We need to talk about a geo-intervention

There was a time to work on (the technologies for) reducing emissions of greenhouse gasses (mitigation), now is the time we also need to work on adaptation and now is the time we need to start having a serious conversation about a geo-intervention. The journalistic hook is a new interesting commentary in the scientific journal Nature. It makes the surprising, at least for me, case that a geo-intervention to reduce the insolation will also reduce greenhouse gas concentrations and ocean acidification.

Geo-intervention is the more accurate term for what is commonly called geo-engineering. We cannot engineer the climate, but we may be able to make the climate crisis less harmful. Also our emissions of greenhouse gases are a geo-intervention and by now we cannot even say anymore that it is an unintended intervention. We know what we are doing and are doing it anyway.

The best known geo-intervention is called Solar Radiation Management, that is, a reduction of the amount of sun that is absorbed at the Earth’s surface. This is possible by making the Earth brighter, especially the dark oceans, it may be possible to make clouds brighter or we could install mirrors in space. The most considered Solar Radiation Management method is creating large amounts particles high up in the air in the stratosphere. We know this works, large tropical volcanoes cool the Earth by emitting sulphur dioxide creating small particles in the stratosphere.

Advantages of Solar Radiation Management would be that it is relatively cheap. A medium sized economy like The Netherlands would have to spend a few percent of its gross domestic product to keep the global mean temperature stable. That sounds like a much better deal than having your culture disappear in the waves and more countries will likely be willing to chip in and join such a coalition of the chilling.

The Nature comment makes the interesting case that reducing the warming, will also reduce the concentrations of carbon dioxide in the atmosphere. It would do so as vegetation would take up more carbon dioxide if they are less stressed by the heat. The Arctic would warm less, which would reduce emissions from thawing permafrost. And also humans tend to use less energy when the planet is colder (for example, less air conditioning). Compared to other methods to remove carbon dioxide from the atmosphere solar radiation management is cheap.



Disadvantages are that this would hurt the ozone layer in the stratosphere. Volcanoes use sulphuric dioxide for their Solar Radiation Management, this would make acid rain worse. However, there is ongoing research on alternative particles and hopefully acid rain becomes better anyway due to the energy transition away from burning fossil fuels, which emits sulphuric dioxide in the troposphere where we live. In the dry stratosphere the particles are not removed as fast (for example due to precipitation) as in the troposphere. So we would need much less sulphuric dioxide emissions to cool the planet in the stratosphere than in the troposphere.

Solar Radiation Management can also not stop all climatic changes. Global warming due to greenhouse gases will mostly warm the Arctic (polar amplification), while solar radiation management would mostly cool the tropics where the sun is the strongest. Thus the temperature difference between equator and pole would become smaller and the circulation and water cycle would still change (although probably less).

The Nature comment argues that we should also talk about using Solar Radiation Management to partially offset global warming. Most studies look at bringing the temperature down to pre-industrial levels, but we could also make smaller reductions. For example, we could stabilise the temperature in the tropics. Then the rest of the planet would still warm, but the impacts in poor and thus vulnerable countries would then be reduced.

Goe-interventions are typically accompanied by academic debates about global governance of such a system. We have seen how good that works for the original problem, geo-engineering by carbon dioxide. In case of carbon dioxide the response has been limited by the people willing to take the largest risks with other people's lives and property. (Hopefully economic forces will now block them.) The only possible climate treaty was one without any obligations beyond reporting back. Still the incompetent president of the historically largest polluter said fuck you to the entire world for no other reason than the pleasure of saying Fuck You!

Similarly the coolest coalition of the chilling will set the temperature. If the hotheads do not like that, I am sure the reasonable cool people will be willing to talk, if the talks are also about carbon dioxide emissions.



We would have to keep on managing the insolation for millennia or until someone finds a cheap way to remove carbon dioxide from the air. The largest danger is thus that humanity gets into trouble over these millennia and would no longer be able to keep the program up, the temperature would jump up quickly and make the trouble even worse. Looking back at our history since Christ was born and especially the last century, it seems likely that we will be in trouble once in a while over such a long period.

This danger could also be an advantage, just as the mutual assured destruction (MAD) with nuclear arms brought us a period of relative peace, the automatic triggering of Mad Max would force humanity to behave somewhat sensibly and make people who love war less influential.

My impression is that the main objection from scientists against geo-interventions is their worry about creating such an automatically triggered doomsday machine. Those people seem to think of a scenario without mitigation, where we would have to do more and more Solar Radiation Management. While carbon dioxide accumulates in the atmosphere over millennia, the stratospheric particles (after a volcanoes) are removed after a few years. So we would need to keep adding them to the stratosphere and if we do not reduce greenhouse gas emissions increasingly many particles.



I do not think humanity will forgo mitigation, but we will likely be too slow. My expectation is that we will stabilise the temperature, but after quite a lot of warming. Renewable energy is getting very cheap and still rapidly declining in price. Also batteries are declining in price. Thus I would see the energy transition as unstoppable for electrical power and private transport. That would break the political power of the fossil fuel industry and then make the rest of the transition (heating and industrial processes) a lot easier.

About 20 percent of historical warming is due to methane, which is mostly due to animal husbandry (read burping cows) and rice paddies. The residence time of methane is about a decade. It thus accumulates thus much less than carbon dioxide and would be something we could fight with a modest and importantly stable amount of Solar Radiation Management. Hopeful was a recent study that feeding cows seaweed reduces their methane emissions almost to zero. (There are many other ethical and environmental problems with industrial agriculture, but the global warming part of it would then be solved.)

At current costings per hectare, it will take 4 Trillion dollars to artificially restore corals on the #GreatBarrierReef lost from bleaching pic.twitter.com/IvuBJwt9Zy

— Terry Hughes (@ProfTerryHughes) 31 August 2017

Thus I expect us to stabilise the climate, but at a level that will be harmful. If we stabilise at 3°C of warming, would it not be better to reduce the warming to 2°C, 1.5°C, or our current 1°C. The internationally agreed upon 1.5 and 2°C levels are not "safe" levels, below them there are clear damages (and above them the word will not suddenly end).

There are scientific justifications for the 2°C level, for example looking at some tipping points in the climate system, but this level is not set by science. In the end it is a political compromise between the risks of climate change and political difficulty of changing the energy system. As a Dutch person, my compromise is to go back to the old temperature. Also if the warming would stop now immediately, sea level rise would continue for millennia.

The question is not whether it would be nicer not to have climate change, but whether a geo-intervention can improve the situation. Some worry that a geo-intervention would reduce the pressure to reduce greenhouse gas emissions. In a rational world that may partially be the case, although a geo-intervention would not stop the market forces moving us to renewable energy. In the real, not rational, world it may well do the opposite.



Most people like to see the world become a better place, some for all, some for a large group they identify with, some for their community, some for their family. That may make these people blind for the possibility that some do not mind if their own situation becomes worse, as long as it becomes even worse for others and relatively they “win”. Let’s call these people supremacists or fascists.

