder accepts this. Not? That only showed my lack of economic training.

Wednesday, 5 March 2014

Be careful with the new daily temperature dataset from Berkeley

The Berkeley Earth Surface Temperature project now also provides daily temperature data. On the one hand this is an important improvement, that we now have a global dataset with homogenized daily data. On the other hand, there was a reason that climatologists did not publish a global daily dataset yet. Homogenization of daily data is difficult and the data provided by Berkeley is likely better than analyzing raw data, but still insufficient for robust conclusions about changes in extreme weather and weather variability.

The new dataset is introuduced by Zeke Hausfather and Robert Rohde on Real Climate:
Daily temperature data is an important tool to help measure changes in extremes like heat waves and cold spells. To date, only raw quality controlled (but not homogenized) daily temperature data has been available through GHCN-Daily and similar sources. Using this data is problematic when looking at long-term trends, as localized biases like station moves, time of observation changes, and instrument changes can introduce significant biases.

For example, if you were studying the history of extreme heat in Chicago, you would find a slew of days in the late 1930s and early 1940s where the station currently at the Chicago O’Hare airport reported daily max temperatures above 45 degrees C (113 F). It turns out that, prior to the airport’s construction, the station now associated with the airport was on the top of a black roofed building closer to the city. This is a common occurrence for stations in the U.S., where many stations were moved from city cores to newly constructed airports or wastewater treatment plants in the 1940s. Using the raw data without correcting for these sorts of bias would not be particularly helpful in understanding changes in extremes.

The post explains in more detail how the BEST daily method works and presents some beautiful visualizations and videos of the data. Worth reading in detail.

Daily homogenization

When I understand the homogenization procedure of BEST right, it is based on their methods for the monthly mean temperature and this only accounts for non-climatic changes (inhomogeneities) in the mean temperature.

The example of a move from black roof in a city to an airport is also a good example that not only the mean can change. The black roof will show more variability because on hot sunny days the warm bias is larger than on windy cloudy days. Thus part of this variability is variability in solar insolation and wind.

Also the urban heat island could be a source of variability, the UHI is strongest on wind and cloud free days. Thus part of the variability in observed temperature will be due to variability in wind and clouds.

A nice illustration of the problem can be found in a recent article by Blair Trewin. He compares the distribution of two stations, one in a city near the coast and one at an airport more inland. In the past the station was in the city, nowadays it is at the airport. The modern measurements in the city that are shown below have been made to study the influence of this change.

For this plot he computed the 0th to the 100th percentile. The 50th percentile is the median, 50% of the data has a lower value. The 10th percentile is the value where 10% of the data is smaller, and so on. The 0th and 100th percentile in this plot are the minimum and maximum. What is displayed is the temperature difference between these percentiles. On average the difference is about 2°C, the airport is warmer. However, for the higher percentiles (95th) the difference is much larger. Trewin explains this by cooling of the city station by a land-sea circulation (sea breeze) often seen on hot summer days. For the highest percentiles (99th), the difference becomes smaller again because offshore wind override the sea breeze.

Clearly if you would homogenize this time series for the transition from the coast to the inland by only correcting the mean, you would still have a large inhomogeneity in the higher percentiles, which would still lead to non-climatic spurious trends in hot weather.

Thus we would need a bias correction of the complete probability distribution and not just its mean.

Or we should homogenize the indices we are interested in, for example percentiles or the number of days above 40°C. etc. The BEST algorithm being fully automatic could be well suited for such an approach.

Tuesday, 4 March 2014

Falsifiable and falsification in science

"You keep using that word. I do not think it means what you think it means."

In a recent post, Interesting what the interesting Judith Curry finds interesting, I stated that "it is very easy to falsify the theory of global warming by greenhouse gasses." The ensuing discussions suggest that it could be interesting to write a little more about the role of falsifiable hypotheses and falsification in science. The main problem is that people confuse falsifiable and falsification, often do not even seem to notice there is a difference, whereas they have very different roles in science.

The power of science and falsification are beautifully illustrated in this video by asking normal people on the street to discover the rule behind a number sequence (h/t U Know I Speak Sense).


Karl Popper only asked himself what distinguishes a scientific hypothesis from an ordinary idea.
Popper's beautiful thesis was that you can distinguish between a scientific and a non-scientific statement by asking oneself if it can be falsified. If it cannot, it is not science. Thus the worst one can say about an idea that is supposed to be scientific is that it is not even wrong.

Important side remark: Please, note that also non-scientific ideas can be valuable, Popper's philosophy itself is not science, just like most philosophy, political ideas, literature and religion.

And please note that wrong hypotheses are also scientific statements; that they are wrong automatically shows that they can be falsified. Even falsified hypothesis are still scientific hypothesis and can even still be useful. An good example would be classical mechanics. This illustrates that Popper did not think about whether hypothesis were right or wrong (falsified), useful or not, but whether a statement is scientific or not scientific.

