Global Warming

[parmenides3]

I've just written a detailed reply to your post, P3, only to find that my connection got dropped and I lost the whole thing... Including interruptions it's taken me nearly an hour, so I'm a little bummed by that! I shall try to rewrite what I said in a while (must remember to copy and paste my messages into Word so it doesn't happen again!).

However, the gist of it was that I find the AGW debate far too specific considering that it is based upon models with many assumptions and large gaps in the data - the Earth is a vast and complicated chaotic system (that's chaotic in the mathematical sense, not some arbitrary sense of messiness!). Even the simplest chaotic systems are difficult, if not impossible, to predict. So how can definitive predicitons be made from our current models?

Also, not all "skeptic" counter-claims are without merit or validity, and it is important to approach all evidence with an open mind. That's what I'm doing: being as open-minded as possible, and with that open mind I have not been wholly convinced by either side of the argument as yet. I don't regard myself as being ignorant, nor of having my head in the sand - I have an inquiring mind and my inquiries are far from over!

I look forward to your opinions on the Kyoto treaty - it's so refreshing to have an intelligent debate that requires thought and research rather than, as I have seen on so many chat boards, a numb mud-slinging contest.

Ciao

C-Bob

Don't you just hate it when that happens! No matter. In the meantime, there are a lot of points mixed up in your comment which need to be separated out. You'll need to answer a couple of questions, I'm afraid, before it's clear to me what your concerns are. Starting from the top: what do you mean by far too specific? Are you referring to the focus on CO2, or on Anthropogenic influence, or something else? Or are you saying that you find it hard to believe the climate models' suggested futures, given gaps in the information?

Connected, but distinct, is the concept of (mathematical) chaos. The weather system is chaotic, in the sense that no single event in a large chain of events which form an analysis or a forecast can be predicted with certaintly, and any event can become more or less probable with any change of the predicted preceding conditions, but the climate is not quite the same. It is chaotic only in the sense that a number of potential events are purely non-predictable (like large volcanic eruptions), but climatology is the study of long-term patterns and, as such, has a degree of predictability about it (the 'pattern' element) You are right in saying that 'definitive' predictions cannot be made from the models, but nobody (in the science community. at least), is claiming that their output is definitive; what they present is a 'most likely outcome'. Some of the components of the models are, because of the physics, rather than the modelling, quite predictable. For example, the relationship between the amount of CO2 in the atmosphere and the mean global temperature (which is moderated by aerosol and other effects), is well understood.

I knew someone would think I was implying that all skeptic claims are without merit; this was not my intention. Perhaps we should distinguish between 'skeptic' claims and challenges to the current hypotheses. The latter are important and need to be addressed. The former tend to be reiterations of the same old mumbo-jumbo and are very rarely of merit. Though it can be difficult, sometimes, to distinguish between the two; as you say, an open mind is generally best.

When you mention 'either side' of the argument, which argument are you referring to? The argument about whether we are warming the planet by burning fossil fuels, the argument that we need to cut emissions drastically or face difficulties in the future, or some other argument?

When I started looking at climate change in detail in July of this year, I went through several stages of learning. First, I found out that I knew a lot less than I thought; then I found out that I had made assumptions about certain things which weren't necessarily justifiable; then I learned that, if I wanted to sort the wheat from the chaff, I'd have to go to the source material. Later, I worked out that the internet is a fantastic resource, but also a frustrating one, but that most of the key material is available. I have learned that many people have similar doubts to those I had after a month or two of research. So where have I got to, if anywhere?

These are some things I now feel I can be confident in saying:

1. I know the basic principles of climate change, GW and AGW, and understand the subject matter better than I did.

2. I know (quite well) a large number of 'skeptic' and 'denialist' counter-claims and their refutations, and can distinguish between these and genuinely significant challenges to the current state of climate science, of which there are a number.

3. I know which websites, authors and organisations I cannot trust, and some which, to me, are reliable and honest about their content. I also have a decent list of favourites where I can rely on finding source material or commentary if I come across something new or unfamiliar.

4. I know quite a lot about the climate science debate; that is, the rhetoric of the subject, rather than the science.

5. I know that climate science is imprecise in some ways, but, in general, has a sound foundation and a large number of excellent and dedicated practioners.

6. I know that I only know a tiny fraction of what is a huge subject, and that I will never, in a zillion years, know it all.

7. I know my own opinion about the subject(s), which is similar to some people's, but unique in its own way.

8. I know I get boring on the subject; time to stop.

I'm still thinking about Kyoto. My political opinions are less well-formed than my climatological ones. I wish you pleasure in your voyage of discovery. Make use of the links people post; this is often where I have learned the most, through discovery, pursuit and thought, to a better understanding.

:)P (sorry to be so dull).

[Admiral_Bobski]

Don't you just hate it when that happens! No matter. In the meantime, there are a lot of points mixed up in your comment which need to be separated out. You'll need to answer a couple of questions, I'm afraid, before it's clear to me what your concerns are. Starting from the top: what do you mean by far too specific? Are you referring to the focus on CO2, or on Anthropogenic influence, or something else? Or are you saying that you find it hard to believe the climate models' suggested futures, given gaps in the information?