The term supremacy or Trump’s slogan “America first” is already a hint that these people want to be on top, it does not say that the top is a nicer place, it is a relative measure. When the Second World War still went "well" for the Nazi’s, they were on top, but the suffering was enormous, less so, but also for the Germans. The Nazi’s did not care, for them war and violence is a natural state. They call normal people “Good people”, seeing themselves as bad people, as people who enjoy bringing about suffering of humans they perceive as less valuable. America’s white supremacists dream of a race war, which will also bring a lot of suffering on the people they claim to love.

When these people hear Greenpeace argue that vulnerable people will suffer most from climate change, it would make sense that they like this and want more of this. It is not possible to convince these people that climate change is real, they already accept it is real, they only claim they do not. The best way to get more climate change is to claim that you do not accept the science of climate change. That way you can also convince some conservatives who do not like to see others suffering, but are naturally sceptical of any claim that powerful corporations can do something wrong and trust their politicians who work for the fossil fuel companies (campaign contributions, cosy jobs afterwards).

I think the fascists are stupid to listen to Greenpeace. Yes, more people will die in poor countries, that means they will have more kids and multiply faster. Living in a harsh environment makes you flexible and strong. Our power and pampered life style is based on a fragile just-in-time economy, where everything is optimised and thus every change produces damages. Where a mid-sized bank going bust can produce a decade long recession. If civilisation goes down, the poor will have the more useful skills.

The mitigation sceptical movement seems to be against all types of geo-intervention, except for emitting greenhouse gases. Reading between the lines when they complain that scientists spread too much fear, one almost gets the impression they fear climate change more than most. That could be because they are fighting to make the worst case scenario happen and expect to be “successful”.

The fascists among them would hate it when geo-interventions would make their life’s work mostly futile. If they are no longer fighting for a bad world that would make the transition again a lot easier.

Hopefully they will move on to lie about other stuff, preferably claims that are easily checkable, like the size of inaugurations. (It is a sad state of affairs, that I thought is was worthwhile to add a link.)



Let me end this post with a And-Then-There's-Physics-style last paragraph. I know a little about the quality of climate data, but this post is just written as a participant in the climate debate. As far as I can judge nearly all scientists worry about geo-interventions and many do not even like doing research on it. So even if pro-intervention people are very present in the media, I am an outlier. Feel free to point out my thinking mistakes and alternative solutions.

Related reading

Do dissenters like climate change?

Nature commentary: solar geoengineering reduces atmospneric carbon burden. (Open Access with this link.)

Gernot Wagner co-author of the book Climate Shock: It's time to take solar geoengineering seriously, even though it seems outlandish.

Raymond T. Pierrehumbert in The Bulletin of Atomic Scientists The trouble with geoengineers “hacking the planet”.

Reto Knutti, Joeri Rogelj, Jan Sedláček & Erich M. Fischer, 2016: A scientific critique of the two-degree climate change target. (pay-walled)

Frieler, K., Mengel, M., and Levermann, A.: Delaying future sea-level rise by storing water in Antarctica, Earth Syst. Dynam., 7, 203-210, doi: 10.5194/esd-7-203-2016, 2016.


* Top photo by NASA, Filament Eruption Creates 'Canyon of Fire' on the Sun used with a Creative Commons Attribution 2.0 Generic (CC BY 2.0) license.

Photo of thawing permafrost by NPS Climate Change Response used with a Creative Commons Attribution 2.0 Generic (CC BY 2.0) license.

Photo Collecting salt under desert sun by Armando G Alonso used with a Creative Commons Attribution-NonCommercial 2.0 Generic (CC BY-NC 2.0) license.

Photo of a strong African lady Use No Hooks by Michał Huniewicz used with a Creative Commons Attribution 2.0 Generic (CC BY 2.0) license.

Ottmar Edenhofer in 2010 on international climate politics and redistribution of wealth

If you give me six lines written by the hand of the most honest of men, I will find something in them which will hang him.
Cardinal Richelieu (or his circle)

[[Ottmar Georg Edenhofer]] (born in 1961 in Germany) currently holds the professorship of the Economics of Climate Change at the Technical University of Berlin. He is deputy director and chief economist of the Potsdam Institute for Climate Impact Research (PIK). From 2008 to 2015 he served as one of the co-chairs of the Intergovernmental Panel on Climate Change (IPCC) Working Group III "Mitigation of Climate Change".

Some hold the view that climate scientists are conspiring against humanity to bring down capitalism. (Not so sure whether a natural science is the best place to start the biggest, longest, global conspiracy, whether an abstract, slow and distributed environmental problem is the best way to motivate people, whether an economic sector whose business model is political corruption is the easiest one to topple, nor whether using another energy source would change capitalism.)

As evidence they occasionally cherry pick from an article by Ottmar Edenhofer, then the co-chairman of Working Group III on solving climate change (mitigation) of the Intergovernmental Panel on Climate Change. He was describing the political reality and explained why "the owners of coal and oil are not enthusiastic" about fighting climate change when he wrote: "We redistribute de facto the world’s wealth by climate politics."

The quote comes from an interview in the Swiss Newspaper Neue Zürcher Zeitung. So I can use my comparative advantage of knowing a little German. Fortunately people in Switzerland merely speak Swiss German, Schwyzerdütsch, they write standard German, Hochdeutsch, which is hard enough for a poor Dutch natural scientist.

This is the key part of the NZZ interview with Ottmar Edenhofer in 2010:

Grundsätzlich ist es ein grosser Fehler, Klimapolitik abgetrennt von den grossen Themen der Globalisierung zu diskutieren. Der Klimagipfel in Cancún Ende des Monats ist keine Klimakonferenz, sondern eine der grössten Wirtschaftskonferenzen seit dem Zweiten Weltkrieg. Warum? Weil wir noch 11 000 Gigatonnen Kohlenstoff in den Kohlereserven unter unseren Füssen haben – und wir dürfen nur noch 400 Gigatonnen in der Atmosphäre ablagern, wenn wir das 2-Grad-Ziel halten wollen. 11 000 zu 400 – da führt kein Weg daran vorbei, dass ein Grossteil der fossilen Reserven im Boden bleiben muss.

De facto ist das eine Enteignung der Länder mit den Bodenschätzen. Das führt zu einer ganz anderen Entwicklung als der, die bisher mit Entwicklungspolitik angestossen wurde.

Zunächst mal haben wir Industrieländer die Atmosphäre der Weltgemeinschaft quasi enteignet. Aber man muss klar sagen: Wir verteilen durch die Klimapolitik de facto das Weltvermögen um. Dass die Besitzer von Kohle und Öl davon nicht begeistert sind, liegt auf der Hand. Man muss sich von der Illusion freimachen, dass internationale Klimapolitik Umweltpolitik ist. Das hat mit Umweltpolitik, mit Problemen wie Waldsterben oder Ozonloch, fast nichts mehr zu tun.

