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Dr. Victor Venema

Dr. Victor Venema


Meteorological institute
University of Bonn
Auf dem Huegel 20
53121 Bonn, Germany

Email: Victor.Venema@uni-bonn.de

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Date Publication
15.11.2007 Article: Two adaptive radiative transfer schemes for numerical weather prediction models
V. Venema, A. Schomburg, F. Ament, and C. Simmer
Atmospheric Chemistry and Physics, 7, 5659-5674
SRef: 1680-7324/acp/2007-7-5659
12.09.2006 Article: Statistical characteristics of surrogate data based on geophysical measurements
V. Venema, S. Bachner, H. W. Rust, and C. Simmer
Nonlinear Processes in Geophysics, 13, 449-466
SRef: 1607-7946/npg/2006-13-449
26.07.2006 Article: A Stochastic Iterative Amplitude Adjusted Fourier Transform algorithm with improved accuracy
V. Venema, F. Ament, and C. Simmer
Nonlinear Processes in Geophysics, 13, 321-328
SRef: 1607-7946/npg/2006-13-321

Latest Blog Posts

  • 20.06.2017: On the recent warming explosion

    "Incidentally, when in the journal Science in 2007 we pointed to the exceptionally large warming trend of the preceding 16 years, which was at the upper end of the [climate] model range, nobody cared, because there is no powerful lobby trying to exaggerate global warming."

    "And of course in our paper we named natural intrinsic variability as the most likely reason. But when a trend at the lower end of the model range occurs it suddenly became a big issue of public debate, because that was pushed by the fossil fuel climate sceptics’ lobby. There is an interesting double standard there."

    Maybe the comment is deleted in shame. At least I cannot find it any more. Someone on Reddit was making exactly the same errors as the fans of the infamous "hiatus" to argue that global warming since 2011 is exploding and we're soon gonna die. Deleted comments can be freely paraphrased.

    The data

    So let's have a look at what the data actually says. Below are warming curves of two surface temperature datasets and two upper air temperature satellite retrievals. I shortened the warming curve of Berkeley Earth to match the period to the one of GISTEMP. All the other datasets are shown over their full lengths. Taking this step back, looking at the overview, there clearly is no "hiatus" and no "explosive warming".

    The red dots are the annual temperature anomalies, which are connected by a thin grey line. The long-term trend is plotted by a thick blue line, which is a [[LOESS]] estimate.

    If you want to see the "hiatus" you have to think the last two data points away and start in the temperature peak of 1998. Don't worry, I'll wait while you search for it.

    A hiatus state of mind

    After seeing reality, let's now get into the mindset of a climate "sceptic" claiming to have evidence for a "hiatus", but do this differently by looking at the data since 2011.

    Naturally we only plot the recent part of the data, so that context is lost. I am sure the climate "sceptics" do not mind, they also prefer to make their "hiatus" plots start around the huge 1998 El Nino warming peak and not show the fast warming before 1998 for context.

    The thick blue lines are quadratic functions fitted to the data. They fit snugly. As you can see both the linear and quadratic coefficients are statistically significant. So clearly the recent warming is very fast, faster than linear and we can soon expect to cross the 2 °C limit, right?

    I am sure the climate "sceptics" do not mind what I did. They also cherry picked a period for their "hiatus" and applied a naive statistical test as if they had not cherry picked the period at all. The climate "sceptics" agreeing with Christopher Monckton doing this on WUWT will surely not object to our Redditor doing the same and will conclude with him that the end is nigh.

    By the way, I also cherry picked the dataset. The curves of the upper air temperature retrievals are not as smooth and the quadratic terms were not statistically significant. But in case of the "hiatus" debate our "sceptical" friends also only showed data for the datasets showing the least warming. So I am sure they do not object to this now.

    Some more knowledgeable catastrophists may worry that it looks as if 2017 may not be another record scorching year. No worries. Also no worries if 2018 is colder again. The Global Warming Policy Foundation thinks it is perfectly acceptable to ignore a few politically inconvenient years and claims that we just have to think 2015 and 2016 away and that thus the death of the "hiatus" has been greatly exaggerated. I kid you not. I have not seen any climate "sceptic" or any "luckwarmer" complaining about this novel statistical analysis method, so surely our Redditor can do the same. Catastrophic warming explosion claims are save till at least 2019.

    Don't pick cherries

    Back to reality. What to do against cherry picking periods? My advice would be: don't cherry pick periods. Not for the global mean temperature, not for the temperature of the Antarctic Peninsula, not for any other climate variable. Just don't do it.

