Interview Matt Ridley bij FD Energie Pro

Het FD heeft een nieuw online product opgezet, FD Energie Pro. De site is net online gegaan en vooralsnog is de content gratis te lezen. Karel Beckman van de Energy Post heeft als interim hoofdredacteur de eerste verhalen uitgezet. Hij vroeg mij of ik er als freelancer voor wilde schrijven en het toeval wilde dat ik een dag later Matt Ridley zou opzoeken op diens landgoed ten noorden van Newcastle. Beckman wilde graag een interview met hem en zodoende staat dit interview nu als een van de eerste verhalen online. Het verhaal is nu nog gratis integraal te lezen. Hier de intro:

Viscount Matt Ridley is politicus, auteur, journalist, klimaatcriticus, bioloog, natuurliefhebber, ex-bankier, en eigenaar van een steenkolenmijn. Maar hij is bovenal: rationeel optimist. Hij gelooft dat de mensheid dankzij steeds verdere specialisatie en handel een welvarende toekomst tegemoet kan zien. Daarbij is een efficënte energievoorziening onmisbaar – en die kan volgens Ridley niet komen van bronnen als windenergie en biomassa. Journalist Marcel Crok bezocht Matt Ridley op zijn landgoed in Noord-Engeland.



Bengtsson in 1990: “one cannot oversell the greenhouse effect”

Lennart Bengtsson recently joined the Academic Council of the GWPF. This generated quite some attention on blogs and in the media. I interviewed him, but also Hans von Storch on Klimazwiebel, Axel Bojanowski had a story in Der Spiegel (English version), and there was an article in the Basler Zeitung.

Bengtsson emphasized that he has always been a “sceptic”. In the interview with me he said:

I have always been sort of a climate sceptic. I do not consider this in any way as negative but in fact as a natural attitude for a scientist. I have never been overly worried to express my opinion and have not really changed my opinion or attitude to science.

We all know that in climate discussions climate scientists are quick to say “we are all sceptics” so such a remark says little about Bengtsson’s exact viewpoints. The renowned Dutch science writer Simon Rozendaal then sent me a copy of his interview with Bengtsson published on 27 October 1990 (!) in the Dutch weekly Elsevier (for which Rozendaal still works as a science writer).

We can now confirm that Bengtsson was pretty “sceptic” in 1990. Here is the full translated Elsevier article:

A cool blanket of clouds

Climate expert Bengtsson puts the threat of the greenhouse effect in perspective

Next week, a large conference on the global climate will be held in Geneva. The most important topic of discussion: the greenhouse effect. Many hold the opinion that our planet is warming by the increase in carbon dioxide and that a climate disaster is looming. Maybe so, says Lennart Bengtsson, Europe’s most important climate scientist. Or maybe not. Bengtsson doesn’t actually know for sure. It could go either way.

Lennart Bengtsson is so far not daunted by the looming climate disaster. He frowns when looking at the tierische Ernst with which the rest of the world embraces the prediction that the planet warms due to the increase in gases like carbon dioxide (CO2). ‘It would become serious if the atmospheric CO2 concentration would decrease. Thanks to the greenhouse effect Earth is a habitable place. Were its concentration to decrease, then mean temperatures would plummet far below freezing. That really would be a catastrophe.’

The Sweed, who appears and talks like Max von Sydow, is director of the European Center for Medium Range Weather Forecast in Reading (United Kingdom), which supports eighteen European national weather centers like Dutch KNMI with computer models and simulations. Soon he will become director of the Max Planck institute in Hamburg and thereby will be in charge of Europe’s most important greenhouse effect computer model. ‘Until now the greenhouse effect research has concentrated in the United States, but Europe is advancing.’

There is something strange about the greenhouse effect. Many scientists babble and publish about it, but few really understand its ins and outs. Most of them treat assumptions as were they facts. Suppose that it would become two degrees warmer, how much higher would the Dutch dikes have to become? Or: suppose that we want to reduce CO2 emissions and still maintain economic growth for not so strong economies of Poland, Greece, and China, how much would the emissions of the wealthy Netherlands have to decrease? For the question whether the underlying assumptions are actually correct, one has to ask climate experts like Bengtsson.