I would translate that as:

Fundamentally, it is a big mistake to discuss climate politics separately from the big issues of globalization. The climate summit in Cancún at end of the month is not a climate conference, but one of the largest economic conferences since the Second World War. Why? Because we have 11,000 gigatons of carbon in the coal reserves under our feet – and we can only add 400 gigatons more to the atmosphere if we want to stay within the 2 °C target. 11,000 to 400 – we have to face the fact that a large part of the fossil reserves must remain in the ground.

De facto, this is the expropriation of the countries with these natural resources. This leads to an entirely different development than the one that has been initiated with development policy.

First of all, we as industrialized countries have quasi expropriated the atmosphere of the world community. But one must explicitly say: We de facto redistribute the world’s wealth due to climate politics. That the owners of coal and oil are not enthusiastic about this is obvious. One has to free oneself from the illusion that international climate politics is environmental politics. This has almost nothing to do any more with environmental politics, [as is was with] with problems such as deforestation or the ozone hole.

That is a wordy way of saying that climate policies have large economic implications and that these impact different countries differently. For most governments economics is more important than the environment. That means that the world leaders sit at the table and not the environment ministers. Ironically in the sentence most often quoted by the mitigation sceptics Ottmar Edenhofer is expressing understanding for the owners of coal and oil.

They were used to violating the property rights of others without paying for it, the large-scale equivalent of dumping your trash in your neighbours garden. Then it is annoying if the neighbour finds out what you are doing, wants you to stop and clean up the mess.

Also doing nothing is redistributing wealth: "we as industrialized countries have quasi expropriated the atmosphere of the world community." This is a kind of redistribution social Darwinists may find natural, but it goes against the property rights our capitalism system is based on. That is socialism for the owners of coal and oil.

I guess it is natural for people who are willing to pretend that climate science is wrong to defend their political views to assume that people who accept climate science do so for political reasons. That is [[psychological projection]] and Karl Rove strategy #3: Accuse your opponent of your own weakness. My impression is the opposite: most people prefer to be grounded in reality, not just in my science bubble.


* Photo of Prof. Dr. Ottmar Edenhofer Chefökonom des Potsdam-Instituts für Klimafolgenforschung by Stephan Roehl licensed under the Creative Commons Attribution-Share Alike 2.0 Generic license.

David Rose's alternative reality in the Daily Mail

Peek-a-boo! Joanna Krupa shows off her stunning figure in see-through mesh dress over black underwear
Bottoms up! Perrie Edwards sizzles in plunging leotard as Little Mix flaunt their enviable figures in skimpy one-pieces
Bum's the word! Lottie Moss flaunts her pert derriere in a skimpy thong as she strips off for steamy selfie

Sorry about those titles. They provide the fitting context right next to a similarly racy Daily Mail on Sunday piece of David Rose: "Exposed: How world leaders were duped into investing billions over manipulated global warming data". Another article on that "pause" thingy that mitigation skeptics do their best to pretend not to understand. For people in the fortunate circumstances not to know what the Daily Mail is, this video provides some context about this Murdoch "newspaper".

[UPDATE: David Rose' source says in an interview with E&E News on Tuesday: “The issue here is not an issue of tampering with data”. So I guess you can skip this post, except if you get pleasure out of seeing the English language being maltreated. But do watch the Daily Mail video below.

See also this article on the void left by the Daily Mail after fact checking. I am sure all integrity^TM-waving climate "skeptics" will condemn David Rose and never listen to him again.]



You can see this "pause" in the graph below of the global mean temperature. Can you find it? Well you have to think those last two years away and then start the period exactly in that large temperature peak you see in 1998. It is not actually a thing, it is a consequence of cherry picking a period to get a politically convenient answer (for David Rose's pay masters).



In 2013 Boyin Huang of NOAA and his colleagues created an improved sea surface dataset called ERSST.v4. No one cared about this new analysis. Normal good science. One of the "scandals" Rose uncovered was that NOAA is drafting an article on ERSST.v5.

But this post is unfortunately about nearly nothing, about the minimal changes in the top panel of the graph below. I feel the important panel is the lower one. It shows that in the raw data the globe seems to warm more. This is because before WWII many measurements were performed with buckets and the water in the bucket would cool a little due to evaporation before reading the thermometer. Scientists naturally make corrections for such problems (homogenization) and that helps make a more accurate assessment of how much the world actually warmed.

But Rose is obsessed with the top panel. I made the graph extra large, so that you can see the differences. The thick black line shows the new assessment (ERSST.v4) and the thin red line the previously estimated global temperature signal (ERSST.v3). Differences are mostly less than 0.05°C, both warmer and cooler. The "problem" is the minute change at the right end of the curves.

The mitigation skeptical movement was not happy when a paper in Science in 2015, Karl and colleagues (2015), pointed out that due to this update the "pause" is gone, even if you use the bad statistics the mitigation skeptics like. As I have said for many years now about political activists claiming this "pause" is highly important: if your political case depends on such minute changes, your political case is fragile.



In the mean time a recent article in Science Advances by Zeke Hausfather and colleagues (2016) now shows evidence that the updated dataset (ERSSTv4) is indeed better than the previous version (ERSSTv3b). They do so by comparing the ERSST dataset, which comes from a large number of data sources, with data that comes only from only one source (buoys, satellites (CCl) or ARGO). These single-source datasets are shorter, but without trend uncertainties due to the combination of sources. The plot below shows that the ERSSTv4 update improves the fit with the other datasets.



The trend change over the cherry-picked "pause" period were mostly due to the changes in the sea surface temperature of ERSST. Rose makes a lot of noise about the land data, where the update was inconsequential. As indicated in Karl and colleagues (2015) this was a beta-version dataset. The raw data was published; that is the data of the International Surface Temperature Initiative (ISTI) and the homogenization method was published. The homogenization method works well; I checked myself.

The dataset itself is not published yet. Just applying a known method to a known dataset is not a scientific paper. Too boring.

So for the paper NOAA put a lot of work into estimating the uncertainty due to the homogenization method. When developing a homogenization method you have to make many choices. For example, inhomogeneities are found by comparing one candidate station with multiple nearby reference stations. There are settings for now many stations and for how nearby the reference stations need to be. NOAA studied which of these settings are most important with a nifty new statistical method. These settings were varied to study how much influence that has. I look forward to reading the final paper. I guess Rose will not read it and stick to his role as suggestive interpreter of interpreters.

The update of NOAA's land data will probably remove a precious conspiracy of the mitigation skeptical movement. While, as shown above, the adjustments reduce our estimate for the warming of the entire world, the adjustments make the estimate for the warming over land larger. Mitigation skeptics like to show the adjustments for land data only to suggest that evil scientists are making global warming bigger.

