Mertonian norms

There are a set of norms of science, first presented by Robert K Merton and known as the Mertonian norms. I found what seems to be a good description of them here. There are four Mertonian norms, called universalism, communalism, disinterestedness, and organised skepticism.

You can read the links above for more detailed descriptions, but they’re essentially that research results should not be judged on the basis of those presenting them, that the results of research should be available to all, that researchers should not conduct research for personal gain, and that research claims should not be accepted by the scientific community until they’ve been suitably tested.

The reason I thought I would discuss this is because Roger Pielke Jr, in his never-ending quest to withdraw from the public climate change debate, has a new Op-Ed in the Wall Street Journal. The title is A litigious climate threatens scientific norms. I wanted to focus on one particular claim in Roger’s Op-Ed. Roger says

Another of Merton’s norms is “universalism”—that the substance of scientific claims is what matters, not the characteristics of the people advancing them. A layman has as much right to challenge a scientific claim as a scientist does. But Mr. Mann’s case illustrates an important asymmetry: Scientists are bound by Mertonian norms, but nonscientists are not. Mr. Mann’s critics were unfair, obnoxious and wrong, but adherence to Mertonian norms means that Mr. Mann not respond in kind, much less go to court. It may seem unfair, but what makes science different from ordinary political discourse is also essential to making science strong.

The first two sentences seem like reasonable representations of Merton’s norm, but the rest is just nonsense. I think most scientists would recognise Merton’s norms as reasonable representations of how scientists should – in general – conduct themselves, but I’d be surprised if many had actually heard of Merton’s norms specifically (I hadn’t, until recently). They’re clearly not formal rules that scientists abide by; at best they’re guidelines. Scientists are certainly not bound by them and, as with most things, reality is not quite as simple as these norms might suggest.

Furthermore, Merton’s norms are intended to describe responsible research conduct, which should – ideally – apply to anyone who engages in such activities. If anything, universalism implies that anyone can conduct research and that their results should not be judged on the basis of who they are. If a layperson challenges a scientific claim then, in some sense, they’re no longer a layperson. If Merton’s norms apply, then they should apply to all who think that they are in a position to challenge scientific claims.

Also, Merton’s norms say nothing about how scientists should conduct themselves in the public realm, or what they’re expected to endure. Scientists are as entitled to protection under the law as any citizen of the country in which they reside. Merton’s norms do not indicate that scientists should not respond in kind, or that scientists should not go to court to resolve disputes. This does not mean that I think that it’s necessarily wise to do so, or that those who do so are justified in doing so, simply that there is no reason why they should be prohibited from doing so. In some cases I think it is justified, in others not.

The suggestion that scientists are not entitled to use the courts to defend themselves is pretty bizarre, but there’s – in my view – an even more insidious issue. One thing that Roger’s narrative promotes is the idea that we can be dismissive of some research areas when we regard scientists as not behaving as they should (the irony of this is probably lost on Roger). He even confirmed, on Twitter, that he is indeed suggesting that these factors are beginning to corrupt the field (the field, in this case, being climate science).

What I fully expect is that as it becomes clear that we’ve ignored an important issue, there will be increasing attempts to find people to blame. We really should – in my view – push back against suggestions that a problem is that the behaviour of the scientific community – or some in the scientific community – does not satisfy some set of norms. If we do end up regretting not having taken this issue more seriously, the reason is not going to be because some scientists chose to use the courts, or because others were rude on Twitter.

Posted in Climate change, ClimateBall, Roger Pielke Jr, Scientists, The philosophy of science, The scientific method | Tagged , , , , , | 31 Comments

A real time global warming index

This is a guest post by Karsten Haustein, a researcher in the School of Geography and the Environment at the University of Oxford. The post is about a new paper that discusses their real time global warming index.

Have you ever wondered what the current level of human-induced warming really is? Well, here is something that might help.

Published in one of the more recent Nature spin-offs (Haustein et al. 2017), we introduce a real-time Global Warming Index (GWI) which provides an estimate of the fraction of anthropogenically caused warming up to the current date (or even second for that matter).

The initial idea was put foward in a paper led by my colleague and co-author Fredi Otto (Otto et al. 2015), using annual data only. Since it didn’t come with an uncertainty analysis, we went back to the drawing board, updated all the forcing estimates and included a sophisticated uncertainty analysis based on the best available science to date. The result is made publicly available on the aptly named website. The index is updated monthly as soon as the lastest global temperature estimate is released. In the meantime, the counter on the top of the website extrapolates the current (10-year) warming trend up until the current second.

