I was blocked on Twitter by Zion Lights after I, somewhat snarkily, retweeted one of her tweets. Zion Lights is the UK director of Michael Shellenberger’s organisation, Environmental Progress. Zion Lights has had a bit of a rough week, having been criticised by Extinction Rebellion for her association with Michael Shellenberger. I largely agree with their criticism of Shellenberger, but my impression is that Zion Lights is genuinely concerned about climate change and is sincerely promoting nuclear as a solution, unlike Shellenberger.

The tweet that I responded to was the one below

My slightly snarky response was simply “New?” It may have been poorly timed, but I was trying to make a serious point. There are many reasons to criticise the environmental movement. I’ve done so myself. However, the idea that it’s made up of people who think other humans are “bad”, who don’t accept evidence, who don’t think people should have access to clean, reliable energy, and who don’t regard positive change as possible, is a little bizarre.

I was going, though, to make a broader point about policy decisions being “evidence-led”. I’m a physicist. I completely agree with the idea that we can collect evidence and develop robust understandings of the world around us. In some cases we may even get to a stage where we regard some things as essentially true. However, this does not mean that some obvious policy immediately follows from some piece of evidence. Many other factors influence decision making. Our values and opinions, economic feasibility, and even the political climate, all play a role in how we go from evidence to policy.

It’s perfectly possible for nuclear to be safe and for people to still not want it to be one of the solutions. Its perfectly possible for nuclear to be a great source of alternative energy and it, currently, not being economically viable. It’s perfectly possible for people to accept the need for alternative energy sources and to still not want wind turbines all over the Scottish Highlands. Its perfectly possible for people to recognise that agriculture is a big source of emissions and still realise that the farming sector is an important part of our economy. You don’t have to agree with all of these to understand that reasonable people can hold these views.

In my view, we should distinguish between those who don’t accept things that are almost certainly true, and those who disagree with us about the implications of these truths. This would seem to be especially true if you really do want to work together with other people. Most would interpret a desire to “work together” as a willingness to work with other people even if they don’t completely agree with you, rather than only being willing to work with those who completely agree with you.

I think this is a really complex issue and if we are going to implement alternatives on a timescale that will avoid some of the worst impacts of climate change, then I do think we need to find ways to work together, rather than splintering into ever smaller factions. Currently, I seem to be seeing more of the latter than the former.

Posted in Climate change, ClimateBall, Philosophy for Bloggers, physicists, Research, Science | Tagged , , , , , | 44 Comments

The Auditing Problem

Auditing leads to an open problem. Let’s try to specify it as lightly as possible. Technical notes follow the main text, they’re tagged using curly brackets, like {this note}.

§1. Alvaro’s Story

Alvaro wrote a piece called What’s Wrong with Social Science and How to Fix It: Reflections After Reading 2578 Papers. Here’s his announcement:

Since many of us are up in arms about how academia and science actually work, Alvaro’s piece was cheered. Last time I checked his tweet gathered nearly a thousand retweets, more than two hundred quote tweets, more than two thousand likes, probably thousands of comments. The TL;DR for individual researchers:

Just stop citing bad research […] Read the papers you cite […] When doing peer review, reject claims that are likely to be false […] Stop assuming good faith.

For my purpose, the episode boils down to this. An auditor concludes that scientists should beware their citations. His piece goes viral. Speed and enthusiasm of the shares and likes indicate that very few paid any due diligence before citing it.

When life gives you irony, make an iron-clad tirade.

So here goes. The story rests on a {DARPA} auction mechanism that I have not seen investigated. Alvaro claims having spent about 2.5 minutes on each paper. He offers no data. No real number crunching can be found. The conclusions follow from prejudices more than analysis. There’s no way to replicate this piece.

There are two other tells. First, the triviality of the moralism. “Stop citing bad research” is as useful as “stop playing bad moves” as Poker advice. Second, check the social network. Lip service to Bryan Caplan in the About page. Citations of Scott Alexander and Gwern. Thanks to Alexey Gusey. Interactions with Eliezer Yudkowsky on Twitter. High five to Gareth Evans’ {10% Less Democracy}. Lesswrongian would be my safe bet, which usually indicates to me Panglossian unreasonableness.

