Lomborg science

I was going to write a post about the whole Lomborg saga, but I really can’t be bothered writing too much. If you want to read about his many errors, you could read Graham Readfearn’s Guardian article. If you want to read a defense of Lomborg, you could read Roger Pielke Jr’s. Roger’s article makes the perfectly reasonable suggestion that we shouldn’t demonise academics, but fails to acknowledge that Lomborg is not an academic by any standard definition, that criticising what someone says is not demonising them, and fails to recognise the irony of suggesting that we shouldn’t demonise Lomborg, while essentially demonising his critics. In fact, if you want to read a good discussion of why Lomborg’s appointment is anything but academic, this is pretty good.

However, ignoring that Lomborg appears to have a rather tenuous grasp on the basics of climate science, my main issue with what he says is its simplicity. Take all the problems in the world, determine some kind of priority ordering, and then start at the top and work your way down – climate change, obviously, being well down the list. It’s as if Lomborg doesn’t realise that the world is a complex place and that many of the problems we face are related. We can’t necessarily solve something if we don’t also try to address many of the other issues at the same time. It’s this kind of simplistic linear thinking – and that some seem to take it seriously – that irritates me most. It reminds me of another theory that I saw presented some time ago.

Posted in Climate change, ClimateBall, Comedy, Satire, Science | Tagged , , , , , , | 22 Comments

Testing the IRIS Hypothesis

I thought I might revert back to a bit of physics and discuss a recent paper that aims to try and test the Iris hypothesis. The Iris hypothesis originates with Lindzen &Chou (2001) and proposes that as we warmed, there would be a reduction in cloud cover in the tropics, which would allow for more infrared radiation to escape to space and would – consequently – act as a strong negative feedback.

credit : Mautitsen & Stevens (2015) Figure 2

credit : Mautitsen & Stevens (2015) Figure 2

The recent paper that tests this is Missing iris effect as a possible cause of muted hydrological change and high climate sensitivity in models by Thorsten Mauritsen & Bjorn Stevens. There are, I think, two motivations for this recent paper. One is that recent observations suggest that climate models might be over-estimating climate sensitivity and (which I had not realised) under-estimating changes to the hydrological cycle. There is also one model-data mismatch that may be consistent with an Iris effect. The figure on the right shows the short- (horizontal axis) and long-wavelength (vertical axis) sensitivity in the tropics. Climate models produce the same kind of short-wavelength sensitivity to that observed, but tend to underestimate the long-wavelength sensitivity. This suggests that the increase in outgoing long-wavelength flux with temperature is greater than climate models suggest, and is at least consistent with an Iris-like effect.

Since the Iris effect is essentially a reduction in cloud cover, and an increase in the size of the infrared window, in the tropics, this was implemented in the models by simply introducing a term, I_e, that allowed them to adjust the rate, C_p(T_s), at which cloud water was converted to rain. Essentially

C_p(T_s) = C_o (1 + I_e)^{T_s - T_o},

where C_o is the default rate, T_s is the surface temperature, and T_o is a typical temperature in the tropics.

The basic result is shown in the figure below. The grey dots in the left-hand panel show the equilibrium climate sensitivities (ECS) for a range of different climate models. The red dot is for the ECHAM6 model, which has an ECS of 2.8K. The yellow, light-green, and dark-green symbols show the impact of the Iris effect for I_e = 0.2, 0.5 and 1.0, but considering the long-wavelength effect only. This brings the ECS down into the range suggested by Lindzen & Chou (2001). The blue symbols, however, show the ECS when the short-wavelength and other feebacks are also included. The net effect is relatively small, with the ECS reduced from 2.8K, to between 2.2 and 2.5K, depending on the value of I_e. The right hand-panel illustrates why. The long-wavelength effect is quite large, changing the feedback from around +0.5Wm-2K-1, to between -0.4 to -0.8Wm-2K-1. However, there are also changes to the water vapour feedback, lapse rate feedback, and short-wavelength cloud feedback that results in a relatively small net change in overall feedback.

credit : Mauritsen & Stevens (2015) Figure 3

credit : Mauritsen & Stevens (2015) Figure 3

So, this seems like an interesting paper that is really just testing what would be the consequences of there being an Iris effect, without actually demonstrating that it does exist. There are, however, some interesting hints. The results suggest that the Iris effect would reduce the ECS to bring the models more in line with what recent observations suggest. The change is, however, not big enough to bring it down to the kind of values suggested by Lindzen & Chou and, for the model considered here (ECHAM6), the change is from 2.8K to 2.2K at most. The Iris effect would also increase the hydological sensitivity which, again would make models more consistent with observation. Additionally, models currently underestimate the long-wavelength sensitivity in the tropics which is, again, consistent with a possible Iris effect.

