Economics and Values

Since I don’t seem to have time to write much that is new, here is a reblog of an old post.

...and Then There's Physics

Michael Tobis has a post in which he argues that what we are doing to the climate will persist for many generations and, consequently, that it is immoral to continue what were’e doing and that we should address this as soon as possible (at least, that is my interpretation, but MT can correct me if I’m wrong). Stoat, unsurprisingly, disagrees and seems to argue that we should treat global warming as an economic, rather than moral issue.

The problem I have with Stoat’s post is not that I necessarily disagree, it’s that I don’t even really understand what he’s actually suggesting. As this response says

posing potential solutions as economics versus ethics is profoundly misleading, mostly because they are inextricably intertwined.

I have no economic experise, nor do I claim any. However, my understanding of economics as a discipline, is that the goal is to understand aspects of the world/society…

View original post 684 more words

Posted in Uncategorized | 51 Comments

RCP8.5 and net-zero

There’s a narrative that seems to be developing that suggests that the requirement to reach (net) zero emissions is largely based on the high-emission RCP8.5 scenario. Since this is (according to some) no longer plausible, we should give up on our (net) zero plans, because they’re no longer necessary and will do more harm than good.

One obvious problem with this isn’t that there isn’t some boundary beyond which catastrophe ensues, and below which everything is fine. We expect the impacts to become increasingly severe as warming continues. Just because we’re unlikely to follow an RCP8.5-like pathway doesn’t mean that there won’t be severe impacts. If anything, there are already regions, and communities, that are being impacted by climate change and the difficulty of reliably estimating the impacts means that we may well be under-estimating the impacts of even the lower levels of warming.

Another issue is that there is a complex relationship between emissions, concentrations, and warming. This means that even if we don’t follow an RCP8.5 pathway, we still can’t rule out that we’ll experience levels of warming typically associated with RCP8.5 (> 4C, for example). Hence, ruling out an RCP8.5 pathway doesn’t immediately rule out RCP8.5-like impacts.

Finally, there is an element of irony to this narrative. One of the reasons why RCP8.5 has become much less likely is because of the progress that has already been made and the expectation that the promised climate policies will be implemented, and strengthened. Essentially, there’s an expectation that emissions will soon peak and start to decline. So, in some sense, the reason why RCP8.5 is much less likely than it once was is largely because we now think that we’re on a pathway towards (net) zero.

So, to suggest that the implausibility of RCP8.5 means we can give up on current climate policies is essentially arguing for a pathway that makes RCP8.5 more likely. To be clear, it’s always been a worst-case scenario, rather than being a pathway we were likely to follow. However, that’s mostly because it was unlikely that we would simply not develop, and implement, alternatives that would reduce emissions, not because it was absolutely impossible to follow an RCP8.5-like pathway.

Posted in Climate change, Global warming, Policy | Tagged , | 30 Comments

Clintel report Bingo.

Clintel, a group who thinks there is no climate emergency, and whose name – rather ironically – stands for Climate Intelligence, has published an analysis of the IPCC. You can download it here, if you’d really like to read it. You need to provide an email address and a name. I have downloaded and read (most of) it, mostly so that you don’t have to.

In some sense, it’s quite remarkable. It repeats many of the climate “myths” that have been debunked time and time again, and relies on the same small group of contrarians whose work has also been regularly debunked. It talks about the Holocene Thermal Maximum and the Little Ice Age. It criticises the Hockey Stick. It suggests that estimates of the global surface temperature aren’t reliable. It argues that the IPCC ignores the role of the Sun, and that models are unreliable. It suggests that climate sensitivity is lower than the IPCC reports suggests and, in a somewhat more modern twist, it also criticises the use of scenarios in climate models.

There are many other topics, but you probably get the general idea. It would do well in a game of Climate Bingo.

Some would argue that rather than simply dismissing this, the arguments should be systematically rebutted. The problem is that this has been done many times before, and there is only so much time that people can spend doing so. However, Skeptical Science has a large list of rebuttals to common Global Warming and Climate Change myths, which is a very useful resource.