    If you have a physical reason to expect a trend change, by all means use that date as start of the period to compute a trend. But for 1998 or 2011 there is no reason to expect a trend change.

    Our cheerful Redditor had even a bit more physics in his claim. He said that the Arctic was warming and releasing more carbon dioxide and methane. However, these emissions were not large enough to make the increase in the global greenhouse concentrations speed up. And they count. From our good-natured climate "sceptics" I have never heard a physical explanation why global warming would have stopped in 1998. But maybe I have missed their interest in what happens with the climate system.

    If you have no reason to expect a trend change the appropriate test would be for a trend change test at an unknown date. Such a test "knows" that cherry picked periods can have hugely different trends and thus correctly only sees larger trend changes over longer periods as statistically significant. Applied to temperature data the result of such as test does not see any "hiatus" nor any "warming explosion".

    This test gave the right result during the entire "hiatus" madness period. Don't fool yourself. Use good stats.

    Related reading

    Cranberry picking short-term temperature trends

    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%

    Source: Variable Variability

  • 11.06.2017: My unsolicited advice for a UK government

    After my spectacular success as UK election pollster let my try my luck as UK political adviser. Offering outsider continental perspective from a citizen of a countries where coalition governments are normal.

    The electoral results could not have been more complicated. The conservatives lost their majority. Against British custom collaboration is necessary.

    Conservative Prime Minister Theresa May has proposed to govern together with the [[Democratic Unionist Party]] (DUP), a small deeply conservative Northern Irish protestant party with ties to terrorists after decades of religious terrorism.

    That coalition has a majority of only 2 seats.

    Other possible Conservative coalitions would be with the Liberal Democrats, with the Scottish National Party and the taboo option with Labour. Reversely, the only realistic coalition for Labour would be with the conservatives.

    A Tory-DUP coalition is highly problematic. The DUP will have to get something in return for their collaboration. Typically a small coalition partner needs to get a lot more than their vote share to make it worthwhile and to survive the next election. Given how extreme they are, a majority of only 2 seats will often mean that more moderate conservatives will not be willing to give them what they bargained for and need.

    The UK government is, furthermore, supposed to be neutral in Northern Irish problems. I have the impression that the UK does not fully realise that also in the Brexit negotiations Northern Ireland will be an extremely difficult problem. If the UK really wants a hard border this would cut Northern Ireland off from the rest of Ireland, which will cause economic problems for everyone and will make it harder to visit family and friends (for Catholics).

    The DUP would at least make sure this problem is not ignored until it is too late, but their role would be far from neutral.

    h/t Simon Noone‏

    The two seat majority will likely dissipate quite quickly in future special elections. That could lead to another election in the middle of the Brexit negotiations.

    The Brexit clock is ticking and the UK will have to make decades worth of political decisions in about one year time. I do not see that happening with a two-seat majority. It would have been a herculean task with a large majority and a capable prime minister.

    More logical coalition parties for the Conservatives would be the Liberal Democrats and the Scottish National Party. However, they both do not want to be add-ons to a dominant Conservative party, especially after the bad experiences the Liberal Democrats had in their recent coalition with the Conservatives. Still given the situation I feel these parties should give this option more thought (after the disposal of May).

    For the UK it would be highly unorthodox, but I see a coalition of the Conservatives and labour as the best option. Possibly together with the Liberal Democrats and the Scottish National Party. In Germany and The Netherlands we have such coalitions of conservatives and social democrats more often, although only as coalition of last resort. In Switzerland the government is always made up of all parties governing in partnership.

    Not being used to coalition governments the UK is lacking a culture of adult behaviour and professional political debate, especially between the Tories and Labour. Maybe a neutral Prime Minister (of the Liberal Democrats) could help to hold a grand coalition together. I realise that that makes the coalition even more unorthodox. But these are also not normal times.

    This would be nothing for a non-communicative prime minister with brittle personality and a penchant for kabuki theatre. Also Boris Johnson would also be an utter catastrophe, I hope this does not need explaining, but he may be a useful tool for regicide.

    The kind of personality able to lead a grand coalition would also be the best personality for the Brexit negotiations with the EU. Many in the UK seem to see the EU as the enemy who is now laughing at UK's misery. On Twitter someone asked for a German word for the current predicament. Most offered was "Schadenfreude". I would say "Mitleid" (sympathy), "Verunsicherung" (confusion) and "Beunruhigung" (worry).