Ultimately what this seems to be showing is that if observations do suggest that models are over-estimating climate sensitivity and under-estimating hydrological sensitivity, this could due to an Iris effect that is not being properly represented in the models. It’s almost certainly too early to know if models really are missing something like an Iris effect and consequently over-estimating climate sensitivity, but it’s an interesting paper that certainly presents some intriguing hints.

Posted in Climate change, Climate sensitivity, Global warming, Science | Tagged , , , , , , , , | 58 Comments

The Avoidance of the Intellectual

I came across a quote that I found quite compelling, and so thought I would also post it here. I first saw it on this site, which got it from here, but I think it’s actually out of this book. The quote, from Edward Said, is:

Nothing in my view is more reprehensible than those habits of mind in the intellectual that induce avoidance, that characteristic turning away from a difficult and principled position which you know to be the right one, but which you decide not to take. You do not want to appear too political; you are afraid of seeming controversial; you need the approval of a boss or an authority figure; you want to keep a reputation for being balanced, objective, moderate; your hope is to be asked back, to consult, to be on a board or prestigious committee, and so to remain within the responsible mainstream; someday you hope to get an honorary degree, a big prize, perhaps even an ambassadorship.

I don’t particularly agree with the rather cynical reasons given at the end, but the first part of the quote really struck a chord. I do think there is a tendency (amongst some, at least) to avoid taking some kind of stance. I suspect there are many reasons, some of which are simply related to human nature; it’s easier to just keep out of things. I also think that academia, in particular, has become very specialised. People focus on their own little area and don’t always seem interested in the broader picture. It can also be quite a selfish environment; it’s a competitive environment where permanent jobs are difficult to get, funding is hard, and your career depends on standing out in some way. You don’t have time to really care about other things that may be relevant, but don’t necessarily affect you directly.

Universities are also now run more as a business than as some institution of learning that provides a service to the broader public, be that through educating students, doing research that may have some kind of broader impact, or providing some kind of intellectual leadership. As such, the priorities are to generate income, either through teaching or through research. Of course, universities do need to be financially viable, but I do think they should be careful of prioritising income generation over the intrinsic value of education and scholarship, and I do think we’ve tipped over a bit too much in favour of the former. I think a consequence of this is that academics are encouraged to primarily focus on how to get the next research grant or on how to publish the next high-impact paper. This leaves little time for engaging more broadly and considering things outside your specific area.

Having generalised wildly about universities and academics, I do think that there is an even more insidious problem; I do think that taking some kind of stand is actually discouraged. It’s certainly very clear in the climate debate. Anyone who speaks out is regarded as some kind of activist, labelled as an environmentalist, and their objectivity is immediately questioned. Yes, objectivity and balance is important for research, but so is passion and enthusiasm. The idea that someone who feels strongly about something shouldn’t speak out because they might lose their ability to do objective research is just a little absurd. In fact, I would argue that it would be better if people did speak out more, because then it would be harder to hide their biases under a veneer of supposed objectivity. I also feel that it would be better if people who were regarded as experts were to speak out more, than if they felt that being experts required them to avoid taking a stand.

So, I’ve managed to do what I normally do, which is to start what is intended to just be a quick post, and write much more than I intended. I was really just trying to highlight the quote, some of which struck a chord. I should make clear that I’m not suggesting that academics should be given some kind of special platform, simply suggesting that it’s unfortunate that people who spend their lives trying to understand the world around them, seem content to stay in their own little bubble, rather than engaging with the broader community. Of course, this is just a gross generalisation and there are many who do, but I do think that specialisation and the commercialisation of the university sector has changed what many regard as their role. I’ve also focused here on academics, but I’m certainly not suggesting that they’re the only people who should be encouraged to speak out; it’s just the environment with which I’m most familiar.