Okay, Let me start from the top! By "far too specific", I mean the predictions that are commonly presented (often by the media, admittedly) that temperatures in such-and-such a year will be x degrees higher. The predictions that the "hole" in the ozone layer will be y percent larger, that sea levels will rise by z metres and so on. These statistic, often presented with little or no (mathematical) tolerance, are based on models which are necessarily lacking in detailed information. It would be more honest to state that temperatures are likely to continue to rise, that the ozone "hole" is probably going to grow and that sea levels may rise, based on current conditions and data. (These statements are a little vague, I admit, but are the opposite end of the spectrum from the quoted predictions.) It's not the focus on specific elements of GW that I'm complaining about but rather the "definitive" results that are presented.

Connected, but distinct, is the concept of (mathematical) chaos. The weather system is chaotic, in the sense that no single event in a large chain of events which form an analysis or a forecast can be predicted with certaintly, and any event can become more or less probable with any change of the predicted preceding conditions, but the climate is not quite the same. It is chaotic only in the sense that a number of potential events are purely non-predictable (like large volcanic eruptions), but climatology is the study of long-term patterns and, as such, has a degree of predictability about it (the 'pattern' element) You are right in saying that 'definitive' predictions cannot be made from the models, but nobody (in the science community. at least), is claiming that their output is definitive; what they present is a 'most likely outcome'. Some of the components of the models are, because of the physics, rather than the modelling, quite predictable. For example, the relationship between the amount of CO2 in the atmosphere and the mean global temperature (which is moderated by aerosol and other effects), is well understood.

No, climate is inherently chaotic - events such as volcanic eruptions are unpredictable, true, but even if that kind of event never happened then the climate would still be inherently unpredictable, the reason being that we can never know every detail with sufficient accuracy to determine long-term specifics. Thanks to Jurassic Park most people have heard of the "Butterfly Effect": a butterfly flaps its wings in Tokyo and in New York you get rain instead of sunshine. This is an exaggerated example, but it gives the general feel for what happens - a small perturbation, over a large distance and a long time period, can cause a large divergence from expectations. Small-scale events (much smaller than volcanic eruptions) can, in the long run, cause surprisingly large-scale effects. It's true that long-term patterns are, on the surface, helpful, but a long-term pattern can be suddenly thrown out of kilter by a small disruption (given a sufficient time span).

The relationship between CO2 in the atmosphere and the mean global temperature is not that well understood, or else there would be no debate about which precedes the other. It is a fact that CO2 is more soluble in cold water than warm water, therefore if the water warms then it will release CO2 (and hence, in this case, temperature increase precedes CO2 increase). I will investigate this CO2/temperature correlation some more and let you know what I find.

I knew someone would think I was implying that all skeptic claims are without merit; this was not my intention. Perhaps we should distinguish between 'skeptic' claims and challenges to the current hypotheses. The latter are important and need to be addressed. The former tend to be reiterations of the same old mumbo-jumbo and are very rarely of merit. Though it can be difficult, sometimes, to distinguish between the two; as you say, an open mind is generally best.

I apologise for insinuating that you dismissed all skeptic claims - what I intended to suggest was that "skeptic" was not a dirty word and that, despite there being a fair amount of dismissive rubbish around, many skeptics present rational, intelligent objections. Someone who "challenges the current hypothesis" is, by definition, skeptical of that hypothesis and so can fairly be described as a "skeptic" without any suggestion of their being foolishly dismissive, deluded or misinformed.

When you mention 'either side' of the argument, which argument are you referring to? The argument about whether we are warming the planet by burning fossil fuels, the argument that we need to cut emissions drastically or face difficulties in the future, or some other argument?

The argument to which I refer is the debate concerning Anthropogenic Global Warming (I'm using "argument" as a synonym for "debate", which is valid although my choice of word is not a conscious decision).

When I started looking at climate change in detail in July of this year, I went through several stages of learning.

I've been reading about climate change for a year or more - not deeply, I'll grant you, but generally keeping abreast of current thoughts and objections...I don't claim to know more than anyone else, and I'm sure I'm missing many, many details and whole areas of the debate. But what I have read and heard over that time has failed to sway me one way or the other. It is, indeed, extremely difficult at times to sort the chaff from the grain - you think you've found a great article, only to find that the guy who wrote it has been in and out of mental hospitals for twelve years and secretly tries to teach goats to tap-dance. Then you read a totally loony paper and it's written by one of the most highly-regarded scientists in the known universe. That kind of thing. But, as ever, I keep an open mind and see who I can trust and who I can't. I'd be very interested to see your list of trusted resources - it might save me a lot of time sorting through the vast grey areas on the internet!

I'm still thinking about Kyoto. My political opinions are less well-formed than my climatological ones.