There’s nothing wrong with trying to make things better. Unless, of course, it creates unrealistic expectations. Here is one crucial problem that auditing can’t solve.

§2. Audit World

Suppose two worlds. In the first, Audit World, one would need to {double check} every single claim in Alvaro’s piece before approving or opining on it. The second is ours, in which we do more or less as we please. Which one do you believe is more efficient?

Alvaro obviously does not live in Audit World—witness how his piece was received. To put money where the mouth is, praising Audit World would commit us to live there. I would not bet on Audit World, as it implies what I would call omnipotent auditing.

To see why, let’s review the implications. Should you choose to live in Audit World, everything Alvaro and I say would need to be double checked before commenting below. To reply to you, I would need to double check your claims, but I would also need to double check if you double checked your claims about mine. And this would need to occur at each and every point of the exchange.

In Audit World, auditing would not end there; in fact it never does. The claims made by me or Alvaro do not stand alone—they are supported by others. Due diligence needs to be paid to their works, also to their sources, and so on and so forth. Notwithstanding all reciprocal checks and balances to ensure that communication flows smoothly!

Thus the Auditing Problem obtains: we can’t go on forever with suspicious minds. To resolve that predicament, {trust is key}.

§3. Toward Auditing Sciences

One way to build trust is to communicate. So I asked Alvaro about what he calls his bottom line, i.e. what is acting like one knows what will replicate. His response: not citing weak papers. I find this response weak. Does it mean that my post perpetuates what makes social science bad? I don’t think so.

There are many reasons to cite a paper: to criticize, by deference, for historical background, as literature survey, etc. Among questions I ask myself before citing a paper, “would I bet if the research replicates” seldom appears. Only if I’d mention its robustness would I double check. Citing should save time, not waste mine.

Alvaro’s non-response shows other weaknesses. First, betting and double checking are opposite activities. Second, on what to bet isn’t quite clear: papers often contain many results. Third, most published papers are {barely cited}. Fourth, reinforcing reactance with incredulity goes against openness.

For me, the last one breaks the deal. In general, main claims (i.e. theses) are meant to be provocative; empty claims can be reproduced trivially. A knowledge system that prioritizes full replication over exploratory research ought to converge toward eternal boredom. I doubt that discovery success rates would improve with a Panopticon in which every scientist plays cop.

Look. I’m all for revising citation practices. My own policies are radical, e.g.:

As you may know, I try to mention people by their first names. From now on, I will also omit journal names and paper authors: year-month-title-url suffices. (See §5 for how it looks.) That said, I don’t impose my personal policies on others, and more importantly I don’t sell them as a recipe to improve scientific results. That’s just magical thinking.

ClimateBall connoisseurs already experience how easily contrarians weaponize the auditing biz. Research always comes with trade-offs. Writing is hard because it forces us to juggle between multiple contradictory constraints. We can’t say everything. We can’t be fully transparent. Editing, like auditing, never ends. At some point we need to hit “send” and accept that we may fail again, in the hope that this time we fail better.

All in all, here would be my bets as to what to expect next. Institutions should soon create {distrust networks} to establish auditing sciences as a scientific field. Scientific communities will continue to be powered by trust. Humans will find ways to exploit new metrics, starting with a {Replication Cop Game}. Distrust will continue to be gamified by reactionary forces.

Maybe one day we’ll learn to embrace crappiness, but I’m not holding my breath.

§4. Notes

{This note} – Known academic note conventions suck. Time to try something else. Renumbering pains me; numbers don’t replace titles; notes usually come first; etc.

{DARPA} ~ “DARPA” stands for Defense Advanced Research Projects Agency. The page Alvaro cites mentions:

DARPA’s Systematizing Confidence in Open Research and Evidence (SCORE) program aims to develop and deploy automated tools to assign “confidence scores” to different SBS research results and claims. Confidence scores are quantitative measures that should enable a DoD consumer of SBS research to understand the degree to which a particular claim or result is likely to be reproducible or replicable.


My educated guess is that Alvaro participated in a tournament with cash prizes to train a machine-learning textual analyzer. That’s just a guess. Military folks are only into Open Science when it suits them.

