Marcel Crok Responds To The KNMI Statement

knmi logoAfter I published the response I received from the KNMI I did a few pokes on Twitter towards Anthony Watts and Marcel Crok to see if they were willing to respond to it.

I also left a comment about it on Crok’s website where I quote what the KNMI said (I couldn’t do this on Watts’ website as the comment section was already closed).

So far I haven’t received a response from Watts, but Marcel Crok was kind enough to engage me in his comment section. I’ll be going through his responses to me in this post and my take on them.

Before I do that though I have to compliment Crok for being respectful and civil towards me, despite me being quite critical towards him. It’s something that’s often severely lacking from any public exchanges that take place. Being able to engage someone while being quite critical and at the same time having a civil exchange was a breath of fresh air. It’s just sad that this is the exception.

Now lets start with his first response towards me, which I found a bit strange:

Hi Collin,

thanks for dropping by and for asking a reaction to Rob van Dorland. Of course my interpretation of their submission is not completely the same as theirs, what did you expect? They have to be as diplomatic as possible not to offend the IPCC and other countries. As I am an independent observer I can be much more frank in a blog post and also in several parts I give my own opinion as is clearly stated.

Of course, as Rob notes, IPCC pays attention to natural factors. But the recent slowdown of the warming and the quite big overestimation of the models in the past 30 years makes clear IPCC probably didn’t pay enough attention to natural influences, e.g. the behaviour of the oceans and oscillations like AMO and PDO, which models cannot simulate yet. Given this background let’s now go back to the sentence in the submission:

“The IPCC needs to adjust its principles. We believe that limiting the scope of the IPCC to human induced climate change is undesirable, especially because natural climate change is a crucial part of the total understanding of the climate system, including human-induced climate change.”

If the treatment of natural climate change in the IPCC reports would be 100% perfect in the eyes of the Dutch government, do you really think they had to make this explicit point in their submission? Just to make the mandate more fitting with the report? Why only now after The Netherlands accepted the more limiting scope for two decades? It makes no sense Collin and I am sure most other countries will also regard the Dutch submission as quite critical.


I have a really big problem with this response. The biggest reason being that the KNMI clearly stated in their response to me what they meant, as shown by this snippet:

We (the Dutch IPCC delegation) believe it is important that the scope of this statement should be widened, namely that natural variability should be explicitly mentioned in the mandate of the IPCC.

In practice, the IPCC reports (WG1 and 2) on climate change mention natural and anthropogenic factors, simply because of the fact that the human factor only gains credence when compared to natural changes.

The proposed change from the Netherlands is that the mandate of the IPCC should be much more in line with what they’ve been doing for years. This also makes clear that the response in the media is not true, namely that the Netherlands find that natural variability is more important than the human influence. As this isn’t the intent of the Dutch submission.

That should end all discussion about interpretations or implied meanings. It doesn’t matter what you think it says or what you think they are implying, it matters what they actually say. And of course further explanations from them if something wasn’t clear.

If that shows the interpretation wasn’t correct Crok should concede the point and move on, not suggest that they are somehow being pressured to be diplomatic in their language.

It’s also irrelevant that they, as far as I know, never said anything about changing the IPCC principles document. This is them responding to a request from the IPCC where they asked for recommendations. KNMI is just publicly responding to this request, it’s as simple as that.

I’ve also seen the claim that global warming has stopped a lot lately, often this is done to criticize the IPCC and claim that the projections made by climate models are wrong. But that is at the very least based on a misunderstanding of the models involved and how these projections are made. As plateaus, like the one we are currently experiencing, are replicated by the models.

This is the very reason why I used an explanation from Ben Santer on climate noise in my video on this subject:

This is from a climate model, a Japanese climate model, uhm, these are from experiments that were performed in support of the IPCC fourth assessment report in 2007.

What you see here are tropospheric temperature time series. And you can see that there is this black line here, this small overall warming trend. This is an experiment, or a model, that is driven by changes in greenhouse gases, changes in the sun’s energy output, changes in aerosols in ozone. We call them also colloquially everything in the kitchen sink experiments, where you try and drive a climate model with your best estimate of the actual.. uh… factors that have been important over the twentieth century.