    The UK gutter press like to cite anonymous antagonistic EU assholes. Anyone on twitter will be able to confirm that anonymous assholes are never short in supply. But that a few percent of humanity does not deserve that title does not change geography: Europe and the UK will always be neighbours. People in England seem to often forget that we are even neighbours with a land border.

    The EU is interested in friendly relations with its neighbours. A concept that may be difficult to comprehend for (formerly) fascist rags. We are grateful for Monty Python, British expertise on the weather, and for the liberation from fascist occupation. A Russian liberation would have been much less pleasant. Just like young Brits got to know other Europeans as mostly nice people with shared values, European appreciate the UK. One day these young people may want to join their EU friends again.

    No deal or a bad deal is damaging for the UK, but thus also unfavourable for the EU. A no-deal Brexit in no way fits to the nearly 50/50 outcome of the referendum.

    Thus negotiations based on a common appreciation of long-term friendly relations would give the best results for all. There are so many topics that need to be negotiated that kabuki theatre on Gibraltar or holding EU citizens in the UK hostage are an enormous distraction. Next to EU negotiations the UK will have to negotiate trade relations with dozens of countries and trading blocks. The UK will have to build up institutions on the EU borders and institutions for the safety of drugs, chemical consumer product, banking products, etc.

    Before the Brexit referendum we had ludicrous have-your-cake.and-eat-it propaganda. We are now nine months after the referendum and it is about time to have a public discussion what Brexit means. It is unfortunately only a slight exaggeration that this discussion was limited to Brexit is Brexit.  It is not.

    It beats me why the UK also wants to leave [[Euratom]], which is not part of the EU. If necessary that could have been done later. They do not only work on nuclear power, but also nuclear medicine. Does the UK want the European Centre for Medium-Range Weather Forecasts, [[ECMWF]], to stay in Reading? It is not officially part of the EU, but has many of the same member states.

    Does the UK want to keep student exchanges with the continent, [[Erasmus]]? Does the UK want to stay part of the European research community? If yes how? There are programmes for applied joint European research, [[Horizon 2020]], for fundamental science, [[ERC]], and for scientific coordination, [[COST]]. The UK could pay into those programs. Switzerland pays their researchers directly if they are part of it and in case of COST even gives them some bonus funding for additional research to stimulate participation.

    Those are just the examples from my field, science. Similar hard choices will have to be made on so many topics. Personally I would suggest to change as little as possible and (initially) contribute to EU programmes. Just the minimal Brexit program, rights of EU citizens currently in the UK and UK citizens currently in the EU (residence, work, healthcare, benefits, pensions, voting rights), trade and borders (seas, fishing, exploration, Northern Ireland, Gibraltar), are though to get done in about a year. Loosening the ties on all the other topics can be done later.

    That requires a friendly and communicative leader and government. Clearly Theresa may should go and Boris Johnson is not an alternative. A grand coalition may be the best way to get a concrete national debate going and to have fruitful negotiations.

    Related reading

    New York Review of Books: Britain: The End of a Fantasy

    Desmog UK: Let's Take A Closer Look at the DUP's Climate Science Denial
    Source: Variable Variability

  • 06.06.2017: Comrade Trend predicts the UK general election outcome

    Poll whisperer Nate Silver himself just predicted that in the UK elections the conservatives would win by 7 %. My prediction is 2 %.

    The prediction of Silver is a simple average of the last polls of the ten main polling organisations. He uses the same data as I do, kindly gathered by the volunteers of Wikipedia, who also made the plot below.

    The statistics normally used to estimate the outcome of elections assumes that there is a fixed value and the surveys are noise around this value. In this case you have to average (in a smart way) to remove the noise of the surveys and get a better estimate of the fixed value.

    Wikipedia uses the same assumption to compute the curve of the running average of all polls and takes the average over the 10 most recent polls.

    Comrade Trend

    However, if the polls are moving it typically keeps on moving in the same direction. Germans call this Genosse Trend, Comrade Trend. If you are going up in the polls Comrade Trend is a great friend.

    This could be because it takes time until "everyone" has heard the news, only small part of the population is a news junky. You may also want to wait whether refuting information comes in some time later, whether a campaign changes its position or you may want to talk about the news with your family and friends.

    It takes some time until people have found time to read the manifestos (Conservative | Labour). Hopefully many do, there is a real choice this time. Also the strengths and weaknesses of the campaigns mostly stay the same during the campaign. Each time Theresa May openly refuses to answer basic policy questions she loses voters, at least for people like me.