However, I do want to highlight one very obvious error early in the report. In Figure 5 of Chapter 1, it claims that there was a large change in the GISS temperature anomaly between the 2001 and 2015 datasets. If you have any understanding of this, you might think that this is because they haven’t used the same baselines. It appears to be even worse than this. They appear to have simply overlaid two plots, not bothered to align the y-axes, and even left both axes visible [Edit: As Paul points out in this comment, this is correct, but very poorly illustrated. There is actually a 0.4C difference between the warming from 1880 – ~2000 in the 2001 data, when compared to the 2015 data, which is related to updates in their methods].

It’s quite something that there are still people willing to promote these arguments, and that there are others who are still willing to take them seriously. It also highlights how difficult it is to actually counter misinformation. It doesn’t matter how often it gets debunked, some people will simply continue to promote it, knowing that most who spend their time countering it will eventually give up. Brandolini’s Law in action.

Posted in Climate change, Climate sensitivity, ClimateBall Bingo, Global warming | Tagged , , , | 115 Comments

Tropospheric temperature trends

Roger Pielke Jr appears to have been pondering why it is that discussions, on social media, about the physical science of climate change (WG1 in IPCC-speak) has dissipated in recent years. There are probably many reasons, but amongst them might be that some, who used to be quite active, have done this for so long that they just don’t have the energy to keep doing so. Another is that the debate does appear to have moved on a little. There is now slightly more focus on what we should do, given the reality of climate change, rather than discussions about the reality of climate change.

However, this lack of discussion about the physical science of climate change has motivated Roger to experiment with such discussion on his substack and he encourages all to comment, in particular experts. The only real constraint is that comments should be respectful, polite and generous. Of course, having alienated many physical science experts who engage on social media, Roger may struggle to attract much engagement with actual experts, but that probably won’t bother Roger.

It might be interesting to look at Roger’s first attempt at a post on the physical science of climate change. It’s about a paper by Zou, Xu, Hau and Liu on Mid-Tropospheric Layer Temperature Record Derived From Satellite Microwave Sounder Observations With Backward Merging Approach. It’s a new version of NOAA’s mid-troposphere temperature time series. The potentially interesting result is that it finds a trend that is lower than climate models typically suggest. This, however, isn’t all that surprising, since it’s long been known that there is an apparent discrepancy between tropospheric temperatures estimated from satellites, and those suggested by climate models.

So, what does this mean? Well, almost certainly not what Roger’s post title implies; it doesn’t suggest that global warming is less than we thought. Global warming typically refers to warming of the surface, and there’s no real reason to think that this result implies that surface warming is somehow lower than we currently think. Of course, maybe Roger was going for Betteridges Law of Headlines, but this wasn’t obvious.

If you want a slightly more thorough look at this issue, you could read this Realclimate post. It’s true that climate models tend to predict a larger tropospheric temperature trend than is observed, but if you screen for TCR (essentially, don’t include the models that appear to be running hot) then the fit is better. Also, if you consider the models that were intialised with observed sea surface temperatures, then the fit is better still. So, it’s not clear that this discrepancy is all that significant.

On a slightly tangential note, one of the reasons why there has sometimes been a focus on tropospheric temperatures, is that there is expected to be a tropospheric “hot spot” in the tropics. In other words, we expect part of the troposphere to warm faster than the surface. If the troposphere is warming slower than the surface, then this might imply that the expected “hot spot” is not emerging. However, this is related to lapse rate feedback (water vapour evaporates at the surface, is carried aloft, and then condenses, heating the tropical troposphere). This is a negative feedback, so if it’s not emerging, it might actually imply a slightly higher, rather than lower climate sensitivity. It’s not a big effect, because it also implies a lower water vapour feedback, but it doesn’t imply a substantially lower climate sensitivity.