The political implications are, I feel, the main reason for the support of Kyoto. I think the intended "benefits" of agreeing to Kyoto are narrow-minded and, when looking at the big picture, largely inconsequential. Don't worry about the politics; what do you think about its scientific principles?!

For now I shall continue looking at the latest research and one day, maybe, I'll be able to choose which side of the fence to fall on!

:)P (sorry to be so dull).

No, no - not, dull but thorough! I appreciate that

Keep up the debate - it's always a pleasure

C-Bob

[Dawlish]

Nice reply Cap'n. When you investigate CO2, look, as well, at increasing partial pressure, as the concentration of the gas increases. It may offset the release from the oceans' warming.

Are you actually bang on the fence, Cap'n? ie would you propose that C02 has an equal chance of being the main cause as it has of not being the main cause? I always like to use odds in these circumstances, it allows a much clearer picture of preference, or belief, to be painted, whilst allowing the proposer to show that he/she has an open mind still (that "1" in the odds signifies that one recognises that what one is proposing has a measure of doubt).

I go 1/6 C02 being the main cause, 7/1 it is natural cycles, 12/1 it is changes in Solar output, and 20/1 the field. At the start of this year, I was saying 1/4 C02, which shows how my thinking has changed, as I've learned more.

Paul

Edited November 11, 2006 by Dawlish

[Admiral_Bobski]

Nice reply Cap'n. When you investigate CO2, look, as well, at increasing partial pressure, as the concentration of the gas increases. It may offset the release from the oceans' warming.

Are you actually bang on the fence, Cap'n? ie would you propose that C02 has an equal chance of being the main cause as it has of not being the main cause? I always like to use odds in these circumstances, it allows a much clearer picture of preference, or belief, to be painted, whilst allowing the proposer to show that he/she has an open mind still (that "1" in the odds signifies that one recognises that what one is proposing has a measure of doubt).

I go 1/6 C02 being the main cause, 7/1 it is natural cycles, 12/1 it is changes in Solar output, and 20/1 the field. At the start of this year, I was saying 1/4 C02, which shows how my thinking has changed, as I've learned more.

Paul

Thanks DawliDoh a dumb swear filter got the better of me (Or may I call you Paul?!) I'll check out the partial pressure issue, too, as you suggest. As for The Fence, I mean I am disinclined from falling either way at the moment with regards the entire debate - personally I think that CO2 is less of a cause than is made out, largely due to the uncertainties involved in determining its rate of absorption and emission from various sinks (oceans, rocks, plantlife and so forth). This is why I am particularly interested in determining the answer to the "which came first" question. If CO2 increases temperature and temperature increases emission of CO2 then why do we have an atmosphere composed of anything other than CO2 and, more to the point, why is CO2 such a (relatively) tiny proportion of the atmosphere? Why aren't temperatures stupidly higher than they are, as this CO2/temperature feedback loop would have been operating for millions of years...? Of all the separate issues in the (A)GW debate, the CO2/temperature issue is one of the thornier ones, I feel.

However, if it is ever proved beyond a shadow of a doubt that CO2 has a negligible effect on GW (I'm not suggesting it does, but - hypothetically - if it did), I would be inclined towards the "Skeptic" side. That's not to say I would be on the skeptic side, as there is far more to the debate than simply the CO2 issue. But it is an issue I'd like a definitive answer to!

As for odds...I'm not good at odds. Never been a gambling man, myself, so wouldn't know where to begin! I shall, however continue to keep my mind open, to the best of my ability

Ciao for now!

C-Bob

[Devonian]

No, climate is inherently chaotic - events such as volcanic eruptions are unpredictable, true, but even if that kind of event never happened then the climate would still be inherently unpredictable, the reason being that we can never know every detail with sufficient accuracy to determine long-term specifics.

C-Bob

This is a point that causes much disagreement, but I think indicates which side of the fence you really are

I can't see that climate is inherently chaotic, it's simply too predictable - yes, predictable. If it were truly chaotic the March next year might have a CET of 20C - it WILL NOT.

This choas thing does seem to be a divide. Many AGW sceptcs claim climate is truly chaotic, I've not come across a climatologist/warmer who thinks it truly is. This is a divide and know to which side I fall

Edited November 11, 2006 by Devonian

[parmenides3]

This is one of the more interesting threads on 'Chaos and climate' which I have read recently: http://www.realclimate.org/index.php?p=204 . What makes it especially interesting are some of the comments following the article, which pursue the argument further still. It is not easy reading, but worth the effort. Annan and Connolley, the authors, are highly respected scientists, as is Pielke, who weighs in on the thread. It is an argument why climate can be predictable, but also raises the same questions that you do, in the sense that some of the correspondents dispute the argument.

No time to respond fully to your earlier post; I'll come back to it later.

:)P

[Admiral_Bobski]

This is a point that causes much disagreement, but I think indicates which side of the fence you really are

I can't see that climate is inherently chaotic, it's simply too predictable - yes, predictable. If it were truly chaotic the March next year might have a CET of 20C - it WILL NOT.