This is no longer the case. A recommendable overview paper by Philip Jones, The Reliability of Global and Hemispheric Surface Temperature Records, analyzed the new NOAA dataset. The results for land are shown below. The new ISTI raw data dataset shows more warming than the previous NOAA raw data dataset. As a consequence the homogenization now does not change the global mean appreciably any more to arrive at about the same answer after homogenization; compare NOAA uncorrected (yellow line) with NOAA (red; homogenized).



The main reason for the smaller warming in the old NOAA raw data was that this smaller dataset contained a higher percentage of airport stations. That is because airports report their data very reliably in near real time. Many of these airport stations were in cities before and cities are warmer than airports due to the urban heat island effect. Such relocations thus typically cause cooling jumps that are not related to global warming and are removed by homogenization.

So we have quite some irony here.

• Rose never mentions that the adjustments make our estimate of global warming smaller; that would not have fit into the conspiracy he is trying to sell.
• The "pause" is based on bad statistics and cherry-picking a specific period, which is bad "science". With good statistics, there is no evidence of any trend change.
• The "pause" hype assumes that climate data is perfect. I have warned against that over and over again; for example in 2013. Well before the Karl and colleagues (2015) paper showed these uncertainties indeed cannot be ignored for such a short period.
• With the last 2 years of data in it is clear that there never was any pause, you no longer need any statistics to see that.
• Recent new evidence makes the case stronger that the new ERSST.v4 dataset is an improvement.

Still Rose sees a scandal in these minute updates and dubs it Climategate 2; I thought we were already at 3 or 4. In this typical racy style he calls data "wrong", "rogue", "biased". Knowing that data is never perfect is why scientists do their best to assess the quality of the data, remove problems and make sure that the quality is good enough to make a certain statement. In return people like David Rose simultaneously pontificate about uncertainty monsters and assume data is perfect and then get the vapors when updates are needed.

Rose gets some suggestive quotes from an apparently disgruntled retired NOAA employee. The quotes themselves seem to be likely inconsequential procedural complaints, the corresponding insinuations seem to come from Rose.

I thought journalism had a rule that claims by a source need to be confirmed by at least a second source. I am missing any confirmation.

While Rose presents the employee as an expert on the topic, I have never heard of him. Peter Thorne, who worked at NOAA, confirms that the employee did not work with surface station data himself. He has a decent publication record, mainly on satellite climate datasets of clouds, humidity and radiation. Ironically, I keep using that word, he also has papers about the homogenization of his datasets, while homogenization is treated by the mitigation skeptical movement as the work of the devil. I am sure they are willing to forgive him his past transgressions this time.

It sounds as if he made a set of procedures for his climate satellite data, which he really liked, and wanted other groups in NOAA to use it as well. Was frustrated when others did not prioritize enough updating their existing procedures to his.

For David Rose this is naturally mostly about politics and in his fantasies the Paris climate treaty would not have existed with the Karl and colleagues (2015) paper. I know that "pause" thingy is important for the Anglo-American mitigation skeptical movement, but let me assure Rose that the rest of the world considers all the evidence and does not make politics based on single papers.

[UPDATE: Some days you gotta love journalism: a journalist asked several of the diplomats who worked for years on the Paris climate treaty, they gave the answer you would expect: Contested NOAA paper had no influence on Paris climate deal. The answers still give an interesting insight into the sausage making. What is actually politically important.]

David Rose thus ends:

Has there been an unexpected pause in global warming? If so, is the world less sensitive to carbon dioxide than climate computer models suggest?

No, there never was an "unexpected pause." Even if there were, such a minute change is not important for the climate sensitivity. Most methods do not use the historical warming for that and those that do consider the full warming of about 1°C since the 19th century and not only short periods with unreliable, noisy short-term trends.

David Rose:

And does this mean that truly dangerous global warming is less imminent, and that politicians’ repeated calls for immediate ‘urgent action’ to curb emissions are exaggerated?

No, but thanks for asking.

Post Scriptum. Sorry that I cannot talk about all errors in the article of David Rose, if only because in most cases he does not present clear evidence and because this post would be unbearably long. The articles of Peter Thorne and Zeke Hausfather are mostly complementary on the history and regulations at NOAA and on the validation of NOAA's results, respectively.

Related information

Buzzfeed (October 2017): This Is How A Bogus Climate Story Becomes Unstoppable On Social Media

New York Times (September 2017): British Press Watchdog Says Climate Change Article Was Faulty

2 weeks later. The nailing New York Times interviewed several former colleagues of NOAA retire Bates: How an Interoffice Spat Erupted Into a Climate-Change Furor. "He’s retaliating. It’s like grade school ... At that meeting, Dr. Bates shouted that Ms. McGuirk was not trustworthy and belonged in jail, according to an internal log ..." Lock her up, lock her up, ...

Wednesday. The NOAA retiree now says: "The Science paper would have been fine had it simply had a disclaimer at the bottom saying that it was citing research, not operational, data for its land-surface temperatures." To me it was always clear it was research data, otherwise they would have cited a data paper and named the dataset. How a culture clash at NOAA led to a flap over a high-profile warming pause study

Tuesday. is a balanced article from the New York Times: Was Data Manipulated in a Widely Cited 2015 Climate Study? Steve Bloom: "How "Climategate" should have been covered." Even better if mass media would not have to cover office politics on archival standards fabricated into a fake scandal.

Also on Tuesday, an interview of E&E News: 'Whistleblower' says protocol was breached but no data fraud: The disgruntled NOAA retiree: "The issue here is not an issue of tampering with data".

Associated Press: Major global warming study again questioned, again defended. "The study has been reproduced independently of Karl et al — that's the ultimate platinum test of whether a study is to be believed or not," McNutt said. "And this study has passed." Marcia McNutt, who was editor of Science at the time the paper was published and is now president of the National Academy of Sciences.

Daily Mail’s Misleading Claims on Climate Change. If I were David Rose I would give back my journalism diploma after this, but I guess he will not.

Monday. I hope I am not starting to bore people by saying that Ars Technica has the best science reporting on the world wide web. This time again. Plus inside scoop suggesting all of this is mainly petty office politics. Sad.

Sunday. Factcheck: Mail on Sunday’s ‘astonishing evidence’ about global temperature rise. Zeke Hausfather wrote a very complementary response, pointing out many problems of the Daily Mail piece that I had to skip. Zeke works at the Berkeley Earth Surface Temperature project, which produces one of the main global temperature datasets.

Sunday. Peter Thorne, climatology professor in Ireland, former NOAA employee and leader of the International Surface Temperature Initiative: On the Mail on Sunday article on Karl et al., 2015.

Phil Plait (Bad Astronomy) — "Together these show that Rose is, as usual, grossly exaggerating the death of global warming" — on the science and the politics of the Daily Mail piece: Sorry, climate change deniers, but the global warming 'pause' still never happened

You can download the future NOAA land dataset (GHCNv4-beta) and the land dataset used by Karl and colleagues (2015), h/t Zeke Hausfather.