He emphasizes that the greenhouse excitement is founded in computer simulations. And that computer generated models are not complete nonsense. ‘If for example such a model starts with a globally uniform temperature, then within a few months of simulation one would start to see the tropics warming and polar regions cooling. Remove the Amazon and after some time it reappears due to the torrential tropical rains. Such general characteristics of the global climate are part of the models.’

However, the models provide insufficient insight. ‘They are too coarse. While weather predictions nowadays have grid sizes of 100 by 100 kilometer, climate models work on a 500 by 500 km grid. In addition, models have problems with clouds. They are not able to predict what effect clouds have and they cannot distinguish between high and low clouds, yet we know that this differentiation has important consequences.’ Many other important aspects are lacking. Some of those cannot be incorporated simply because they are not well understood. ‘For a large part of the emitted carbon dioxide we do not know where it stays.’


Would there be no clouds, everything would be simple. ‘With a clear sky, increasing carbon dioxide or methane would lead to a reduction of heat radiation from the earth to the atmosphere. In addition, water vapor would amplify the so-called greenhouse effect. If temperatures increase, more water evaporates and water vapor is a powerful greenhouse gas.’

However, clouds do exist. It is these fluffy tufts that diminish much of the commotion surrounding the climate disaster. Clouds cool because they reflect sunlight. On the ground we notice this when we’re in a shadow. At the same time clouds warm because they prevent heat radiation from directly escaping to space: ground frost nearly always occurs under cloud free conditions. The simple question as to whether clouds cool or warm the Earth was until recently unanswered, and this says a lot about the current state of meteorology.

Among climate experts the opinion that clouds cool Earth is gaining ground, Bengtsson observes. ‘There are recent satellite observations, as reported in the scientific magazine Nature, showing that clouds reduce the greenhouse effect. In particular low level clouds are efficient cooling agents.’

Theoretically, the greenhouse effect could even cause a cooling rather than a warming of Earth. ‘The cooling effect of clouds is five times as strong as the temperature increase due to a doubling of atmospheric CO2.’ There is even an amplification of this feedback. Bengtsson: ‘If it gets warmer, clouds become whiter and thereby reflect more solar radiation.’

Such feedbacks are hardly part of the computer models that predict the warming, according to Bengtsson. ‘Almost no model is capable of dealing with the behavior of clouds. The models builders claim they do, but when we redo the calculations that turns out not to be true.’

There are other problematic issues. Were climate to really warm, snow and ice would have to melt. That would result in additional warming because white surfaces reflect more sunlight. ‘This additional warming is not present.’ Maybe the largest omission in knowledge about climate are the oceans.’ In most models it is assumed that the ocean is fifty meters deep, which is an average. But there are parts of the oceans that are several kilometers deep. Those would slow any potential warming. You could hide thousand years of warming in the ocean.’

The one small meteorological detail from the enormous amount of uncertainties, ambiguities and question marks that has become better understood is that an increase of CO2 and some other gases potentially has a warming effect. And that is what politics is focusing on right now. Bengtsson: ‘What happens in the Atlantic Ocean could have bigger consequences, but nevertheless all attention is focusing on the greenhouse effect.’


Bengtsson believes that climate experts should not pretend to be more knowledgeable than they really are. ‘In case of the greenhouse effect there is an interaction between media, politics and science. Every group pushes the other groups. Science is under pressure because everyone wants our advice. However, we cannot give the impression that a catastrophe is imminent. The greenhouse effect is a problem that is here to stay for hundreds of years. Climate experts should have the courage to state that we are not yet sure. What is wrong with making that statement clear and loudly?’

The excitement of the last weeks has moved everything into high gear. A United Nations committee (the IPCC) has released a report at the end of August which suggests that there is a broad scientific consensus about the existence of the greenhouse effect. This already has had political ramifications in many countries. For example, halfway October hundreds of Dutch politicians, experts, civil servants and industrialists have been discussing in Rotterdam themes from the 1960s like whether and how the Netherlands could lead the way (again). And early November there will be a global conference in Geneva about the global climate.

