Discussion > Let's get real about climate models
Martin A (3:06 PM): I would disagree with you and the "clouds trapping heat myth", as my own observations (yeah, anecdotal, I know…) are that, when there is cloud cover, the night tends to be warmer than when the sky is clear. This is a point that I have made in the past, questioning the effectiveness of CO2 compared with water – the most obvious example being in a desert, where, under clear night skies, the surface temperatures may plummet from over 30°C to close to – or even below – zero. In the more humid environs of, say, Singapore, the nights may be just a few degrees cooler than the days, with the difference being even lower should the skies be overcast. In both scenarios, the amount of CO2 involved is about the same. To me, this indicates that the attention given to CO2 as the principle driver of global warming/climate change/call it what you will is… well, let’s call it misguided.
Radical Rodent
aTTP:
…written by someone who has extensive expertise in this topic.Yes…
…end up being climate change denialists....and is someone with a heavy bias, I’m afraid. Can you be sure the information is genuine, and has not been manipulated to suit the author’s evident prejudice? Well, of course you can – you completely agree with it! As I noted at the time, perhaps you should look before you link.
Radical Rodent
Simon,
I think you misunderstand what I was getting at. I don't care. I expect little else. How you behave is entirely up to you. If you're happy to behave like this, that's fine. It certainly doesn't reflect on me at all.
I haven't misunderstood. How I am is very much a reflection of, or at least a reaction to, how you are. I recognise that I'm probably more reactive than I could be, but why should I hold back? You don't and you liberally troll all the day long. It's cathartic to push back every now and again. Don't know ya, don't wanna.
Simon Hopkinson
For those demanding evidence of damage from climate change present or future, I'd ask you simply to name one single person who can be proved to have died of lung cancer because of smoking.Jan 23, 2016 at 2:52 PM | Unregistered CommenterRaff
It's the same old same old reversion to tobacco arguments. It's like Godwin's Law. We're on page 18 and past 400 comments on a BH thread. Most people still reading have seen the tobacco argument before, and it doesn't wash.
Individual cases are indeed very hard , if not impossible, to prove. Raff, you need to start asking yourself a different class of question. The rest of us have seen your standard lame questions many times before and no advancement is being made.
Simple association is frequently very misleading, and the real world often doesn't afford you the opportunity of the experiment you would like. Thus, the scientist would be taught to ask the question "So if I increase the number of smokers, or the amount they smoke, would I expect (in my model) to see an increase in the incidence of lung cancer?"
And the answer will very probably be "Yes" in a well controlled study. We don't disagree there. And the same researcher will usually already have a mental formulation to the next obvious question which is "But how much of an increase?". They have reasonable models for that, with acknowledged uncertainties.
Now, changing subjects, we ask the question "So if I increase the amount of carbon dioxide in the atmosphere, would I expect (in my model) to see an increase in the atmospheric temperature?" Many skeptics will answer "Yes". The obvious question then follows: "So how much warming does your model predict or project?"
Well....the climate scientists did their predictions and projections, and they were badly wrong. Which strongly suggests they should revisit their models. Yet the so-called climate-community has failed to do so, while surfing the public wave of publicity generated by the worst models. Then some of them claim the frequency of hurricanes will increase, or the Arctic will be ice-free in 2015, and other other events. Which, like the tropospheric hot-spot, failed to happen, even by the IPCC assessments. More model fails.
The list of climate-model fails goes on, and on, and on. It's not a skeptic's job to catalogue the climate model fails. That is the job of a proper scientist before they consider publishing their model results. By their standards yea shall judge them.
Re-quoting you again,
For those demanding evidence of damage from climate change present or future...
There is no evidence of present climate change exceeding historical limits when looking back through even a small part of human history. The 'alarm' is, and always seems to be, in future. And the same people who wrongly predicted catastrophe less than one human lifetime ago are still predicting catastrophe at some point after they are dead or retired.
