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Post by sentient on Aug 16, 2009 18:43:01 GMT
glc: Its probably fitting, and ultimately quite natural, to distill an argument down to just a single variable, in this case the CO2 hypothesis. It may be the genus Homo's single greatest accomplishment prior to the present interglacial. 2.8 million years ago the genus Homo split off from the Australopithecines with the singular discovery accredited to them for the astonishing discovery of rocks. Homo habilis, or handy man, kicked off the stone-age, with development of the single variable processing strategy rapidly (well, over the next million years or so) evolving into the Acheulian tool period at 1.8 mya, hand axes and bi-face tools. Made from, you guessed it, rocks.
Still in single variable processing mode, it took almost the next 1.8 million years to figure out how to cook metals out of rocks, jump-starting in the process the metals ages (Iron, Bronze etc.).
Recently, evolution may have been having its wicked way with us once again as it would seem to have taken the advent of multivariate processing for James Watt to have cobbled together fire, metals and water to generate steam. The multi-variate processing Homo was on his way.
Commensurate with this came the industrial revolution, many more variables requiring processing leading us to the present time where we have super-computers to handle what we literally cannot.
Where climate change enters the picture in earnest began just a few short decades ago, during one of those rare periods in geologic history when climate was more or less stable, possibly and even probably towards the end of an interglacial.
However, if we stick to just the single variable of CO2, and look at it over time, there has been a steady, natural decline in levels of this "contaminant" over the past few million years. In high concentrations, this "contaminant" has been proven to be quite effective at enhancing outbreaks of one of the earth's most intractable infestations called plants.
Could it possibly be that by tapping into into accessible stored reserves of this "contaminant", and releasing it in large quantities, we may have reversed the natural sequestration of this pollutant thereby saving plants from certain extinction?
Obviously, if we are at or near "peak oil" at the present time, this "problem" will probably be self-extinguishing as reserves decline. Meaning of course, left alone, this "experiment" may not fully occur at all.
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Post by socold on Aug 16, 2009 18:55:49 GMT
Actually the correct analogy would be the skeptic about to jump off the roof in their prototype which all models show will fail. The logic being that the models might be wrong. Tiz the models that are showing the failure. One has to respect the historical climate shifts etc. The models seemingly do not do that. By ignoring the evidence from the past, their usefullness to present anything in the future is quit scant. You know we have quite the contradiction here. One person claims models can be tweaked to show anything. The other claims models fail to show historical climate shifts. How to resolve this contradiction?
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Post by socold on Aug 16, 2009 19:01:50 GMT
Indeed socold maybe no self respecting scientist can parameterize a model that doesn't lead to warming. . . .but thats about as reliable of an argument as flying a machine that you haven't yet invented the operational technology for yet It's the precursor for the powerful argument that our understanding of how physics in the atmosphere and oceans work shows that human emissions will cause significant warming. And it is also a powerful argument against the meme that climate models can be tuned to show anything.
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Post by woodstove on Aug 16, 2009 19:58:55 GMT
The profound need to obfuscate among some of our commenters is, at times, chilling. The Little Ice Age, including and especially the Maunder Minimum, was real. What you have yet to do, glc, is propose a driver that began getting us out of the Little Ice Age two hundred years ago. So far, you're stuck with time-traveling co2 molecules.
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Post by sentient on Aug 16, 2009 20:04:49 GMT
Socold:
I suspect that the physics in the laboratory shows what you speak, and indeed this is not only a powerful argument, but I think this is THE winning argument, if we manage to keep this in its present state, a single variable equation. The thing we are best at manipulating mentally. Intermixed with the plethora of variables we do understand, and more importantly, the variables we do not yet fully comprehend, it becomes what it really is, just one of many variables in a remarkably complex chaotic melange of equilibria yet to be resolved.
Take, for instance the glacial/interglacial transitions. These happen regularly enough that at least since the Mid Pleistocene Transition we can set our geologic clocks by them. At glacial maxima, when the land surfaces are, on average, covered 30% by ice, CO2 levels much lower than during the interglacials and falling all the way to the glacial maximum, one must become very creative to enlist GHGs to swing sea levels 400 feet in just a few thousands of years with all faunal species also at their nadir in populations.
In fact, just the opposite is documented to be the case. Temperatures rise, naturally, far faster than any computer model has yet been even near capable of, with CO2 levels increasing, like clockwork, but always delayed by from 800-1,300 years!