To be falsifiable, falsification is only needed to be possible in principle. It does not matter whether falsification would be hard or easy for the question whether it is science. This is because the main value of the criterion is that it forces you to write up very clearly, very precisely what you are thinking. That allows other scientists to repeat your work, test the idea and build upon it. It is not about falsification, but about clarity.

That also implies that the daily job of a scientist is not to falsify hypothesis, especially not solid and well-validated ones. Scientists are also not writing down new falsifiable hypothesis most of the time, in fact they rarely do so. Those are the rare Eukeka moments.

The terms scientist and science are clearly much broader and also much harder to capture. The ambitious William M. Connolley set out to define science and what a scientist does in a recent post. Definitely worth reading, especially if you are not that familiar with science. Disclaimer: not surprisingly, the aim was not completely achieved.

Psycho analysis

A classical example for Popper of a non-scientific hypothesis would be Freud's psycho-analysis. The relationship between the current psychological problems of a patient and what happened long ago in the patients childhood is too flexible and not sufficiently well defined to be science. That does not mean that what happens to a child is not important, there are many modern findings that point into that direction (Joachim Bauer, 2010). If someone else would succeed in making Freud's ideas more specific and falsifiable, it would even be a valuable contribution to science. It also does not mean that psycho-analysis does not help patients. Finally, it also does not mean that it is wrong, rather it means that it is not even wrong. It is too vague.

Morphic fields

Another example is the idea of Rupert Sheldrake about morphic fields. Sheldrake claims that when an idea has been invented before, it becomes easier to reinvent it. He has a large number of suggestive examples where this seems to be the case. Thus there is a lot of information to validate his idea.

The problem is, it is impossible to falsify the idea. This idea is, again, too vague and if you do not find the effect in an experiment, you can always claim that the effect is smaller, that the experiment was not sensitive enough or not well executed.

When I was studying physics in at Groningen University, Sheldrake gave a talk and afterwards naturally got the question whether his ideas were falsifiable. He dogged the question and started about the science philosophy of Thomas Kuhn on paradigm changes that shows that in practice it can be hard to determine whether an idea is falsified. However, whether an idea is falsifiable is clearly another question as how falsification works, which will be discussed below. Then Sheldrake started fueling tribal sentiments, by complaining that only physicists would be allowed to have hypotheses with fields, why not biologists? Discrimination! As the climate "debate" illustrates, adding some tribal conflict is an effective way to reduce critical thinking.

This does not mean that the ideas of Sheldrake may not turn out to be valuable. The list of examples that validate his ideas is intriguing. This may well be a first step towards making a scientific hypothesis. That is also part of the work of a scientist, to translate a creative, fresh idea you got during a hike into a solid, testable scientific idea. Morphic fields are, however, not yet science.

Anthropogenic global warming

The hypothesis that the man-made increases in the concentration on greenhouse gasses leads to an increase in the global mean temperature can be falsified and is thus a scientific hypothesis. There is no need to go into details here, because Hans Custers just wrote an interesting post, "Is climate science falsifiable?", which lists ten ways to falsify the "AGW hypothesis". One would have been sufficient.

A clear example is that if the average world temperature drops one degree, back to values before 1900 and stays there for a long time without there being other reasons for the temperature decrease (e.g. volcanoes, sun, aerosols) the theory would be falsified. To get to ten ways, Custers has to come up with rather adventurous problems that are extremely unlikely because so many basic science and experiments would need to be wrong.

Seen in this light, the climate ostriches are almost right, it is highly unlikely that the theory of man-made global warming will be refuted, that would require highly surprising new findings and in most cases it would require basic physics, used in many sciences, to be wrong. However, just because it is highly unlikely in practice that the hypothesis will be falsified because there are so many independent lines of evidence and the hypothesis is well nested into a network of scientific ideas, that does not make it theoretically impossible, thus AGW is falsifiable.


It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong. Richard P. Feynman

This quote is a favorite one of the climate ostriches. Unfortunately, falsification is a little more complex in practice.

Wednesday, 26 February 2014

THE HOCKEY SCHTICK: I am ostridge practitioner of the CAGW religion

Maybe this is the right background music to the name calling orgy the climate ostriches are throwing this month.

My comment below was not published by the Hockey Schtick (THS), which has a post about the new manuscripts of the Connelly family, below which I wrote a comment to point the readers to my post about these manuscripts.

In my post I wrote that I did not think it was a good idea that the authors of the manuscripts are also the editors and the owners of the journal. I think that at the very least, this should be made very clear on their homepage. The Hockey Schtick does not see any problems with such a pal review and praised the reviews for being open. When I explained that the editor has to make an impartial decision on whether to publish or not, THS no longer replied.