The most accessible article on the topic rightly emphasizes the industrial production of doubt for political reasons: Mail on Sunday launches the first salvo in the latest war against climate scientists.

A well-readable older article on the study that showed that ERSST.v4 was an improvement: NOAA challenged the global warming ‘pause.’ Now new research says the agency was right.

One should not even have to answer the question, but: No, U.S. climate scientists didn't trick the world into adopting the Paris deal. A good complete overview at medium level.

Even fact checker Snopes sadly wasted its precious time: Did NOAA Scientists Manipulate Climate Change Data?
A tabloid used testimony from a single scientist to paint an excruciatingly technical matter as a worldwide conspiracy.

Carbon Brief Guest post by Peter Thorne on the upcoming ERSSTv5 dataset, currently under peer review: Why NOAA updates its sea surface temperature record.

Cranberry picking short-term temperature trends

If you look at the data and sort of cherry-pick a micro-trend within a bigger trend, that technique is particularly suspect
John Grego, professor of statistics at the University of South Carolina.

If you choose your start points and your end points carefully enough you can make it look as if any trend you want is happening.

Christopher Monckton, sacked UKIP climate change spokesman
& former chair and demolisher of UKIP Scotland.

Monckton is a heavy user of this disingenuous "technique" and should thus know better: you cannot get any trend, but people like Monckton unfortunately do have much leeway to deceive the population. This post will show that political activists can nearly always pick a politically correct period to get a short-term trend that is smaller than the long-term trend. After this careful selection they can pretend to be shocked that scientists did not tell them about this slowdown in warming.

Traditionally this strategy to pick only the data you like is called "cherry picking". It is such a deplorable deceptive strategy that "cherry picking" sounds too nice to me. I would suggest calling it "cranberry picking". Under the assumption that people only eat cranberries when the burn peeing is worse. Another good new name could be "wishful picking."

In a previous post, I showed that the uncertainty of short-term trends is huge, probably much larger than you think, the uncertainty monster can only stomach a few short-term trends for breakfast. Because of this large uncertainty the influence of cranberry picking is probably also larger than you think. Even I was surprised by the calculations. I hope the uncertainty monster does not upset his stomach, he does not get the uncertainties he needs to thrive.

Size of short-term temperature fluctuations

To get some realistic numbers we first need to know how large the fluctuations around the long-term trend are. Thus let's first have a look at the size of these fluctuations in two surface temperature and two tropospheric temperature datasets:

• the surface temperature of Berkeley Earth (formerly known as BEST),
• the surface temperature of NASA-GISS: GISTEMP,
• the satellite Temperature of the Total Troposphere (TTT) of Remote Sensing Systems (RSS),
• the satellite Temperature of the Lower Troposphere (TLT version 6 beta) of the University of Alabama in Huntsville (UAH).

The four graphs below have two panels. The top panel shows the yearly average temperature anomalies over time as red dots. The Berkeley Earth data series starts earlier, but I only use data starting in 1880 because earlier data is too sparse and may thus not show actual climatic changes in the global mean temperature. For both surface temperature datasets the second world war is removed because its values are not reliable. The long-term trend is estimated using a [[LOESS]] smoother and shown as a blue line.

The lower panel shows the deviations from the long-term trend as red dots. The standard deviation of these fluctuations over the full period is written in red. The graphs for the surface temperature also gives the standard deviation of the deviations over the shorter satellite period written in blue for comparison with the satellite data. The period does not make much difference.









Both tropospheric datasets have fluctuations with a typical size (standard deviation) of 0.14 °C. The standard deviation of the surface datasets varies a little depending on the dataset or period. For the rest of this post I will use 0.086 °C as a typical value for the surface temperature.

The tropospheric temperature clearly shows more short-term variability. This mainly comes from El Nino, which has a stronger influence on the temperature high up in the air than on the surface temperature. This larger noise level gives the impression that the trend in the tropospheric temperature is smaller, but the trend in the RSS dataset is actually about the same as the surface trend; see below.



The trend in the preliminary UAHv6 temperature is currently lower than all others. Please note that, the changes from the previous version of UAH to the recent one are large and that the previous version of UAH showed more (recent) warming* and about the same trend as the other datasets.

Uncertainty of short-term trends

Already without cranberry picking short-term trends are problematic because of the strong influence of short-term fluctuations. While a average value computed over 10 years of data is only 3 times as uncertain as a 100-year average, the uncertainty of a 10-year trend is 32 times as large as a 100-year trend.**

To study how accurate a trend is you can generate random numbers and compute their trend. On average this trend will be zero, but due to the short-term fluctuations any individual realization will have some trend. By repeating this procedure often you can study how much the trend varies due to the short-term fluctuations, how uncertain the trend is, or more positively formulated: what the confidence interval of the trend is. See my previous post for details. I have done this for the graph below; for the satellite temperatures the random numbers have a standard deviation of 0.14 °C, for the surface temperatures 0.086 °C.

The graph below shows the confidence interval of the trends, which is two times the standard deviation of 10,000 trends computed from 10,000 series of random numbers. A 10-year trend of the satellite temperatures, which may sound like a decent period, has a whooping uncertainty of 3 °C per century.*** This means that with no long-term trend the short-term trend will vary between -3°C and +3 °C per century for 95% of the cases and for the other 5% even more. That is the uncertainty from the fluctuations along, there are additional uncertainties due to changes in the orbit, the local time the satellite observes, calibration and so on.

Cherry picking the begin year

To look at the influence of cranberry picking, I generated series of 30 values, computed all possible trends between 10 and 30 years and selected the smallest trend. The confidence intervals of these cranberry picked satellite temperature trends are shown below in red. For comparison the intervals for trends without cranberry picking, like above, are shown in blue. To show both cases clearly in the same graph, I have shifted the both bars a little away from each others.



The situation is similar for the surface temperature trends. However, because the data is less noisy, the confidence intervals of the trends are smaller; see below.



While the short-term trends without cranberry picking have a huge uncertainty, on average they are zero. With cranberry picking the average trends are clearly negative, especially for shorter trends, showing the strong influence of selecting a specific period. Without cranberry picking half of the trends are below zero, with cranberry picking 88% of the trends are negative.

Cherry picking the period

For some the record temperatures the last two years are not a sign that they were wrong to see a "hiatus". Some claim that there was something like a "pause" or a "slowdown" since 1998, but that it recently stopped. This claim gives even more freedom for cranberry picking. Now also the end year is cranberry picked. To see how bad this is, I again generated noise and selected the period lasting at least 10 years with the lowest trend and ending this year, or one year earlier or two years earlier.

The graphs below compare the range of trends you can get with cranberry picking the begin and end year in green with "only" cranberry picking the begin year like before in red. With double cranberry picking 96% of the trends are negative and the trends are going down even more. (Mitigation skeptics often use this "technique" by showing an older plot, when the newer plot would not be as "effective".)