Bengtsson thinks that the IPCC has been particularly actuated for political reasons. ‘The IPCC prediction that with a doubling of CO2 in the atmosphere the temperature on Earth would rise by two degrees should be taken with a grain of salt.’

Due to the lack of understanding a thermometer remains crucial. And it is not pointing in the direction of a doomsday. ‘The temperature over the Northern Hemisphere has decreased since about 1950. In some countries the eighties were very warm, but there are countries where this is not the case. On Greenland there is little to be seen of the greenhouse effect. It has been very cold during the last couple of years.’

‘If you talk to the greenhouse mafia about these observations, they provide some answers, but those are not real. There is no proper support for the claim that the greenhouse effect should already be visible. It is sometimes stated that the Southern Hemisphere is warming. But there are so few observational sites over there that it is very difficult to draw any definitive conclusions about the temperature in the Southern Hemisphere.’

Bengtsson is not the only climate expert who thinks that much of the excitement about the greenhouse effect is undue. Many of his colleagues have been rather uneasy about what happened after they opened Pandora’s box. They have become afraid, now that politicians, camera crews, pressure groups and environmental departments worldwide have thrown themselves at the climate disaster, to openly state that what they have declared may have been a bit premature.

Bengtsson: ‘Many of us feel rather uncomfortable with much of what has been claimed about the greenhouse effect. No one had been talking about it because temperatures had been slightly on the decline during the last 30 years. Only after Jim Hansen of NASA had put the issue back on the agenda after the warm summer of 1988 has it become part of the political agenda. In itself there is no problem with that. Looking hundreds of years ahead the greenhouse effect could become a serious problem. Some policies are obviously a clever thing to do: save energy, become less dependent on oil, those are good ideas. But one cannot oversell the greenhouse effect. There are many environmental problems that are much more urgent like that of the sulphur dioxide in Eastern Europe.’


Elsevier (1990): Bengtsson relativeert dreiging van broeikaseffect

[Update: Met dank aan Simon Rozendaal is hier nu ook het volledige interview met Bengtsson destijd in Elsevier]

De beslissing van Lennart Bengtsson om toe te treden tot de Academic council van de GWPF heeft behoorlijk wat aandacht getrokken. Na mijn eigen interview met hem volgden interviews met Hans von Storch, Axel Bojanowski in Der Spiegel en een verhaal in de Basler Zeitung. Wat opvalt is dat Bengtsson telkens benadrukt dat hij altijd “sceptisch” is geweest.

In zijn interview met mij schreef Bengtsson:

I have always been sort of a climate sceptic. I do not consider this in any way as negative but in fact as a natural attitude for a scientist. I have never been overly worried to express my opinion and have not really changed my opinion or attitude to science.

Nu zegt dat op zichzelf weinig. In debatten tussen sceptici en mainstreamers zeggen mainstreamers ook geregeld dat “alle wetenschappers sceptisch zijn” en het zegt dus op zichzelf weinig over hoe mainstream dan wel sceptisch Bengtsson feitelijk is.

Simon Rozendaal van Elsevier stuurde me een e-mail met citaten van Bengtsson waaruit blijkt dat Bengtsson inderdaad al heel vroeg in het klimaatdebat openlijk zeer kritisch was over de dreiging van het broeikaseffect. Uit de e-mail van Rozendaal:

Ik publiceerde op 27 oktober 1990 (!), toen hij al directeur was van het centrum in Hamburg, een interview met hem in Elsevier. De kop: Een koele deken van wolken. Onderkop: Klimaatdeskundige Bengtsson relativeert dreiging van broeikaseffect.

In het interview benadrukt Bengtsson o.a. de onvolledigheid en grofmazigheid van de computermodellen waarop de broeikascommotie is gebaseerd en dat we veel te weinig van wolken begrijpen.

Wat citaten:

‘Er is bij het broeikaseffect een wisselwerking tussen de media, de politiek en de wetenschap. Elke partij vuurt de andere aan. De wetenschap staat onder druk, omdat iedereen een advies van ons wil. Wij mogen echter niet de indruk wekken dat de catastrofe aanstaande is. Het broeikaseffect is een probleem dat nog honderden jaren onder ons zal zijn. De klimaatdeskundigen moeten de moed hebben om te zeggen dat we het nog niet zeker weten. Wat is er verkeerd aan dat luid en duidelijk te zeggen?’