The basic idea in a nutshell: the temperature response to any given change in external radiative forcing (accounting for fast and slow responses, with e-folding response times of 4.1 and 219 years, respectively) is regressed against global mean surface temperature; with the resulting slope determining the magnitude of the forced signal. This is done separately for anthropogenic and natural forcing contributions. The former includes greenhouse gases (CO2, ozone, methane, a variety of trace gases), land use change and aerosol effects (direct and indirect for SO2, NH3, OC, BC, as well as BC on snow), whereas the latter includes explosive volcanic eruptions and changes in solar incoming radiation. Apart from the associated forcing uncertainty, we have also accounted for response model uncertainty, observational uncertainty and last but not least uncertainty due to internal variability.

Figure 1: Global Warming Index from Jan 1950 to May 2017 for HadCRUT4. The anthropogenic contribution in orange (with 5–95% confidence interval). The natural contribution (solar and volcanic) in blue. The red line shows the combined (total) externally-driven temperature change. The dark red line shows the evolution of the GWI when only past forcing and temperature data are used. The thin black line are the monthly (HadCRUT4) GMST data. For illustration, blue diamonds indicate when major climate summits took place in context of the monthly GMST at that time. (Figure 1 in Haustein et al. 2017)

Since anthropogenic forcing components tend to change slowly over time (for example, greenhouse gases are well-mixed in the atmosphere and therefore concentrations increase fairly linearly), short-term fluctuation from ENSO or volcanic eruptions are effectively filtered out. We have demonstrated the robustness of the index by going back in time to re-assess what the attributable warming would have been (see figure 1 which is an updated version of Fig 1 in the paper). Turns out, the inappropriately named “hiatus” left no more than a barely visible dent in the index estimate. That said, it is important to understand that – by construction – the GWI is controlled by the forcing rather than the temperature. Hence the fact that the trend appears to be increasing during the last 5 years (the current rate of warming based on 10 year trends is +0.16-0.17K/decade as shown in figure 2) or so is somewhat worrying, as it merely reflects an accelerated increase in radiative forcing, primarily due to an upward revision of methane forcing.

Figure 2: Figure showing 3, 5, 10 and 20 year trends, plotted against time, and the 5-95% uncertainty interval for the 20 year trend.

This is one of the strengths of our index: it shows straight away why we shouldn’t have been surprised by the rapid temperature uptick during the strong 2015/16 El Niño, as much as we shouldn’t expect the temperatures to ever go back down to pre-2014 levels (barring a strong volcanic eruption).

Given that the latest IPCC report (AR5) provided a quantitative assessment of the human-induced warming for the 1950-2011 period only, the public was left guessing what the fraction of anthropogenic warming since pre-industrial times really is. This has now also changed, and we certainly hope that our work fosters a more conclusive statement in the next IPCC report.

Figure 3: Same as Figure 1, except using the HadCRUT4-Cowtan/Way surface temperature dataset.

We note two more things: (1) the exact definition of what “pre-industrial” means remains somewhat contentious. While the 1850-79 period chosen in our paper is defensible given the rather small amount of greenhouse gas induced radiative forcing before that time, there is still some debate about the optimal definition (see Hawkins et al. 2017 for more details). (2) Despite having accounted for observational uncertainty, the bias due to the missing coverage of the Arctic in HadCRUT4 is larger than their error model suggests. Hence the choice of the observational temperature dataset is adding to the overall index uncertainty as highlighted by the figure on the right (Figure 3), by comparing the GWI based on HadCRUT4 with the version using HadCRUT4-Cowtan/Way (Cowtan et al. 2015). The index goes up from 1.02°C to 1.08°C. Using Berkeley Earth instead (not shown), the index is as high as 1.12°C. Arguably, HadCRUT4 is biased low and so is the associated GWI estimate. Eventually, infilling will become the standard and the products should converge in the not-so-distant future.

Together with continuously updated estimates of the ocean heat content and Earth’s energy imbalance (see for example von Schuckmann et al. 2016), we believe that the GWI is a helpful tool to monitor of the state of the rapidly changing (near-surface) atmosphere in real-time. It neatly bridges the information gap caused by the periodic nature of our academic assessments.

For more information, we refer to the Supplementary information and the info page on our website. Also, we encourage everyone to download the accompanying spreadsheet and play around with it 🙂

Finally, all credit belongs to my co-authors Fredi Otto, Piers Forster, Dave Frame, Dann Mitchell and Damon Matthews in general, and Myles Allen, who had the original idea, in particular.

Posted in Climate change, Global warming, Research, Science, Uncategorized | Tagged , , , , , , | 23 Comments

I’m confused….