And you can calculate from this climate model something akin to the satellite temperatures that I’ve shown you. And in this particular run of this Japanese model you have a La Niña, that’s that blue thing, near the end which tends to cool it down. And you have an El Niño near the beginning, that’s the red thing, which tends to warm things up. Because this is a short record uh… only a little over twenty years, and you have a warm blip near the beginning and a cool blip near the end you don’t get much overall change.


But in the climate model world you can essentially rerun the twentieth century many times and get many different sequences of these things. And what you do then at the end is you average over all of these things, you average over these five realisations, and that beats down the noise. Because the noise is not correlated from one realisation to the next so you get a better estimate of the thing you’re really interested in which is the slow overall increase in temperature. In this case in response to human caused changes in greenhouse gases and and all that other nice stuff.

japanese mri model

To summarize: the models used by the IPCC replicate periods similar as to what we are now experiencing. But you don’t see those periods in the projections as they are filtered out by doing multiple runs so you can see the underlying climate signal. They do this to make sure climate noise doesn’t mask these signals or skew the projections.

Also the scenario Ben Santer used to explain this is very close to our current scenario. As we had a very strong El Niño in 1998 and we’re now in a period where we’ve had more La Niña events and weaker El Niño events. All this isn’t new to climatology.

Multivariate ENSO Index (MEI) from 2013-07-03

Multivariate ENSO Index (MEI) from 2013-07-03

But that was just a little piece of the entire puzzle of what is going on currently. The following presentation by Richard Alley perfectly explains the rest and shows why the planet is still warming, the trend is just masked in the global surface temperatures:

Most of this I mentioned or referenced in my response comment on Crok’s blog. To which Crok responded with the following comment:


“This also makes clear that the response in the media is not true, namely that the Netherlands find that natural variability is more important than the human influence. As this isn’t the intent of the Dutch submission.”

This is also a misrepresentation of what I said. I didn’t say that “natural variability is more important than the human influence” although it might be. I said: “The (almost) obsession of IPCC with greenhouse forcing has greatly limited progress in climate science in my opinion.” Now of course this is a statement that needs much more explanation and in a sense my whole book De staat van het klimaat is dealing with this issue. Lindzen in his excellent essay Climate Science: Is it currently designed to answer questions? is dealing with this and Judith Curry on her blog also frequently makes this point that IPCC should pay much more attention to our understanding of natural climate changes.

So people like Lindzen, Curry and myself simply disagree with Rob that IPCC is already perfectly doing this in their reports and that the only thing the IPCC has “forgotten” is to mention this explicitly in their principles. As Curry notes in her reaction to the Dutch submission on the url above, it is far from sure that IPCC will change their scope as it is tightly coupled to UNFCCC which has a very narrow definition of climate change, namely only changes that are the result of changes in the atmosphere (greenhouse gases).

Also, if “the media” in Rob’s comment refers just to my blog post we have a misrepresentation again.
Maybe you could post your original email to KNMI so that we can see where the misrepresentations started.


No, it’s not a misrepresentation of what Crok said. As it wasn’t me saying that Crok made that point or the KNMI responding to him as such. Let me show what I said after I used that quote:

The KNMI disagrees with your interpretation, that should be the end of the story. It doesn’t matter what you think it says, or what you think they are implying, it matters what it actually says. And of course further explanations from them if something wasn’t clear.

My point was that Crok is disagreeing with the KNMI while they have made clear that any other interpretations aren’t true. This is in reference to them stating what they did mean and clarifying what their intent was. I just didn’t make my point clear enough that this is what I meant.

In my e-mail towards them I never mentioned or referenced Crok’s blog post or any other articles. I didn’t even mention the media at all. As demonstrated by what I sent to them via their contact form on the 6th of July (translated from Dutch):

A few days ago the KNMI produced a document where they state their recommendations on the procedures of the IPCC.

One of the passages in that document (see attached URL) seems to suggest that the IPCC does not pay attention to natural causes of climate change:

“We believe that limiting the scope of the IPCC to human induced climate change is undesirable, especially because natural climate change is a crucial part of the total understanding of the climate system, including human-induced climate change.”

This sounds weird because the IPCC discusses contributions from natural causes in detail in their reports.

What is the intent and context of this passage in the document?

I’ll highlight two parts of my enquiry.