This choas thing does seem to be a divide. Many AGW sceptcs claim climate is truly chaotic, I've not come across a climatologist/warmer who thinks it truly is. This is a divide and know to which side I fall

But air currents follow chaotic progressions - a simple example is when smoke curls up from the end of a cigarette. Try to predict the exact pattern the smoke will be in after ten or fifteen seconds and you'd be at a bit of a loss - give a broad brush-stroke idea of the pattern and you could say that the smoke will rise, spread out and disperse. You wouldn't conclude that the smoke would eventually envelope the sun! The broad brush-stroke idea would be absolutely correct (most of the time, but there is always a teeny tiny probability that the smoke might all clump together - such is the nature of chaos!), but distinctly lacking in any fine detail.

Similarly, climate models can give an idea for basic, straightforward trends, but can't give definitive small-scale predictions. These models wouldn't conclude a 20C CET next March for the same reasons you wouldn't conclude the smoke would envelope the sun - the models won't allow it. Chaos does allow a degree of predictability, but only in broad brush-strokes.

This doesn't show "which side of the fence I'm on" so much as explains why I'm not on the GW side of the fence. Yet.

I'm sure there must be some climatologists who accept the chaotic nature of the atmosphere. I shall have to see if I can find some!

And, to P3, thanks for the link - I've got the kids shipped off to bed now, so I'll have a read through and see what it says!

C-Bob

[Admiral_Bobski]

Whew! That was quite a read, but I got through it all! It was, as you say P3, a very interesting debate but left me none the wiser, really. Some very good points on both side of the argument of whether or not "climate" by definition is chaotic. I did pick up on a few points, which I hope you'll forgive me for outlining below.

(Please bear in mind that, although I am "sitting on the fence" vis a vis AGW, I do believe that the climate is chaotic, and therefore my points show some obvious bias - however I do see where their concept of climate being non-chaotic as they have defined it comes from.)

First off, a quote from the initial article:

At time t=0, the parameter "r" (which relates to an idealised thermal forcing) is changed from 26 to 28. When viewed in close-up detail, the trajectory looks qualitatively similar before and after the change, but in fact the long-term statistics such as the mean value of z, and its 95% range, are changed. In this simple model, the steady pertubation changes the climate in a highly linear manner - increasing r again to 30 would add the same change on top of that shown for 26 to 28, and r=27 would sit half-way between the cases shown.

Interesting that this wasn't mentioned in the responses, but it occurs to me that this (simplified, by their own admission) example assumes that the "Ideal Thermal Forcing" is not, in and of itself, inherently chaotic, the forcing being determined by various, potentially chaotic, factors. Perhaps this is what they mean by "Ideal", but it seems that this example is too simple to explain away chaos in the climate system.

Next, William says, in one of his responses, that "Everyone studies climate as a complex non-linear system. Few however expect chaotic behaviour from it."

How can you study climate as a complex non-linear system but not expect chaotic behaviour from it? Chaos is based on complex non-linear systems!

Back to the article, the authors define "Climate" as "the statistics of weather, averaged over suitable time and perhaps space scales". This seems a bit of a vague definition to me. This definition is challenged by Roger Pielke, who states that "the more appropriate scientific definition of climate is that it is a system involving the oceans, land, atmosphere and continental ice sheets with interfacial fluxes between these components, as we concluded in the 2005 National Research Council report". William responds to this by saying "you appear to have your own, curious definition. You're welcome to use your own definitions, for your own purposes; but if you redefine words in that way you can expect to have confusing conversations. We're using the standard definition of climate. See, for example, the IPCC glossary "

I don't see how Pielke's definition of "Climate" is, in any way, "curious". It seems like an exact definition to me, which is surely what is needed when making a precise global model? They then argue the IPCC definition, and the difference the IPCC means between "Climate" and "Climate Systems". But surely the definition of "Climate" should cover everything that the definition of "Climate Systems" covers, since the climate systems determine the climate at any point in time?

As a quick aside, I particularly liked this post:

"It is of course hard to form a view of the likely rate of world economic growth over the next hundred years; but it is striking that all the IPCC scenarios incorporate a heartwarmingly rapid rate of growth in the developing world, so that by the end of the century income per head in the developing world is well above what it is in the rich world today. This may happen - I hope it does - but it is clear that the IPCC scenarios do not capture the true range of realistically possible outcomes..."

It points out a potential inaccuracy in the model (although that inaccuracy can be justified if you are specifically looking for a worst case scenario), but the main reason I liked it was because of the use of the word "heartwarmingly".

Back to the main argument, though... A reply later on said: "Re Butterflies and climate: If one took the two meteorlogies(?) at 90 days and developed them forward [in climate model steps] to 50+ years hence. Are you certain that these two worlds would then have near-identical climate statistics?" to which William replied "Yes". Well, it kind of depends on what the guy meant. Certainly, if you took two climate setups 90 days apart (which, I think is what he means?!), the later one derived from the first, and ran them both to the same point, using the same model and the exact same data, then they would end up with the same result, since you would be running precisely the same experiment twice in a row. However, if you took two setups 90 days apart, one derived from the other and allowed a tolerance of, say, +/-0.5% in the initial data, then there would be a divergence. This post wasn't helped by ambiguity on behalf of the poster, but the answer seemed a little blunt considering the uncertainty of the question.