{10% Less Democracy} ~ From Gareth’s blurb:

Discerning repeated patterns, Jones draws out practical suggestions for fine-tuning, focusing on the length of political terms, the independence of government agencies, the weight that voting systems give to the more-educated, and the value of listening more closely to a group of farsighted stakeholders with real skin in the game―a nation’s sovereign bondholders.

{Double Check} ~ By this term I’m referring to anything one would need to do to verify or validate what is being said or done in some work at some required level. The audit metaphor bypasses the need to create an explicit list for all tasks. Hopefully you get the point. But no, you can’t really double check this note, at least not without my help.

{Trust is Key} ~ This may sound farfetched, but technical issues resurface as soon as we seriously think about interaction between artificial agents, for which we can’t take nothing for granted. The problem is worse when considering the relationship between humans and AI, like autonomous vehicles or medical devices.

{Barely Cited} ~ Citation numbers sound very noisy to me. They would deserve due diligence. I assume that the following gives us a fair ballpark:

Academics publishing in particular fields of chemistry or neuroscience are virtually guaranteed to be cited after five years, but more than three-quarters of papers in literary theory or the performing arts will still be waiting for a single citation.

2018-04. Uncited Research. https://www.insidehighered.com/news/2018/04/19/study-examines-research-never-receives-citation

It’s hard to tell how revising citation practices will prevent bad and barely cited papers.

{Distrust Networks} ~ I already mentioned that idea, which I still need to flesh out. Another time. For now, think of all the tools and facilities that verify textual products. Control version systems. Online stores that certify applications. Bitcoin machines. Banking transactions. Etc. In principle, replication could be as simple as a checksum.

{Replication Cop Game} ~ Take a Science Cop. Let’s name him S*, in honor of Stuart. Let a Game G be dominated by a strategy by which S* gets rewarded every time he finds faults. Exercise for readers: after how many iterations does S* turn into Anton Ego? The point of Ratatouille is that everyone can cook, not that everyone’s a critic.

§5. Further Readings

2014-03. Implementations are not specifications: Specification, replication and experimentation in computational cognitive modeling. https://doi.org/10.1016/j.cogsys.2013.05.001

2018-11. A Causal Replication Framework for Designing and Assessing Replication Efforts. https://doi.org/10.1027/2151-2604/a000385

2018-11. Openness and Reproducibility: Insights from a Model-Centric Approach.

2019-10. The Value of Failure in Science: The Story of Grandmother Cells in Neuroscience. https://doi.org/10.3389/fnins.2019.01121

2020-04. The case for formal methodology in scientific reform. https://doi.org/10.1101/2020.04.26.048306

2020-07. What is Replication? https://doi.org/10.1371/journal.pbio.3000691

Posted in Philosophy for Bloggers, Research, Science, Scientisits, Sound Science (tm), The philosophy of science, The scientific method | Tagged , , , , , , , | 23 Comments

Cosmopolitan knowledge

I’ve been reading a recent paper by Sujatha Raman and Warren Pearce called Learning the lessons of Climategate: A cosmopolitan moment in the public life of climate science. I’m always a little uncomfortable writing about climategate, partly because it’s been blown completely out of proportion and should probably be mostly ignored, and partly because – having watched last year’s BBC show about it – it’s clear that it was a rather traumatic experience for some of those involved.

Although I don’t want to delve into what was presented about Climategate, I thought I would just present some quotes from the paper that my readers can mull over.

For example

…and alleged data manipulation by the scientists to “hide the decline” in global temperatures.


Conventionally, policy is meant to follow from science that has been validated within the scientific community alone and authorized by a passive and trusting public.

What about

Second, while the scientific norm of openness has been re-established, and extended peer review become more accepted, there could be greater openness about the inevitable flaws and limitations of scientific knowledge about climate change.

and finally

The legacy of Climategate may be mixed….

What I thought I would briefly discuss instead is what was presented in a section titled The promise of cosmopolitan knowledge. Now, I realise that scientific knowledge alone cannot tell us what we should do; there are many other factors that play a role in establishing how we should respond to information. However, the ideas presented in this section seem to be going beyond just suggesting that broader views should be taken into account when considering the implications of some scientific knowledge

Importantly, this means not just paying attention to attitudes, opinions, or even values, but to how different cultures, professions, movements, and faiths “know” the world.