No sale. When they have a good model I might start to take them seriously. And then they will need to make some predictions that come close enough to correct. And even then they could be lucky, just like some on-the-make financial charlatans will get lucky when the stock market turns in their favour. But, like aTTP with his previous blog attacks on Anthony Watts, they have previous offences to expunge from the record and need to change their behaviour before I consider them worthy of parole.
michael hart
Radical Rodent:
I would disagree with you and the "clouds trapping heat myth", as my own observations (yeah, anecdotal, I know…) are that, when there is cloud cover, the night tends to be warmer than when the sky is clear.
I concur, also anecdotally, so I think we're agreed this is just spitballing. Conversely, when there is cloud cover during the day, the day tends not to get as warm as when the sky is clear. In fact the time-of-day of cloud formation seems to me a significant influence on daily minima/maxima. Are we any good at predicting the timing of cloud formation? I'm not sure we have a grasp on the myriad contributing forces/feedbacks which determine such things.
Simon Hopkinson
Michael Hart: it is a very good point, though – there really is very little evidence supporting the “smoking causes cancer” meme. The only undeniable result of the Doll and Hill doctors study that this is based on is that smokers tend to die younger than non-smokers. When it started, it was found that about 90% of lung cancer sufferers were smokers; as about 90% of the population were smokers, this should not be surprising. Now that less than 40% of the population are smokers, what do you think is the proportion of lung cancer sufferers who are smokers is? Logically, if smoking was the cause of cancer, one would assume that, if not 90%, it should be not too far off that figure; however, the reality is that smokers make up less than 40% of lung cancer sufferers. There really is no obvious connection.
(Interest to declare: I do not smoke. I have never smoked. I do not understand why anyone would want to smoke. But then, neither do I understand why anyone would want to chase a ball around a field, bat a ball around a room or leap off great heights with a sheet strapped to your back or an elastic rope tied to your ankles – but, so long as you do not inconvenience me too severely, I will not stop you doing what you seem to enjoy.)
Radical Rodent
I would disagree with you and the "clouds trapping heat myth", as my own observations (yeah, anecdotal, I know…) are that, when there is cloud cover, the night tends to be warmer than when the sky is clear.
Jan 23, 2016 at 4:24 PM | Registered CommenterRadical Rodent
RR - I agree that it feels warmer under clouds at night. I said previously 'while, at night in winter, it can seem colder with a clear sky than with a cloudy sky, this does not necessarily mean that the clouds are "trapping heat" '
Clouds absorb and radiate IR effectively. I have only to point my IR temperature measurer at a cloud at night and it reads far warmer than if I point it at the open sky. So no question that there is plenty of IR energy shuttling back and forward between gound and the lower side of clouds. And no question that, with convection, and with transport of water vapour containing latent heat, energy is reaching cloud height by other means also.
But what counts in terms of global warming is the temperature of the layer of the atmosphere from which radiation to space finally takes place, not what goes on between ground level and the underside of clouds.
Martin A
Simon,
How I am is very much a reflection of, or at least a reaction to, how you are.
Come on, don't pass the buck. The only person responsible for your behaviour is yourself.
Radical,
Can you be sure the information is genuine, and has not been manipulated to suit the author’s evident prejudice? Well, of course you can – you completely agree with it!
Whether I agree with it is somewhat irrelevant. I was suggesting that if you (or Martin) disagree with it, you could simply explain why, ideally by actually presenting an argument, not by simply suggesting that they must be biased because they used the word "denialist".
Michael,
But, like aTTP with his previous blog attacks on Anthony Watts, they have previous offences to expunge from the record and need to change their behaviour before I consider them worthy of parole.
I don't hugely care what you think, but I think everything I have written still exists. Are you going to be one of those who claims I've attacked "Anthony Watts" without actually illustrating how or where. I am, of course, assuming that criticising what someone has said/written doesn't really qualify as an attack. I may of course be wrong in this assumption, as it seems to me that there are many who regard mild criticism of those with whom they agree as an inexcusable attack.