Recently, Warren Pearce and colleagues published a paper called [b]eyond climate consensus which I wrote about here. There was a response from John Cook, one from Naomi Oreskes, and a Guardian article by multiple authors. Pearce et al. have now published a response to these responses.

So, why am I confused? The first Pearce et al. comment suggested that [q]uantification of consensus within climate science continues to occupy a central role in public discussions of climate change and discussed the focus on consensus messaging. The second Pearce et al. comment, though, says

the data shows a clear majority position among Americans: that climate change is real, important and worrisome, and that the US should take policy action and invest in public education. These positions have been reached in the absence of accurate knowledge about the scientific consensus.

If there has been some kind of undue focus on consensus messaging, then how can one claim that the public position has been reached in its absence? The above, therefore, seems inconsistent with what was suggested in the first Pearce et al. comment. On the other hand, maybe the word accurate in the above quote has some significance, but that still doesn’t make much sense. You can’t really imply something about the accuracy of consensus study without some kind of evidence to support that suggestion, and I’m not quite sure how the public would know if the estimates of the scientific consensus were accurate, or not.

So, it seems that the two comments are rather inconsistent. Either we’re giving undue focus to consensus messaging and crowding out more effective/appropriate alternatives, or consensus messaging is having no impact on how people develop their positions, but it can’t really be both.

Let me make an additional comment. The more recent Pearce et al. comment says

First, the debate over the hiatus/pause in global temperature increase was not invented by fossil fuel interests, but is a subject of genuine scientific disagreement ….. . Second, there is increasing expert debate regarding how much carbon dioxide can be emitted while keeping global temperature rise below 1.5°C….. For climate scientists, there is no obvious consensus about questions such as these. On the other hand, Cook, Oreskes and others persist in messaging the minimalist fact that human influence on a changing climate is uncontroversial amongst scientists.

Well, if it is so uncontroversial why do people keep criticising its use? Also, the two examples above essentially miss the point. The consensus position is very simply that humans are causing global warming; it says nothing about specific issues like short-term variability, or carbon budgets. There are also certainly no suggestions that we should promote consensus messaging ahead of discussions about more specific aspects of the topic. Furthermore, the so-called pause certainly does not challenge the basics of anthropogenically-driven climate change and I would argue that there is a consensus about keeping global temperatures below 1.5oC; it’s going to be very difficult to do so.

Let me be clear about something, though. If someone could convince me that consensus messaging was actually counter-productive and that there was a clear alternative that was more appropriate and effective, then I would happily endorse that. However, that there is a strong consensus about the basics is true, and so – in my view – one needs to make a pretty strong argument if one is going to essentially argue that we should avoid highlighting something that is true. Furthermore, we don’t live in a world in which there was no consensus messaging. Therefore, it would seem difficult to make claims about its effectiveness if you don’t really have a control in which it was not used.

So, until someone presents some pretty compelling evidence to support their claims about going beyond consensus messaging, I’m going to continue to be confused as to why its use is so controversial. I’m also quite happy for people to follow many alternative communication strategies, I’m simply unclear as to why there seems to be such a need to criticise consensus messaging. Why not promote your alternative, rather than undermining one that is aimed at highlighting a simple truth?

Update: Steve Bloom’s Twitter comment has clarified – I think – the significance of the term accurate in the bit I’ve quoted above. I think the argument is that a majority regard climate change as important and worrisome despite not having an accurate understanding of the level of consensus. I can see some logic to this argument, but I still think that without some kind of control (which is essentially impossible) it is difficult to draw any strong conclusions about the effectiveness of consensus messaging from these kind of surveys – i.e., you don’t know what the outcome would have been in its absence.

Posted in Climate change, ClimateBall, Global warming | Tagged , , , | 110 Comments

If it’s a fight?

I’ve had very little to say recently, and still don’t have much to say. However, just to keep things ticking over, I thought I would highlight this David Roberts article called [c]onservatives probably can’t be persuaded on climate change. So now what?. The basic suggestion is that

One more round of “messaging” won’t do it.

which I find myself mostly agreeing with. To be clear, though, this is a very US-centric article, so this does not apply everywhere, or at all times.

However, I do think we spend a lot of time arguing about how best to communicate when, in reality, there are some people who are unconvinceable, and it’s probably worth recognising that if you want to move forward, then it’s going to involve doing so despite these people, rather than trying to find ways to convince them to do so.

Of course, there are scenarios where something like consensus messaging can have an impact, and others where taking cultural cognition into account can have an impact. However, this doesn’t change that there will probably be some core of people who will never be convinced and trying to find clever messaging strategies that might do so, is probably a waste of time.

