Limits to growth?

I’ve been doing some reading to try and better understand the debate between decoupling and degrowth. I should acknowledge upfront that I haven’t really grasped the complexities of these issues, so this post will probably be rather confused and rambling. However, the debate is essentially between those who think we can continue to grow the global economy, but can reduce resource depletion and the impact on the environment through decoupling, and others who regard this as essentially not possible and, hence, that we should actively reduce consumption and production.

What motivated this post was an extremely optimistic article by Michael Liebreich called The secret of eternal growth. The basic argument is that there is no real limit to growth and that we can utilise unlimited energy sources to both grow our economies and minimise our negative impacts on the environment. There are, however, a number of responses to this article. One by Tim Jackson, who is mentioned in Liebreich’s article, called how the light gets in, and another by Rob Dietz called the secret of eternal growth? It’s wishful thinking.

The latter response mentions Tom Murphy, who is a physicist who has written posts on economic growth, such as can economic growth last? and galactic scale energy. These posts approach the issue for the perspective of real physical limits, and suggest that unlimited growth is essentially impossible.

A criticism I’ve heard of this is that when people talk about unlimited economic growth, they don’t really mean growing forever, they mean for some reasonable time into the future. Liebreich’s article, however, certainly seems to essentially imply virtually unlimited, saying:

This is a real scientific expert on entropy proving that the economy can grow for as long as there is still a sun in the sky (which would give us about another five billion years).

As Tom Murphy’s posts point out, there are real physical limits to our energy usage on the surface of the planet.

As I understand it, the response to this is then that economic growth simply refers to economic activity which doesn’t have to be associated with ever increasing energy usage. I can understand that this is possible, but can you really have a economy that grows to the point where a vast majority of the activity is not associated with the use of any energy (I really don’t know the answer to this, so maybe it is possible)?

I can quite understand that it is probably possible to develop energy sources that have minimal impact on the environment and that minimise our depletion of resources. Similarly, we can also aim to minimise the impact of our economic activity on the environment, and on resource depletion, either by actually developing activities that don’t have much impact, or by using some of the available energy to minimise this impact (which is essentially what I think Liebreich is arguing for).

However, given that severe impacts are potentially going to materialise within decades, we need to start doing this sooner rather than later. This is really where I have a problem; I don’t see much evidence for this. I realise there has been some relative decoupling (the impact per unit of economic activity has decreased), but I see little evidence that we will get close to absolute decoupling anytime soon.

As I understand it, we can’t have economic activity that simply doesn’t have any impact on the environment, but we can choose to commit resources to minimising this impact (i.e., use some of the available energy to avoid increasing entropy, as Liebreich suggests). However, this would seem to have a cost and it seems to me that we mostly spend our time convincing ourselves that we shouldn’t yet pay this cost, or shouldn’t pay too much now because people in the future will be richer. So, my issue isn’t that I think we can’t continue to grow our economies while decoupling economic activity from environmental impact, I just think that we won’t.

Okay, this has got rather long, so I’m going to stop. As I said at the beginning of the post, I’m still trying to get my head around this whole issue. I may well be wrong about some of this, in which feel free to point it out in the comments. Similarly, I’m also interested in what others think about this topic.

Links:
The Secret of Eternal Growth – by Michael Liebreich.
How the light gets in – by Tim Jackson.
The secret of eternal growth? It’s wishful thinking – by Rob Dietz.
Galactic scale energy – by Tom Murphy.
Can economic growth last? – by Tom Murphy.
Decoupling vs degrowth – by Linus Blomqvist.
Towards Peak Impact – by Linus Blomqvist.
Here’s a simple solution to the green growth / degrowth debate – by Jason Hickel.

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The benefits of acting now, rather than later

This is a post that I’ve been thinking about for a while, but have been somewhat reluctant to actually write. This is partly because maybe I’m wrong, partly because it is clearly going to be a bit too simplistic, and partly because I don’t want to suggest that issues other than climate change are not important; I think they are. However, I want to try to make an argument as to why climate change is a problem that is fundamentally different to many of the other issues we face.

You often see claims that people don’t regard climate change as a particularly important issue, or that there are other issues that are more pressing at the moment. Global poverty, inequality, healthcare, education, crime, to name but a few. It’s certainly not unreasonable that many people regard these type of issues as more important than climate change; something that they may regard as not (yet) impacting them, or something that will only start to clearly manifest itself in the future.

As a society we always have to make decisions about our priorities. Not everyone will agree, and in many cases we may well change our minds as to what problems we should focus on. Whatever we choose to do, some will benefit more than others and, in some cases, some people may suffer unnecessarily. However, in most cases, even if we delay addressing some issue, we can still do things in the future that will improve the situation. Climate change is something for which this is not true, and is why I think it is an issue that is quite distinct from many of the other issues we may wish to address.