‘Er is geen enkele steun voor de claim dat het broeikaseffect al merkbaar zou zijn. Men zegt dan dat het zuidelijk halfrond al opwarmt. Daar zijn echter maar zo weinig observatieposten dat er over de temperatuur daar hoegenaamd niets zinnigs te zeggen is.’

‘Velen van ons voelen zich uiterst ongemakkelijk met wat er allemaal over het broeikaseffect wordt beweerd. Het is al dertig jaar bekend. Niemand had het er over omdat de temperatuur de afgelopen dertig jaar lichtelijk is gedaald. Pas nadat in de warme zomer van 1988 Jim Hansen van de Nasa het onderwerp weer oppikte, is het op de politieke agenda gekomen. Daar is niets op tegen. Als je een paar honderd jaar vooruit kijkt zou het broeikaseffect best een ernstig probleem kunnen worden. Sommige maatregelen zijn ronduit verstandig: energie besparen en minder afhankelijk worden van olie, dat zijn goede zaken. Maar men mag het broeikaseffect niet oversellen. Er zijn talloze vervuilingsproblemen die urgenter zijn, zoals het probleem van de zwaveldioxide in Oost-Europa.’

Wow! Wat mij het meest frappeert aan de uitspraken is dat ze anno 2014 nog steeds opgaan. Wolken zijn nog steeds onbegrepen, de grofmazigheid van modellen is nog altijd een issue. “Als je een paar honderd jaar vooruit kijkt zou het broeikaseffect best een ernstig probleem kunnen worden.” Ook die opmerking kun je nog steeds prima maken. De citaten laten helaas ook zien hoe bedroevend weinig vooruitgang er is geboekt in het wetenschappelijke klimaatdebat.

Rozendaal voegde er nog dit aan toe:

De wereld is niet zwart of wit (scepticus of alarmist), er zijn op zijn minst vijftig tinten grijs.



IPCC report: Global warming slowdown sparks new debate

I was interviewed by Skype yesterday by Jon Laurence of The Telegraph. The interview is now up at their website. Their introduction:

Science writer Marcel Crok says the 15-year slowdown in the expected rate of global warming shows the climate of the planet “is much less sensitive then we thought”.

The world’s foremost authority on the greenhouse effect, the Intergovernmental Panel on Climate Change (IPCC), will release its most comprehensive study to date on Friday in Stockholm.

The report is expected to say that the IPCC is now 95 per cent sure that humans are to blame for climate change, up from 90 per cent in 2007.

However, there has been a slowing in warming since 1998. The panel is expected to say this was caused by a temporary cooling cycle in the weather system and lower-than-expected solar activity.

Science writer Marcel Crok argues the Earth’s climate sensitivity – the estimate of how much the Earth’s climate will warm in response to the increased greenhouse effect – is less affected by human activity than the mainstream science community believes.

“Right now there is not really a good explanation for the slowdown, and this is really refreshing for the international debate because suddenly even mainstream climate scientists start to disagree with each other.

Note: I did not say that the lower climate sensitivity is due to the 15 year slowdown. The pause has not much influence yet on our observational estimates of Equilibrium Climate Sensitivity (ECS). This was shown for example in the Otto et al letter where the ECS for the most recent decade was slightly higher than for earlier decades (due to a more efficient heat uptake in the oceans). I did say that the slowdown is largely unexplained so far and that are currently many hypotheses around.



Fritz Vahrenholt: “The sun is giving us time to come up with smarter solutions”

Recently I had a long interview in Essen with Fritz Vahrenholt, the ceo of RWE Innogy (the arm of RWE that is producing renewable energy) and author of the controversial German book Die Kalte Sonne. Today, the interview (in English) has been published on the (free) online magazine European Energy Review.

The book, which he wrote together with Sebastian Lüning, who is also working for RWE, is impressive. As the title suggests, it focuses on the role of the sun, which they claim the IPCC has underestimated in their assessments. They go one step further than I did in my own book, they come up with their own ‘prediction’ for the coming century (page 318). With the sun going asleep and natural oscillations like the PDO and the AMO on the decline, they don’t expect warming to resume before 2035 or even later.