A negative trend in the above examples of random numbers without any trend would be comparable to a real dataset where a short-term trend is below the long-term trend. Thus by selecting the "right" period, political activists can nearly always claim that scientists talking about the long-term trend are exaggerating because they do not look at this highly interesting short period.

In the US political practice the cranberry picking will be worse. Activists will not only pick a period of their political liking, but also the dataset, variable, region, depth, season, or resolution that produces a graph that can be misinterpreted. The more degrees of freedom, the stronger the influence of cranberry picking.

Solutions

There are a few things you can do to protect yourself against making spurious judgements.

1. Use large datasets. You can see in the plots above that the influence of cranberry picking is much smaller for the longer trends. For a 30-year period the difference between the blue confidence intervals for a typical 30-year period and the red confidence intervals for a cranberry picked 30-year period is small. Had I generated series of 50 random numbers rather than 30 numbers, this would likely have shown a larger effect of cranberry picking on 30-year trends, but still a lot smaller than on 10-year trends.

2. Only make statistical tests for relationships you expect to exist. This limits your freedom and the chance that one of the many possible statistical tests is spuriously significant. If you make 100 statistical tests of pure noise, 5 of them will on average be spuriously significant.

There was no physical reason for global warming to stop or slow down after 1998. No one computed the trend since 1998 because they had a reason to expect a change. They computed it because their eyes had seen something; that makes the trend test cranberry picking by definition. The absence of a reason should have made people very careful. The more so because there was a good reason to expect spurious results starting in a large El Nino year.

3. Study the reasons for the relationship you found. Even if I would wrongly have seen the statistical evidence for a trend decrease as credible, I would not have made a big point of it before I had understood the reason for this trend change. In the "hiatus" case the situation was even reversed: it was clear from the beginning that most of fluctuations that gave the appearance of a "hiatus" in the eyes of some was El Nino. Thus there was a perfectly fine physical reason not to claim that there was a change in the trend.

There is currently a strong decline in global sea ice extent. Before I cry wolf, accuse scientists of fraud and understating the seriousness of climate change, I would like to understand why this decline happened.

4. Use the right statistical test. People have compared the trend before 1998 and after 1998 and their uncertainties. These trend uncertainties are not valid for cherry picked periods. In this case, the right test would have been one for a trend change at an unknown position/year. There was no physical reason to expect a real trend change in 1998, thus the statistical test should take that the actual reason you make the test is because your eye sampled all possible years.

Against activists doing these kind of things we cannot do much, except trying to inform their readers how deceptive this strategy is. For example by linking to this post. Hint, hint.

Let me leave you with a classic Potholer54 video delicately mocking Monckton's cranberry picking to get politically convenient global cooling and melting ice trends.




Tweet

Related reading

Richard Telford on the Monckton/McKitrick definition of a "hiatus", which nearly always gives you one: Recipe for a hiatus

Tamino: Cherry p

Statistically significant trends - Short-term temperature trend are more uncertain than you probably think

How can the pause be both ‘false’ and caused by something?

Atmospheric warming hiatus: The peculiar debate about the 2% of the 2%

Temperature trend over last 15 years is twice as large as previously thought because much warming was over Arctic where we have few measurements

Why raw temperatures show too little global warming


* The common baseline period of UAH5.6 and UAH6.0 is 1981-2010.

** These uncertainties are for Gaussian white noise.

*** I like the unit °C per century for trends even if the period of the trend it shorter. You get rounder numbers and it is easier to compare the trends to the warming we have seen in the last century and expert to see in the next one.

**** The code to compute the graphs of this post can be downloaded here.

***** Photo of cranberry field by mrbanjo1138 used under a Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0) license.

Climate scientists are now grading climate journalism

Guest post by Daniel Nethery and Emmanuel Vincent Daniel Nethery is the associate editor and Emmanuel Vincent is the founder of Climate Feedback. Climate Feedback is launching a crowdfunding campaign today.

The internet represents an extraordinary opportunity for democracy. Never before has it been possible for people from all over the world to access the latest information and collectively seek solutions to the challenges which face our planet, and not a moment too soon: the year 2015 was the hottest in human history, and the Great Barrier Reef is suffering the consequences of warming oceans right now.

Yet despite the scientific consensus that global warming is real and primarily due to human activity, studies show that only about half the population in some countries with among the highest CO₂ emissions per capita understand that human beings are the driving force of our changing climate. Even fewer people are aware of the scientific consensus on this question. We live in an information age, but the information isn’t getting through. How can this be?

While the internet puts information at our fingertips, it has also allowed misinformation to sow doubt and confusion in the minds of many of those whose opinions and votes will determine the future of the planet. And up to now scientists have been on the back foot in countering the spread of this misinformation and pointing the public to trustworthy sources of information on climate change.

Climate Feedback intends to change that. It brings together a global network of scientists who use a new web-annotation platform to provide feedback on climate change reporting. Their comments, which bring context and insights from the latest research, and point out factual and logical errors where they exist, remain layered over the target article in the public domain. You can read them for yourself, right in your browser. The scientists also provide a score on a five-point scale to let you know whether the article is consistent with the science. For the first time, Climate Feedback allows you to check whether you can trust the latest breaking story on climate change.


An example of Climate Feedback in action. Scientists’ comments and ratings appear as a layer over the article. Text annotated with Hypothesis is highlighted in yellow in the web browser and scientists’ comments appear in a sidebar next to the article. Illustration: Climate Feedback

Last year the scientists looked at some influential content. Take the Pope’s encyclical, for instance. The scientists gave those parts of the encyclical relating to climate science a stamp of approval. Other “feedbacks,” as we call them, have made a lasting impact. When the scientists found that an article in The Telegraph misrepresented recent research by claiming that the world faced an impending ice age, the newspaper issued a public correction and substantially modified the online text.

But there’s more work to be done. Toward the end of the year the scientists carried out a series of evaluations of some of Forbes magazine’s reporting on climate change. The results give an idea of the scale of the problem we’re tackling. Two of the magazine’s most popular articles for 2015, one of which attracted almost one million hits, turned out to be profoundly inaccurate and misleading. Both articles, reviewed by nine and twelve scientists, unanimously received the lowest possible scientific credibility rating. This rarely occurs, and just in case you’re wondering, yes, the scientists do score articles independently: ratings are only revealed once all scientists have completed their review.

We argue that scientists have a moral duty to speak up when they see misinformation masquerading as science. Up to now scientists have however had little choice but to engage in time-consuming op-ed exchanges, which result in one or two high-profile scientists arguing against the views of an individual who may have no commitment to scientific accuracy at all. Climate Feedback takes a different approach. Our collective reviews allow scientists from all over the world to provide feedback in a timely, effective manner. We then publish an accessible synthesis of their responses, and provide feedback to editors so that they can improve the accuracy of their reporting.