    Comrade Trend seems like a good assumption to me. The polls in the UK move so fast that the difference in assumptions really matters this time. The smoothing method [[LOESS]] estimates the trend at a certain time to make the best estimate at that time. It fits a line to the data over a subperiod. Estimating a fixed value would correspond to assuming the line is horizontal over this subperiod. LOESS thus takes Comrade Trend into account. It gives the figure below.

    The predictions for election day, this Thursday, were made by assuming a linear trend for the period since the 1st of May.

    Election turnout

    An important reason that it is hard for polling to predict the outcome of an election is that it is not known who will actually get off the couch and vote. The figure/tweet below shows for one of the polls how much difference various turnout assumptions makes. The spread in the polls is very large this election. That may well be because turnout is very important this time. Older people tend to favour the conservatives and faithfully show up. The question we will not know until election day is how much young people will show up.

    For the first time, our results model (using latest poll averages) projects a hung parliament *if* turnout is 78% across all ages. #GE2017 pic.twitter.com/Wv7PzEufLY

    — Ian Jones (@ian_a_jones) 2 June 2017

    Polling bias

    Then there is the question whether polls are not just noisy estimate, but whether they are also biased relative to the election. Nate Silver writes:
    Exactly how strong the Conservative tendency to outperform their polls has been depends on where you measure from. Since 1992, Conservatives have beaten their final polling margin over Labour by an average of 4.5 percentage points, and have done so in all but one election. (That was 2010, when both Conservatives and Labour gained ground as Liberal Democrats’ support collapsed, but Labour slightly outperformed its polling margin against the Tories.) Go all the way back to 1945, however, and the average Conservative overperformance is just 1.8 percentage points and is not statistically significant.
    I prefer to look at all the data and would say that the bias is not statistically significant. It would be weird for the bias to have become worse, except maybe for really recent elections where parts of the population can no longer be reached with landline telephones. That you can find a period with a higher bias may well be cherry picking. As long as no one can provide a reason for a change in bias since 1992, picking a specific period after looking at the data is statistically suspect.


    According to Nate Silver UK polling tends to have a relatively high uncertainty and misses the election outcome typically by about 4%. Estimating a trend is harder than estimating a mean, thus it could be that my 2% prediction is even a bit more uncertain. Thus if my best estimate is right and the conservatives are only 2% ahead the election is a toss up: the difference is less than the uncertainty.

    Let's see who turns out.

    Related reading

    Nate Silver at 538: Are The U.K. Polls Skewed?

    Uk polling report: How the polls have changed since 2015

    Source: Variable Variability

  • 30.05.2017: The IPCC underestimates global warming

    A month ago the New York Times insulted its subscribers with a climate change column by Bret Stephens, their new hire from the Wall Street Journal. The bizarre text was mostly a sequence of claims that did not follow from the arguments presented.

    The column also contained one fact. Which was wrong and later corrected. Stephens claimed:

    Anyone who has read the 2014 report of the Intergovernmental Panel on Climate Change knows that, while the modest (0.85 degrees Celsius, or about 1.5 degrees Fahrenheit) warming of the Northern Hemisphere since 1880 is indisputable, as is the human influence on that warming, much else that passes as accepted fact is really a matter of probabilities.
    As a dutiful watcher of Potholer54, which any real skeptic should be, you know that it is a good idea to check the source and Stephens helpfully provided a link to the Summary for Policymakers of the 5th assessment synthesis report of the Intergovernmental Panel on Climate Change (IPCC). This summary mentions the number "0.85" in the sentence:
    The globally averaged combined land and ocean surface temperature data as calculated by a linear trend show a warming of 0.85 [0.65 to 1.06] °C over the period 1880 to 2012, when multiple independently produced datasets exist (Figure SPM.1a). {1.1.1, Figure 1.1}

    Figure SPM.1a. Annually and globally averaged combined land and ocean surface temperature anomalies relative to the average over the period 1986 to 2005. Colours indicate different data sets.

    Thus Stephens confused the global temperature with the temperature of the Northern Hemisphere. Not a biggy, but indicative of the quality of Stephens' writing.

    A related weird claim is that the "warming of the earth since 1880 is indisputable, as is the human influence on that warming, much else that passes as accepted fact is really a matter of probabilities."