Still later on...

"Re: #45, "To Stefan: The ability to construct simple non-chaotic phenomenological models that "explain" D-O events or Milankovich cycle doesn't prove that the events are not chaotic in their nature." to which this was the reply:

"Nor does it prove that they are chaotic in nature, either. The evidence points in the direction that they are not chaotic, so unless anyone can prove they are chaotic, most of the scientific community (i.e. the IPCC, et al.) are of the opinion that they are not chaotic, but are generated by predictable periodic shifts (such as variation of axial tilt or distance from the sun)."

The authors of the original paper won't "prove" that the system is non-chaotic, citing only that "evidence point to" the fact, but they demand proof that it is chaotic. Isn't that a bit of a double-standard? They offer no suggestion as to what this "evidence" is, since various points have been raised earlier that suggest that it must be chaotic.

My final quote (you'll be pleased to hear!) is this reply, near the end of the discussion:

"It is known that the ocean is a turbulent chaotic system, atmospheric models....have also chaotic behaviors in certain areas of parameters. Therefore, it is a given that the whole Earth system is a coupled set of chaotic subsystems, which makes it a chaotic by definition."

I don't think they responded to this comment, but it seems valid enough to me.

Anyway, sorry to ramble on (again!) and, as I say, I know this is a very biased overview of the discussion, but I think it is important to raise the criticisms against the article. The article itself, for those who haven't read it, is not too long (it's the replies that take the time to read!), and is not complicated. I highly recommend reading through it to get a feel for the argument.

Great link, P3 - keep 'em coming!

Toodle-pip!

C-Bob

[parmenides3]

Morning, Cap'n.

Rather than try to respond to everything, (we are in danger of filling pages at a time), I'll just make a couple of points. Before that, though, if anyone wants to look at some of the background material referred to in the RC discussion: http://www.nap.edu/openbook/0309095069/html . is a long but important paper which discusses many of the points raised in your earlier posts, as well as the main problem. The main document is 50-odd pages long, but the executive summary or conclusions give the main points clearly. The other is: http://blue.atmos.colostate.edu/publications/pdf/R-210.pdf .

I know it's cutting corners, but what the debate seems to boil down to are one or two important principles. Annan and Connolley (& the majority of the CS community) operate on the assumption that climate is a boundary state problem. Pielke and others argue that it is an initial value problem. As this is at the limits of my mathematical knowledge, I can't really argue either way, but it seems that one can be constrained and the other cannot. Annan argues that, as climate models based on physical principles reproduce response to seasonal and geographical variables, this is evidence (not all of it, & not proof) that they do, broadly, capture the essential elements of the climate system. He allows that these are 'broad brush-strokes' and that they are not ideal, but contends that this is sufficient to justify the community's confidence that the models are pointing us in the right direction. He also makes the point, which seems to be relevant, that 'weather is ruled by stochastic fluctuations, climate is not...', which would also suggest a reason why climate can, in principle, be predictable.

Pielke's argument is not really that the others have it wrong, per se, he is concerned that they are not justified in presenting the models' findings with confidence to policymakers as a grounds for policy and planning, and that, therefore, policies based on the model findings may not be well-founded, or may be ineffective.

All of this takes us to what seems to me to be a central issue (perhaps the central issue) of this debate; do the climate models work? As you say, there is supporting evidence that they do, but also an argument that, as a matter of principle, they cannot. Strangely, I am reminded of the case of the bumble bee and the principles of flight; it shouldn't be able to, but it can. Perhaps this is the case for the climate models, perhaps, more simply, the models are, more or less, an effective description of the large-scale elements of the climate and their interactions.

Off shopping: more later.

:)P

[Devonian]

Morning, Cap'n.

...

Off shopping: more later.

:)P

Good post, nicely explained.

There are millions/billions of butterflies in the world. Climate seem to go on unaffect by their flapping wings ...

Edited

Edited November 12, 2006 by Devonian

[Dawlish]

Whew!

Great link, P3 - keep 'em coming!

Toodle-pip!

C-Bob

Tha article hound at his best! I like that realclimate site, it teaches you and make you think and although the comments following the article, take some time to plough through, there's a lot of commonsense in the opposing views. Perhaps the one which I agree with the most was this combination of nice hunour and knowledgeable comment:

"........I tend to be more interested in the really big patterns, like the natural greenhouse effect keeping us warmer & adding to it likely increases that warmth. Past mass extinctions caused by runaway GW (then, obviously, triggered by a convergence of natural events), resulting in few left to breathe out CO2 (among other constraints), leading to stabilization and retreat back to a climate more hospitable to a wide range of biota. See: http://news.nationalgeographic.com/news/20...18_fossils.html

These make so much sense & are so dangerous in their implications, that the burden of proof should be on the contrarians or skeptics to prove these things are not happening. And even if they do, we still have many many other reasons, aside from GW, to reduce our actions that increase GHGs. So, to the extent that we're smart and able, let's ease up on the GHG trigger, or we might be shooting our own descendents.