On another somewhat tangential note, the topic of Roger’s post is – I think – also related to discussions that took place on climate blogs about 14 years ago. If you wanted to get a taste of this, you could read this post, and follow some of the links. It might give you some idea of why experts aren’t likely to be rushing over to Roger’s new site to discuss this topic.

If anyone has anything further to add, they’re welcome to do so in the comments, but let’s keep it respectful, polite, and generous. Of course, if you want to experience what the online climate debate used to be like, you could always head over to Roger’s.

Posted in Climate change, ClimateBall, Contrarian Matrix, Roger Pielke Jr, Science | Tagged , , , | 104 Comments

10 Years

I’ve just realised that this is the 10th anniversary of me starting this blog. We have family visiting, so am too busy to write anything substantive, but thought I would just highlight the anniversary.

Posted in Personal | 14 Comments

The Secret Square

People send me stuff {1}.

Brandon Gates (whom I often refer to as BG) has been toying with the free version of ChatGPT. He grilled it about climate science. He also asked it about Climateball. The first response to “what is Climateball?” underwows:

Climateball is a term used to describe debates and arguments that occur around climate change and global warming. It is often characterized by heated discussions between individuals with differing opinions on the subject, where the debate can sometimes feel like a game or sport. The term “Climateball” was coined by blogger and software engineer Daniel M. MacKenzie in a 2014 post on his blog, “And Then There’s Physics.”

The game is characterized by the use of rhetorical tactics and logical fallacies, as well as the tendency for individuals to stick to their predetermined positions and not engage in productive discussion or consideration of evidence. The term is intended to emphasize the confrontational nature of these debates and the difficulty of finding common ground between individuals with opposing views on the subject of climate change. The term has gained popularity among those involved in the discussion of climate change, particularly those who are interested in the psychological and social aspects of the debate. It is often used to describe the difficult nature of finding common ground on the subject, despite the overwhelming scientific evidence supporting the reality of climate change and the need for action to mitigate its effects.

(2023-04, Brandon Gates, personal correspondence)

The bot is not the best auditor. The fact that he’s trying to BS his way out of the question shows definitive intelligence. Without that skill, humans would need to pass more exams.

After some cues on Calvinball, the bot had to answer the question “What is Climateball?” as if it is the first time it was being asked:

Climateball is a term that originated on the blog “And Then There’s Physics” and is inspired by the game “CalvinBall” from the comic strip Calvin and Hobbes. It is a metaphor for the heated and often contentious debates that occur in discussions about climate change, particularly on social media and online forums. Like in CalvinBall, there are no fixed rules or referees to enforce them in Climateball. This can lead to an environment where the players make up their own rules to suit their arguments and attack their opponents’ positions, often resulting in arguments over the rules rather than productive debates about the actual science of climate change.

The term Climateball has become popular among those who study and discuss climate change, as it aptly describes the contentious and unpredictable nature of these debates. The game is often played out on social media platforms and discussion forums, where individuals with varying levels of scientific knowledge and differing viewpoints engage in arguments over climate change. The goal of Climateball is often less about reaching a shared understanding of the science behind climate change, and more about winning arguments and persuading others to one’s point of view.

Despite its negative connotations, some argue that Climateball can be a productive way to engage with climate change skeptics and deniers, as it allows for the exchange of ideas and can help to clarify misunderstandings about the science. However, others believe that it can be counterproductive, as it often leads to polarization and reinforces existing biases. In either case, it is clear that Climateball is an important and ongoing phenomenon in discussions about climate change.

(Op. Cit., a few minutes later)

To be frank, I’m quite flabbergasted. It’s more or less a perfect response. It only lacks the meta part of Climateball. By that I mean the phenomenon by which many of the players’ communication efforts is spent on managing the communication itself.

This phenomenon echoes the secret square of Climateball Bingo:

The best way to escape Climateball might not be to blame otters that they’re playing Climateball.


{1} Tony used to start his most conspiracy laden blog posts with that first line. Search for “people send me stuff”.