To be clear, I don’t think that research should only be undertaken by those employed in formal research positions; there are plenty of examples of people who’ve made positive contributions even though they don’t hold a traditional research position. I also think there are plenty of examples where the general public have been involved in helping to undertake research. There are also examples where science has ignored something culturally relevant that should really have influenced how some evidence was interpreted, or how some research should have been undertaken. Science also has lots of issues with diversity and inclusion that we should be dealing with and taking much more seriously.

However, there’s a difference between the above and suggesting that our overall scientific understanding should incorporate other peoples’ knowledge of the world. I can see value in debating what we should do about sea level rise, but our estimates of sea level rise shouldn’t be influenced by those who think it isn’t happening because they haven’t noticed anything yet. We should certainly be much more inclusive when considering what to do about the possibility of an increase in the frequency and intensity of heatwaves, droughts, floods, tropical cyclones, or damage to ocean and land ecosystems. However, I don’t see any value in incorporating the views of those who think climate change can’t be happening because the greenhouse effect violates the second law of thermodynamics.

Maybe I misunderstand what is being suggested by a promise of cosmopolitan knowledge. If not, then I really don’t see how it really is something that would be of benefit to society. I don’t think we should put scientists onto pedestals and allow then to have undue influence over decisions that will influence society. However, I also don’t think we should elevate the views of those who don’t have the skills, or expertise, to develop reliable knowledge about a complex topic.

I do think that we have to do a better job of both interogating expertise so as to establish reliable “knowledge” and how to then incorporate this “knowledge” into decision making processes. In this context, there may well be a benefit to broadening who is regarded as providing relevant “knowledge”. However, understanding complex physical systems typically requires a skillset, and a level of expertise, that takes years to develop. This doesn’t mean that those who have developed this expertise are somehow special, but it does suggest that maybe we should be cautious of taking seriously views presented by those who very clearly have not developed the relevant expertise.

Posted in Climate change, ClimateBall, Environmental change, Research, Scientists, The philosophy of science, The scientific method | Tagged , , , , | 108 Comments

Tropical cyclones and climate change

Michael Shellenberger has a recent Forbes article on [w]hy Deaths From Hurricanes And Other Natural Disasters Are Lower Than Ever. The article is based quite strongly on the work of a friend of this blog. The basic argument being that even though natural disasters are getting more expensive, it’s because we are so much richer, not because hurricanes and floods are so much more severe.

One problem is that not everyone agrees that the increase in damage costs is solely due to us being richer. Another friend of the blog is an author of a paper showing [e]conomic losses from US hurricanes consistent with an influence from climate change. Aslak Grinsted, and colleagues, also recently published a paper where they normalised in terms of equivalent area of total destruction and showed that [t]he frequency of the very most damaging hurricanes has increased at a rate of 330% per century.

Additionally, our understanding of how tropical cyclones will respond to global warming goes back more than 30 years. It’s well understood that increasing sea surface temperatures will increase the potential maximum intensity of tropical cyclones. We’re also very confident that anthropogenically-driven global warming (AGW) is the dominant cause of sea level rise, which can then impact storm surge. To date, sea level rise may not be that large, but as Gavin Schmidt pointed out, it’s the last foot that does the most damage. We also have examples where AGW almost certainly intensified tropical cyclone precipitation.

Credit: Kossin et al. (2020)

Kossin et al. have also recently published a paper looking at tropical cyclone exceedance probability over the past four decades. As the figure on the right shows, globally there is a clear increase in the probability of a tropical cyclone exceeding major hurricane intensity (which they define as winds exceeding 100 knots). This is also consistent with the theoretical expectation that we’ll see an increase in the frequency and intensity of the strongest tropical cyclones, even if we don’t see an overall increase in the frequency of tropical cyclones.

Also, as Andrew Dessler highlights, the strongest tropical cyclones dominate the damages, and so an increase in the frequency and intensity of these extreme tropical cyclones can have an enormous impact on the future cost of natural disasters. To assume, as Shellengerger and his sources suggest, that disaster preparedness dwarfs the change in whatever your favorite hurricane metric is seems somewhat optimistic to me. What’s more, this seems to ignore that some regions may be more able to build resilience than others, and that tropical cyclones may start to impact regions that have never before – or rarely – seen such events.