This same pattern repeats itself on the lesser stadial/interstadial shifts, which follow the same pattern, but at least six times faster.
Something else would seem to be responsible for the dramatically larger natural "noise" that we are attempting to resolve our anthropogenic signal out of.
The signal to noise problem is well understood in physics, with isolation of a signal particularly difficult if the noise is many times larger than the signal one seeks to resolve.
And that is indeed the crux of the question I am posing. In the human psyche, is belief in a thing the paramount driver in mental cogitation? Although a single variable is proven beyond the shadow of a doubt in an isolated laboratory setting to be correct, but pales and even reverses in the natural environment, should this not give one pause in drawing a solid conclusion?
The answer would seem to be right there in the historical record. One wonders just what it was that Fred Flintstone said to Barney Rubble when Barney started chipping up his very first sharp rock. What actually seems to occur in nature, human nature, is that it takes an ice age to smarten old Homo up. We could sure use one right about now, and as we speed down the interglacial highway, the next ice age exit may be just ahead.
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Post by jimcripwell on Aug 16, 2009 20:15:01 GMT
glc writes "We don't need references for arctic ise. It's obviously fragile or it wouldn't have lost so much in 2007 due to "wind". Point me to the Eddy/Maunder Minimum stuff. It's you who so convinced by this stuff. What is it that's convinced you?"
Absolute garbage. Arctic sea ice is routinely blown all over the place. Just because the wind can move it, does not mean that it is fragile. Ask anyone who has been in the Arctic Ocean when there is ice around. The ice can crush any ship that is not specially ice hardened. It may be you opinion that it is obviously fragile. But then that is typical of your attitude. (Sarcasm mode on. ) You dont need a reference because you are always right. (Sarcasm mode off.)
Those of us who live in Canada know what winter ice can do. I have a cottage on a lake, and everyone I know who is in the same position, knows that you need to take anything of value out of the lake before it freezes over. In wont happen every year, but one year when the wind is just wrong, the destruction can be complete. To suggest that ice is fragile shows your complete ignorance of the subject.
As to references I have given them before. I am at the cottage, and I dont have the exact reference. The one is in Science, entitled The Maunder Minimum, and is, I am reasonably sure, 1976. The second is Scientific American The Case of the Missing Sunspots. Here I am a little more certain May 1977 page 80. If you have not bothered to read these sorts of references, it is impossible for me to explain what convinces me that they are correct. That is the sort of opinion one forms when one reads what scientists write.
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Post by socold on Aug 16, 2009 21:15:15 GMT
Take, for instance the glacial/interglacial transitions. These happen regularly enough that at least since the Mid Pleistocene Transition we can set our geologic clocks by them. At glacial maxima, when the land surfaces are, on average, covered 30% by ice, CO2 levels much lower than during the interglacials and falling all the way to the glacial maximum, one must become very creative to enlist GHGs to swing sea levels 400 feet in just a few thousands of years with all faunal species also at their nadir in populations. I agree, but one must also be creative to dismiss GHG changes as a significant contributing factor to the glacial-interglacial transitions. The orbital forcings on these timescales alone are far from sufficient to explain the temperature variation. Without the climate system itself amplifying the forcing in some way, and ghg changes are one such way, it is not possible to explain the magnitude of temperature change. Explainations for variation within the glacial-interglacial transitions, such as DO events, perhaps involve non-linear processes kicking in which have little significance to the longer scale temperature changes, eg: chriscolose.wordpress.com/2009/07/22/more-on-abrupt-climate-change/
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Post by glc on Aug 16, 2009 22:39:39 GMT
Absolute garbage. Arctic sea ice is routinely blown all over the place. Just because the wind can move it, does not mean that it is fragile.
But in 2007 it moved it a bit too easily.
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Post by glc on Aug 16, 2009 22:52:22 GMT
The Little Ice Age, including and especially the Maunder Minimum, was real.
This just a statement based on what exactly?
What you have yet to do, glc, is propose a driver that began getting us out of the Little Ice Age two hundred years ago. So far, you're stuck with time-traveling co2 molecules.
What you have to do is provide solid evidence that the LIA existed and the precise timeframe of it's duration. I'm going to adopt the Jim Cripwell strategy from now on. I don't believe the LIA is based on anything more than a few anecdotes and some iffy proxies. As for the MWP - forget it .