    As quoted above the warming since 1880 is not exactly known, but probably between 0.65 and 1.06 °C. That it was warming is so certain that a journalist may call it "indisputable". There is thus no conflict between probabilities and certainty. In fact they go hand in hand. When scientists talk about uncertainties, they are quantifying how certain we are.

    However, I did not want to attack the soft target Bret Stephens. The hard target IPCC is much more interesting. They put some thought in their writing. More precisely I have problems when they write in the summary for policy makers: "temperature data as calculated by a linear trend show a warming of 0.85". That means that they fitted a linear function to the data — using [[least squares regression]] — and used this trend and the length of the period to estimate the total warming over this period.

    This is a problem because calculating the total amount of warming using a linear trend underestimates global warming.* I show this below for two global temperature datasets by comparing the linear warming estimate with a nonlinear (LOESS) warming estimate. The linear estimate is smaller: For NASA's GISTEMP it is 0.05 °C smaller and for Berkeley Earth it is 0.1 °C smaller.

    Such linear estimates are well suited for comparing different datasets because it is well defined how to compute a linear trend and the bias will be similar in the different datasets. That is why linear estimates are used a lot in the scientific literature and scientists reading this know that a linear estimate can be biased when the curve itself is not linear.

    But this was a warming estimate for the summary for policy makers. Policy makers and the public in general should get an unbiased estimate of the climatic changes we have seen and are before us.

    Tending to underplay the problem is quite typical. There is even an article on climate Scientists Erring on the Side of Least Drama and also The Copenhagen Diagnosis gives several examples such as the very low predictions for the decline in sea ice or the increase in sea level.

    When it comes the warming found in station data, we did study the main possible warming bias (urbanization) in depth, but hardly did any work on cooling biases that may lead us to underestimate the amount of warming.

    In a recent study to define what "pre-industrial" means when it comes to the 2 °C warming limit, the authors suggest a comparison period with relatively few volcanoes, which is thus relatively warm. This underestimates the warming since "pre-industrial". The authors wanted to be "conservative". I think we should be unbiased.

    I understand that scientists want to be careful before crying wolf, whether we have a problem or not. However, when it comes to the size of the wolf, we should give our best estimate and not continually err on the side of a Chihuahua.

    Related reading

    Climate Scientists Erring on the Side of Least Drama

    Why raw temperatures show too little global warming

    The NY Times promised to fact check their new climate denier columnist — they lied

    * The linear estimate is typically smaller, sometimes a lot, whether the actual underlying function is convex or concave. I had expected this estimate to be always smaller, but noticed while writing this post that for polynomial functions, f(t) = tp, it can also be a few percent higher for p between 1 and 2. Below you can see 4 example curves, where the time runs between zero and one and thus also f(t) goes from zero to one. The total "warming" in all cases is exactly one. The linear estimates are generally less than one, except for the f(t) = t1.5 example.

    The bottom graph shows these linear estimates as a function of exponent p, where you can see that for an exponent between 1 (linear) and 2 (quadratic) the estimates can be a little higher than one, while they are generally lower. Probably Carl Friedrich Gauss or at least Paul Lévy already wrote an article about this, but it was a small surprise to me.

    ** Top photo of a Chihuahua is licensed under the Creative Commons Attribution 3.0 Unported license.
    Bottom Chihuahua photo by Inanishi is licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0) license.

    *** The R code to generate the plots with the linear and nonlinear warming from two global temperature datasets is on GitHub. The R code to study the influence of the polynomial exponent on the linear estimate is also on GitHub.
    Source: Variable Variability

  • 11.05.2017: Trump's I-am-not-a-witch moment

    Dear Director Comey,
    While I greatly appreciate you informing me, on three separate occasions, that I am not under investigation, I nevertheless concur with the judgment of the Department of Justice that you are not able to effectively lead the Bureau.
    Donald J. Trump
    Donald, even if Comey were prime evil himself, you can not fire someone who is investigating you. (Even if Democrats did or do not like him.)

    Donald, it would have been better not to talk about the FBI investigating you. (It only puts more focus on these investigations.)

    Donald, you can not talk to Comey about ongoing investigations, especially investigations about yourself. (And there is no evidence that Comey informed you.)

    Donald, do not write about your FBI investigations when your official reason for firing Comey was that he was not fair to Clinton. (And a many months old incident is not a good excuse for firing someone in a panic.)

    Donald, you cannot write that refraining from investigating you would be a reason not to fire Comey. (The rule of law makes America a free country.)