And in my post, I summarized the long discussion at the blog And Then There's Physics about one of the manuscripts about the greenhouse effect. The discussion suggests that the Connolly's do not believe in the greenhouse effect, but cannot explain for what other reason the surface temperature is 33°C higher as it would be without greenhouse effect.

In this respect the Connolly's are much more moderate as THS, who thinks that greenhouse gasses cool the atmosphere. No typo (the webcite for history).

The argument of THS uses the dry adiabatic lapse rate, would thus only work for the greenhouse gas water vapor and not for the others. And it uses the current effective radiative height as natural constant, not determined by the concentration of greenhouse gases. The result is also physically impossible, for the radiative transfer of heat radiation (cooling of the Earth), an atmosphere without greenhouse gasses is the same as no atmosphere. Whereas the theory of THS claims that in the first case, the surface is 49°C warmer and would consequently radiate stronger toward space.

My comment

For full transparency, I thought it would be a good idea to post my forbidden comment here. I am curious whether my readers also feel that I misbehaved. Feel free to be honest. (You can also comment anonymously.)

Sunday, 23 February 2014

Global Warming Solved in Open Peer Review Journal

Roger Pielke Sr. pointed our attention to a new game-changer article.

If you click on the link, you come to an unknown scientific journal and a manuscript open for peer review.

Everything looks very professional and it could have been the homepage of a real scientific journal. The article looks good, lay-outed perfectly with LaTex and it surely looks like a real scientific article. Maybe almost a bit too good. The article cites the main studies on the topic. Well made.

However, if you look a little further, there are some disappointments. If you look at the list of articles, you notice that the journal is very new. They have not published any articles yet and eight manuscripts are under review. All manuscripts have been uploaded in January 2014, and all are written by Ronan Connolly & Michael Connolly or by Michael Connolly & Ronan Connolly. Father Michael and son Ronan.

Open Peer Review Journal

The journal is called "Open Peer Review Journal", subtitle: "for rigorous open peer review". Being an unknown journal, I was curious who was behind this journal, but the homepage does not mention an editorial board. Fortunately, there is also a blog by the Connolly family called Global Warming Solved. At this blog they state that they themselves have started the journal.

The idea of peer review is to give a paper more credibility, that can only be achieved by sending the manuscripts to an independent journal. Getting published in your own journal will not lead to much credibility, I am afraid scientists will not see this as different from publishing your ideas here on your blog. This will thus not create much incentive to read the eight long articles. I would advice the authors: If your ideas are strong, you should have nothing to fear with going to a real scientific journal. There is also an open review journal: Climate of the Past. If I had a controversial paper, that is where I would go.

Thursday, 6 February 2014

Workshop on novel approaches to homogenization, Boulder, July 2014

By Peter Thorne.

We have long recognized that the enabling framework aspects of the Initiative (databank, benchmarks, data serving) are but one aspect of the problem. What is needed in addition are new approaches to the data homogenization so that we can better understand the data and their uncertainties. This is not something the Initiative can mandate nor something that the 10 cents coin I found following exhaustive searching down the back of my sofa will get us very far in funding. So, we have been and continue to pursue novel means to increase the number of independent groups and individuals undertaking the analysis of the data.

As one such activity, the Initiative put forward a proposal for a SAMSI (Statistical and Applied Mathematical Sciences Institute) summer program activity - which got selected. Over the past few months we have been working with colleagues from SAMSI and NCAR IMAGe (Institute for Mathematics Applied to Geosciences) who joined as substantive co-sponsors to arrange the meeting logistics. We are now in a position to announce the workshop.

So, without further ado ...

Applications are invited for participation in a workshop to be held in Boulder, Colorado July 8th-16th. The aim of the workshop is to develop new and novel techniques for the homogenisation of land surface air temperature data holdings. The workshop participants will have access to the almost 32,000 stations held in the first version databank release (which will be publicly available by then) and also to several of the benchmark datasets. The workshop will mainly be practically based - with few talks and lots of coding and discussions either in plenary or in smaller breakout groups. A final agenda will be forthcoming nearer the time.

Applications are welcome from all. The final meeting is space limited to 44 people. Participants from non-traditional backgrounds, early career scientists and members of under-represented groups are particularly encouraged to apply.

Further meeting details and application form are available at

(Reposted from the ISTI surface temperatures blog, please comment there.)

Tuesday, 4 February 2014

WUWT and Co. not interested in my slanted opinion, part II

The Hockey Schtick broke a story about homogenization, which was picked up by Watts Up With That? They found an article, which they claimed showed that homogenization makes the influence of an enhanced Urban Heat Island stronger. I disagreed with their conclusions, the homogenization method in the paper was designed to study the UHI more accurately and removed other effects that masked it. However, for the global data sets other homogenization methods are used that reduce the influence of urbanization.

