Open letter across the barricade

By Ken Perrott 08/01/2012

Here I respond to a letter sent to The Listener by a former scientific colleague, Doug Edmeades. He is now a science spokesperson for local groups which attack the current scientific consensus on climate change as well as attacking local climate scientists.

Doug and I are old mates. In the past we fought together against commercial and bureaucratic attacks on our research. Now we find ourselves on opposite sides of the “barricade.” But I am sure there is enough mutual respect to enable a reasoned discussion of the claims made by Doug about climate change science in his letter.

I have invited him to respond in turn to my comments and hopefully he will be happy that I post his response, at least in part, here.

Hi Doug,

I am responding to claims you made in your recent letter to The NZ Listener reproduced on the Climate Conversation Group Blog (see In a climate of listening). Space limitations clearly prevented you from justifying these  five claims (your refer to them as “facts”). However they are, in my view, either not factual or misleading. I explain why below and welcome your response to my comments.

1: Claim of “no recent global warming” is misleading

Climate change is a multi-decadal phenomenon – short-term temperatures are strongly affected by natural variability. This is clear in a recent figure portraying five different global temperature records (Fig. 1).

Figure 1: From The Yale Forum on Climate Change & the Media. (Click on figure to see article)

Choosing short time periods (eg a decade) may give an entirely misleading impression as you can see from Figure 2 where I have plotted temperature trends of separate periods.

Figure 2: Uses GISTemp data

The most relevant comparison here is the 1998 – 2008 and the 1999 – 2010 periods (the dotted trend lines). The table makes it clear how incorporating 1998 in a short period like this distorts one’s conclusions – because it purposely includes a large variation which confuses the trend (see Table below). This is a classic ploy used by many people who attack the current scientific understanding of climate change.

Period Trend (°C/decade) 95% confidence range
1970-2010 0.20 0.16 – 0.23
1998-2008 0.16 -0.09 – 0.41
1999-2010 0.28 0.10 – 0.45

Comparison of trends for the  1970 – 2000 and 1970 – 2010 periods also suggests that  temperature increases over the last ten years probably have not declined. If anything they may have even increased (see Figure 3). This test was presented on the Yale Climate Media Forum – I realise it cannot be conclusive but would be interested in a statistician’s opinion of the test.

Figure 3: From The Yale Forum on Climate Change & the Media. (Click on figure to see article)

So Doug your claim may well be technically true, maybe even statistically “true” depending on which data set is used, especially if the data for 1998 is included. But it is clearly unwarranted. And misleading.

2: “Medieval warm period” regional, not global.

While contrarians, deniers and climate sceptics have sometimes made a big issue of the “medieval warm period” the conclusion has usually been that it is not a global effect. That is, it may have occurred for parts of the northern hemisphere but is not seen strongly in the global data. See Hemispheric Temperatures in the ‘Medieval Warm Period’ in Working Group I Report “The Physical Science Basis” (AR4).

3: All warming factors are considered

Yes, many factors are involved in driving global temperatures – both natural and human effects. But here is the fact which concerns climate scientists and governments around the world. We just can’t explain the observed temperature trends over the last 50 years without incorporating human inputs as well as natural ones. This is demonstrated in Figure 4 below.

Figure 4a included all the natural and anthropogenic influences.  The black line is the actual measured global temperature anomaly (obtained by subtracting the average temperature for 1901 to 1950).  The individual simulations are shown as thin yellow curves. The red line is the multi-model ensemble mean (see Figure 9.5 — AR4 WGI Chapter 9: Understanding and Attributing Climate Change).

Figure 4: From AR4 Working Group I Report "The Physical Science Basis"

Figure 4b is a similar plot using simulations which consider only the natural influences on climate. The individual simulations are shown as thin blue curves. The thick blue line is the multi-model ensemble mean.

So, climate scientist have considered both natural and anthropogenic influences. And they are unable to reproduce the global temperature changes since 1970 unless anthropogenic influences are included.

That is why the IPCC has concluded that there is a high probability (>90%) that human influences are contributing to the current observed global temperature increase.

4: Models are not reliant on incorrect assumptions about clouds

You misrepresent the current understanding of the influence of clouds in climate models. The fact is that cloud effects are just not well understood yet – the IPCC reports acknowledge that. Figure 5, for example, is from the last IPCC report (Figure 2.20 — AR4 WGI Chapter 2: Changes in Atmospheric Constituents and in Radiative Forcing). It shows the estimated influences of several human caused effects and solar radiation since 1750. Notice the error bars. They are much bigger for clouds and aerosols than they are for the others. Notice the assessment of scientific understanding for these influences. The IPCC acknowledges the low understanding for clouds and aerosols.