Climate change is essentially irreversible on human timescales; whatever changes are induced by our emission of CO₂ into the atmosphere will persist for centuries, if not millenia. So, the longer we take to address climate change, the bigger the change that we are committing ourselves to, and the more likely it becomes that climate change will severely negatively impact ourselves and natural ecosystems.

Even though we can’t easily reverse the changes that have already taken place, it is not technically impossible to stop it. Doing so, however, will require getting net emissions to ~zero. Since we can’t do this instantly, we will be committed to increasingly severe climate change, until we get net emissions to ~zero.

What I getting at is that, unlike many other issues we face, delaying action on climate change has very long-term implications. The more we delay, the greater the change to which we’re committing ourselves, and the more likely it becomes that this change will be severely negative. This is not, however, to suggest that we should focus on climate change above all else; there clearly are other important issues that we should be addressing. However, the implications of delaying addressing climate change are potentially serious and I think we should bear this in mind.

Additionally, climate change may well exacerbate many of the other issues that we regard as important. Therefore, it’s not a simple either or situation. Not only does delaying acting on climate change have long-term implications, addressing it now could have a positive impact on many of the other issues that we regard as important.

This is clearly a complex issue, and I’m not suggesting otherwise, but I do think that we should be careful of thinking that climate change is simply one of many issues that we need to address and that we can simply deal with it at some point in the future, when it’s more convenient to do so. What we might be dealing with then could be vastly different to what we would be dealing with today, and if we do delay action, we may well have locked in severely negative changes that will persist for many generations.

Addendum
Something I’ve ignored is the possibility that we could address climate change through geo-engineering, or through negative emission technologies. This is, of course, a possibility. However, geo-engineering carries its own risks and negative emission technologies are as yet undeveloped. We could hope that we manage to develop reliable technologies for artificially drawing down atmospheric CO₂, but there’s no guarantee that this will be possible, or that it will be easier than trying to find ways of generating energy that doesn’t also involve emitting CO₂ into the atmosphere.

New ocean heat content analysis

I wanted to just briefly mention the recent paper that [quantifies] ocean heat uptake from changes in atmospheric O2 and CO2 composition, by Resplandy et al. The interesting thing about this paper is that it uses proxies to infer the change in ocean heat content. What it finds is that the change in ocean heat content is probably at the high end of earlier estimates, which are based mostly on direct measurements of ocean temperature.

What this implies is that observationally-based estimates of equilibrium climate sensitivity (ECS) are probably also on the low side. Fortunately, BlueSkiesResearch has already repeated this calculation. Essentially, it increases the lower limit by about 0.1K, the upper limit by about 0.5K, and the median by about 0.2K. This slightly resolves the issue I had with the slightly high TCR-to-ECS ratios that come out of these type of analyses.

However, the paper suggests that this increase in the change in ocean heat content implies a reduction in the carbon budget for staying below 2^oC, and I don’t think that is correct. The carbon budget depends mostly on the transient climate response (or the transient response to cumulative emissions). This doesn’t really depend on how much the ocean heat content has changed; it primarily depends on how much we we’ve warmed for a given change in external forcing.

So, I don’t think that this new ocean heat content estimate really implies anything with respect to carbon budgets; I think the main significance is that it is suggests that some observationally-based estimates of equilibrium climate sensitivity are probably too low and that the likely range for equilibrium climate sensivity is still something like 2^oC to 4.5^oC.

Update:
There is now a guest post on Realclimate by one of the authors in which they discuss errors in the uncertainties and in the trend estimate.

A defense of science?

Susan highlighted a New York Times article about Bruno Latour, that I had actually seen and had been considering writing about. I have written about Bruno Latour before and I’m still not sure what to make of this article. One issue is that it seems somewhat revisionist; highlighting how he’s been misunderstood. If part of someone’s research is to understand the link between science and society, then you might hope that that they’d have some understanding of how what they said would be received.

I thought I would highlight a couple of things that caught my eye. The article says

Latour believes that if scientists were transparent about how science really functions — as a process in which people, politics, institutions, peer review and so forth all play their parts — they would be in a stronger position to convince people of their claims.

I do think that this is an aspect of the scientific process that we don’t highlight enough. I think it would be good if we were clearer about the actual messy business of doing science. I don’t, however, really think that this would put us in a stronger position when it came to convincing people, especially those who are pre-disposed to reject some scientific information. I also think it’s important to distinguish between the details of the scientific process, which involves people and is infuenced by various societal factors, and the ability of this process to uncover information about whatever is being studied.