...and Then There's Physics
Simon: that is a point that I missed out – clouds can inhibit the incoming radiation during the day in a similar way they affect the outgoing radiation. However, one small correction: “… myriad contributing forces/feedbacks factors which determine such things.” There, fixed it for you.
Radical Rodent
Thanks RR ;)
Simon Hopkinson
ATTP - No I really did want to know what you meant by "boundary conditions". Previously you had said
However, it is also a boundary value problem and the general view is that the boundary values start to dominate when it comes to the overall average climate state.
and
The issue is whether or not it is dominated by the initial conditions or the boundary conditions.
It's clear that you (and the article you pointed to and, perhaps, climate science in general) use the phrases "boundary conditions" and "boundary value problem" to mean a thing quite different from their normal meanings in the theory of differential/partial differential equations.
I think I now understand what you were saying - that the conditions at t = 0 don't much affect the solution at t = (very big), where external factors dominate what happens.
Martin A
[pSnip- Response to snipped comment.]
Entropic man
Martin,
I assume that you're thinking of the standard hydro conditions, such as density, thermal energy, velocity. The underlying equations in a climate model are the navier-stokes equations and so such boundary conditions do exist. However, what ultimately constrains the energy flows are the energy fluxes on the boudary, and these are largely set by things like the incoming solar flux and albedo.
I think I now understand what you were saying - that the conditions at t = 0 don't much affect the solution at t = (very big), where external factors dominate what happens.
Essentially, yes. The average climate state is more determined by the conditions that influence/set the energy fluxes at the boundary, than by the initial conditions.
...and Then There's Physics
Martin,
Actually, did you bother to read your own link? I'll even copy the relevant bit belowHigh clouds are much colder than low clouds and the surface. They radiate less energy to space than low clouds do. The high clouds in this image are radiating significantly less thermal energy than anything else in the image. Because high clouds absorb energy so efficiently, they have the potential to raise global temperatures. In a world with high clouds, much of the energy that would otherwise escape to space is captured in the atmosphere. High clouds make the world a warmer place. If more high clouds were to form, more heat energy radiating from the surface and lower atmosphere toward space would be trapped in the atmosphere, and Earth’s average surface temperature would climb.
Jan 23, 2016 at 3:35 PM | Unregistered Commenter...and Then There's Physics
Yes, I did read it. And I was deeply unimpressed.
Some of it was trivially true:
High clouds are much colder than low clouds and the surface. They radiate less energy to space than low clouds do. The high clouds in this image are radiating significantly less thermal energy than anything else in the image.
Hard to be sure what was the ratio of area covered by low cloud to the area covered by high cloud: 5:1? 10:1?
The rest seemed to be a load of "if", "have the potential to", "would be", "would climb" - attempting to sound authoritative and to give the impression that high clouds are known to be a key player in the forthcoming climate catastrophe.
But very last last paragraph showed a sudden outbreak of frankness. What gives me the idea that it was tacked on at the last minute?
Clouds impact temperatures in other ways as well. They also reflect energy, shading and cooling the Earth. On balance, scientists aren’t entirely sure what effect clouds will have on global warming. Most climate models predict that clouds will amplify global warming slightly. Some observations of clouds support model predictions, but direct observational evidence is still limited. Clouds remain the biggest source of uncertainty (...) in predicting how much global temperatures will change.
Translation: Climate science is buggered if it knows what are the effects of clouds on climate and on climate change. Climate models are programmed on the hypothesis that clouds increase warming but observational evidence on this is unconvincing.
Martin A
Hamster, Simple Simon
The best source I know on the impact of climate change is here.
I recommend you download the Summary for Policymakers.
Entropic man
[snip response to snipped commment.]