    Related reading

    Experts on authoritarianism are absolutely terrified by the Comey firing

    Source: Variable Variability

  • 30.04.2017: Red cheeks team

    The idea has been simmering a few years, but now that their president is in office, the mitigation sceptical movement is increasingly pushing the idea of a "Red Team". In the last "hearing" of Lamar Smith in US House of Representatives, John Christy and Judith Curry repeated the claim that climate science needs a "Red Team". Roger Pielke Sr. contributes some tweets. In Murdoch's Wall Street Journal also Steven Koonin made this call on the opinion pages (pay-walled). This is the part of the newspaper the journalists of the news section are embarrassed by.

    The [[Red Team]] should aim to destroy the results of climate science. This idea comes from the military and corporations. Monolithic strongly hierarchical organisations where dissent is normally not appreciated and there is thus a need to break this culture by explicitly ordering a group to show that plans may not work out. Many mitigation sceptics work in such organisations and this seems to guide their erroneous thinking of how science works.

    Red Teams galore

    Science is organised in thousands of Red Teams already. Every national weather service is independent. Some countries even have multiple ones. That makes about 200 Red Teams. I do not know of any weather service that does not find it is warming.

    If you are a conspiracy theorist, thinking they are making up the warming, these 200 Red Teams would have to coordinate intensively to make sure that the weather variability is smoothly correlated from one country to its neighbours, that the climate modes (El Nino, North Atlantic Oscillation, etc.) look similar in a region, including [[teleconnections]] to other continents, including modes and teleconnections not known at the time, and make sure that the spatial pattern of the long-term warming fits to the physics and all the other observed variables.

    Proof of how devious climatologists are is that no communications were intercepted showing this biggest coordination project in human history. Scientists may be too stupid to fool WUWT, but they are at least smarter than the NSA and HCSQ.

    In Germany alone there are easily over a hundred university groups and research institutes (partially) working on climate and climate change. There are close collaborations with related fields, from statistics and physics to geography and economics. Also counting these there could be hundreds of Red Teams in a medium-sized country like Germany already.

    Scientific progress

    Every single of these groups would love to be the one to show there is a problem that needs attention. That is why scientists become scientist. No one has ever gotten funding saying: my field has solved all problems, but I would like to keep on doing what I have always done.

    Many of these groups only partially work on climate change. Meteorology is a much larger field than climatology; Meteorology is directly needed to save lives and avoid economic damages, while climatology "only" produces politically inconvenient results about the future.

    Thus for many of these groups it would be no problem whatsoever if they showed evidence for the most extreme case that the world is not warming or humans are not responsible. On the contrary, that would be an enormous boost to their reputations and they can use that social capital to work on related problems.

    Explicit Red Teams are for organisation working like planning economies. Science is a free market system.

    Climate “sceptics” sometimes give the impression that they think that a single study will vindicate their political battle and settle it once and for all. Reality is that there are many different lines of evidence that it should be warming, that it is warming (see graph below), and that we are creating the increase in atmospheric CO2 (see also additional arguments by Richard Alley) and the warming.

    A challenge to one of these lines of evidence will have to refute a lot of evidence and this will normally take years. It would not be enough to disproof one line of evidence, but all of them should fall. Not only the instrumental temperature record would need to be wrong, but the melting of glaciers, the sea level rise, the start of spring, the decrease in Arctic sea ice and so on.

    If I had the winning idea that something is fundamentally flawed, it would take decades of research until we again have a consensus on how the climate is (not) changing, just like our current understanding of climate change took decades to centuries to develop.

    Science or PR?

    John Christy:
    One way to aid congress in understanding more of the climate issue than what is produced by biased “official” panels of the climate establishment is to organize and fund credible “Red Teams” that look at issues such as natural variability, the failure of climate models and the huge benefits to society from affordable energy, carbon-based and otherwise. I would expect such a team would offer to congress some very different conclusions regarding the human impacts on climate.
    The benefits from affordable energy do not change the human impacts on climate. That kind of sloppy thinking hints at the Red Team being intended as a PR shop.

    As an aside, the benefits of energy are naturally large and the energy sector used to be substantial, but it is nowadays just a few percent of the economy. Even if another energy source would be a lot more expensive that would nowadays hardly change the economy.

    The idea that climatology does not study natural variability is ludicrous. I used to think I was not a climatologist because I had never computed an empirical orthogonal function ([[EOF]]) to study the North Atlantic Oscillation. The biggest group in the World Climate Research Program is CliVar, studying, hold it: Climate variability. What the mitigation sceptical movement knows about natural variability, from El Nino to the QBO, they know from the scientific community.