You have no reliable temperature data to support the existence of the LIA or MWP.
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Post by magellan on Aug 16, 2009 22:55:11 GMT
Take, for instance the glacial/interglacial transitions. These happen regularly enough that at least since the Mid Pleistocene Transition we can set our geologic clocks by them. At glacial maxima, when the land surfaces are, on average, covered 30% by ice, CO2 levels much lower than during the interglacials and falling all the way to the glacial maximum, one must become very creative to enlist GHGs to swing sea levels 400 feet in just a few thousands of years with all faunal species also at their nadir in populations. I agree, but one must also be creative to dismiss GHG changes as a significant contributing factor to the glacial-interglacial transitions. The orbital forcings on these timescales alone are far from sufficient to explain the temperature variation. Without the climate system itself amplifying the forcing in some way, and ghg changes are one such way, it is not possible to explain the magnitude of temperature change. Explainations for variation within the glacial-interglacial transitions, such as DO events, perhaps involve non-linear processes kicking in which have little significance to the longer scale temperature changes, eg: chriscolose.wordpress.com/2009/07/22/more-on-abrupt-climate-change/You keep saying "it is not possible to explain.....", yet are provided several references in the literature that say otherwise, not to mention your examples are invariably derived from climate models. In another post you tow the AGW party line about climate modelers not being able to explain warming by other than CO2, yet here it is, once again rearing its ugly head........climate models versus reality: As it is summed quite well by the author of the paper I posted several weeks back, but you may have possibly contracted amnesia: What was done, was to take a large number of models that could not reasonably simulate known patterns of natural behavior (such as ENSO, the Pacific Decadal Oscillation, the Atlantic Multidecadal Oscillation), claim that such models nonetheless accurately depicted natural internal climate variability, and use the fact that these models could not replicate the warming episode from the mid seventies through the mid nineties, to argue that forcing was necessary and that the forcing must have been due to man.
and What we see, then, is that the very foundation of the issue of global warming is wrong.
In a normal field, these results would pretty much wrap things up, but global warming/climate change has developed so much momentum that it has a life of its own – quite removed from science. One can reasonably expect that opportunism of the weak will lead to efforts to alter the data (though the results presented here have survived several alterations of the data already). Reality seems to have floated over your head like a lead balloon.
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Post by sentient on Aug 16, 2009 22:59:25 GMT
Oops, I forget how time flies! This is in response to Socold's last post:
To a large degree confirming one of my points, that we do not yet know what causes the abrupt transitions. We lack a recurrent variable that yet cannot be explained or modeled. However I disagree almost entirely that such things as D-O events "have little significance to the longer scale temperature changes". Au contraire, with D-O events averaging 1,500 years within a natural range of 1,000 to 4,000 years, and seemingly paced by the 1,500 year average isotopically known solar variation, these abrupt shifts are indeed relevant.
But back to not knowing what causes them and the success of modeling them, here are some current observations on the dynamic:
A study by Liu et al (Z. Liu et al., Science 325, 310 (2009) and referenced by Timmermann and Menviel (Science, 17Jul09, v.325) found that the transient modeling approach "simulates the climate evolution since the Last Glacial Maximum by prescribing the time evolution of the external boundary conditions based on astronomical theory, ice-sheet reconstructions, and the history of greenhouse gas concentrations. It thus offers the unique possibility to study the full spatiotemporal behavior of climate change, including the mechanisms of abrupt climate change, and to directly compare the resulting temporal features with paleoclimate data—for example, from sediment cores and ice cores."
"However, such ambitious projects are computationally very demanding, and it might take several years before similar transient simulations can be carried out routinely with other coupled general circulation models. Even completing the CCSM3 simulation ( 1) by running it into the present will require another 2 to 3 million CPU hours on the Jaguar supercomputer."
On 14Jul09, Rice University posted this:
Global warming: Our best guess is likely wrong Unknown processes account for much of warming in ancient hot spell
No one knows exactly how much Earth's climate will warm due to carbon emissions, but a new study this week suggests scientists' best predictions about global warming might be incorrect.The study, which appears in Nature Geoscience, found that climate models explain only about half of the heating that occurred during a well-documented period of rapid global warming in Earth's ancient past. The study, which was published online today, contains an analysis of published records from a period of rapid climatic warming about 55 million years ago known as the Palaeocene-Eocene thermal maximum, or PETM.