So, I do think that those who want to actively promote change will probably have to – at times – approach this more as a fight than as some kind of polite debate. This doesn’t mean that everyone has to do so; I certainly have no great interest in approaching it in this way and I think scientists, in general, are probably more interested in constructive engagement, than fighting. However, I do think that scientists have to be careful of assuming that everyone has to behave as they would.

If anything, those contrarians who complain about tone probably do so because they are aware that it’s better for them if people continue to approach this as a debate, rather than as a fight. A polite debate is something that they can appear to win. The last thing they want is people actively trying to make them look stupid, because that’s too close to the truth, for comfort.

Posted in advocacy, Climate change, ClimateBall, Policy, Politics | Tagged , , , , , , | 155 Comments

Jordan Peterson speaks the truth

I may, justifiably, be accused of this post having a clickbait title. What it refers to, though, is a youtube debate between Philip Moriarty (a Physics Professor at the University of Nottingham) and Fred McVittie (whose credentials I, unfortunately, do not know). It was done as a series of shortish youtube clips, each presenting an opening statement, a first rebuttal, a second rebuttal, and closing remarks. The series can be found here.

I watched the whole series, and I found it very interesting. I don’t want to give away too much, but Tom McVittie was essentially arguing that Jorden Peterson is discussing some kind of greater truth (moral/societal) that encompases the universal truths that emerge from the scientific process. Philip Moriarty – on the other hand – argued that it’s quite hard to know what Jordan Peterson is saying, because it doesn’t make much sense and seems highly inconsistent; critisicing post-modernism, while essentially engaging in it himself.

I did, however, want to highlight something specific. Philip Moriarty stressed the epistimology of empiricism, which just means that truth emerges through collecting data, making observations, and testing hypotheses – the scientific method, essentially. Fred McVittie argued, in his closing statement, that some scholarship in the humanities doesn’t conform to this epistimology of empiricism. This – according to Fred McVittie – does not mean that this is not scholarship and that it can’t generate knowledge, or discover truths.

This suggestion really did make me stop and think; maybe I really have misunderstood some forms of scholarship within the humanities, and that what seems obscure and meaningless, might simply be an alternative epsitimology that I simply do not understand. In fact, it even seemed somewhat appealing. I think we can sometimes overplay the scientific method, in the sense that even within the physical sciences, not every step is a perfect representation of empiricism. We can make mistakes, we can over-interpret/mis-interpret data, we can use methods that are inapproriate, and we can draw conclusions that turn out to be wrong.

However, we only start to trust results when we’re confident the data is suitable, that the analysis methods are sound, and that the conclusions are justified. Even though every step may not be a good representation of empiricism, we still apply the epistimology of empiricism when determing the value of emergent truths. So, if there are areas in the humanities that can uncover knowledge and reveal truths without following something akin to empiricism, how do they do this? How can they be confident in the value of the knowledge/truths that they’ve uncovered, if they don’t go out and collect some data, or make some observations, or test their hypotheses?

So, I can see how there might be aspect of scholarship in the humanities that doesn’t conform to the epistimology of empiricism, but I can’t see how one can be claim to have uncovered new truths if one doesn’t do something that is essentially a form of empiricism.

On the other hand, if the kind of knowledge/truths that emerge from this non-empirical form of scholarship is not universal, but some kind of societal/moral knowledge/truth, then maybe it can emerge without undertaking any kind of empirical research. However, if this is the case, then is this knowledge/truth emerging, or being generated? In other words, if this non-empirical scholarship is revealing societal/moral knowledge/truths, or is it actually influencing what society regards as knowledge/truth. If the former, I still don’t see how this can not involve any form of empiricism. If the latter, how does this differ from someone successfully imposing some kind of ideology onto society? There’s nothing wrong with people promoting their views about knowledge/truth, but why does this qualify as scholarship?

To be clear, I’ve worked with people in the humanities, and published a number of social science papers, so this is certainly not a criticism of the humanities in general. If anything, I think social science research is very difficult, because you don’t have fundamental laws that underpin your discipline, and that constrain what can be “true”. However, I have found some of what I’ve come across to be quite bizarre (and have written about it on a number of occasions). I still don’t see how it is possible to reveal knowledge/truth without engaging in a form of empiricism, but I am willing to be convinced otherwise if someone is willing to spend some time explaining how this non-empirical process is actually able to uncover knowledge/truth.