Figure 5: From AR4 Working Group I Report "The Physical Science Basis"

Obviously this problem is getting attention in current and planned future research.

5: Criticism of NIWA temperature record wrong and malicious

New Zealand’s temperature record, being regional, has very little relevance to the overall global record. However, politically it has been contentious because of unwarranted attacks on the record, and on NIWA climate scientists, by the organisations you represent.

Richard Treadgold crudely attacked the previously published record, and NIWA scientists, in his article “Are we getting warmer yet?” Campaigning by the extreme right wing  ACT Party in parliament resulted in finance to repeat the calculations your organisations were claiming fraudulent. This produced a new temperature record, together with details of adjustment calculations and methodology which confirmed the previously published record.This would have settled any real, but misguided, concern about the data.

Of course, your Climate Science Coalition and The Climate Conversation Group have continued their campaign – probably not at all surprising because their purpose is political, not scientific. And they have adopted the common denier strategy of McCarthyist attacks on climate scientists we are seeing around the world. The promotion of Treadgold’s article at the very time the “climategate” email scandal erupted highlights the common strategy.

This raises the important question of scientific integrity – a subject that I know has concerned both of us over the years. In his article Treadgold made claims that were damaging, malicious and probably libellous. He said that:

NIWA scientists ’created a warming effect where none existed.’ That ’the shocking truth is that the oldest readings were cranked way down and later readings artificially lifted to give a false impression of warming.’ And ’we have discovered that the warming in New Zealand over the past 156 years was indeed man-made, but it had nothing to do with emission of CO2 — it was created by man-made adjustments of the temperature. It’s a disgrace.’

At the same time he included his own “scientific” analysis which ignored completely effects due to inevitable changes in  recording station. (Obviously because erroneously using the uncorrected raw data fitted his picture better). At the time he claimed that his report was based on work done by scientists in his group – scientists which he refused to name, claiming they wished to remain anonymous!

You may remember I wrote to you at the time asking if you had been involved, or had reviewed the article before its release. This is still a relevant question to me. Despite scientific rubbishing of Treadgold’s article he refuses to withdraw those  malicious comments, or acknowledge the faulty, naive, analysis reported. And, his article still gets used to attack New Zealand scientists.

Well, I am not so naive as to expect politically motived people to be concerned with the truth. But I think this issue does present a problem for us because, unless we take a principled stand on it our scientific integrity is threatened. So, could you please comment on your position with respect to Treadgold’s article, his analysis and his malicious criticism of NIWA scientists? Do you support him? Or have you criticised them within your organisations and attempted to get their withdrawal?

Doug, I am sure you will take my comments and questions in the spirit they are intended and hope you will take the time to respond to this open letter. I certainly look forward to your response and any continuing discussion of these issues.

Ken Perrott.

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0 Responses to “Open letter across the barricade”

  • Hi Ken I haven’t seen the Listner article but I recently read a series of articles relating to your figure 2 that impressed me with it’s apparent throughness. It tells an interesting story if you Google Bob Tisdale he has a blog I’m sure you will be able to link into the work. WUWT had it featured as well.

    Perhaps we should be talking about heat content rather than temperature as this paper indicates

    One thing is for sure climate science is in its infancy and certainly not “settled”

    • Kevin, It has not yet been published and probably won’t (Still Doug has more success than me in getting letter published in The Listener). It’s just that I had promised to comment on a couple of articles Doug had written and had not got around to it for family reasons. So I “owe him” these comments, if you like.

      I haver provided a link to the full text of Doug’s letter which is on the Climate Conversation Group’s blog.

      Figure 2 was my own construction from downloaded data. It’s being heavily critcised by one person on my original blog but I don’t think anyone else has commented on it.

      Boy, your “Friends of Science ” blog is a humdinger. Their post The Earth is Cooling makes the same point that Doug does (1) – so my refutation is relevant. They are really dishonest – I hope you don’t rely on them for information.

      This is a clear example of a denier group claiming the “science is settled” (cooling from 2002 on) using dishonest data. Come on – that mantra should be put to bed.

  • Thanks Ken, I was trying to dig out something I had read recently on your figs 4 and this popped up this morning worth a read.
    Ken my real issue is that the solution ETS is wrong. and the corruption of the science and politics at UNFCCC and IPCC level is impinging on our politicians ability to make good policy decisions for the future. No rational person would believe that a change in the make-up of the atmosphere will not have an effect, it is how much and in comparison to other inputs what that effect will be or what is the sensitivity to CO2 and how should we respond that is the issue.