"In a nutshell, theoretical models cannot explain what we observe in the geological record," said oceanographer Gerald thingyens, a co-author of the study and professor of Earth science at Rice University. "There appears to be something fundamentally wrong with the way temperature and carbon are linked in climate models."
During the PETM, for reasons that are still unknown, the amount of carbon in Earth's atmosphere rose rapidly. For this reason, the PETM, which has been identified in hundreds of sediment core samples worldwide, is probably the best ancient climate analogue for present-day Earth.
In addition to rapidly rising levels of atmospheric carbon, global surface temperatures rose dramatically during the PETM. Average temperatures worldwide rose by about 7 degrees Celsius -- about 13 degrees Fahrenheit -- in the relatively short geological span of about 10,000 years.
Many of the findings come from studies of core samples drilled from the deep seafloor over the past two decades. When oceanographers study these samples, they can see changes in the carbon cycle during the PETM.
"You go along a core and everything's the same, the same, the same, and then suddenly you pass this time line and the carbon chemistry is completely different," thingyens said. "This has been documented time and again at sites all over the world."
Based on findings related to oceanic acidity levels during the PETM and on calculations about the cycling of carbon among the oceans, air, plants and soil, thingyens and co-authors Richard Zeebe of the University of Hawaii and James Zachos of the University of California-Santa Cruz determined that the level of carbon dioxide in the atmosphere increased by about 70 percent during the PETM.
That's significant because it does not represent a doubling of atmospheric carbon dioxide. Since the start of the industrial revolution, carbon dioxide levels are believed to have risen by about one-third, largely due to the burning of fossil fuels. If present rates of fossil-fuel consumption continue, the doubling of carbon dioxide from fossil fuels will occur sometime within the next century or two.
Doubling of atmospheric carbon dioxide is an oft-talked-about threshold, and today's climate models include accepted values for the climate's sensitivity to doubling. Using these accepted values and the PETM carbon data, the researchers found that the models could only explain about half of the warming that Earth experienced 55 million years ago.
The conclusion, thingyens said, is that something other than carbon dioxide caused much of the heating during the PETM. "Some feedback loop or other processes that aren't accounted for in these models -- the same ones used by the IPCC for current best estimates of 21st Century warming -- caused a substantial portion of the warming that occurred during the PETM."
It is this which I seek. Are we really nine times more permeable to rumor (myriad model results necessarily qualify) than we are to the facts of how these models are not there yet? A significant part of the puzzle still evades us. If it is astronomical, then we might have to wait awhile, as we have only recently become this sentient. But maybe not quite so long. Recent studies indicate that even the strength of sunspots has declined over the past 15 years at least. Combining that with the scarcity of the darn things for the past 2 years might pique ones remembrance of just how fast these things can naturally change:
“Briefly, the data indicate that cooling into the Younger Dryas occurred in a few prominent decade(s)-long steps, whereas warming at the end of it occurred primarily in one especially large step of about 8°C in about 10 years and was accompanied by a doubling of snow accumulation in 3 years; most of the accumulation-rate change occurred in 1 year (National Research Council, 2002)”
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Post by glc on Aug 16, 2009 23:02:02 GMT
As it is summed quite well by the author of the paper:
what paper?
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Post by magellan on Aug 16, 2009 23:17:09 GMT
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Post by socold on Aug 16, 2009 23:18:16 GMT
You keep saying "it is not possible to explain.....", yet are provided several references in the literature that say otherwise, not to mention your examples are invariably derived from climate models. I haven't been provided with any such references. I am sure you have at some time or other referenced something, but I am sure it didn't say what you think it said. I'll repeat what I said again for clarity: Without the climate system itself amplifying the forcing in some way, and ghg changes are one such way, it is not possible to explain the magnitude of temperature change (from glacial to interglacial) That isn't an attempt to explain the warming and is thus off topic. I don't wish to get divided into multiple subtopics, I know that's the common "tactic" to derail my points rather than addressing them, but on this occasion I will not comply.
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Post by glc on Aug 16, 2009 23:38:17 GMT
Today at 6:02pm, glc wrote:
As it is summed quite well by the author of the paper:
what paper? Ah yes, it is amnesia..... tinyurl.com/p48rob tinyurl.com/rxjtowIs it possible, at some point, for you to outline your exact position on AGW. I only ask because I thought you completely rejected the idea of CO2 induced warming,
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