Posted in Climate change, ClimateBall, Global warming, Science, Universities | Tagged , , , , , , | 37 Comments

Ecology and the environment

I was thinking a little more about the Ecomodernist manifesto and I realised that one problem I have is that I’m simply a physicist. I don’t really understand ecology, or how we can look after the environment while also having continued economic growth and while continuing to improve the standard of living of people on the planet. I should clarify that when I say “I don’t really understand” I don’t mean that I don’t think it’s possible; I really just mean that I personally don’t understand how we would go about doing it.

View1I have, however, lived in and seen some remarkable places on this planet. In case it isn’t obvious by now, I’m South African. In fact, I see myself as African and certainly identify with Africa more than with any other region. I was born in Cape Town and spent the first 10 years of my life living on a mountainside overlooking a large bay. My brother and I would bring home snakes that my mother would then let go into the bushes next to our house. I went to stay with a friend whose father was the head game ranger at the local game reserve. They had an injured Lynx in their garden and I remember waking up to find two bat-eared foxes wandering around the bedroom. We could see whales from the veranda of the house where my parents still live.

We moved to Durban – on the east coast – when I was about 10. I saved up to buy a paddleski (a fat surfboard that you sat on, rather than stood on), but when I finally had enough money I ended up buying one that was too small and so got a cheap surfboard from a friend, and took up surfing instead. I still surf, but it’s a damn site harder in the North Sea than in the Indian Ocean, and being closer to 50 than I would like to admit doesn’t help either. Surfing off Durban you’d see dolphins now and again, and a friend on a paddleski once shouted that he could see a fin, but didn’t tell me – till I’d paddled like mad for the beach – that, whatever it was, it was very small.

I used to go shark diving on a reef about 5 miles off the KwaZulu-Natal south coast. When the water was clear, it was amazing to be doing your 5 metre safety stop while watching 10 or 20 sharks circling below you. My wife wouldn’t dive during shark season, but I had great pleasure – during one dive – pointing out the large grey objects just behind the two pretty fish she was admiring. Admittedly, she then ran out of air a good deal faster than was normal, so the dive was somewhat shortened.

As a student we used to go hiking in the mountains and would regularly spend time at one or other of the various game reserves. One of the most memorable was staying in a bush camp; a set of small bedrooms on stilts, a kitchen, and a large veranda overlooking a river; all just in the middle of the bush. You’d spend your early mornings and late afternoons walking, and the rest of the time napping or watching the animals coming down to the river. We tracked lion (the paw prints were first seen around our cars), we had a crocodile rush out of the bushes in front of us on one walk, we sat a few yards away from a white rhino and its calf, and ran away from a black rhino.

Albatross4While doing my PhD I did 3 trips to the Antarctic, including one where I over-wintered. Standing on the helicopter deck watching wandering albatrosses gliding behind the ship is one of my fondest memories. Having Adelie penguins follow you around the bay ice is another. When the old South African base was deemed uninhabitable (being under 20 metres of ice can do that), and the new base wasn’t yet ready, we spent some time on Marion Island; a volcanic, sub-Antarctic island that was mainly used as a weather station, and whose main occupants were many types of petrels, penguins, mice, and wandering albatross chicks sitting on their mud nests.

WandererChickI’ve also lived on the East and West coasts of the USA and now live in Scotland. I’ve had the priviledge to see some of the most amazing places on this planet, and to have had many unforgettable experiences. I might only be a lowly physicist, but I find it hard to believe that the natural world doesn’t have some kind of intrinsic value, as well as being crucial for our own survival. I don’t know how we can develop a future that is good for both us and for the natural environment, but whatever we do, I just hope we don’t stuff it up.

Posted in Climate change, Personal | Tagged , , , , , , , , , | 343 Comments


One of the motivations behind yesterday’s post was the sense that we will start to see people, who might be regarded as contrarians (or mitigation skeptics, as Victor might say), starting to adjust their views to be more consistent with that of those who’ve been arguing for action. I suspect, however, that if they do so, they will not acknowledge the role that they may have played in delaying action, will attempt to portray these ideas as new and their’s, and will probably do so with the goal of controlling the narrative and marginalising those who’ve already been speaking in favour of action.

However, I do think climate change is a serious issue and that there does come a time when you should forget past infractions, and try to start again. A time when we should assume that those with whom we might have disagreed do have good intentions, and that not all that they say is without merit. Forgive and forget, maybe, although that does sound a little trite. With that in mind, I wondered if others had had a chance to have a look at the newly released Ecomodernist manifesto?