    The "failure of climate models" presupposes models failed. If we assume they failed and cannot be used to assess the quagmire we are in, the uncertainties would be even larger. We would still have a lot of physics and observations of the (deep) past to make clear that climate change is real. Uncertainties can go both ways and mean higher risks. This should thus be a topic the Red Team should avoid.

    The suggestion to only study the "failure of climate models" is a strange way of doing science. Normal science would be to study what the main discrepancies between models and observations are, try to understand what the causes are and then try to fix this. Sounds like Christy is more interested in the first step than in understanding and fixing.

    This fits to his approach to his UAH tropospheric temperature dataset. Already in the 1990s when the UAH dataset still showed cooling and contained major errors (did not take the change of the orbit of the satellites into account, had a minus wrong in the software, etc.) he blamed models for the differences without first trying to understand the reasons.

    Chinese calligraphy with water on a stone floor. Do not dig in, but let your position flow with the evidence.
    The main reason for the discrepancy is that there is an amplification of temperature changes in the tropical upper troposphere. The stronger long-term warming this causes in models is called the "tropical hotspot". Christy's UAH temperature trends do not show it. It is seen in the stronger response to El Nino in the tropospheric temperatures, both in models and in observations. The hotspot is observed in the radiosonde winds and in a recent carefully homogenized radiosonde temperature dataset.

    Christy seems to be happy with claiming that the models failed. I would not ignore the possibility that there are remaining errors in the UAH estimates, especially after all the errors that have already been found. Had I been Christy I would have tried to make my claim that the models are the problem stronger by trying to understand the reasons. Which processes are wrong in the models that produce this hotspot, but should not? That would then need to be something that does produce the hotspot signs in the winds and also shows the amplification for El Nino on shorter time scales. That sounds hard to me, but Christy had a few decades to study it.

    A similar audit Red Team gave us the Berkeley Earth initiative, funded by the Heartland Institute funded by the Koch Brothers. Judith Curry was part of that, but got out before the politically inconvenient result was published. Anthony Watts, the host of the mitigation sceptical blog WUWT, claimed he would accept the results not matter what. That vow lasted until Berkeley Earth found the same result as any other global temperature dataset. Call me sceptical that this Red Team hullabaloo will have any impact on the US climate "debate".

    There is PLENTY of ROOM within the climate science to hold extreme views, both about the science and policy. However, there is no room for the lunacies of unicorns, for sun nuts, for folks who don't get chaos, for radiative physics deniers
    Steve Mosher

    I am sure it is a coincidence that the terms Red Team and Blue Team fit to the political configuration of country were the climate "debate" takes place, the United States of America. A country were the elite stays in power by pitting the Red Team and the Blue Team against each other. The main reason to support the Red Team is to at least not be the Blue Team. In Georgia the Republicans courted voters with the slogan: Make a liberal cry. Just the thing the coal and oil oligarchs would love to promote in the US climate "debate". Just the thing science should not want to replicate.

    Scientists are humans, one of the main biases a scientists needs to fight against is not dig in and defend your own old studies, claims, methods or datasets. I respect scientists that developed good homogenisation methods and talk about their downsides and the strengths of other methods. I respect that because it is hard and promotes scientific progress. To force a scientist to take the Red or Blue position strengthens defensiveness and thus hurts progress. It is political thinking. In science the evidence determines your position. It is the end, not the start.

    At least John Christy seems to mostly think of doing research, Judith Curry and Steven Koonin want to make jet another audit or report. This would an alternative IPCC report, following the example of the NIPCC report, the Nonsense IPCC, an embarrassing regurgitation of zombie WUWT myths authored by tobacco stooge Fred Singer. The NIPCC report is clearly PR. If the Red Team advocates think they have a scientific case, one would expect them to seek funding for science that would convince scientists, rather than bypassing the scientific literature and going straight to the public.

    Red and Blue Team framing not only contributes to the politicization of science, it also promotes the false-balance media narrative of two equal groups. Judith Curry, John Christy and Steven Koonin should be debating Peter Wadhams, Guy McPherson and Reddit Collapse.

    An important political strategy of the mitigation sceptical movement is to pretend that the science is not in yet. That is why they keep on claiming there is no scientific consensus, provoking consensus studies that find that nearly all scientists and articles agree on the basics. (And then complain that consensus exists.)