Simon Hopkinson
EM, I read the SPM cover to cover. I missed the bit where there is anything of the sort. Can you give me a page number and paragraph please. Or just quote it directly perhaps? Otherwise you just look like you're deflecting and you can't actually identify anything.
Simon Hopkinson
Michael, I have no idea from any personal experience whether models have been useful in climate research or whether they are able to project future climate states. I suspect the same can be said for most of those commenting here. So what do I do? Ignoring the agnostic position, which is a bit uninteresting, I seem to be faced with two positions: one is from those who work on models and organizations like the IPCC and suggests that models are useful, have provided insights into the climate, have made various correct predictions and are the best avenue we have for understanding whether increased CO2 is a threat; the other is from people like you and others here who who would prefer there to be no models, or at least none that had any contact with the real world in which decisions must be made. That the latter position presents nothing to take the place of models in understanding CO2 is odd unless its holders have already established beyond doubt that increasing CO2 is no problem. Yet they have no obvious way to do so. I might listen to someone who questioned models but had a reasonable and pragmatic view of what models can and cannot achieve. But such people would probably be real skeptics, not "skeptics" and would be unlikely to comment here.
Whoever asked about looming climate crises, ecological disruption in the oceans seems likely. As always, it will be difficult to separate climate effects from over-fishing, so I don't expect "skeptics" will accepts whatever happens.
Sandy, can you explain Homewood's post? The sonde data show a clear upward trend at all altitudes except 40000ft which doesn't really support the satellite data. I commented to that effect over there, but it didn't appear. You obviously thought that it supported the satellite view although maybe since then you've searched out your real skeptic hat, given it a brush and taken a skeptical look - and now you have doubts. If not, can you explain?
Raff
Martin A
Read this
Entropic man
EM, you can't convince someone of the presence of god by quoting the bible at them. That's just not.. no! Why don't you get it? LOL
Simon Hopkinson
Simon Hopkinson
If you have read the AR5 Summary for Policymakers cover to cover and still do not believe that climate change is a problem, nothing I or anyone else says is going to change your beliefs.
Entropic man
Martin A
Read this
Jan 23, 2016 at 9:20 PM | Unregistered CommenterEntropic man
Why? What's innit?
Martin A
Well dodged, EM. You have answered the question without actually answering it, merely pointing us to a report full of airy-fairy ifs, buts and maybes, without any categorical point to be made, just worded to generate the fear, or maintain it with those who are already infected. There are so many things going on in this great, wide world that almost every one of the disasters the IPCC warn us of are likely to happen – many have already happened many times in times past, so it is a good prospect that they will happen again. Even the definition of climate change indicates that they really have no way of actually verifying that any change has occurred, certainly in the time-span we refer to:
Climate change: Climate change refers to a change in the state of the climate that can be identified (e.g., by using statistical tests) by changes in the mean and/or the variability of its properties, and that exists for an extended period, typically decades or longer.Note that it does stipulate changes “that persist for an extended period, typically decades or longer”, yet it later states that volcanic eruptions can cause climate change. While I know that there have been eruptions that have affected the global climates for a few years (Krakatoa, for example), I know of none that have existed for decades or more. In other words, within two sentences, they contradict themselves. However, let’s ignore that: so, what change in the climate (any climate, and not even a change that has been shown to be human-induced) has yet been identified?
Radical Rodent
Well, I read it [edit: the SPM] and it doesn't contain any pointers to any evidence which is compelling. By compelling, I DO mean based on observational evidence rather than computer models. Literally none of it which is *alarming* that I can find (and I really have looked) is based on actual science. But I am, we are, open to being shown some. The tenets of global warming are that it is a) happening, b) man-made, c) dangerous. In order to make a compelling case and give impetus, all 3 conditions must be met.
Simon Hopkinson
Simon,
I think you misunderstand what I was getting at. I don't care. I expect little else. How you behave is entirely up to you. If you're happy to behave like this, that's fine. It certainly doesn't reflect on me at all.