What might help is if there were people who studied the link between science and society, they could be the ones making the broader public more aware of how science really functions, while also being clear that this does not mean that the scientific “truths” that emerge are somehow strongly influenced by the various societal factor that influence the underlying process. Maybe we could call these people Science and Technology Studies researchers?

The article then goes on to say

Climatologists, he says, must recognize that, as nature’s designated representatives, they have always been political actors, and that they are now combatants in a war whose outcome will have planetary ramifications.

I think this is mostly wrong, but he’s not alone in making this kind of suggestion. There seem to be quite a lot of people who recognise the seriousness of this issue, but still seem to think that the responsibility for communicating this lies with climate scientists. I think climate scientists do have a responsibility to communicate their research, but I don’t think they’re really “nature’s designated representatives” and that they have some obligation to fight this “war” (ironically, I had thought that there was a tendency amongst science and society researchers to criticise war metaphors). Rather than passing the buck back to climate scientists, why don’t those who recognise the importance of this, get out and communicate it themselves (to be fair, Latour does seem to be doing some of this)?

I would be interested to know what others think of the article. There were parts that were interesting and some good points were made. I have written quite a lot about Science and Technology Studies (STS) and have quite often been less than impressed, so this may somewhat colour my interpretation of the article. A great deal of what I’ve seen from STS has appeared rather confused. Of course, this could simply be the messy business of doing research and maybe there are amazing insights emerging from this that I’m somehow missing. If so, I’d be keen to have them pointed out. However, I’d also be keen to understand how a discpline that itself is engaged in the messy business of doing research, thinks it can somehow also comment on the messy business of doing research. It feels as though there must be a point at which it becomes essentially impossible to objectively comment on a process in which you’re also involved, but maybe someone can convince me that this isn’t the case.

Why do we do research?

I thought I would briefly comment a little more about the claims made in John McLean’s thesis. Something to bear in mind is why we do research. Essentially, research is very simply about trying to understand something; to answer some question, or test a hypothesis. If you’re lucky, you can undertake a carefully designed, controlled experiment that produces data that can be easily use to answer the question that was posed. In many cases, however, this isn’t possible, and you need to undertake some kind of complex data analysis in order to get an answer.

Consider global surface temperatures. We’d like to understand if we’ve warmed over the last 100 years or so and, if we have, by how much. The problem is that we didn’t set up monitoring stations in the mid-1800s with this in mind. We do, however, have temperature measurements that go back to the 1800s, so we can work with these. However, instruments have changed, measuring stations have moved, the number of measurements has changed, the environment in which the measurements are made can have been artificially altered, the time at which measurements were made can have changed, and – in some cases – even the way in which measurements were made has changed. Therefore, if you want to construct some kind of global surface temperature record, you need to try and correct for these various non-climatic factors.

However, doing so requires developing some kind of data analysis technique and also using some judgement as to how to process this data. It can’t be perfect, but you can test to see how various methodological choices influence the results. People might even disagree with some of these choices; this doesn’t make them wrong. Some of the data might even be processed in a way that is clearly wrong, but if there is a lot of data, you might not be able to check how every data point is influenced by the analysis method. Again, you can check how this kind of thing would influence the results.

So, what about John McLean’s thesis? There’s nothing wrong with checking the data used to generate global temperature datasets. However, if this is to be a serious research project, then a key aspect is to understand how potential errors might influence the results. Simply pointing out possible errors tells us little if we don’t also understand the significance of these errors. By itself, it doesn’t really advance our understanding at all. If you really want to advance our understanding, you need to do more than simply highlight possible data errors (I’m ignoring for now that Berkeley Earth appears to have already flagged most of the issues highlighted in McLean’s thesis).

All I’m really trying to point out is that research is fundamentally about improving our understanding. Auditing a data set so as to point out possible errors can certainly play a role, but by itself does little. This is especially true if another analysis has already identified most of these issues and shown that the impact on the result is negligible.

John McLean, PhD?

A recent PhD thesis from James Cook University has been receiving a reasonable amount of attention on sites that either dispute anthropogenic global warming (AGW), or its significance (I won’t link to them, but you can probably find them if you want). The PhD is by someone called John McLean. His PhD supervisor was initially Bob Carter, who died a couple of years ago (Stoat’s post about his death caused a bit of a furore). After Bob Carter’s death, he was then supervised by Peter Ridd, who was fired earlier this year by James Cook University.

If you really want to read the thesis, you can download it here. It has two main parts, one of which considers problems with the HadCRUT4 data, and the other considers alternative causes for the warming, and that bleaching on the Great Barrier Reef has happened before. It’s all very amateurishly written; it’s more like blog science, than something that could be submitted for a PhD.