Of course, the impact of AGW is not just about the increasing intensity and frequency of extreme tropical cyclones. If that’s all we were likely to face, we may well regard drastic emission reductions as an over-reaction. There’s also the increasing frequency and intensity of heatwaves, which could make some regions almost uninhabitable, and the increasing frequency and intensity of extreme precipitation events, which could impact flooding and agricultural practices. There’s sea level rise, which could substantially impact many coastal regions. There are already some impacts, such as the loss of tropical coral reefs, that are probably already unavoidable.

I realise that some do use tropical cyclones as a poster-child for the impacts of AGW and do sometimes exaggerate how climate change has impacted these events, or their impacts. I don’t, though, see how suggesting that AGW has had no impact is a suitable response to this. AGW will almost certainly have impacts that we may want to avoid. We can only really do so by limiting future CO2 emissions. That some regions may be able to deal with more intense tropical cyclones isn’t, in my opinion, a particularly good counter-argument.

Why Deaths From Hurricanes And Other Natural Disasters Are Lower Than Ever – Forbes article by Michael Shellenberger.
Economic losses from US hurricanes consistent with an influence from climate change – Estrada et al. 2015.
Normalized US hurricane damage estimates using area of total destruction, 1900−2018 – Grinsted et al. 2019.
Global increase in major tropical cyclone exceedance probability over the past four decades – Kossin et al. 2020.

Posted in Uncategorized | Tagged | 64 Comments

Directly observing the earliest stages of star and planet formation

Since I haven’t had much to write about recently (or, haven’t felt much like writing recently) I thought I would highlight one of my recent papers. It was lead by James Cadman, a PhD student who is been working with me, and is essentially an extension of some work done by Cassandra Hall, who worked with me while a PhD student in Edinburgh (and who is about to start a tenure-track position at the University of Georgia).

Spiral density waves in a simulation of a disc around a young protostar.

As I may have mentioned before, stars form from clouds of gas and dust that collapse under their own gravity. Conservation of angular momentum prevents most of the material from falling directly onto the young protostar in the centre; instead, most of the material forms a protostellar disc through which mass can then flow onto the central protostar.

When very young, these discs may be massive enough to be what we call self-gravitating, which could lead to them forming spiral density waves (left), much like what is seen in spiral galaxies (as an aside, these spiral waves may then play a role in driving mass onto the central protostar).

Recently, the latest astronomical instruments (ALMA) have become able to directly observe spiral density wavs in protostellar discs. These may be due to the disc self-gravity but they could also be due to some kind of interaction, with either an embedded planet, or a passing star.

In this latest work we wanted to better understand the properties of the systems that would most likely show evidence for these self-gravitating spiral density waves. The systems need to be young (less than 1 million years old) and they need to be reasonably strongly accreting. However, what we’ve shown in this recent paper is that it might be slightly easier to observe these spirals than previously thought, if some amount of grain grain has already occurred in the system.

The reason for this is related to some work I did about 15 years ago. It turns out that the interaction between dust grains and gas in a protostellar disc depends on the size of the dust grains. Very small grains are very strongly coupled to the gas, while very large grains are completely de-coupled. There’s an intermediate size (in the mm-cm range) where this interaction causes grains to drift towards pressure maxima. A consequence of this is that these grains will drift, and collect, in the spiral density waves.

Figure from Cadman et al. (2020) showing how grains collecting in the spirals can enhance the emission, making them easier to observe, and allowing us to probe grain growth.

Hence, if grain growth has occurred in these discs, and you observe at wavelengths that are sensitive to the emissions from these grains, the collection of these grains will enhance emission in these spirals, making them easier to observe. So, even when these spirals are quite weak, we may still be able to observe them.

The figure on the right illustrates how, if you take this grain enhancement effect into account, the spirals become more evident in synthetic observations. What’s more, you can potentially use these observations to constrain the growth of solid particles in these discs. When these discs form, the grains are pre-dominantly micron-sized, and don’t emit much at wavelengths longer than this. If you start to see emission at longer wavelengths (in, for example, the sub-millimeter and millimeter) then you can infer that some amount of grain growth must have occurred.

So, what we’ve shown in this recent paper is that it may be easier to observe these self-gravitating spirals than we had previously thought, and we’ve illustrated the optimal observations for doing so. The reason this is important is that these spiral waves may play an important role in driving mass onto the central protostar. Directly observing them may then allow us to probe a crucial part of the star formation process.