We’ve got proof of concept. Now we need to scale up, and for that we need the support of everyone who values accuracy in reporting on one of the most critical challenges facing our planet. Climate Feedback won’t reach its full potential until we start measuring the credibility of news outlets in a systematic way. We want to be in a position to carry out an analysis of any influential internet article on climate change. We want to develop a ‘Scientific Trust Tracker’ – an index of how credible major news sources are when it comes to climate change.

We’re all increasingly relying on the internet to get our news. But the internet has engendered a competitive media environment where in the race to attract the most hits, sensational headlines can trump sober facts. We’re building into the system a new incentive for journalists with integrity to get ahead. Some journalists are already coming to us, asking our network of scientists to look at their work. We want readers to know which sources they can trust. We want editors to think twice before they publish ideological rather than evidence-based reporting on global warming.

On Friday 22 May 2016, more than 170 countries signed the Paris climate agreement. But this unprecedented international treaty will lead to real action only if the leaders of those countries can garner popular support for the measures needed to curb greenhouse gas emissions. The fate of the Paris deal lies largely in the hands of voters in democratic countries, and we cannot expect democracies to produce good policy responses to challenges of climate change if voters have a confused understanding of reality.

Scientists from all over the world are standing up for better informed democracies. You can help them make their voices heard. We invite you to stand with us for a better internet. We invite you to stand with science.

Victor Venema: I am also part of the Climate Feedback community and have annotated several journalistic articles when they made claims about climate data quality. It is a very effective way to combat misinformation. Just click on the text and add a short comment; Climate Feedback will take care of spreading your contribution. If you are a publishing scientist, do consider to join.

Tweet



* Photo at the top. Severe suburban flooding in New Orleans, USA. Aftermath of Hurricane Katrina. Photo by ark Moran, NOAA Corps, NMAO/AOC (CC BY 2.0)

The global warming conspiracy would be huge

The concept of global warming was created by and for the Chinese in order to make US manufacturing non-competitive.
Republican front runner Donald Trump on Twitter

Snowing in Texas and Louisiana, record setting freezing temperatures throughout the country and beyond. Global warming is an expensive hoax!
Republican front runner Donald Trump on Twitter

How do you know the climate didn't actually cool?
Eric Worrall, the main contributor to WUWT

Why use discredited surface data which everyone knows is fraudulent?
"Scottish" "Sceptic"

I am working on a study to compare nationally homogenized temperature data with the temperatures in the large international collections (GHCN, CRUTEM, etc.). Looking for such national datasets, I found many graphs in the scientific literature showing national temperature increases, which I want to share with you.

Mitigation skeptics like to talk about "The Team", as if a small group of people would be "in charge". That makes their conspiracy theories a little less absurd, although even small conspiracies typically do not last for decades. The national temperature series show that hundreds of national weather services and numerous universities would also need to be in the conspiracy of science against mankind. To me that sounds unrealistic.

The mitigation skeptics have a rough time and nowadays more often claim that they do not dispute the greenhouse effect or the warming of the Earth at all, but only bla, bla, bla. Which is why I thought I would show that this post is not fighting strawmen by citing some of the main bloggers and political leaders of the mitigation skeptical movement at the top of this post.

Anthony Watts, the weather presenter hosting Watts Up With That (WUWT), typically claims that only half of the warming is real, although he recently softened his stance for the USA and now only claims that a third is not real. If half of the warming in the global collections were not real, many scientists would have noticed that the global data does not fit to their local observations.

---

Plot idea: 97% of the world's scientists contrive an environmental crisis, but are exposed by a plucky band of billionaires & oil companies.
Scott Westerfeld

---

And do not forget all the other scientists studying other parts of the climate system, the upper air, ground temperatures, sea surface temperature, ocean heat content, precipitation, glaciers, ice sheets, lake temperatures, sea ice, lake and river freezing, snow, birds, plants, insects, agriculture. One really wonders with Eric Worrall how on Earth science knows the climate didn't actually cool.

Another reason to write this post is to ask for help. For this comparison study, I have datasets or first contacts for the countries below. If you know of more homogenized datasets, please, please let me know. Even if it is "only" a reference. Also if you have a dataset from one of the countries below: multiple datasets from one country are very much welcome.

Countries: Albania, Argentina, Armenia, Australia, Austria, Belgium, Benin, Bolivia, Bulgaria, Canada, Chile, China, Congo Brazzaville, Croatia, Czech Republic, Denmark, Ecuador, Estonia, Finland, France, Germany, Greece, Hungary, Iran, Israel, Italy, Latvia, Libya, Macedonia, Morocco, Netherlands, New Zealand, Norway, Peru, Philippines, Portugal, Romania, Russia, Serbia, Slovakia, Slovenia, South Africa, Spain, Sweden, Switzerland, Tanzania, Uganda, Ukraine, United Kingdom, United States of America.
Regions: Catalonia, Carpathian basin, Central England Temperature, Greater Alpine Region.

Alpine region

The temperature for the Greater Alpine Region from the HISTALP project (Ingeborg Auer and colleagues, 2007). The lower panel shows the temperature for four low altitude regions. The top panel their average (black) and the signal for the high altitude stations (grey). All series are smoothed over 10 years.

Armenia

The increase in the annual temperatures and the decrease in annual precipitation in Armenia. From Levon Vardanyan and colleagues (2013), see also Artur Gevorgyan and colleagues (2016).

Australia

The temperature signal over Australia for the day-time maximum temperature (red), the mean temperature (green) and the night-time minimum temperature. Figure from Fawcett and colleagues (2012).

Canada

From Lucie Vincent of Environment Canada and colleagues (2012).

The Czech Republic

Changes in mean annual and seasonal temperature time series for the Czech Lands in the period 1800–2010. The part of series calculated from only two stations is expressed by a dashed line. Figure by Petr Stepanek of the Global Change Research Institute CAS, Brno, Czech Republic.

China

The temperature change in China over the last 106 years, the annual mean temperature and the seasonal temperatures from QingXiang Li and colleagues (2010).

England

The famous Central England Temperature series of the Hadley Centre.

Finland

The annual average temperature in Finland. National averages are more noisy than global averages. Thus to show the trend better the graph adds the decadal average temperature. From Mikkonen and colleagues (2015).

Gambia

The mean, maximum and minimum temperature from Yundum Meteorological Station in Gambia. From a journal I normally do not read "Primate Biology". From Hillyer and colleagues (2015).

India

The temperature signal since 1900 in India according to Kothawale et al. (2010) of the Indian Institute of Tropical Meteorology (IITM), Pune.

Italy

The temperature series of Italy since 1800 according to Michele Brunetti and colleagues (2006).

Middle America and Northern South America

These graphs show the change in the number of warm days (maximum temperature) and warm night (minimum temperature) and the number of cold days and cold nights computed from daily data from several countries in Middle America and in the North of South America. Figures from Enric Aguilar and colleagues (2005).