Posted in ethics, Philosophy for Bloggers, Pseudoscience, Research, Science, The philosophy of science, The scientific method | Tagged , , , , , , , | 396 Comments

Carbon Dioxide Removal

There’s a bit of a debate going on a about economics and ethics, mostly on MT’s blog, but also on Stoat, and a little bit here. I have to be honest, I’m not entirely sure what people are actually disagreeing about, as it seems to be more about how one should use economic models, than about what is actually ethically/morally right, or wrong. However, I came across a Carbon Brief Guest Post that would seem to indicate that we’re not alone in not agreeing about the role of economic modelling.

The Carbon Brief post is by Glen Peters and Oliver Geden, and discusses who will deliver the negative emissions to avoid 2C of warming. The context is essentially that we’ve now got to the stage where if we still wish to achieve a target of keeping warming below 2oC, then we may need to rely on technologies such as negative emissions, or carbon dioxide removal (CDR).

I wanted to simply highlight a few comments in the article that I found interesting. For example

Integrated Assessment Models (IAMs) also indicate that it is cheaper to have large-scale CDR in the future, than to have deeper mitigation now.

However, it also says

[t]he criticism mainly focused on the conceptual use of untested methods of CDR to keep global warming below 2C above pre-industrial levels in model simulations, the potential risks of deploying CDR technologies at scale, and the role of science in climate policy negotiations.

So, some economic models suggest its cheaper to deploy CDR in the future, rather than undertaking deep mitigation now, despite CDR being largely untested, and there being risks associated with deploying at scale.

Another key part of the article was the political implications of deploying CDR, saying

[m]ost discussions of CDR have been at the global level. This is an unhelpful focal point, as individual actors must deliver CDR. A suitable compromise is the national level, which is particularly useful for climate policy negotiations.

This potentially creates significant political obstacles, for example

The output from the IAMs gives an indication of cost-optimal pathways, but these may deviate substantially from politically-optimal pathways. …..

India and others could argue that they should not provide CDR at a scale like the EU and the US, countries who have a much larger historical contribution to current climate change.


…. Brazil might argue the modelling assumptions behind one particular model overestimate the BECCS potential in Brazil, other countries may argue the opposite.

Okay, I’m not quite sure where I’m going with this. Mainly, that this seems very complex and its not clear that there is any kind of simple answer. Do we have a specific target, or do we try to develop some kind of optimal pathway based on a cost-benefit analysis (as I discussed in this post)? Do we focus on technologies that we are confident can be deployed, or rely on technologies that have yet to be developed, and that may carry their own risks, such as CDR? Do we focus on the global scale, or do we try to incorporate the political realities of trying to actually implement the various possible solutions on the local scale?

I don’t have any good answers, but I’m not really convinced any else does either. I’m happy to be convinced otherwise, though.

Posted in Climate change, ClimateBall, Global warming, Policy, Politics | Tagged , , , , , , , | 77 Comments


A recent discussion has led me to think a bit more about civility. This was partly motivated by my own intention to maintain it when I started this blog (which didn’t always succeed) and by the other party being someone who has publicly discussed how to improve the overall climate debate, and who recently promoted a call for civility in science. I think it would be great if people were more civil, but I’m not a huge fan of explicit calls for more civility. This is partly because it sometimes seems to be motivated more by a desire to deligitmise one’s critics than by a genuine desire to promote more civility, partly because we sometimes seem to value civility even when the person is mostly talking nonsense, and partly because it doesn’t even really make much sense to me.

I can understand how we can define what is unacceptable; personal attacks, prejudice, blatant rudeness, verbal abuse, harassment, etc. How, though, do we define being civil? Is sarcasm allowed? Is it okay to be a bit snarky? Do we always have to say please and thank you? Is highlighting an error that will almost certainly embarass the person who made it acceptable? My own view of what qualifies as civil is essentially “not openly rude”. Others, on the other hand, seem to have their own definitions, often – as far as I can tell – to suit their arguments (i.e., the person they disagree with is somehow being uncivil, while those they agree with are not being uncivil because what they said was jusitified). I’m essentially not convinced that we could even all agree on what actually qualifies.

So, I’m not arguing against people being civil, simply suggesting that I don’t really see the merit of people openly arguing for greater civility. If some think there would be merit in people being more civil, maybe they should really just aim to lead by example. Maybe others will follow, maybe not, but it would – at least – be a start. It would certainly be nice if there were more of it, but I also think it can be over-rated. I, for example, tend to have more time for those who aren’t always civil, but who mostly talk sense, than for those who are religiously civil, but mostly talk nonsense. Others may have different preferences, which might essentially be the point: rather than trying to tell others how to behave, just do what you think is right, because you’re really the only person whose behaviour you can control.

Posted in ClimateBall, Personal | Tagged , , | 152 Comments