When I said “one of the passages in that document (see attached URL) seems to suggest that the IPCC does not pay attention to natural causes of climate change” this was not in reference to what Crok wrote. It’s in reference to Watts using the following title on his blog:

Dutch meteorological institute KNMI critical of IPCC – suggests they are leaving out study of natural climate variability

And him saying the following before he used what Crok had written:

Dutch advice to IPCC: limiting the scope to human induced climate change is undesirable

That’s what Watts either added himself based on statements in the KNMI document or took away as his interpretation from Crok’s post. Considering the response I got from the KNMI that is not a correct interpretation of what they said.

But that’s not even the biggest part of their response to me, most of their response is aimed at answering my question “what is the intent and context of this passage in the document?”

Like I said early their response makes it clear the KNMI isn’t criticizing the IPCC for not spending enough attention on natural climate variability; or them implying that this is the case. You can’t use it to infer anything else than what they are actually saying.

But this is something Crok did do in his comments and suggested with his highlight of “we believe that limiting the scope of the IPCC to human induced climate change is undesirable, especially because natural climate change is a crucial part of the total understanding of the climate system.” Followed by Crok saying this:

I agree with both points. The (almost) obsession of IPCC with greenhouse forcing has greatly limited progress in climate science in my opinion, so I am glad my government now raises this point.

Crok is disagreeing with Rob van Dorland – who identified himself as being part the Dutch IPCC delegation in his response – who explains what they meant and intended. It doesn’t matter if Crok agrees or not with these statements on what the IPCC does. Crok’s opinion on the work of the IPCC is a vastly different discussion than dealing with what the KNMI said in their clarification.

What Crok should have done in my opinion is to correct and clarify the blog post based on this feedback, not to try to justify what he said by suggesting they meant more with this statement than what they actually said and explained. Any further disagreements on what the IPCC does and doesn’t do should be dealt with separately.

For this I’d like to reference what Hans Custers said on the blog of Bart Verheggen, as he makes this point far more eloquently than I ever could:

The IPCC invited the governments of all participating countries to give their view on the future of the climate panel. The IPCC is a complex organization, dealing with a very complex subject, so perfection will be impossible to achieve. Or, from an optimistic point of view: there’s always room for improvement. And of course, a transparent process of self-reflection is a very good start for improvements. But well, this is the IPCC, so there is a catch. Whatever happens in this process, it will be spun by the anti IPCC and anti climate science campaign as ‘evidence’ for their claims. Every bit of criticism on the IPCC’s procedures and methods will be spun as substantial criticism on the scientific content of the assessment reports. And if governments would be reluctant to criticize, because they know it will be taken out of context, it would be seen as ‘evidence’ for the huge climate conspiracy.

The Netherlands has finished their submission and it was published (pdf) on KNMI’s website early last month. In my opinion they did what they should have done: they presented a straightforward view, not worrying about the inevitable spin by the skeptic campaign. And, oh yeah, inevitable it was. The next quote appeared in internet discussions again and again, after skeptics found the submission:

The IPCC needs to adjust its principles. We believe that limiting the scope of the IPCC to human-induced climate change is undesirable, especially because natural climate change is a crucial part of the total understanding of the climate system, including human-induced climate change. The Netherlands is also of the opinion that the word ‘comprehensive’ may have to be deleted, because producing comprehensive assessments becomes virtually impossible with the ever expanding body of knowledge and IPCC may be more relevant by producing more special reports on topics that are new and controversial.

Skeptics don’t seem to understand, or don’t want to understand, that this is about the IPCC organization only, and not about the content of assessment reports, or even climate science in general.

Custers also asked the KNMI (Rob van Dorland) for a clarification and got almost the exact same response as I did. I received their response 8 days after that blog post was published, more than enough time for the KNMI to become aware of what was said about them in the media (which would explain the media addition in the response I got).

But lets also briefly deal with Crok’s position on how the IPCC and climate science in generally function (briefly, as Crok did cite a 36 page document).

For this he references the essay “Climate Science: Is it currently designed to answer questions?” written by Richard Lindzen. What Lindzen says and argues for in this document is the closest I’ve seen him come to saying it’s a conspiracy (page 7):

One could go on at some length with such examples, but a more common form of infiltration consists in simply getting a couple of seats on the council of an organization (or on the advisory panels of government agencies). This is sufficient to veto any statements or decisions that they are opposed to. Eventually, this enables the production of statements supporting their position – if only as a quid pro quo for permitting other business to get done.