Vahrenholt is an interesting figure. He was a friend of the environmental movement after he published his book Seveso is überall, Die tödlichen Risiken der Chemie in 1978. Now after publishing this ‘skeptical’ book  his popularity in climate friendly Germany amongst greens went down rapidly.

The question is why? In the interview Vahrenholt turned out to be merely a realist. He is not against Die Energiewende, but he is against the rushed energy transition that is now taking place in Germany. He thinks that Germany is acting too much on its own and the energy transition should be a pan-European effort.

Read the whole interview here. (first readers should subscribe first which is free)


Dubbelinterview Van Soest/Crok in blad Milieu

In het blad Milieu van de VVM staat deze maand een dubbelinterview dat Jan Paul van Soest en ik enige tijd geleden hadden in Amersfoort. Van Soest noemt zichzelf een sceptische alarmist in het stuk, waarmee hij bedoelt dat hij gezond sceptisch is, maar dat die houding en bestudering van de literatuur er toch toe geleid heeft dat hij een alarmist is. Hij schat dat de klimaatgevoeligheid 4,5 graden is, de bovengrens van de range die het IPCC hanteert.

Van Soest zocht zelf contact met mij na de publicatie van mijn boek. Ik heb eerst lang met hem gesproken op mijn kantoor en de tweede keer hebben we elkaar dus geïnterviewd. Beide gesprekken verliepen bijzonder plezierig en ik denk dat dit soort uitwisselingen van gedachten belangrijk is om het klimaatdebat verder te helpen. (Overigens heb ik uit betrouwbare bron vernomen dat een lid van de VVM zijn lidmaatschap heeft opgezegd omdat ik erin stond. Met dat lid zou ik graag het volgende dubbelinterview willen maken) Lees verder…


interview in Nederlands Dagblad: ‘Klimaatwetenschap moet opener’

Dit weekend stond er een interview met mij in het Nederlands Dagblad. Docent en journalist Tjirk van der Ziel was beter voorbereid dan alle andere journalisten die ik gesproken heb. Hij kwam met een aantal boeken in zijn tas aanzetten bij mijn kantoor, waaronder het uitmuntende Why we disagree about climate change van Mike Hulme en het veel minder bekende A history of the science and politics of climate change van de inmiddels overleden vroegere IPCC-voorzitter Bert Bolin.

Het was een genoegen om met hem over het onderwerp van gedachten te wisselen. Tjirk gaat zelf de komende maanden vanuit Canada onderzoek doen naar de wijze waarop de media bericht hebben over het klimaat.


Gegijzeld klimaat

In de Intermediair van deze week staat een interview met ondergetekende. Het verhaal is online te lezen en uit te printen hier en hier. (Pdf hier en hier). Ik vind de kop ‘Gegijzeld Klimaat’ wel mooi gevonden. Het klimaat gegijzeld door een relatief kleine groep van activisten binnen het IPCC. En de rest die het verhaal dan maar braaf overneemt.


Te gast bij OBA Live

Vanavond tussen 19 en 20 uur ben ik een uur lang te gast bij OBA Live, een radioprogramma van de IKON dat wordt uitgezonden vanuit de Openbare Bibliotheek in Amsterdam (vlakbij CS).

Eerst word ik een minuut of twintig geïnterviewd over het boek. Later in de uitzending volgt een debat met collega wetenschapsjournalisten Martijn van Calmthout (chef wetenschap bij de Volkskrant) en Bo Blanckenburg (freelance) over wetenschapspopularisering in het algemeen en de vraag of het klimaatdebat wel aan een breed publiek uit te leggen is.

Ik begreep dat bezoekers van de bibliotheek de uitzending gewoon kunnen bijwonen. Wie weet tot vanavond.


Volkskrant: ‘Er is geen klimaatdebat’

‘Wat gaat de Volkskrant met je boek doen’, vroegen diverse mensen mij de afgelopen maanden. Een logische en interessante vraag waar ik geen duidelijk antwoord op had.

Lees verder…




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