There was one thing about this interaction with WUWT and Co, that I found interesting. Interesting in the way Judith Curry uses the word, suggestive and non-committal.

I wrote a comment (see below) on five blogs that had covered the story, quite neutral comments not to violate any comment policy. They had a link to my blog article for more information. One would expect skeptical people, in the original meaning of the word, to be interested in an alternative opinion, especially so if it comes from someone that is reasonably well informed. However, only one of the five comments was published. [UPDATE: now two comments, see below.]

The post was published on the 1st of February, at the time of writing 3 days ago.

Five blogs

The Hockey Schtick: New paper finds adjusted temperature data in China has significantly exaggerated warming
Below the post at The Hockey Schtick are two comments, but mine did not appear.
[UPDATE: After a twitter exchange, I have resubmitted my comment and it has appeared. Problem solved.]

Watts Up With That?: Important study on temperature adjustments: ‘homogenization…can lead to a significant overestimate of rising trends of surface air temperature.’
Anthony Watts thought the homogenization article was very important. My comment has not appeared yet. Last time I tried a similar comment, at least the text "[sorry, but we aren't interested in your slanted opinion - mod]" appeared.
I am on the WUWT black list and normally it takes a few hours before my comments appear, at which time the discussion has typically progressed for fresh posts and most people do not seem to notice the comment any more. Three days would be a new record.

Tips on How to Study: Important study on temperature adjustments: 'homogenization…can …
Then I wrote a comment for Tips On How To Study. Looking in more detail now, it does not seem to be an ostrich blog, but rather someone who copies articles from other blogs, mostly not about How To Study.

The Drinking Water Advisor: Beijing adjusted surface temperature data found to have exaggerated warming trends
The fourth comments was at The Drinking Water Advisor, a blog about water, fluoridation and climate change. My comment did not yet show up here.

Errors in IPCC climate science: How many times does a truth have to be told ? – UHI warming has been cemented into global temperature series by adjusting for steps outward from cities

There is one blog where my comment was posted: Errors in IPCC climate science. Chapeau. One of the bloggers, Warwick S. Hughes, has written some scientific articles and comments on station data quality. He should have been able to see the mistake in the WUWT article.


The last few month I have trouble with getting comments published, also on science blogs, but I would estimate this to affect a few percent of my comments. Getting only one [two] comment[s] out of four or five published is less than expected. Being a scientist, I will naturally assume good faith, the reason may well be some sort of spam filter. I hope my critical readers can make up their own mind.

The comment

At WUWT and Tips, I wrote the comment below. On the other blogs shorter ones with a similar tone.

The authors wanted to accurately study the influence of the urban heat island effect and thus removed the cooling effect of two relocations using a special homogenization method. Without this method the importance of urbanization would have been underestimated.

This special homogenization method is not used for global climate data, where the aim is to remove the effect of urbanization as well. Thus this WUWT post is unfortunately inaccurate. For details, please have a look at my blog.

I would personally say, that that is quite neutral. Certainly compared to the way scientists are described in the comments of WUWT.

Further reading

WUWT comes right out and says "We Aren't Interested" in facts
HotWhoppers take on the previous time WUWT was not interested in my slanted opinion.

Saturday, 1 February 2014

Effect of data homogenization on estimate of temperature trend: a case of Huairou station in Beijing Municipality

The climate ostriches are having some fun with an article (Zhang et al., 2013) published spring last year in Theoretical and Applied Climatology (TAAC). According to The Hockey Schtick, the article corroborates that "leading meteorological institutions in the USA and around the world have so systematically tampered with instrumental temperature data that it cannot be safely said that there has been any significant net “global warming” in the 20th century.

And Anthony Watts writes: "From the “we told you so” department comes this paper out of China that quantifies many of the very problems with the US and global surface temperature record we have been discussing for years: the adjustments add more warming than the global warming signal itself.

Not bad!Those are huge implications for a paper about the homogenization of one station, written by a first author that can only cite one previous study written by him in Chinese and in a journal with a rather modest impact factor. I will come back to these two statements at the end.

Wednesday, 29 January 2014

Testimony Judith Curry on Arctic temperature seems to be a misquotation

Looks like the IPCC is not even wrong.

There has been a heated debate between Judith Curry (Climate Etc.) and Tamino (Open Mind) about the temperature in the Arctic. This debate was initiated by Curry's testimony before congress two weeks ago.

In her testimony Judith Curry quotes:
“Arctic temperature anomalies in the 1930s were apparently as large as those in the 1990s and 2000s. There is still considerable discussion of the ultimate causes of the warm temperature anomalies that occurred in the Arctic in the 1920s and 1930s.” (AR5 Chapter 10)
Tamino at Open Mind investigated this claim and found that recent temperatures were clearly higher as in the beginning of the 20th century. In his post (One of) the Problem(s) with Judith Curry Tamino concludes that the last IPCC report and Curry's testimony are wrong about the Arctic temperature increase:
"I think the IPCC goofed on this one — big-time — and if so, then Curry’s essential argument about Arctic sea ice is out the window. I’ve studied the data. Not only does it fail to support the claim about 1930s Arctic temperatures, it actually contradicts that claim. By a wide margin. It ain’t even close."