2010-06; Willard on Meta-Journalism Meta Thread; back in my days, chatbots were human.

2018-10; Ceci n’est pas un Sokal; for the bot puts the whole exercise into question.

Posted in ClimateBall, ClimateBall Bingo | Tagged , , | 85 Comments

How we frame extreme weather events

To maybe move the discussion on from the origins of Covid, I thought I’d write a post about detection and attribution. It is somewhat motivated by a brief dicsussion withTed Nordhaus, from the Breakthrough Institute, who suggested that a good rule of thumb for attribution studies is that they are consistent with “observable trends in climate related phenomena.” The problem, as pointed out in this nice Realclimate post, is that detection and attribution are actually two separate things and there may well be situations where it’s possible to understand the causes (the attribution) of an event without this being associated with some kind of longer-term trend.

In fact, we might actually expect some extreme events to become attributable, well before any trend emerges. You could, of course, decide to be cautious and not make any attribution claims until some kind of trend emerges, but that is almost certainly going to unplay the link between anthropogenically-driven climate change and extreme weather events. So, a decision to do so is essentially equivalent to those who claim that climate change is already super-changing every single extreme weather event. It’s an explicit decision to minimise the impact of climate change. It’s also somewhat ironic, given that it’s often presented in response to suggestions that others have exaggerated the influence of climate change.

On a similar note, there are also some who argue that we should only really consider the marginal impact of climate change. In other words, if we experience a heatwave, then we frame things in terms of how hot it would have been in the absence of climate change and, therefore, how much climate change contributed to the event.

The problem is that it is often these marginal changes that have the most impact. If we live in regions with infrastructure that is designed to cope with a certain level of, for example, precipitation, then the impact of climate change could lead to events that the local infrastructure can’t cope with very well. Essentially, there could be thresholds beyond which extreme events have a lot of impact, and below which the impact is minimal. Climate change could act to push events past these thresholds.

Hence, again, deciding that we should only frame the influence of climate change in terms of the marginal effect it has on extreme events can underplay the impact that these changes are likely to have. It also runs the risk of ignoring that climate change can influence both the frequency and intensity of extreme events.

How we choose to frame things like this probably illustrates our views about the significance of climate change. If you think that we should only really trust attribution studies if they’re associated with some detectable trend, then you probably think that variability will dominate over the changes due to climate change. If you think we should only frame the influence of climate change in terms of the marginal effect it has on extreme events, then you probably think the impact will also be marginal.

Of course, you could make similar comments about those who make strong claims about the influence of climate change on extreme weather events. Personally, I think it’s complicated and we should be willing to acknowledge that. We can do detection and attribution and also try to understand the causal factors that influenced a single extreme weather event. We can both consider the marginal impact of climate change on extreme events and acknowledge that these marginal changes could have a large impact.

We could also acknowledge that how we choose to frame the influence of climate change on extreme weather events is probably strongly influenced by our overall view about the significance of climate change. If you’re choosing to frame things in ways that will probably minimise the impact of climate change then maybe don’t get upset if people point this out. Have the courage to own it.

Posted in Climate change, ClimateBall, Gavin Schmidt, Global warming, Philosophy for Bloggers | Tagged , , , , , | 162 Comments

The origins debate

I’ve mostly tried to avoid the Covid origins debate, but I listened to a very good Guruspod episode, where they covered this. It was an interview with Eddie Holmes, Kristian Andersen, and Michael Worobey, and was partly intended as a response to a Sam Harris podcast with Matt Ridley and Alina Chan.

I encourage you to listen, but they did highlight a couple of things that I thought were particularly interesting. For example, some argue that it’s too much of a coincidence that the Covid virus emerged in a city that has a lab that happens to study coronaviruses. They point out that, firstly, given the properties of the virus, it was almost certainly going to start spreading in a big city, and that Wuhan was certainly amongst the cities in which you might expect such an outbreach to start. Secondly, many of the major cities in which you might expect such an outbreach to start have labs that could, after the fact, seem to be coincidental.