In addition, these observations could also help us to better understand grain growth in these very young systems. Grain growth is, of course, a key part of the planet formation process and there are indications that it starts very early in the star formation process. It’s still not clear how micron-sized dust grains grow to form the kilometre-sized planetesimals that then combine to form terrestrial planets, or the cores of the gas giants. Being able to probe grain growth during the earliest stages of star formation may help us to resolve this mystery.

The observational impact of dust trapping in self gravitating discs – Cadman et al. 2020.
Spiral density waves – a post about one of the first observations of spiral density waves in a protostellar disc.
Observing the earliest stages of star and planet formation – another one of my posts about this topic.

Posted in Astronomy, Research, Science, The scientific method | Tagged , , , , , | 42 Comments

Matt Ridley – How Innovation Works

Despite having been a regular critic of Matt Ridley’s Lukewarmerism, I’ve just finished reading his new book How Innovation Works.

I actually quite enjoyed the book and found it quite an easy read. Ridley is clearly a very convincing writer. The first half was mostly a discussion of the history of various innovations. It covered energy, public health, transport, food, etc. I don’t know if the descriptions of how some innovations developed were correct, but I’ve no reason to think that they weren’t (one criticism is that it wasn’t particularly well referenced).

I also generally agree with the argument that innovation is a complex process, that there are lots of failures along the way, and that it’s much more perspiration than inspiration. There’s not some simple linear process from an idea to some innovative, new technology. I also agree that there’s a difference between the detailed process aimed at understanding how something works, and the more trial and error process associated with developing some kind of useful technology.

The second half of the book is more about how to be promote innovation. As this review suggests, this is where Ridley’s free-market bias becomes more evident. Although I’m sure there is some truth to regulations stifling innovation, too little regulation would seem to also carry risk. Although public-funding isn’t necessarily a good way to drive innovation, there would certainly seem to be examples where it has worked well.

There were also some parts I found a little irritating. Glossing over examples where it seemed clear that regulations had helped. Being critical of big companies whose attempts to develop innovative business practices had failed spectacularly, while failing to mention his role as Chairman of Northern Rock. Being critical of practices that were aimed at maintaining the status quo while still having coal mines on his land.

I’m not sure I’d necessarily recommend it, but it was an interesting book to read. It was fascinating to read about how some innovations developed. It also made some interesting observations, even if Ridley’s bias wasn’t always all that well hidden.

Posted in Philosophy for Bloggers, Policy | Tagged , , , | 88 Comments


Something I’ve done on this blog quite a lot is push back against the narrative that science is social. This doesn’t mean that I think individual scientists can’t be biased, or that we won’t sometimes go down the wrong path when the evidence is weak, but that ultimately we’ll converge towards some kind of reasonable understanding of the system being studied. However, I’ve just finished reading Angela Saini’s book, Superior: the return of race science. Angela Saini also gave a talk yesterday evening as part the Edinburgh Race Lectures. Angela Saini makes a very strong case that there are scientific disciplines where our biases have not only strongly influenced how evidence is interpreted, but have also influenced the assumptions that underpin that discipline.

Reading Superior made me appreciate better why some seem to regard science as being more social than I would normally regard as reasonable. I’ve always been aware that many aspects of science are social, but have been less comfortable with the suggestion that our biases can strongly influence how we interpret evidence. Why would our biases influence our understanding of the origin of the universe, our understanding of orbital dynamics, or how the Earth’s climate will respond to rising atmospheric CO2 levels? One concern I’ve had with the “science is social” argument is that it can potentially undermine the significance of some research if the implications are seen as inconvenient. On the other hand, reading Superior and listening to Angela Saini’s talk yesterday has made me better appreciate that we should be careful of under-estimating how much our biases can influence how we see the world.

I’m not actually sure where I’m going with this. I found Angela Saini’s book very enlightening and it made me more aware of why some might regard science as social. I do still, though, have trouble seeing how this can have a significant influence in the physical sciences. Well-founded conservation laws provide quite strong constraints on how we interpret evidence in the physical sciences. However, everyone probably thinks that their discipline has some way of overcoming these biases, so maybe I’m missing something about how they could influence our understanding of physical systems.