That sounded convincing, but I am not so sure about the IPCC any more.

Tamino furthermore wonders where Curry got her information from. I guess he found it funny that Judith Curry would quote the IPCC as a reliable source without checking the information. Replying to another question of mine, Judith Curry replied on twitter that she indeed got her information from the last (draft) IPCC report:

Later she also wrote a reply on her blog, Climate ect, starting with the above quote from the IPCC report.

Then the story takes a surprising turn, when Steve Bloom hidden in a large number of comments at AndThenTheresPhysics notes that the quote is missing important context. The full paragraph in the IPCC namely reads (my emphasis and the quote in Curry's testimony in red):
A question as recently as six years ago was whether the recent Arctic warming and sea ice loss was unique in the instrumental record and whether the observed trend would continue (Serreze et al., 2007). Arctic temperature anomalies in the 1930s were apparently as large as those in the 1990s and 2000s. There is still considerable discussion of the ultimate causes of the warm temperature anomalies that occurred in the Arctic in the 1920s and 1930s (Ahlmann, 1948; Veryard, 1963; Hegerl et al., 2007a; Hegerl et al., 2007b). The early 20th century warm period, while reflected in the hemispheric average air temperature record (Brohan et al., 2006), did not appear consistently in the mid-latitudes nor on the Pacific side of the Arctic (Johannessen et al., 2004; Wood and Overland, 2010). Polyakov et al. (2003) argued that the Arctic air temperature records reflected a natural cycle of about 50–80 years. However, many authors (Bengtsson et al., 2004; Grant et al., 2009; Wood and Overland, 2010; Brönnimann et al., 2012) instead link the 1930s temperatures to internal variability in the North Atlantic atmospheric and ocean circulation as a single episode that was sustained by ocean and sea ice processes in the Arctic and north Atlantic. The Arctic wide temperature increases in the last decade contrast with the episodic regional increases in the early 20th century, suggesting that it is unlikely that recent increases are due to the same primary climate process as the early 20th century. IPCC(2014, draft, page 10-43 to 10-44).

Steve Bloom dryly comments: "So it was a question in 2007." In other words, the IPCC was right, but Judith Curry selectively quoted from the report. That first sentence is very important, also the age of the references could have revealed that this paragraph was not discussing the current state-of-the-art. The data of the last six years makes a large difference between "with some goodwill in the same range of temperatures" to "clearly higher Arctic temperatures".

This is illustrated by one of the figures from Tamino's post, presenting the data:

This is the annual average temperature in the Arctic from 60 to 90 degrees North as computed by the Berkeley Earth Surface Temperature group. The smooth red line is computed using LOESS smoothing.

And the misquotation is not for lack of space in the testimony. In her blog post, Curry quotes may sections of the IPCC report at length and also the entire paragraph like it is displayed here, just somehow without the first sentence printed here in bold, the one that provides the important context.

Related reading

The congressional Testimony by Curry: STATEMENT TO THE COMMITTEE ON ENVIRONMENT AND PUBLIC WORKS OF THE UNITED STATES SENATE Hearing on “Review of the President’s Climate Action Plan" 16 January 2014, Judith A. Curry.

(One of) the Problem(s) with Judith Curry by Tamino at Open Mind.

The reply by Curry about Tamino's post on her blog, Climate ect.

The answer to that by Tamino suggests that Curry's reply is not that convincing.

Also Robert Way contributed to the discussion at Skeptical Science: "A Historical Perspective on Arctic Warming: Part One". Robert Way made the round in the blog-o-sphere with the paper Cowtan and Way (2013), where they studied the recent strong warming in the Arctic and suggested that that may explain a part of the recent slowdown in the warming of surface temperature.

A previous post of mine of Curry's testimony, focussing on her suggestive, but non-committal language: "Interesting what the interesting Judith Curry finds interesting".

Monday, 27 January 2014

Peer review helps fringe ideas gain credibility

Stoat has a nice new post explaining how peer review works in practice. The climate ostriches sometimes suggest that peer review is just there to keep their ideas out of the scientific literature and derogatively call it pal review. Well, peer review is nowadays practiced in all sciences, so that seems rather far fetched. Thinking about it, I would argue that peer review could actually help the climate ostriches. There is one caveat: they would have a valid critique. That is the bigger problem for them.

So what is peer review, what is its function in science and how could it help the climate ostriches?