The influence of the environmental movement has effectively made support for global warming, not only a core element of political correctness, but also a requirement for the numerous prizes and awards given to scientists. That said, when it comes to professional societies, there is often no need at all for overt infiltration since issues like global warming have become a part of both political correctness and (in the US) partisan politics, and there will usually be council members who are committed in this manner.

And he argues throughout the document that the science is being lead by activism (page 10):

Given the above, it would not be surprising if working scientists would make special efforts to support the global warming hypothesis. There is ample evidence that this is happening on a large scale. A few examples will illustrate this situation. Data that challenges the hypothesis are simply changed. In some instances, data that was thought to support the hypothesis is found not to, and is then changed. The changes are sometimes quite blatant, but more often are somewhat more subtle.

These statements are not a fair representation of what has happened. For one the science is motivating the activism and warnings about what will happen if we don’t act, not the other way around. Sometimes activists go beyond what is supported by the science, but this isn’t an inherent problem to the science itself.

To make his case Lindzen rails against the scientific consensus, even going as far as calling it a “myth” (page 9). But this ignores that a scientific consensus is based on evidence, just like the scientific consensus on evolution.

He also constantly makes the point that most of it is bad science. Attacking the Research of Mann, referring to Santer and the SAR report of the IPCC, and even referring to the plateau we are currently experiencing as evidence for that. A lot of his arguments are the same as the ones you usual hear when talking about climate change. Suffice to say those aren’t good arguments.

One of the main threads in the essay is that dissenting views are attacked and often blocked from being published. In other words, climate scientists don’t want to listen to critics or deal with criticism fairly. But that’s again something that isn’t true. Which was once very nicely demonstrated by Richard Alley:

How do we know – how do we know it’s we not nature?
I mean we’ve got the increase in CO2, but the sceptic would argue wait a second I could go back to 1927 and find articles about glaciers retreating. What’s the difference? I mean, you know you could look at a football team so well they were losing back then and they are losing now, what’s the difference?

Right. So the first one is the physics. We just cannot get away from the warming effect of CO2, it’s been known for over a century. It was really clarified by the air force who were actually very interested in what wavelength should I use for the sensor on my heat-seeking missile. But CO2 interacts with radiation and there’s enough of it to make a difference. And we just can’t get away from that physics.

The second one is… is looking at is there any other possible thing to explain this, and it really took… I’m sorry sir took a few billion dollars of your money and about thirty years just say that there’s nothing else that we can find in nature to do this. And this is because the satellites are expensive. But someone says it’s the sun, well then you need a satellite to watch if the sun is getting brighter, but it isn’t.

And if someone says well it’s volcanoes so we need a history of our volcanoes and we need to know what they’re doing. And someone says it’s cosmic rays we need to have cosmic ray monitors. And has taken sort of thirty years to get to the point of saying no we’ve looked really hard and we can’t find anything else.

Then there’s a third piece which is the fingerprinting, which is what Dr. Santer was discussing. If you were to say, okay that, yeah I know we spent a lot of money on satellites and the satellite say the sun is not getting brighter. But maybe maybe maybe the satellites are wrong and the sun is getting brighter and we can’t see it. That makes a prediction, it gets warmer down here and it gets warmer way up at the top of the stratosphere. CO2 says warmer colder. What’s going on? Warmer Colder. So the fingerprinting and in time and in space says that we got it right on the other two pieces, it’s mostly us.

I’ve never been impressed by these kinds of arguments from the so-called sceptics. Often they are easily verified as being incorrect and without merit. There’s far more to this than I could expand upon here considering how broad this subject is, simply due to the amount of time it would cost. But that’s not uncommon with these type of arguments.

Considering all this Crok doesn’t have a point with what he took away from the statements the KNMI made, that much should be clear from their clarification. It also wasn’t justified to interpret what the KNMI said based on the opinions Crok has on how the IPCC functions or climate research in general. Nor do I think he even has a point with his criticism towards the IPCC and climatology in general.

But I think he and I will probably never agree on this.

Collin Maessen is the founder and editor of Real Skeptic and a proponent of scientific skepticism. For his content he uses the most up to date and best research as possible. Where necessary consulting or collaborating with scientists.