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Post by marchesarosa on Jun 13, 2011 10:15:50 GMT 1
I'm glad nickrr mentioned the Milankovitch cycles because I really thought they had gone out of fashion in alarmist circles.
One of the very first arguments I presented when I was just starting to get interested in the climate debate back in 2007 was Why do you think a few extra molecules of CO2 in the atmosphere is going to turn off the longstanding cycle of glacial (average 100,000 years) and interglacial (average 10,000 years) periods which have been the norm of natural climate variability for a couple of million years?
Milankovitch certainly SEEMS to have put his finger on a fundamentally important variable. So why does nickrr think that instead of heading for another deep freeze, the planet is now heading for catastrophic runaway global warming- courtesy of CO2?
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Post by speakertoanimals on Jun 13, 2011 13:25:31 GMT 1
Nickrr -- thanks for the reply!
One comment:
That is actually quite easily explained, as I understand it. Models are admittedly, simplified versions of actual climate. So, we have loads of other short-term effects on top of expected modelled rise. Hence when we consider the actual data, we wouldn't ever expect the nice linear rise that models predict, except when averaged over enough time to iron-out the fluctuations.
Plus current work in climate change is perfectly in agreement with Milankovitch, and its only the 'skeptics' who keep acting as if this has been forgotten................
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Post by nickrr on Jun 13, 2011 13:51:05 GMT 1
I have never said this. If you want to quote me, quote what I have said, not what you would like, guessed or inferred I have said.
No-one knows whether we are heading for another deep freeze or not - and we may not be able to say for certain for hundreds or even thousands of years.
As ice ages are (I believe) caused largely by changes in the earth's orbit and the current arrangement of the continents, neither of which we have any control over, I suspect that in the long run ice ages will continue. We'll probably have done ourselves in by that time anyway.
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Post by speakertoanimals on Jun 13, 2011 16:35:03 GMT 1
Who said we'd expect to turn it off? It's become apparent that the cycles of glacials and inter-glacials aren't as regular and clockworklike as orbital mechanics might suggest. Hence other factors can and have effected the exact timing of these events. 'A few extra molecules of CO2' is just rather disingenuous. Whilst nosing around, I found this rather nice graph of the EPICA core data. Red is methane, blue is CO2, and black is deuterium (temperature signal). Anyway, you have to remember that this data, although things not triggered by CO2, show CO2 acting as a positive feedback mechanism. Hence if those levels could have effects back then, then seems reasonable to suppose they could do so again. So, this NATURAL climate variability requires CO2 feedback to explain what we actually see, not just orbital mechanics alone. Hence rather than 'forget' about these natural cycles, this sort of data is actually very informative as to how much effect CO2 can have.
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Post by marchesarosa on Jun 13, 2011 17:59:57 GMT 1
The statement that CO2 acts as a positive feedback mechanism is just assertion.
It could just as easily be that CO2 rises because the ocean are warming and outgassing. CO2 change FOLLOWS temperature change both UP and DOWN in the palaeo record - which is what is expected when the dog wags the tail.
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Post by speakertoanimals on Jun 13, 2011 18:29:59 GMT 1
Wrong.
So, to start with, would Milankovitch and orbital dynamics on its own cause distinct glacials and interglacials? Nope, evidence is that the forcing is too weak on its own to do that. But when you add in the effects of CO2, then you get something more sensible. So, orbital dynamics gives you the initial rise, positive feedback of CO2 gives you the final picture.
'Just as assertion' is just trying to claim that all the research on the exact processes acting during interglacials just doesn't exist, which is daft. You are trying to make it sound like some sort of plausible guess after the fact, rather than proper science.
Plus we have the old boring stuff -- GIVEN the exact properties of CO2 molecules, we'd be jolly surprised if it DIDN'T act as a greenhouse gas.
It's just an assertion is nearly as bad as the even more boring, it's just a theory.....................
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Post by marchesarosa on Jun 14, 2011 9:06:51 GMT 1
So what are they? The sun's behaviour perhaps?
You express such bullshitting confidence in stuff that is NOT known but only guessed, assumed and speculated upon. You are a humbug, in other words. I'd so love so see Svensmark or Kirkby making intellectual mincemeat of you.
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Post by marchesarosa on Jun 14, 2011 9:11:40 GMT 1
I missed this bit of flannel.
And are you suggesting that the continents have been "rearranged" recently in the geological past?