How does it work

The short description of peer review at Stoat is:
For a working scientist, peer review is just part of the job. You write up your work, you show it to your colleagues ..., you send it to the best journal you think you can get away with, and eventually you get the reviews back. These will be a mixture of “please cite my paper” (usually disguised as “you need to consider X”), typos, and the occasional well-considered thoughtful comment that genuinely improves things. You sigh, you happily incorporate the thoughtful stuff, you work out how much of the not-very-helpful stuff you can get away with blowing off, and you resubmit ... And sometimes you get a reviewer who really really doesn’t like your paper for what you regard as invalid reasons, and you have to decide whether to fight to the death or go elsewhere.

Function in science

In my previous post, The value of peer review for science and the press, I wrote about its function in 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.
Given that an important function of peer review is to give the article credibility, it is also logical that reviewers pay extra attention if an article makes strong claims, that is claims that clearly deviate from our current understanding. In an ideal world, without any time pressures, peer review would be perfect every instance. However, a run of the mill article by a well-known author is much less likely to contain problems.

I would argue that that should be no problem for the people making strong claims. Every claim should hold up the scrutiny of the reviewers any way. That may be more work, but such an article also brings much more acclaim and is thus worth some work. As quoted above, sometimes reviewers will block your beautiful manuscript. That has also happened to me and probably to any active scientist. Then you just go to another journal. If the idea is valid, you will find a place for it.

That peer review is not perfect may be more of a problem for seasoned scientists. I especially notice that well-written article, by native speakers, are more likely to contain small errors. The smooth language seems to make the reviewers less critical and the author is punished by publishing articles with embarrassing errors.

Saturday, 25 January 2014

Interesting what the interesting Judith Curry finds interesting

I am a little late with this, I just came across the Week in review by Judith Curry. If there is one thing that annoys me about the way Curry communicates, it is her suggestive, but completely non-committal language. The exact opposite of what I am used to among scientists. The word "interesting" is one of her favorite suggestive words.

Here is a quote illustrating the problem. Curry writes:

Freezing is the new warming

RealClearPolitics has an interesting article Freezing is the new warming, that summarizes the current state of the public debate on climate change.  Excerpts:

Or try refuting global warming. Temperatures have stopped warming for more than a decade? That’s just a temporary “pause” in the warming that we just know is going to come roaring back any day now. Antarctic ice is growing? That’s actually caused by the melting of ice, don’t you know. A vicious cold snap that sets record low temperatures? That’s just because the North Pole is actually warming. So if the winter is warm, that’s global warming, but if the winter is cold, that’s global warming, too. If sea ice is disappearing, that’s global warming, but if sea ice is increasing, that’s global warming.

Now we can see what they mean when the warmthers say that global warming is supported by an ironclad scientific consensus. The theory is so irrefutable that it’s unfalsifiable!

Which is to say that it has become a cognitive spaghetti bowl full of ad hoc rationalizations, rather than a genuine scientific hypothesis. 

This is pure and utter nonsense. Let me just discuss the main point, all the other denier memes are debunked at Skeptical Science. It is very easy to falsify the theory of global warming by greenhouse gasses.

If there would be an unexplained temperature drop of one degree and it would stay there for a decade, the theory is completely dead. If the same thing happens to the ocean heat content, the theory is dead within a year.

RealClearPolitics is right in suggesting that anything that will actually happen is very unlikely to refute the theory. Quite of lot of basic science would need to be wrong. And RealClearPolitics is right in suggesting that it is not sufficient for something to happen what feelies intuitively feel should not happen in a warmer climate. You do need some actual proof that the phenomenon should behave that way. His blog is at least honestly called a political blog.

Judith Curry is very intelligent and has much experience as scientist. She naturally knows that this quote was nonsense, but also that her audience likes it. Thus she non-noncommittally calls it interesting.

My wish for 2014 is that Curry comes back to the scientific community and stops using the word "interesting" so much. The scientific way of trying to understand why there is a difference of understanding is making it clearer what you mean.

[UPDATE: The blog Klimaatverandering just has listed 10 ways to "falsify AGW". Worth reading.]

[UPDATE: This post and the ensuing discussion made me think that a long post on the topic may be useful. I would argue that falsifiable is important and that falsification is overrated.]

Sunday, 8 December 2013

Climate myths translated into econ talk

Yesterday, I was at an amazing meeting. The three public lectures about climatology were not that eventful, although it was interesting to see how you can present the main climatological findings in a clear way.

The amazing part was the Q&A afterwards. I was already surprised to see that I was one of the youngest ones, but had not anticipated that most of these people were engineers and economists, that is climate ostriches. As far as I remember, not one public question was interesting! All were trivially nonsense, I am sorry to have to write.

One of the ostriches showed me some graphs from a book by Fred Singer. Maybe I should go to an economics conference and cite some mercantile theorems of Colbert. I wonder how they would respond.

Afterwards I wondered whether translating their "arguments" against climatology to economy would help non-climatologists to see the weakness of the simplistic arguments. This post is a first attempt.