The suggestion is that the most likely origin was a spillover to humans in the Huanan Seafood Market. In fact, the evidence indicates two separate spillover events involving two closely related variants. It could be that someone was infected in the lab and then spread the virus in the market. This, however, becomes less likely if it happened twice. This doesn’t preclude some kind of lab origin, but the overall evidence seems to point much more strongly to a zoonotic origin with the spillover occuring in this market.

However, what I found particularly interesting was the similarities with the climate debate. Those who dispute the mainstream view use emails taken out of context. Many of the scientists who become prominent are publicly attacked. There are claims that the scientific community somehow benefits from promoting a particular narrative. There are claims that dissenting views are silenced and that the mainstream scientific community are not willing to debate these alternative ideas. There are arguments that continually get repeated despite having been debunked time and time again. There are non-experts who suddenly think they know better than experts. In fact, some of these people are the same as in the climate debate (Matt Ridley, for example).

Even though I am a scientist, I certainly have no relevant expertise in this context. I’m having to rely on heuristics to try and get some sense of what is most likely. My general sense is that it’s now pretty clear that the virus could not have been engineered and that some other kind of lab leak is much less likely than the origin being transmission from animals to people in the seafood market. My heuristic is essentially that this seems to be the view of relevant experts and that they seem to present arguments that make sense, that acknowledge uncertainty, and that are well thought out.

My other heuristic is that some who appear to be on the other side of the debate have held similarly contrarian positions with regards to climate change. Past evidence would seem to indicate that they’re not particularly skilled at objectively assessing evidence, and are perfectly comfortable promoting views that most with relevant expertise would regard as obviously wrong.

This doesn’t mean that my current assessment is correct, but it currently seems more likely that the experts are right, than those who hold contrarian views and have been wrong before.

Posted in Scientists, The philosophy of science, The scientific method | Tagged , , , , , | 507 Comments

Methane, again.

I ended up in quite an interesting Twitter discussion about methane and CO2. I got involved when someone mentioned this thread from Ken Caldeira. The point being made is that because CO2 has a long atmospheric lifetime, and because methane oxidises into CO2, the time integrated forcing due to a pulse of methane is dominated by the contribution once its oxidises to CO2, rather than by the contribution when it’s methane.

The point I tried to make in the discussion was that this is only really true for fossil methane emissions, because biogenic methane (from cows, for example) isn’t really adding a “new” carbon into the system. However, although I don’t dispute the original calculation, I also don’t think the comparison is all that reasonable, which I’ll try to explain using a related, but slightly different, comparison.

In a 2015 paper, Ken Caldeira and a colleage (Xiaochun Zhang) showed that the cumulative radiative forcing from CO2 released in fossil fuel combustion exceeds the thermal energy released by a factor of about 100000. They did this in a reasonably detailed way, but I think I can do a ballpark estimate in much simpler way.

If we just consider coal, then 9.46 x 1010 kg of CO2 is released for every EJ (1018 J) of thermal energy. Therefore, if we consider a scenario where we release 1000 GtC = 3600 GtCO2 from burning coal, then this would provide 3.6 x 1015/9.46 x 1010 = 38054 EJ = 3.8 x 1022 J of thermal energy.

If we do emit 1000 GtC, not all will remain in the atmosphere. Once ocean invasion is complete (which would take a few centuries) we’d expect about 25% to remain in the atmosphere. This means atmospheric CO2 would increase by ~250 GtC, which is about 120 ppm. So, it would roughly settle at about 400 ppm. An increase from 280 ppm to 400 ppm produces a change in forcing of about 1.9 W/m2, which will – on average – persist for 10 thousand to 100 thousand years. If you integrate this forcing over those timescales, and multiply by the surface area of the Earth, you get 3.1 x 1026 to 3.1 x 1027 J. So, yes, about 10000 to 100000 times greater than the thermal energy released (remember, this is just a ballpark estimate).