    Once people understand that scientists agree there is a problem, they want solutions. Some extremists in the mitigation sceptical movement may claim that solar and wind energy spell the end of civilization, but that is a hard sell. Sun and wind have enormous and bipartisan support in the USA.

    The 97% of climate scientists who agree on the basics include many conservative scientists. That there is a problem is not a partisan issue. How to solve it, that is politics. The Paris climate agreement was signed by nearly 200 countries and thus many conservative governments. They accept that climate change is a real problem. European conservative parties may be less active, but do not deny there is a problem.

    In Europe only Trumpian racist parties deny there is a problem. That the climate "debate" is mostly an American problem shows that the problem is not conservative versus liberal, that it is not a lack of scientific evidence, it is not a problem of the communication of science. The problem is the corrupting influence of money in US politics and media. A Red Team will not solve this.

    Details please

    ATTP asks very good questions on how this exercise should be organised. "Who would make up the team/teams?" Who are the organisers, the arbiters? Who selects them? What are the criteria? How do they want to prevent normal scientists from joining the Red Team? Scientists normally determine themselves what they work on. Should they be forced to waste their time on this? "How would this work be funded?" Is special funding needed because Red Team ideas do not have sufficient merit to be funded normally? "How would the programme be assessed?"

    With all those Red Teams in science, I am curious how the Red Team advocates want to make sure their Red Team will be on their political side and stay there. Writing explicitly into the funding conditions that the applicant has to have a history of deceiving the public in the media and producing bullshit blog posts would probably be too much honesty.

    Who would be in the Red Teams? Will they fund conspiracy theorists like Tim Ball and Christopher Monckton and corporate smoking shills like Fred Singer and Steven Milloy? That honesty would be a great sight.


    The tension is clear when John Christy writes:
    Decisions regarding funding for “Red Teams” should not be placed in the hands of the current “establishment” but in panels populated by credentialed scientists who have experience in examining these issues.
    The people with experience and credentials are the "establishment" in science.

    The mitigation sceptical movement could maybe organise a Red Team Blue Team exercise themselves and in that way figure out what their position is beyond the only thing they agree on: that climate science is wrong. That way they can demonstrate how enormously valuable this new scientific method is and it would have the added benefit that they waste their own time. I am curious whether they can come to an agreement about whether the Earth is warming or cooling and whether the greenhouse exists and CO2 can produce warming.

    I look forward to a detailed proposal for Red Team research and would expect that it will demonstrate how ludicrous the idea is.

    There is no real need for government funding of Red Teams whatsoever. Every large oil and coal corporation has a huge incentive to show climate science wrong. If they thought that there was a chance of one in a million that climate science was wrong, they would pour millions into studying that rather than in PR misinformation campaigns by networks of thoughtless tanks.

    If John Christy was making the case that science funding should not only be based on scientific merit, but that part of the funding should also be based on what is politically important he may have a case. Already a considerable part of the funding goes to studies that inform (local) governments and companies on how to adapt to climate change. This is mostly a service to society and scientifically less inspiring. If it weren’t so hard to do, this would be a task for engineering firms.

    Similarly, it would be politically important to study the tropospheric temperature trend in more detail for its importance in the American climate “debate”. It has nearly no scientific value because the tropospheric temperature series is so short and buggy. Each update there are huge changes in the trend estimates and the two available series show large differences, although they both try to take into account the currently known problems of the raw data. There is also no societal need for this dataset; no one lives in the tropical troposphere. Consequently only a few people at the University of Alabama in Huntsville and at Remote Sensing system work on these datasets once in a while. Occasionally there is some help in finding the problems with this data from external scientists.

    More independent research in this field, leading to the development of new high quality tropospheric temperature datasets would be politically valuable. Maybe that should also be a funding consideration.

    Related reading

    And Then There's Physics: Red Team vs Blue Team

    Stoat on Red teams: The East is Red

    The killer Rabbet: The Squeegee Kid Returns or Steve Koonin on Team B

    The Blue Team at Daily Kos: Deniers Calling for a Red Team to Create Debate on Climate Science

    * Top photo with birds, shame by Tiago Almeida used with a Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0) license.

    * Black and white photo of boy, shame, by Lee Carson used with a Creative Commons Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0) license.

    * Photo of "Taoist monk" by Antoine Taveneaux - Own work. Licensed under CC BY-SA 3.0 via Wikimedia Commons.

    * Photo of ashamed woman by Naika Lieva used with a Creative Commons Attribution-ShareAlike 2.0 Generic (CC BY-SA 2.0) license.

    Source: Variable Variability

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