I should also be clear that I’m not suggesting that physical scientists are somehow less biased than other scientists; they clearly are not. I’m also not suggesting that there aren’t reasons for addressing existing biases within the physical sciences; these clearly do exist and we should do much more to address this. I’m also not suggesting that these don’t play a role in how we interpret the significance of some scientific evidence. For example, our views about how we might solve climate change, or the significance of the impacts of climate, are probably quite strongly influenced by these biases. I’m just not sure how these biases influence our understanding of physical systems, especially in the presence of conservation laws.

Of course, I’m probably missing something and I’m certainly uncomfortable with suggesting that our understanding of physical systems can’t be influenced by societal biases. I’m just not sure how, or why, they would do so, at least in a substantive sense. Maybe someone can present some kind of argument in the comments.

Posted in ethics, Scientists, The philosophy of science, The scientific method | Tagged , , , | 211 Comments

Climate sensitivity – narrowing the range

Since I’ve discussed climate sensitivity on a number of occasions, it seems worth highlighting the new paper that assesses climate sensitivity using multiple lines of evidence. The authors include many who will be familiar to my regular readers.

Credit: Sherwood et al. 2020

The key figure is on the right and shows that the likely range for the Equilibrium Climate Sensitivity (ECS) is 2.6-3.9K, and the 5-95% range is 2.3-4.7K. Essentially, this now largely rules out very low ECS values (below 2K) and also makes the higher values (>5K) also somewhat less likely.

I don’t need to say much more, since this has been covered extensively elsewhere. I’ll provide links at the end of this post. What I thought I would briefly mention is why I think this illustrates the issue with the general narrative being promoted by people like Shellenberger and Lomborg. They’re essentially suggesting that although climate change is real, it’s manageable. We can deal with sea level rise, and disasters aren’t getting worse. The global economy is going to continue to grow, so people will be more capable of dealing with climate related events in the future than they are now. It’s important, but let’s not do anything too drastic.

Of course, it is possible that we will be able to effectively deal with the impacts of climate change. However, it’s also possible that it will be much more difficult to deal with than people like Shellenberger and Lomborg suggest. Given the results in this new paper, it’s clear that it will be incredibly challenging to limit warming to 2oC above pre-industrial levels. On our current trajectory, we’re probably heading for something like 3oC and that’s assuming that climate sensitivity isn’t on the high side of the range. Even on our current trajectory, we can’t rule out that we’ll end up more than 4oC above pre-industrial levels. There are also various carbon cycle feedbacks that could amplify this even further.

So, yes, we shouldn’t suddenly panic and turn everything off. However, we also shouldn’t – in my view – assume that we will easily deal with whatever climate change happens to throw at us (technically, since we’re doing this, what we’re throwing at ourselves). We actually don’t really know what a 2oC world will be like, let alone a 3oC, or a >4oC world. A key thing to bear in mind, is that once we get there, there is no easy way of going back.

Some amount of future climate change is unavoidable, but how much we experience is largely up to us. I can see why the optimism presented by the likes of Shellenberger and Lomborg is appealing; we’re innovative, we can deal with anything. However, rather than being optimistic that we can deal with any possible climate change impacts, why not be optimistic that we can do innovative things that limit how much climate change we will actually face?

An assessment of Earth’s climate sensitivity using multiple lines of evidence – Paper by Sherwood et al. 2020.
Back to the future – post by James Annan.
Climate Sensitivity: A new assessment – Realclimate post.
Just how sensitive is the climate to increased carbon dioxide? Scientists are narrowing in on the answer – Conversation article by Richard Betts, Jason Lowe and Timothy Andrews.
Guest post: Why low-end ‘climate sensitivity’ can now be ruled out – Carbon Brief article by Piers Forster, Zeke Hausfather, Gabi Hegerl and Steven Sherwood.
Global heating study rules out best and worst case scenarios – Guardian article about the new paper.

Posted in Climate change, Climate sensitivity, Philosophy for Bloggers, Research, Science | Tagged , , , , , | 98 Comments

Deep Adaptation

Something I haven’t paid much attention to recently is the Deep Adaptation arguments. I think it originated with a paper by Jem Bendell. The reason it’s of current interest is because of a critique called the faulty science, doomism, and flawed conclusions of Deep Adaptation. There’s also a response from Jem Bendell.