There’s a very strong Breakthrough Institute influence and a number of those involved are people who – unfortunately – make me automatically suspicious. On the other hand, the document itself seems at least superficially reasonable. It starts with

In this, we affirm one long-standing environmental ideal, that humanity must shrink its impacts on the environment to make more room for nature, while we reject another, that human societies must harmonize with nature to avoid economic and ecological collapse.

I certainly agree with the first point, maybe less so with the second, but I can see that it is likely true: we probably don’t need to harmonize with nature to avoid economic and ecological collapse. My personal preference would be that we do to try to harmonize with nature as much as is possible, but I can see that it isn’t required so as to avoid economic catastrophe. I’m also assuming that harmonize has a much more specific meaning than shrinking impact.

It also says

There remain, however, serious long-term environmental threats to human well-being, such as anthropogenic climate change, stratospheric ozone depletion, and ocean acidification.

which seems quite reasonable. Furthermore

Nations have also been slowly decarbonizing …. But they have not been doing so at a rate consistent with keeping cumulative carbon emissions low enough to reliably stay below the international target of less than 2 degrees Centigrade of global warming. Significant climate mitigation, therefore, will require that humans rapidly accelerate existing processes of decarbonization.

which, again, seems true. And then

Meaningful climate mitigation is fundamentally a technological challenge. ….. Absent profound technological change there is no credible path to meaningful climate mitigation. While advocates differ in the particular mix of technologies they favor, we are aware of no quantified climate mitigation scenario in which technological change is not responsible for the vast majority of emissions cuts.

which is probably true, but may suggest one issue with what is presented in the manifesto; it has a hint of the pragmatic climate policy that seems to be preferred by organisations like the Breakthrough Insitute. Let’s not focus too much on the science, let’s just be pragmatic and work on technology development, since that is going to be the best route forward anyway. Kind of true, but if you don’t have some kind of stimulus for doing so, how can we optimise our chances of developing suitable technology?

So, I would really like to embrace this kind of endeavour and the document itself seems superficially alright; it seems to say many of the right kind of things. On the other hand, I’m still a little cynical and have a suspicion that this is a manifesto that acknowledges the problems we might face, but that is still really just proposing that we don’t do anything specifically to address them; we simply rely on our inate ingenuity to find solutions that will be ready when we need them. I’m all for technology development and have no doubt that it will play a crucial role in addressing climate change. I would, however, prefer that we actively tried to address it, rather than assuming that we’ll address it in the natural course of our, supposedly automatic, advancement.

Posted in Climate change, Global warming, Science | Tagged , , , , , , , | 85 Comments

Judith Curry’s testimony

I’ve been rather busy the last few days, so haven’t had a chance to post anything. Yesterday, however, Judith Curry gave evidence before the House of Representatives Committee on Science, Space and Technology Hearing on the President’s UN Climate Pledge. You can read Judith’s written evidence. It contains most of the standard “skeptic” talking points; the “pause”, Antartic sea ice, lower climate sensitivity, and then a lot of discussion about climate policy.

Steven Mosher, in a comment on an earlier post, gave his interpretation of Judith’s argument, and finished with

Now in truth you dont even need her views on science to come to a similar conclusion. with regards policy, science dont matter much. what matters is what you can get done. you’all got suckered into thinking that speaking truth to power worked. Sorry no cookie.

The time to act globally on emissions has come and gone. Its been 20 years and you clowns still havent done jack. step aside. you are the problem.

Okay, ignoring that I disagree with a great deal of this (and find some of it remarkably irritating) there is some truth to this view: in some sense science doesn’t matter that much, and what we’ve been doing so far hasn’t been particularly effective. So, maybe it is time to at least compromise and start to accept that there are other ways to proceed and that what we’ve been trying to do hasn’t worked? If, however, there are to be new people who drive this forward, surely we’d want them to be those who at least understand the basic science and who can at least construct a coherent argument.

On that note, I thought I might just highlight an exchange between Judith Curry and Rep Beyers in which he explicitly says

I found myself deeply troubled by Dr. Curry’s written and oral testimony, ….. I found the testimony just full of internally conflicting facts and opinions and in almost total conflict with everything I’ve read in the last 15 years in every journal I could get my hands on.