The discussion of problems with the HadCRUT4 data is very odd. It’s well known that HadCRUT4 suffers from coverage bias. However, there are a number of other global temperature datasets that account for this issue and produce results that are broadly consistent with the HadCRUT4 data (HadCRUT4’s coverage bias actually leads to it showing slightly less warming than those datasets that do account for this). It’s possible that there are problems with some of the actual data, but there is lots of data, so a problem with a small fraction of this data is almost certainly of negligible significance. It seems highly unlikely that those who work with these datasets haven’t checked to see how the results might be impacted by potential data issues. You can also sample subsets of the full dataset. Doing so produces results that are consistent with the full dataset.

The next part of the thesis suggests that the observed warming is a consequence of a combination of ENSO events and changes in cloud cover. This appears to be based on a paper he published in 2009 and one he published in 2014 (I had a link to this, but it was giving warnings when some tried to access it, so I’ve removed it). Turns out that I’ve already discussed the latter. Essentially, it ignores that clouds are a feedback not a forcing, so it’s just nonsense. I don’t think anyone ever published a response, but it seems to have been mostly ignored.

There was, however, a response published to the first paper which says

The suggestion in their conclusions that ENSO may be a major contributor to recent trends in global temperature is not supported by their analysis or any physical theory presented in their paper, especially as the analysis method itself eliminates the influence of trends on the purported correlations.

Essentially, the analysis removed the trend, so couldn’t say anything about what might be causing the long-term warming. As far as I can see, the thesis makes no mention of this response.

I’ve probably already wasted enough of my time discussing this thesis, so will stop here. I don’t know how theses are examined at James Cook university, but it would be quite interesting to know who the examiners were. I’ll finish by posting a Media Matters video that discusses McLean’s work.

Focusing too heavily on public mobilization and exposing denial?

I found an article by Matt Nisbet called The IPCC Report is a Wake Up Call for Scholars, Advocates, and Philanthropists. The underlying message in the article is

We have focused too heavily on public mobilization and exposing denial, ignoring other strategies likely to accelerate societal change.

The basic argument is that we’ve spent a lot of money trying to moblise people and exposing, and trying to understand, climate science denial and little has happened. It’s time to try something different.

Although I think it’s always worth thinking about how to do better, I typically find myself irritated by these kind of articles. One problem I have is that it’s never entirely clear quite what the alternative really is. This article points out that once alternatives to fossil fuels become cheap enough, the political motivation to delay action would subside. It also discusses how we could develop, and implement, carbon capture and storage (CCS) technologies that would allow us to continue using fossil fuels. Well, yes, these are both probably true (although CCS may prove very difficult). However, how does this take into account that if we want to avoid some of the more severe impacts of anthropogenically-driven climate change we need to start reducing emissions very soon and get them to essentially zero potentially within decades?

Another issue I have with these kind of articles is that they never seem to consider that one of the reasons the current strategy has been ineffective is the spread of misinformation by those who oppose any kind of climate action. Those trying to communicate about climate science are operating in an environment in which there are many who dispute the basics of climate science and are able to promote their views in some very prominent media outlets. It would seem helpful if those who were giving advice about how to be more effective would be willing to at least acknowledge the existence of such people and highlight that they are indeed wrong about the scientific evidence.

On a similar note, the article criticises explicitly highlighting the existence of climate science “denial”. Again, climate science “denial” does indeed seem to exist. Maybe if there was less focus on it, communication might be easier and more effective. On the other hand, this seems a bit like a form of deficit model thinking; just do something different and everything will be better. As far as I can tell, the reasons why some people reject climate science, and the need to do something about climate change, are complex and often associated with their political/cultural identity. Criticising the tactics used by climate communicators seems more like a convenient excuse than a real reason why some don’t accept the evidence for anthropogenically-driven climate change.

Of course, I do think it is worth thinking about how to engage with those who are pre-disposed to reject the risks associated with climate change, and some are indeed doing so (Katharine Hayhoe, for example). However, I don’t think this is easy and I don’t really think that if climate communicators had behaved differently in the past that it would have made much different to where we are today.

Okay, I was intending to keep this short and have, as usual, failed. One thing I feel strongly about is that if (when?) we realise that we really should have done more to address climate change, the fault will not lie with those who tried to communicate about these risks, even if they could have done better. This isn’t to say that we shouldn’t continually try to do better, but I do think we should be careful of creating a narrative suggesting that the problem was the tactics used by climate communicators. Of course, maybe I’m missing something about what is being presented in these kind of articles (probably am to some extent), so would be keen to hear what other people think.