Having now read the Deep Adaptation paper, I think the critique is pretty spot-on. The Deep Adaptation paper literally claims that climate-induced societal collapse is now inevitable in the near term. The justification for this includes the impact of losing Arctic sea ice, the release of methane from clathrates and hydrates, and that climate change could become non-linear. Almost all of this is either exaggerated, confused, or based on a cherry-picking of the scientific evidence.

I think this is all rather unfortunate, because I do think that we may not be paying enough attention to the possibility of there being societal tipping points. However, this should be based on considering all the available evidence, and should – ideally – be motivated by a desire to avoid these potential tipping points, or minimising their negative impact. A key thing to bear in mind is that future climate change depends pre-dominantly on future emissions (with some caveats). If we were at the stage where some kind of major societal collapse were becoming very likely, then we could still try to take drastic action to avoid this, rather than simply promoting a narrative that claims that it’s now inevitable.

In some sense, this seems broadly equivalent to the typical techno-utopian narrative; don’t worry, technology will save us, as opposed to, don’t worry, there’s nothing we can do. These narratives never seem to really grapple with the complexity of these issues, or recognise that we are still very much in a position where we can influence the outcome. We can actively do things that will allow us to better cope with the changes we are going to experience, and what we do will also determine how much climate change we will have to face. In my view, narratives that suggest that some special technology will magically save us, are no more helpful than narratives that suggest that some kind of societal collapse is now inevitable.

What I find slightly disturbing about the Deep Adaptation movement is that it appears to be associated with retreats where they

will support peaceful empowered surrender to our predicament, where action can arise from an engaged love of humanity and nature, rather than redundant stories of worth and purpose.

Not only is there little evidence to support a claim that societal collapse is now inevitable, but the people who will suffer most – especially if we do simply give up – will be those who can’t afford to spend 900 Euros to reflect on their predicament at a Greek holiday resort.

Posted in Climate change, ClimateBall, Philosophy for Bloggers, Policy | Tagged , , , , | 54 Comments

Cancel culture?

The talking point in social media at the moment (in my bubble, at least) seems to be the letter on justice and open debate, signed by 150 luminaries. It’s not been universally well-received. There was some quite measured comments in this article, and somewhat blunter ones in this article.

I find this quite a confusing issue. This is partly because people whose views I generally respect seem to disagree quite strongly about this, and make some compelling arguments both for, and against. I certainly agree that there are some serious problems with current public discourse; it would certainly be nice if it were easier to have good faith discussions about contentious issues. On the other hand, I’m not convinced that there is some major problem that we might describe as a “cancel culture”.

To be quite honest, I’m not even quite sure what “cancel culture” is, or even if it has been clearly defined. Where do you draw the line between a society threatening “cancel culture” and robust disagreements that might have gone further than we might like? How do we distinguish between someone justifiably objecting to what another person is promoting, and them trying to unacceptably silence/cancel the other person? When is it okay for an organisation to penalise one of their members for what they’ve said publicly and when should we expect organisations to defend their members in the interests of free speech, even if they also object to what was said?

My issue with this narrative is partly based on my experiences in the public climate debate. Most of those who complain about censorship, or being silenced/cancelled, seem to be those who say things that deserve to be criticised and simply don’t want to engage with their critics; it’s more about deligitimising one’s critics, than defending free speech. My understanding is that a number of those who signed the letter have similar reputations.

This, of course, doesn’t mean that one shouldn’t be concerned about attacks on free speech. It doesn’t mean that some of what is highlighted in the context “cancel culture” aren’t things that decent people should object to. However, we should also be careful of dealing with things like this in ways that end up deligitimising valid criticisms, and underming valid social movements. In fact, I can’t quite see how we can deal with some kind of “cancel culture” (however defined) that doesn’t end up doing the very thing we’re trying to avoid.

Of course, I may well misunderstand many aspects of this; it is clearly a complex issue. I had intended to make this a bit of an open thread but, as usual, have written too much. I’d certainly be interested to hear what others think about this issue.

Posted in advocacy, Personal, Philosophy for Bloggers | Tagged , , , , | 398 Comments