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Post by StuartG on Jun 14, 2011 9:51:29 GMT 1
"Shocking: New Zealand and Australia are out of their place on the map" www.abovetopsecret.com/forum/thread543455/pg1"One of the shockiest timeline changes I have noticed is the changed location of New Zealand and Australia on the map. They have dramatically changed their places and we are now talking about paranormal/supernatural events as it looks like those land masses have almost "jumped" to other location....... "
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Post by speakertoanimals on Jun 14, 2011 12:56:01 GMT 1
I think this is part of your general problem of trying to cast doubt on any science that relies on deducing what happened in the past. but it's NOT guessed. We have hypotheses, which can then be tested against data. Assumed, yes, for the purposes of building a model, you may make certain assumptions, but then the validity of the model (hence the assumptions on which it is based) is checked against evidence. Speculated? how else do you think you get started on NEW research -- that cosmic rays causes clouds is a SPECULATION. I don't know why anyone who supports your causes (or seems to), is then held up by you as some paragon of virtue and assumed brilliant scientist and debater. Or why you seem to think that science is about personalities rather than boring old facts................... Re: Continents -- Ice ages have occured back to about 2.4 billion years ago. Within ice-ages,we have glacials and interglacials. So, for example, the Karoo ice-age (360-260 Mya) is thought top be linked to the evolution of land plants and hence more oxygen, less CO2. When it comes to ice-ages in general, and glacials and interglacials within an ice-age, consensus is that several factors have to be considered: Atmospheric composition: our old chums CO2 and methane and greenhouse effect. Either duw to plants arising, or large-scale volcanism. Orbital dynamics: Milankovitch cycles, plus possible other longer-term cycles to do with suns position in the galaxy. Land masses and their distribution: This has an effect of ocean currents, hence on ice-ages. Basic things -- you only get a large southern ice-sheet if there is a continent there on which it can form! Plus solar variation. When it comes to our current ice-age, an important event was the formation of the Isthmus of Panama (3Mya), which changed ocean circulation (gulf stream formed), and contributed to current ice-age. www.whoi.edu/oceanus/viewArticle.do?id=2508Point about Milankovitch cycles is that they (and their effects in terms of amount of sunlight) can be easily computed. But that on its own doesn't explain out two-phase glacial/inter-glacial. In this plot: Q bar is the sunlight graph, whereas bottom two plots are isotopic and ice-core temp data graphs. Q bar on its own doesn't explain the exact shape, we need some other feedback processes. The point being, it's the same sort of combinations of orbital dynamics, atmospheric conditions that is being considered when it comes to ice-ages, or glacials/interglacials. IF CO2 as a positive feedback is needed to explain ice-ages, then why shouldn#t increasing CO2 be considered in the present? You can't just throw out AGW without having to rethink the whole of our understanding of ice-ages on the longer time scale. Plus its the same sort of data being used for both, ice-cores, isotopic analysis etc, whether we are looking at the past 100,00 years, or the past 6.5 million. Of course, if you think all this is bullshit, then seems you are very selective in your choice -- volcanism good, solar variation good, orbital dynamics good, CO2 bad, despite the evidence of previous ice-ages............... P.S. I can spell, I just can't type!P.P.S Really interesting, this larger picture, showing how same elements interact in different ways to try and explain the broader picture over millions of years, the actual science is about more than our current AGW 'debate', and you can't just blithely dismiss some effects out of hand without junking our explanations for climate on a much larger scale.
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Post by speakertoanimals on Jun 14, 2011 13:35:40 GMT 1
Going back to solar heating and the needed effect of CO2 amplification, this page explains it really nicely, with some simplified modelling. The blue curves are solar heating which wiggles aboutn quite a lot, but after a sustained increase, and slight temperature increase, then CO2 kicks in, and sustained warming even though solar goes back down again. betternature.wordpress.com/2009/11/12/co2-lag-during-ice-ages/Individual graphs won't cut&paste, so you'll have to go look at the webpage. But explains why CO2 lags temp in past ice-ages, and why it need not do so in present case. Makes clear WHY solar variation on its own isn't the whole story.....
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Post by nickrr on Jun 14, 2011 13:42:16 GMT 1
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Post by marchesarosa on Jun 14, 2011 14:14:07 GMT 1
You think you can adduce as "evidence" for the current (and contested) fractional warming speculation about "ice-ages" billions of years ago? Pull the other one, puhlease.
Let's stick to the relatively recent 800,000 years, eh, the most "recent" series of alternating glacials and inter-glacials which seem to indicate that we are much closer to the end of the current brief interglacial than the beginning.
I don't class any observable variation as either good or bad. I am indifferent to them. I just want to understand the interplay as far as I am able.
I don't have a "cause" either. Neither do I have a wife, incidentally. I would have to be a man to have a wife. You seem to think you can change words to mean what you and a handful of others WANT them to mean. A priori this is a VERY good indicator of intellectual prowess - lack of - and propensity for ideological "thinking" . So that certainly enters into my holistic judgement of YOUR approach, miss.
I was going to write "of YOUR *ideas*, miss" but I have never actually seen you *express" an idea or an opinion of your own at all - you merely try to clobber everybody else's groping towards to better understanding of phenomena.
And yes, I am very much impressed by "personalities". I judge the "whole person" when reading or listening to their accounts. Kirkby, Courtillot, Svensmark, McIntyre, Spencer, Christie and Lindzen impress me VERY much as individuals and Michael Mann, Phil Jones, James Hansen, Gavin Schmidt, James Houghton and Prof Bob Watson, to name a few so-called "climate scientists", make me feel ill.
I have never yet come across an "alarmist" who impressed me as either honest or unduly intellectually endowed. Scum rises to the top and currently the scum on the scientific bowl is IPCC Climate science.
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Post by marchesarosa on Jun 14, 2011 14:15:54 GMT 1
Nickrr, I assumed you understood the phrase "recent geological past".
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Post by StuartG on Jun 14, 2011 14:27:17 GMT 1
"Makes clear WHY solar variation on its own isn't the whole story..... " ...but 'solar variation' doesn't seem to take into account ALL emissions. Kirkby says that UV plays some part. It's not the whole story, but it could be a bigger part. I can't help feeling that all these graphs use the same set of values, just presented in different ways. Without looking for/at different indicators, the same or similar results will always appear. With thanks to betternature.wordpress.com/2009/11/12/co2-lag-during-ice-ages/
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