However, what actually happens is that this energy accrues in the climate system, which warms until a new equilibrium is reached. If we assume an ECS of ~ 3K, then a change in forcing of ~1.9 W/m2 would produce an equilibrium warming of about 1.54K. Most of this goes into the oceans, which has a heat capacity of ~4000 J/kg/K. The oceans have a total mass of about 1.4 x 1021 kg, which means a warming of 1.54 K would increase the total energy by 1.4 x 1021 x 4000 x 1.54 = 8.6 x 1024 J.

This is still bigger than the thermal energy released, but only by a factor of ~220, rather than by a factor of 10000 to 100000. If we were to consider gas, rather than coal, then it would be bigger by a factor of ~130, rather than ~220. So, I think that considering the time integrated forcing over-estimates the relative impact by quite a large margin, and I think the same is true for the comparison between the impact of methane and the impact of the CO2 to which it will oxidise.

As far as I’m aware, for any reasonable scenario, the dominant waming impact of methane emissions will occur when it’s methane, rather than when it has oxidised to CO2. In GtC, annual methane emissions are about 5% of CO2 emissions (~0.5 GtC versus ~10 GtC) yet more than 5% of the warming can be attributed to methane emissions. So, even though fossil methane emissions will oxidise to “new” CO2 that will have a long atmospheric lifetime, it is still a small fraction of the direct CO2 emissions from fossil fuel burning and from land-use change.

Ultimately, I think that all this really illustrates is that it’s tricky to compare methane and CO2 emissions. CO2 has a long atmospheric lifetime and, hence, is key to determining how much we eventually warm. Methane, on the other hand, can have a very large impact on shorter timescales, and becomes important if we want to avoid crossing some kind of threshold. Personally, I think we should just consider them separately, rather than doing comparisons. Others may, of course, disagree.

Posted in Climate sensitivity, Environmental change, Global warming | Tagged , , , , , | 61 Comments

Conflicts of Interest

Since I have little (no?) self-control, I sometimes find myself checking what RPJ is up to. I mostly find it worth ignoring, but I found myself considering one of his recent posts on [w]hen scientific integrity is undermined in pursuit of financial and political gain. It seems to have been partly motivated by him encountering a researcher who was “taking money not just from one but from many companies that are direct beneficiaries of the legislation he helped to design“, but also because another scholar (Jessica Weinkle) had recently given related testimony to the US Senate.

Although I do think it’s important to acknowledge any conflicts of interest, quite a bit of what is suggested seems rather odd. Firstly, even though the researcher isn’t named, I do happen to know who they are. As far as I can tell, they do openly acknowledge these potential conflicts of interest. That someone has a possible conflict of interest doesn’t immediately imply some kind of problem. The reason it’s important to acknowledge them is so that others can assess their significance.

It also appears that some of this is related to the continued use of climate scenarios that some regard as implausible. This is a topic that is currently under debate and – in my opinion – isn’t quite as straightforward as some would imply. I think it’s healthy to have these kind of debates and it’s perfectly fine to disagree with what others are doing. What seems less healthy is to go around suggesting that what other scholars are doing implies some kind of failure of scientific integrity.

Another issue is that, in the UK at least, there is quite a lot of pressure on academics to have a broader impact, for their research to influence policy, public opinion, or to play some kind of direct role in economic growth. So, scholars are almost expected to engage with policy-makers, with public organisations, and to potentially become involved in activities that could be financially advantageous.

So, when there is a societally significant issue, it’s hardly surprising that scholars with relevant expertise become involved with various groups that are involved in activities related to this topic. If anything, it would seem odd if they didn’t. There may even be some whose are involved in ways that aren’t ideal. However, this hardly seems sufficient to suggest that

Climate change science demonstrates an underappreciated dynamic system of conflicts of interest among climate change researchers, advocacy organizations, and the financial industry.

Others may, of course, disagree.

Posted in Climate change, ClimateBall, Philosophy for Bloggers | Tagged , , , | 22 Comments