    My inclination is toward CO2 being of minor influence and that the eco politicians and eco scientists at the IPCC are twisting the science and it is becoming increasingly obvious. What this has done for us is that we have an ETS that is making us poorer and hence less able to respond if we need to and at the same time not solving the real (though possibly minor) influence of CO2 induced temperature rise.

    Have a read of Scaffetta I think it adds a perspective that is needed.

    • Kevin, I think you ought to widen your information sources – climb out of the denier silo you seem to be trapped in. It is leading you to make the most childish and defamatory claims of corruption etc., (without any evidence advanced for them I notice). Conspiracy mongers deservedly don’t have credibility.

      And personally I have no respect for anyone who refuses to deal with the evidence and science but uses such dishonest tactics in an attempt to descredit the science. There are established and respectful ways to deal with scientific differences – these involve interacting with and consulting reality. Not childish slander.

      OK, your “inclination is toward CO2 being of minor influence”. So what? Why do you think your “inclination” should override the massive evidence in the literature? What makes you so important? Why should anyone listen to such a weak argument when there is just so much real information out there to consult?

      You are welcome to your polical view that “we have an ETS that is making us poorer.” Take it up with your politicians, suggest alternatives to her, but why come here with that complaint? Sure, politically I might even agree with you – but you don’t exactly present a good case by using slander to attack the science do you?

      And what relevance is your political view to this particular post which is about 5 scientific issues on which I and a former colleague potentially disagree?

  • Ken if you think that what has gone on at the IPCC is not corrupt then you had better take a course in ethics, before you do that read Donna Laframboise “The Delinquent Teenager…. and Ross McKitrik’s essay on the IPCC. And the IPCC review if you want evidence. There are systemic problems at the IPCC that have lead to corrupt practices like it or not that is what has happened. I didn’t slander anyone I commented on an organisation, I’m sure that most of the scientists involved are Ok and give their time freely for the betterment of the science however some bad administrative structures and decisions by a few have led to a lack of credibility in my view and I understand many others and that is the political reality. There is no doubt that there is fantastic work going on all around the world in the climate science area some of the best of it in NZ. The science is however not settled nor is it likely to be in the near future,

    I am not a denier and don’t live in a silo of any sort I read widely on the issue and sent you two back up papers relating to your paper that I thought might be of interest to you and Doug. One by Bob Tisdale and the other by Scafetta. Didn’t you Look at them or are you worried that reading them might put a hole in the parachute.

    I make no claim of importance, I have an opinion and will express it. In this case I offered the 2 papers and a political comment.

    Thanks for your comment on going to my politician bit late mate been there done that.

    My political view was an aside to the papers of relevance offered to your discussion with Doug

    Will read your ongoing discussion with Doug with interest.

    Reagrds kevin

    • Kevin, you really discredit your position by using extreme terms like “corruption” – without any evidence or examples. And then this becomes “bad administrative structures and decisions!”

      I think you need to understand what the IPCC is because your attack on the science is like someone who attacked my published work because one of the financial managers in my institution had been sacked for bad procedures. Or more appropriately, attacked Michael Mann’s work because of the behaviour of an administrator in New Zealand!

      The IPCC is tasked with summarising the current climate science and presenting their results in a form which governments and policy makers can use. Climate scientists from around the world review the published peer-reviewed literature and write the reports. Large numbers of scientists are involved, several layers of review are involved, and we end up with reports like the AR4. This means the Physical Science AR4 report is very authoritative (and the work it is based on well referenced). But it also suffers from being conservative and someone dated. Inevitable with the process. Like any review it will give an overall picture, more of a consensus, of the current science rather than the often differing, more radical, conclusions which might come through in a single published paper.

      This makes the AR4 a useful and reliable, if conservative and dated, source of reference. But importantly, any honest criticism of the findings should engage with that science. Not rely on vague, unsupported, accusations of corruption. As I said, conspiracy theorists destroy their argument before they get started.

      And you also discredit yourself with links to well known, unreliable, denier blogs. Your narrow sources are what make me suggest you are in an internet silo.

      I have written a post dealing with 5 issues which are scientific in nature (although I also express my concern for Doug’s scientific integrity as he belongs to political organisations who are carrying out slanderous attacks on leading New Zealand climate scientists). I welcome your interaction with that post.

      If you think I am wrong on any of the 5 scientific points – tell me – and talk about the science. (I am understandably not interested in either your political views or your unfounded conspiracy theories). And tell me the issues – vague advice to read a denier blog or a paper you link to tell me nothing. And I am old enough to rely on evidence and arguments rather than wild references to papers (have a look at the discussion I had with Simon on my blog and you will understand why).