But I do appreciate the meticulous ongoing work to understand in excruciating detail and minutia just how we are harming ourselves".

Comment by Lynn Vincentnathan

With the bulk of scientific opinion favouring a continuation of the warming trend and the bulk of scientific opinion favouring CO2 as the main cause, I do think it is up to the sceptics (I hate that "k" in sceptics!!) to prove it is otherwise.

Paul

Devonian - I agree with you entirely. The whole debate has been good and it will continue; just a note: no need to quote the whole article for a one line comment. I always cut it down to what I am commenting in, or just add a general reply, instead of replying to the whole article :lol:

Hope the anniversary went well, Cap'n.

Edited November 12, 2006 by Dawlish

[Gray-Wolf]

There are millions/billions of butterflies in the world. Climate seem to go on unaffect by their flapping wings ...

...then maybe the 'loss' of a significant proportion of the flapping (due to GW/human environmental destruction) will lead to the upsetting of this finely balenced system as their normal input is lessened over time? (don't forget the propulsion of sea critters is now held to be a major input of oceanic mixing!!!)

[Admiral_Bobski]

(I hate that "k" in sceptics!!)

Yes, that 'k' does look kind of ugly, doesn't it?! It can be spelled with a 'k' or a 'c' but I prefer the 'k' because otherwise I irrationally read it as "septic", which is even more unpleasant!

Hope the anniversary went well, Cap'n.

Thanks, Dawlish - the anniversary was very pleasant, thanks. Nothing too spectacular, but a nice big Pizza Hut and and Breakfast at Tiffany's make for a lovely evening!

In future I shall try and keep my posts shorter - I do tend to get a bit carried away. My main question is not "is GW actually occurring" so much as "why does GW seem to be occurring?" The CO2 argument doesn't sit well with me, for reasons I find difficult to pinpoint - I find myself with a lot of questions about other aspects of GW. The chaos theory debate is a related, but separate, issue. The chaotic nature (or not) of climate is an important issue, but even if it is non-chaotic, it still begs the question of whether or not the models are right. (If climate is chaotic then there's an obvious flaw right away, but if it isn't then there are still other issues regarding other assumptions in the models.)

At the end of the day, reduction of GHGs is a good thing anyway, since GHGs are generally by-products of the combustion of non-renewable energy sources. Even if mankind isn't contributing to global warming, it still makes sense to cut down on these fuel sources and find other, infinitely renewable, sources.

In response to P3

Pielke's argument is not really that the others have it wrong, per se, he is concerned that they are not justified in presenting the models' findings with confidence to policymakers as a grounds for policy and planning, and that, therefore, policies based on the model findings may not be well-founded, or may be ineffective.

Tha's basically my argument, too - how can we make specific predictions, claiming a specific cause, and suggest a specific resolution when we really don't understand the models well enough to make those claims?

Anyway, I'll leave it there for now before I start rambling on again!

I'll be back!

C-Bob

[Dawlish]

Yes, that 'k' does look kind of ugly, doesn't it?! It can be spelled with a 'k' or a 'c' but I prefer the 'k' because otherwise I irrationally read it as "septic", which is even more unpleasant!

Thanks, Dawlish - the anniversary was very pleasant, thanks. Nothing too spectacular, but a nice big Pizza Hut and and Breakfast at Tiffany's make for a lovely evening!

In future I shall try and keep my posts shorter - I do tend to get a bit carried away.

I'll be back!

:lol: :lol:

C-Bob

Don't you dare go for brevity! We're enjoying your contributions!

Paul ( and I've been called a lot worse than Paul on here, I can assure you!)

[Admiral_Bobski]

Don't you dare go for brevity! We're enjoying your contributions!

Paul ( and I've been called a lot worse than Paul on here, I can assure you!)

Thank you, Paul (that is the worst I shall call you!). Now I shall go and have a coffee to stimulate the old grey cells! (Or should that by gray, with an 'a'?! Funny thing, language! )

TTFN

C-Bob

[raritas]

Don't you dare go for brevity! We're enjoying your contributions!

World sea temp anom. Where would anom show first?

The areas at extreme geographical tips of global conveyor if it is slowing?

Would end up not quite reaching those bits, just like your finger tips...more prone to external temps hot/cold (atmosphere) than usual when the main body withdraws some blood flow?

To knock out such a mega huge balanced energy flow would take something like millions of cont. tons of unnatural interference every day for hundreds of years?

How could that happen?? LOL (opps or has it already)

[parmenides3]

rar.; tht is a bt too brf...