The Netherlands

Annual mean temperatures of the actual observations at De Bilt (red), the De Bilt homogenised series (dark blue), the previous version of the Central Netherlands Temperature series (CNT2,7; light blue) and the current Central Netherlands Temperature series (CNT4,6; pink). Gerard van der Schrier and colleagues (2009) from the Dutch weather service, KNMI. De Bilt is a city in the middle of The Netherlands were the KNMI main office is. The Central Netherlands series is for a larger region in the middle of The Netherlands.

New Zealand

The famous New Zealand 7-stations series.

Philippines

Observed annual mean temperature anomalies in the Philippines during the period 1951–2010 computed by Thelma A. Cincoa and colleagues (2014).

Russia

Temperature averaged over Russia from the annual climate report of ROSHYDROMET (2014). The top panel are the annual averages, the four lower panels the seasons (winter, spring, summer and autumn). No homogenization.

The variability in winter is very high. According to mitigation sceptic Anthony Watts this is due to Russian Steam Pipes:

I do know this: neither I nor NOAA has a good handle on the siting characteristics of Russian weather stations. I do know one thing though, the central heating schemes for many Russian cities puts a lot of waste heat into the air from un-insulated steam pipes.

Then it would be surprising that such large regions are affected in the same way and that the steam pipe years are also hot in the analysis of global weather prediction models and satellite temperature datasets.

Spain

Temperature trends computed by José Antonio Guijaro (2015) of the Spanish State Meteorological Agency (AEMET) for 12 river catchments within Spain. Homogenization with CLIMATOL.

The Spanish temperature dataset of the URV University in Tarragona. The panels on the left show the minimum temperature, the panels on the right the maximum temperature. The top panels show raw data before homogenization, the lower panels the homogenized data. The maximum temperature before 1910 had to be corrected strongly because of the use of a French screen before this time.

United States of America

The minimum and maximum temperature of the lower 48 states of the United States of America computed by NOAA. You can see it is an original American-made graph because it is in [[Fahrenheit]].

Switzerland

The temperature signal in Switzerland computed by Michael Begert and colleagues of the MeteoSchweiz. The top panel show original station time series, the lower panel shows them after removal of non-climatic changes.


Tweet

Related reading

Climatologists have manipulated data to REDUCE global warming

Charges of conspiracy, collusion and connivance. What to do when confronted by conspiracy theories?

If you're thinking of creating a massive conspiracy, you may be better scaling back your plans, according to an Oxford University researcher.

References

Aguilar, E., et al., 2005: Changes in precipitation and temperature extremes in Central America and northern South America, 1961–2003. Journal Geophysical Research, 110, D23107, doi: 10.1029/2005JD006119.

Auer, I., Böhm, R., Jurkovic, A., Lipa, W., Orlik, A., Potzmann, R., Schöner, W., Ungersböck, M., Matulla, C., Briffa, K., Jones, P., Efthymiadis, D., Brunetti, M., Nanni, T., Maugeri, M., Mercalli, L., Mestre, O., Moisselin, J.-M., Begert, M., Müller-Westermeier, G., Kveton, V., Bochnicek, O., Stastny, P., Lapin, M., Szalai, S., Szentimrey, T., Cegnar, T., Dolinar, M., Gajic-Capka, M., Zaninovic, K., Majstorovic, Z. and Nieplova, E., 2007: HISTALP—historical instrumental climatological surface time series of the Greater Alpine Region. International Journal of Climatology, 27, pp. 17–46. doi: 10.1002/joc.1377.

Begert, M., Schlegel, T. and Kirchhofer, W., 2005: Homogeneous temperature and precipitation series of Switzerland from 1864 to 2000. International Journal of Climatology, 25, pp. 65–80. doi: 10.1002/joc.1118.

Brunetti, M., Maugeri, M., Monti, F. and Nanni, T., 2006: Temperature and precipitation variability in Italy in the last two centuries from homogenised instrumental time series. International Journal of Climatology, 26, pp. 345–381, doi: 10.1002/joc.1251.

Cincoa, Thelma A., Rosalina G. de Guzmana, Flaviana D. Hilarioa, David M. Wilson, 2014: Long-term trends and extremes in observed daily precipitation and near surface air temperature in the Philippines for the period 1951–2010. Atmospheric Research, 145–146, pp. 12–26, j.atmosres.2014.03.025.

Fawcett, R.J.B., B.C. Trewin, K. Braganza, R.J Smalley, B. Jovanovic and D.A. Jones, 2012: On the sensitivity of Australian temperature trends and variability to analysis methods and observation networks. CAWCR Technical Report No. 050.

Gevorgyan, A., H. Melkonyan, T. Aleksanyan, A. Iritsyan and Y. Khalatyan, 2016: An assessment of observed and projected temperature changes in Armenia. Arabian Journal of Geosciences, 9, pp. 1-9, DOI 10.1007/s12517-015-2167-y.

Guijaro, J.A., 2015: Temperature trends. AEMET Report.

Hillyer, A.P., R. Armstrong, and A.H. Korstjens, 2015: Dry season drinking from terrestrial man-made watering holes in arboreal wild Temminck’s red colobus, The Gambia. Primate Biol., 2, pp. 21–24, doi: 10.5194/pb-2-21-2015.

Jain, Sharad K. and Vijay Kumar, 2012: Trend analysis of rainfall and temperature data for India. Current Science, 102.

Kothawale, D.R., A.A. Munot, K. Krishna Kumar, 2010: Surface air temperature variability over India during 1901–2007, and its association with ENSO. Climate Research, 42, pp. 89-104.

Li Q.X., Dong W.J., Li W., et al., 2010: Assessment of the uncertainties in temperature change in China during the last century. Chinese Science Bulletin, 55, pp. 1974−1982, doi: 10.1007/s11434-010-3209-1

Mikkonen, S., M. Laine, H.M. Mäkelä, H. Gregow, H. Tuomenvirta, M. Lahtinen, A. Laaksonen, 2015: Trends in the average temperature in Finland, 1847–2013. Stochastic Environmental Research and Risk Assessment, 29, Issue 6, pp 1521-1529, doi: 10.1007/s00477-014-0992-2.

Schrier, van der, G., A. van Ulden, and G.J. van Oldenborgh, 2011: The construction of a Central Netherlands temperature. Climate of the Past, 7, 527–542, doi: 10.5194/cp-7-527-2011

Ulden, van, Aad, Geert Jan van Oldenborgh, and Gerard van der Schrier, 2009: The Construction of a Central Netherlands Temperature. Scientific report, WR2009-03. See also Van der Schrier et al. (2011).

Vardanyan, L., H. Melkonyan, A. Hovsepyan, 2013: Current status and perspectives for development of climate services in Armenia. Report, ISBN 978-9939-69-050-6.

Vincent, L.A., X.L. Wang, E.J. Milewska, H. Wan, F. Yang, and V. Swail, 2012: A second generation of homogenized Canadian monthly surface air temperature for climate trend analysis. J. Geophys. Res., 117, D18110, doi: 10.1029/2012JD017859.