      If you really think, as you claim, that NZ climate scientists are doing good work – well take a stand on my point 5. Condemn these local denier groups who have been slandering our scientists. And what about also condemning the McCarthyist attacks on climate scient6ists like Michael Mann.

      And enough with the “science is not settled” mantra. As a scientist I know that from experience. And the assurances that Doug has given that science is settled in favour of his claims is false.

      This mantra is a desperate political attempt to prevent humanity from taking action on a serious question. The fact is that the current understanding (global warming is occurring and that it is very likely to currently be mainly caused by human inputs) is sufficiently strong for governments and peoples to be concerned and to consider action. Governments know that scientific knowledge is always provisional, and open to revision. That is why they are continuing to fund climate change research in many areas. And governments are very used to working in the real world where they often have to make decisions based on insufficient knowledge and poor economic models.

      Actually, they probably appreciate the fact that the nature of the information and models they have in the climate science area is far better than what they usually have to work with.

      So, Kevin, I welcome your continuing comments. I just ask that they relate to the scientific issues and be specific.

  • Kevin Hearle (aka non entity) so this is where you’ve been hiding! And why are you citing an old bogus paper on ocean heat?

    Check out the NODC data sets, and this SkS article I wrote on Von Schuckmann & Le Traon (2011).

    Bob Tisdale is a bit of a giggle too – I find it hard to get past his interminable waffling. I suspect he thinks it makes him seem smart, but someone who thinks he knows better than 97% of publishing climate scientists doesn’t strike me as smart. I did note that when the ocean data showed marked warming in the deeper ocean he infers it’s fraud. Yawn.

    Just to recap:

    You’ve yet to explain how the oceans can warm from cosmic rays. You’ve yet to explain how the climate is influenced by cosmic rays, yet don’t follow temperature trends. You’ve yet to demonstrate some causative mechanism when even the CERN results haven’t done so yet. And just as crucially, you’ve yet to explain why the The Laschamp Anomaly. 40,000 years ago – when the Earth’s magnetic field went haywire & the Earth was bombarded by cosmic rays did a big fat zero to Earth’s climate.

    Handwaving by linking to long-debunked papers by climastrologists Scarfetta and Svensmark, will be considered a non-answer. I’m talking about peer-reviewed scientific papers that have withstood scrutiny by other experts.

  • Hi Rob, you must be one of Ken’s mates, I don’t know who you are and I’m sure you have no idea who I am, but I can assure you I am not hiding. Your opening insult however says more about you than any qualification you have in climate science.
    Let me explain the context, I read Ken’s blog and had seen both the Tisdale, and Scafetta papers both of which pertained to what he and Doug were discussing. I drew them to Ken’s attention without comment as to there veracity nothing more than that. The Scafetta paper is published in the Journal of Atmospheric and Solar-Terrestrial Physics and is pay walled. I have only seen Bob Tisdales work on his site. As far as the science is concerned that is the story anything else I said was an aside to Ken.
    From a purely lay perspective I find your denigration of Svensmark in particular as uncalled for. It seems to me that theory (while not confirmed 100% by CERN Cloud experiment) neither did it falsify it. More work is being done and that in itself says that there might be something interesting to discover. Given that it is proceeding surely adds some credibility to Sevensmark and further given the complexity of Climate science one would have to give the theory some credit until proved otherwise. It might not be the full story I suspect it is a component of an explanation of the climate situation and for sure CO2 will be in there, along with all the other natural forces.
    You apparently have a great garden relax spend more time in it and work off that aggression.

  • Kevin, You are simply parroting (almost exactly) the same fake-skeptic nonsense I have run across elsewhere quite recently. Seems a case of mistaken identity – my bad.

    But regardless, the facts remain Scarfetta’s work particularly is laughable. All these mysterious planetary cycles that only vaguely match now, but skew off course markedly when travelling forward and back in time. And he expects to be taken seriously?

    As for Svensmark – the insurmountable obstacles remain. If the climate ignores cosmic rays when the Earth is bombarded by them it just shows their influence, if any, is negligible.

    And what is it with the Bob Tisdale cites? Do you even understand the twaddle he writes? I suspect you’re taken in by all the graphs and fancy words. That’s your choice, but don’t expect non fake-skeptics to be taken in.

    And yes CO2 is the big kahuna. It’s Earth climate control knob. Turn it up and the greenhouse gas forcing on the ocean makes it accumulate heat. No way around that. The oceans cover of 70% of the Earth’s surface, and because they have a heat capacity a thousand times that of the atmosphere, over 90% of global warming is going into the ocean. The oceans are still warming of course, and they will continue to do so, don’t expect a respite any time soon.