Where does the anomaly show first? I'm not sure what you're asking for. There are always anomalies in the sea surface temperature, some positive, some negative. Recently, there have been more pos. than neg., so warmer overall. Why does it matter?

'...extreme tips...'? The Norwegian Atlantic current has slowed slightly in the past ten years and got about a degree warmer, on average. There's no strong evidence that the conveyor is slowing overall, beyond normal variability, but when it does, it'll start to slow in the areas where the main deep convection happens. Note that it is probably deceptive to imagine the THC as some kind of river-like 'current', anyway.

What would knock it out? One recent paper suggested a freshwater influx of 0.6 Sv ; about 600,000 cubic metres per second chucked into the North Atlantic. Another paper suggested an excess of freshwater in the GIN near the Greenland-Shetland ridge of c. 25,000 Km3, overflowing into the North Atlantic all at once. Some of the GCMs already model a slow-down as a result of GW; none model a shutdown.

Cap'n; there's a link somewhere with 'how do we know that CO2 is responsible..?' answered; I'll look for it. I am still unsure why it wouldn't sit well, though. It seems as if the idea that CO2 in the atmosphere reflects back heat into the atmospheric system has been accepted (tested, analysed and worked on) for twenty years or more. Why would you have a doubt about this? In response to your question: do scientists give specifics, or is this rather the work of the media and politicians? The scientists are well aware of the uncertainties; the politicians/media aren't always, and often fail to communicate them.

Don't underestimate the models, though. Yes, they are imperfect and, yes, there are doubts about some of the components/assumptions, but this is in the context of a vast amount of physics, mathematics and climate science which has been put into them, along with vast quantities of data. My feeling is that too much emphasis is placed on the uncertainties, and too little on the real power of the GCMs. One question on this score is; if they can show skill in hindcasting using the variables and parameters they have, why should we believe that they show no skill in forecasting. We can't wait twenty years to find out how good they are; we have to decide now whether, for the purpose of approximating a probable future global climate, they are 'good enough'.

:)P

[Dawlish]

Don't underestimate the models, though. Yes, they are imperfect and, yes, there are doubts about some of the components/assumptions, but this is in the context of a vast amount of physics, mathematics and climate science which has been put into them, along with vast quantities of data. My feeling is that too much emphasis is placed on the uncertainties, and too little on the real power of the GCMs. One question on this score is; if they can show skill in hindcasting using the variables and parameters they have, why should we believe that they show no skill in forecasting. We can't wait twenty years to find out how good they are; we have to decide now whether, for the purpose of approximating a probable future global climate, they are 'good enough'.

:)P

I agree. There is such a difference, for me, in the models being used to produce forecasts out to 16 days and the models being used to predict climate out to 100 years. The variability in the atmospheric models, with slightly different initial conditions producing massive differences in well under 16 days time, is not reflected to the same degree in climate models IF and only if, C02 is the main cause and there isn't another cause that is greater and will override it.

The reason for the difference is the inherent simplicity in the variables used in the climate models, compared to the complexity of the variables being modelled in, say, the gfs models.

If C02 is the main culprit in GW, the models will, to the error limits that define them, probably be correct. As PM3 rightly says, the hindcast accuracy is good. The only problem with the models, for me, would be if the main model input were to be masked by another factor (solar output, natural cycles, astrometeorology?? etc.). That's why I feel, at my personal odds of 1/6 C02 being the main cause, that the predictions of the climate models are more likely to be correct, than not.

Paul

Edited November 12, 2006 by Dawlish

[Admiral_Bobski]

Cap'n; there's a link somewhere with 'how do we know that CO2 is responsible..?' answered; I'll look for it. I am still unsure why it wouldn't sit well, though. It seems as if the idea that CO2 in the atmosphere reflects back heat into the atmospheric system has been accepted (tested, analysed and worked on) for twenty years or more. Why would you have a doubt about this? In response to your question: do scientists give specifics, or is this rather the work of the media and politicians? The scientists are well aware of the uncertainties; the politicians/media aren't always, and often fail to communicate them.

Hello again! Yes, I read an article a week or so back that talked about the relative abundace of various isotopes of carbon in the atmosphere (locked up in CO2 molecules). Unfortunately I haven't got the link, and I confess I wasn't paying a great deal of attention to the article.. I'll see if I can find it in my History folder, re-read it and post the link.

The reason it doesn't sit well is because I think the effect of CO2 warming is being greatly exaggerated, and not enough attention is being given to other factors. (I will, once again, have to check my sources, but where some people are suggesting a large effect - say 10C over 75 years (not an actual figure, but an example) - others are suggesting a small effect - e.g. 0.5C over 75 years. Since there is a huge discrepancy in these estimated outcomes, depending upon the source of the information, I think it is crucial to find out why the discrepancy is there, what is causing the discrepancy and who, if anyone, is correct.)