You can read the comment yourself, but I thought I might just discuss a few of Judith’s responses. For example,

The issue is how much of the change is caused by humans. We don’t know. We don’t know what the 21st century holds. The climate change may be really … unpleasant, and that may happen independently of anything that humans do. My point is that we don’t know how much humans are influencing climate and whether it’s going to dominate in the 21st century. Given that we don’t know this, we are still going to see extreme weather events whether or not humans are influencing the climate.

We don’t know? Really? This may only be true in the sense that we can’t really know anything, but that is a remarkably odd thing for a scientist to say. We may not know, but we’re fairly certain that anthropogenic influences have dominated since 1950 and that it will continue to dominate if we continue to increase our emissions. That Judith failed to even acknowledge this is remarkable. Also, we have plenty of evidence to suggest that our climate has been broadly stable for the last few thousand years. Why would we suddenly expect it to naturally do something unpleasant in the coming century. It might, I guess, but suggesting that it’s as likely as something unpleasant happening due to our influences just seems absurd.

Judith then goes on to say

The climate has been warming since the 1700’s. Okay? Since we came out of the Little Ice Age. We don’t know what’s causing that warming, in the 18’th century, in the 19’th century, it’s not attributed to humans. So there are other things going on in the climate system that have been contributing to a warming over several centuries. We can’t blame all of this on humans. Okay? And we don’t know how all of this is going to play out in the 21’rst century. We just don’t know.

Again with all the we don’t knows. Yes, we might not know but we have a pretty good idea of what caused the Little Ice Age (reduced solar insolation and increased volcanic activity) and it was obviously not attributed to humans. Why is that even worth mentioning? Again, we might not know what will happen in the 21st century, but we have a fairly good idea of what will happen if we continue to increase our emissions.

So, if we’re going to move forward by acknowledging that what we’ve been trying so far has failed and that others should have a stronger voice, why would we do so if some of those others don’t appear to know anything? Given this, I’ll expand a little on my thoughts with regards to Mosher’s point that with regards to policy, science doesn’t much matter. Yes, in some sense I agree with this; let’s stop arguing about science and just get on with deciding on the optimal policies. However, science does inform policy and I fail to see how we can develop sensible policy if we start with the view that we don’t know anything.

Posted in Climate change, Climate sensitivity, ClimateBall, Global warming, IPCC, Judith Curry | Tagged , , , , , , | 187 Comments

Two years

I was reminded by WordPress that today is the second anniversary of me starting this whole blogging lark. In some sense I’m amazed that it’s been that long. In another sense, it seems as though I’ve been doing this for much longer than just two years. I’m a little surprised that I’ve kept it going. I don’t really have good reason for doing so and I think my goal from now on is to focus on it less, and focus more on what is probably more important (anything but this, really :-) ).

I’ve certainly learned a lot in the last two years; about climate science, about science in general, about myself, about society, and about many other things. Some of it’s been good, but some not so good. There are many things I would probably do differently had I known then what I know now (like not start this in the first place, probably :-) ). Some things I wouldn’t change. Someone did comment recently that maybe I should start again, but they didn’t come back and explain what they meant or how I would do so.

One thing that seems pretty clear about the online climate debate is that you’re never forgiven for what are seen as your past mistakes. As much as I may try, I’ll probably still continue to make the same mistakes I’ve made in the past, and probably some new ones too (although these will probably not be what others would regard as the mistakes for which I can never be forgiven). You also never quite get over not achieving what you claimed you wanted to do. Having a tagline Trying – and sometimes failing – to keep the discussion civil means that you get criticised if you ever fail to be as civil as you might hope. That you’re at least trying doesn’t appear to be worth recognising. On that note – and since it’s time for at least some changes – I thought I would change my tagline to something that I think is relevant, and that also reflects my heritage.

Anyway, I wish I could actually say something positive about all of this, but I am rather struggling. I do find the whole endeavour interesting (or else I would just stop) but I don’t think I can say that I regard it particularly positively. If I could be more cynical, I probably would be. The only positive thing that I can think of, is that most of what goes on probably stays in the blogosphere and that the rest of society isn’t quite this absurd. That may not be strictly true, but it’s what keeps me going. Since many regulars seem to appreciate Monty Python, I thought I would finish with something of their’s that nicely puts everything into perspective.

Posted in Climate change, Personal, Satire, Science | Tagged , , , | 104 Comments