Seven translations

#1. That there is and always have been natural variability is not an argument again anthropogenic warming just like the pork cycle does not preclude economic growth.

#2. One of our economist ostriches thought that there was no climate change in Germany because one mountain station shows cooling. That is about as stupid as claiming that there is no economic growth because one of your uncles had a decline in his salary.

#3. The claim that the temperature did not increase or that it was even cooling in the last century, that it is all a hoax of climatologists (read the evil Phil Jones) can be compared to a claim that the world did not get wealthier in the last century and that all statistics showing otherwise are a government cover-up. In both cases there are so many independent lines of research showing increases.

#4. The idea that CO2 is not a greenhouse gas and that increases in CO2 cannot warm the atmosphere is comparable to people claiming that their car does not need energy and that they will not drive less if gasoline becomes more expensive. Okay maybe this is not the best example, most readers will likely claim that gas prices have no influence on them, they have no choice and have to drive, but I would hope that economists know better. The strength of both effects needs study, but to suggest that there is no effect is beyond reason.

#5. Which climate change are you talking about, it stopped in 1998. That would be similar to the claim that since the banking crisis in 2008 markets are no longer efficient. Both arguments ignore the previous increases and deny the existence of variability.

#6. The science isn't settled. Both science have foundations that are broadly accepted in the profession (consensus) and problems that are not clear yet and that are a topic of research.

#7. The curve fitting exercises without any physics by the ostriches are similar to "technical analyses" of stock ratings.

[UPDATE. Inspired by a comment of David in the comments of Judith Curry on Climate Change (EconTalk)
#8 The year 1998 was a strong El Nino year and way above trend, well above nearby years. Choosing that window is similar to saying that stocks are a horrible investment because the market collapsed during the Great Depression.]

[UPDATE. Found a nice one.
Daniel Barkalow writes:
Looking at the global average surface temperature (which is what those graphs tend to show), is a bit like looking at someone's bank account. It's a pretty good approximation of how much money they have, but there's going to be a lot of variability, based on not knowing what outstanding bills the person has, and the person is presumably earning income continuously, but only getting paychecks at particular times. This mostly averages out, but there's the risk in looking at any particular moment that it's a really uncharacteristic moment.

In particular, it seems to me that the "pause" idea is based on the fact that 1998 was warmer than nearly every year since, while neglecting that 1998 was warmer than 1997 or any previous year by more than 15 years of predicted warming. If this were someone's bank account, we'd guess that it reflected an event like having their home purchase fall through after selling their old home: some huge asset not usually included ended up in their bank account for a certain period before going back to wherever it was. You wouldn't then think the person had stopped saving, just because they hadn't saved up to a level that matches when their house money was in their bank account. You'd say that there was weird accounting in 1998, rather than an incredible gain followed by a mysterious loss.

One interesting question

The engineers and economists were wearing suits and the scientists were dressed more casually. Thus it was easy to find each other. One had an interesting challenge, which was at least new to me, he argued that the Fahrenheit scale, which was used a lot in the past is uncertain because it depends on the melting point of brine and the amount of salt put in the brine will vary.

One would have to make quite an error with the brine to get rid of global warming, however. Furthermore, everyone would have had to make the same error, because a random errors would average out. And if there were a bias, this would be reduced by homogenization. And almost all of the anthropogenic warming was after the 1950-ies, where this problem no longer existed.

A related problem is that the definition of the Fahrenheit scale has changed and also that there are many temperature scales and in old documents it is not always clear which unit was used. Wikipedia lists these scales: Celsius, Delisle, Fahrenheit, Kelvin, Newton, Rankine, Réaumur and Rømer. Such questions are interesting to get the last decimal right, but no reason to become an ostrich.


I find it a bit disturbing that so many economists come up with so simple counter "arguments". They basically assume that climatologists are stupid or are conspiring against humanity. Expecting that for anther field of study makes one wonder where they got that expectation from and shines a bad light on economics.

This was just a quick post, I would welcome ideas for improvements and additions in the comments. Did I miss any interesting analogies?

Thursday, 5 December 2013

Announcement of the 8th Seminar for Homogenization in Budapest in May 2014

The first announcement has been published of the 8th Seminar for Homogenization. This is the main meeting of the homogenization community. It was announced on the homogenization distribution list. Anyone working on homogenization is welcome to join this list.

This time it will be organized together with the 3rd conference on spatial interpolation techniques in climatology and meteorology. As always it will be held in Budapest, Hungary. It will take place from the 12th to the 16 May 2014. The pre-registration and abstract submission deadline is 30 March 2014.

[UPDATE: There is now a homepage with all the details about the seminar.]