If the idea of CO2 reflecting back heat in the atmosphere is so well accepted then why are there so many people - scientists, that is - who still refute the evidence? Why is there still the discrepancy in the results? I think the issue of CO2 in the atmosphere is still rather cloudy (if you'll forgive the pun!), and I think to make serious decisions based on contentious science is rather shortsighted. Since the Kyoto treaty specifically targets CO2 emissions and does not address any other potential sources of GHGs, I think it is a supremely narrow-minded attempt at environmental control.

As for the specific details, I know climatologists talk of sea levels rising anywhere between 5 and 88cm in the next 50 years (or 100 years, I forget which), and the media immediately says "Sea Levels Rise 1 meter Within Our Lifetimes!!!". It appears to be the media's job to distort the facts until they have a story that's deemed newsworthy. However, climatologists have been known to give specific details in the past. Actually, now I stop and think about it, the sea level rise of between 5 and 88cm is not an exagerrated example - I actually read that somewhere (must find the reference). If this is the official line of sea level rise, that's one heck of an uncertainty in the data. Again.

One question on this score is; if they can show skill in hindcasting using the variables and parameters they have, why should we believe that they show no skill in forecasting.

I meant to ask about this, in fact...have the current models been used to retrospectively predict today's climate using data from, say, 1880? If so, do you know where I might be able to find the results of the experiment? I've been meaning to look that up.. I think I said a day or two ago that if the current models fail to predict today's climate from archive data then there's obviously a problem with the models, and I would have thought that this kind of experiment would be essential to determine the accuracy of our models. I'd be grateful if you could help out on this one...

I'll see if I can find some references to corroborate my stance!

TTFN :lol:

C-Bob

[Dawlish]

If the idea of CO2 reflecting back heat in the atmosphere is so well accepted then why are there so many people - scientists, that is - who still refute the evidence?

When you are talking about "so many people" Cap'n, you are actually referring to a small minority of scientists. There may be hundreds, but when you measure that against the many tens of thousands of scientists that accept AGW, then it is a small minotiry! By not fully accepting C02's role in causation, I'm actually in the minority, but the weight of the majority has been slowly persuading me, over the last 2 years in particular. To change one's mind is very, very difficult.

Paul

PS Hope I've got my "so many people's" actual focus right there!

Edited November 12, 2006 by Dawlish

[Admiral_Bobski]

When you are talking about "so many people" Cap'n, you are actually referring to a small minority of scientists. There may be hundreds, but when you measure that against the many tens of thousands of scientists that accept AGW, then it is a small minotiry!

Yes, those who oppose the commonly-held view are in the minority. However, if the minority is a group of 7 people you could dismiss them as crackpots, denialists or playing devil's advocate. If all 7 of them are from the same institute you could argue political motives, or institutional indoctrination. If, on the other hand, the "minority" consists of hundreds of scientists, or thousands, even if there are many tens of thousands who accept AGW, that's still quite a large number of scientists even if it's not a large proportion of them. I think it's unreasonable to dismiss the views of hundreds of people, even if they are a small proportion of the whole.

If 99% of the Third Reich agreed with Hitler's ideals, but 1% disagreed, does that mean that the 1% were wrong?

As long as there is a disagreement among respected scientists, as opposed to crackpots and denialists, I shall continue to plead my case. As I say, I am not denying AGW itself, I am merely pointing out issues that are by no means open-and-shut cases. :lol:

C-Bob

[frozen_north]

How did the last ice age suddenly end. There wasnt any emissions from humans back then was there. So how are humans the cause now. The climate changes over time. It is never static.

Edited November 12, 2006 by frozen_north

[Dawlish]

Yes, those who oppose the commonly-held view are in the minority. However, if the minority is a group of 7 people you could dismiss them as crackpots, denialists or playing devil's advocate. If all 7 of them are from the same institute you could argue political motives, or institutional indoctrination. If, on the other hand, the "minority" consists of hundreds of scientists, or thousands, even if there are many tens of thousands who accept AGW, that's still quite a large number of scientists even if it's not a large proportion of them. I think it's unreasonable to dismiss the views of hundreds of people, even if they are a small proportion of the whole.

If 99% of the Third Reich agreed with Hitler's ideals, but 1% disagreed, does that mean that the 1% were wrong?

As long as there is a disagreement among respected scientists, as opposed to crackpots and denialists, I shall continue to plead my case. As I say, I am not denying AGW itself, I am merely pointing out issues that are by no means open-and-shut cases. :lol:

C-Bob

You do absolutely right and long may you do so! However, I invoke Godwin's Law here!

Paul

[Gray-Wolf]

You do absolutely right and long may you do so! However, I invoke Godwin's Law here!

Paul

Donner and Blitzen! you beat me to it!!!

[Optimus Prime]

How did the last ice age suddenly end. There wasnt any emissions from humans back then was there. So how are humans the cause now. The climate changes over time. It is never static.

If you could see how much pollution humans give off you wouldn't even think twice that humans are the main cause.

80 million barrells of oil are burnt ever day. Or 29,000,000,000 (billion) per year. I just can't see how that doesn't have an impact on our atmosphere and climate.