The announcement is available as PDF. Some excerpts:


At present we plan to organize the Homogenization Seminar and the Interpolation Conference together considering certain theoretical and practical aspects. Theoretically there is a strong connection between these topics since the homogenization and quality control procedures need spatial statistics and interpolation techniques for spatial comparison of data. On the other hand the spatial interpolation procedures (e.g. gridding) need homogeneous, high quality data series to obtain good results, as it was performed in the Climate of Carpathian Region project led by OMSZ and supported by JRC. The main purpose of the project was to produce a gridded database for the Carpathian region based on homogenized data series. The experiences of this project may be useful for the implementation of gridded databases.

Monday, 2 December 2013

On the importance of changes in weather variability for changes in extremes

This is part 2 of the series on weather variability.

A more extreme climate is often interpreted in terms of weather variability. In the media weather variability and extreme weather are typically even used as synonyms. However, extremes may also change due to changes in the mean state of the atmosphere (Rhines and Huybers, 2013) and it is in general difficult to decipher the true cause.

Katz and Brown theorem

Changes in mean and variability are dislike quantities. Thus comparing them is like comparing apples and oranges. Still Katz and Brown (1992) found one interesting general result: the more extreme the event, the more important a change in the variability is relative to the mean (Figure 1). Thus if there is a change in variability, it is most important for the most extreme events. If the change is small, these extreme events may have to be extremely extreme.

Given this importance of variability they state:
"[Changes in the variability of climate] need to be addressed before impact assessments for greenhouse gas-induced climate change can be expected to gain much credibility."

The relative sensitivity of an extreme to changes in the mean (dashed line) and in the standard deviation (solid line) for a certain temperature threshold (x-axis). The relative sensitivity of the mean (standard deviation) is the change in probability of an extreme event to a change in the mean (or standard deviation) divided by its probability. From Katz and Brown (1992).
It is common in the climatological literature to also denote events that happen relatively regularly with the term extreme. For example, the 90 and 99 percentiles are often called extremes even if such exceedances will occur a few times a month or year. Following the common parlance, we will denote such distribution descriptions as moderate extremes, to distinguish them from extreme extremes. (Also the terms soft and hard extremes are used.) Based on the theory of Katz and Brown, the rest of this section will be ordered from moderate to extreme extremes.

Examples from scientific literature

We start with the variance, which is a direct measure of variability and strongly related to the bulk of the distribution. Della-Marta et al. (2007) studied trends in station data over the last century of the daily summer maximum temperature (DSMT). They found that the increase in DSMT variance over Western Europe and central Western Europe is, respectively, responsible for approximately 25% and 40% of the increase in hot days in these regions.

They also studied trends in the 90th, 95th and 98th percentiles. For these trends variability was found to be important: If only changes in the mean had been taken into account these estimates would have been between 14 and 60% lower.

Also in climate projections for Europe, variability is considered to be important. Fischer and Schär (2009) found in the PRUDENCE dataset (a European downscaling project) that for the coming century the strongest increases in the 95th percentile are in regions where variability increases most (France) and not in regions where the mean warming is largest (Iberian Peninsula).

The 2003 heat wave is a clear example of an extreme extreme, where one would thus expect that variability is important. Schär et al. (2004) indeed report that the 2003 heat wave is extremely unlikely given a change in the mean only. They show that a recent increase in variability would be able to explain the heat wave. An alternative explanation could also be that the temperature does not follow the normal distribution.

Tuesday, 26 November 2013

Are break inhomogeneities a random walk or a noise?

Tomorrow is the next conference call of the benchmarking and assessment working group (BAWG) of the International Surface Temperature Initiative (ISTI; Thorne et al., 2011). The BAWG will create a dataset to benchmark (validate) homogenization algorithm. It will mimic the real mean temperature data of the ISTI, but will include know inhomogeneities, so that we can assess how well the homogenization algorithms remove them. We are almost finished discussing how the benchmark dataset should be developed, but still need to fix some details. Such as the question: Are break inhomogeneities a random walk or a noise?

Previous studies

The benchmark dataset of the ISTI will be global and is also intended to be used to estimate uncertainties in the climate signal due to remaining inhomogeneities. These are the two main improvements over previous validation studies.

Williams, Menne, and Thorne (2012) validated the pairwise homogenization algorithm of NOAA on a dataset mimicking the US Historical Climate Network. The paper focusses on how well large-scale biases can be removed.

The COST Action HOME has performed a benchmarking of several small networks (5 to 19 stations) realistically mimicking European climate networks (Venema et al., 2012). It main aim was to intercompare homogenization algorithms, the small networks allowed HOME to also test manual homogenization methods.

These two studies were blind, in other words the scientists homogenizing the data did not know where the inhomogeneities were. An interesting coincidence is that the people who generated the blind benchmarking data were outsiders at the time: Peter Thorne for NOAA and me for HOME. This probably explains why we both made an error, which we should not repeat in the ISTI.