| Citizen Runner |
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You've said a couple times that, if you believe the lower (orange) reconstruction, that temperatures have been rising since 800 AD or so. I find that a strange interpretation of that graph. What I see is a minimum there followed by a warm period consistent with the Medieval Warm Period which is documented in various histories (i.e. Vikings colonizing Greenland), followed in turn by other more or less stable periods of a few hundred years, most reecently by the "Little Ice Age" 1500-1900 or so, and finally by a big jump. Drawing a line from the lowest point you can find to the highest seems disingenuous.
It's often the case that the strength of a scientific theory isn't so much evidence supporting a theory as it is the absence of evidence contradicting the theory. I agree that we can't with certainty conclude that global temperature is warmer now than it has been in the last couple millenia, but neither is there evidence that says it's not. Such contradictory evidence would be a significant blow to the AGW theory unless there were some other strong forcing in play. A similar observation can be made about the CO2 levels from ice core samples we discussed earlier in the thread. That's the basis for my ongoing contention that it is the ensemble of evidence that is important. There is no single piece of evidence that conclusively demonstrates the validity of the theory, but as long as the theory is consistent with available data, has value in suggesting additional lines of investigation to test the theory, and is not contradicted, it is a "good theory" in the scientific sense. |
| rose colored glasses? |
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Similarly, emphasizing recent annual to decade-scale RECORDED fluctations by contrast with century or millenial-scale fluctuations in weakly reconstructed backward predictions seems disingenuous. It seems to me that the crux of the argument in favour of AGW is the temporal coincidence of an apparently unusual fluctuation in recorded climate with the occurrence of an apparently unusual spike in atmospheric CO2, which is assumed must necessarily be largely anthropogenic. I can see the allure of this argument, but please admit that several of the descriptors I've just used are inferred, not demonstrated, and then please recall the fundamental truth that correlation does NOT equal causation. There is really no doubt that the AGW hypothesis is a plausible explanation for observations, and perhaps even "most likely" on the basis of what we know. But when we are dealing with uncertainties of the scale being discussed in this thread, "most likely" may still (and I believe, still, does) represent a very small probability. |
| rose colored glasses? |
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... being dwarfed by the probability that some other factor is the root cause, our inability to imagine or describe such a cause notwithstanding. |
| rose colored glasses? |
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And maybe just a couple of comments on this admission: I've often heard the argument to the effect that, "OK, well maybe we're not really 100% sure, but there seems some good reason to believe it could be true, so shouldn't we do something about it?" Here's where I'll admit I'm in favour of making reasonable accommodations to try to protect the environment. There are a lot of development activities in the world that are unreasonably destructive to the natural environment (irrespective of whether climate, specifically, is affected either directly or indirectly), and I think we need to work toward a balance between necessary development with unavoidable impacts, and unnecessary activities with avoidable impacts. So I see some value in hedging society's bets, and I'm not opposed to the AGW lobby pushing for CO2 reductions (since I can acknowledge that it is possible this would be beneficial) or other things, nor would I specifically argue against such efforts. However, if the case is being oversold, and this becomes clear in a few years, the crying wolf will most probably have done irreparable harm to the cause, notwithstanding that it would have been well intended. |
| Randy Oldman |
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The dinosaurs started the process of global warming 5000 years ago when they lived among us. Yabba dabba doo! |
| Citizen Runner |
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My work here is done. You two work it out and let me know what you come up with. |
| No Way |
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Valiant effort. Your time will be better spent working on things you can control rather than educating the dumb and unwilling.
My work here is done. You two work it out and let me know what you come up with.[/quote] |
| Should have been obvious |
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[/quote] It truly was a valiant effort. I would say that it was effort spent trying to educate someone who was intelligent and disingenuous (not really dumb, just playing the part). |
| Roses, from the phone |
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Ok, well thanks for the constructive contributions, I feel I've learned some things in the discussion, and appreciate the links you've provided and the arguments you've presented. You know it's funny, I think I made the point at the start if this discussion that people carry deeply entrenched views into debates like this and nobody wants to change their mind. I think I set out with the idea that as a fence sitter I would be more amenable to consider different viewpoints, but as the discussion evolved I could feel myself digging in to protect my "non position," as others were protecting positions one one clear sude or the other. Happy trails everyone |
| Roses, from the phone |
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Ok, well thanks for the constructive contributions, I feel I've learned some things in the discussion, and appreciate the links you've provided and the arguments you've presented. You know it's funny, I think I made the point at the start if this discussion that people carry deeply entrenched views into debates like this and nobody wants to change their mind. I think I set out with the idea that as a fence sitter I would be more amenable to consider different viewpoints, but as the discussion evolved I could feel myself digging in to protect my "non position," as others were protecting positions one one clear sude or the other. Happy trails everyone |
| rose colored glasses? |
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I know the thread is dead, but I was working with some other weather data in relation to work, and thought I would throw up a quick plot: Image: http://i43.tinypic.com/280zlj.jpg Daily temperatures in St Lucia from 1941 to 2011, with a big gap. Mean increase is about 1 degree C per century, in the same general ballpark as the other numbers we've been looking at, both from the Canadian data and in the various plots of instrumented temperature trends. No particular point, just sharing in case some people are visual thinkers like me. |
| rose colored glasses? |
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Interesting article in today's Globe and Mail, with some indirect relevance to this dead conversation: http://www.theglobeandmail.com/news/national/healthy-polar-bear-count-confounds-doomsayers/article2392523/ The main point I draw from this is simple reinforcement of my skepticism when scientists report predictions of future behaviour of chaotic natural phenomena. A similar thing happened last year with the west coast salmon run. Unbelievably high populations of fish returned to spawn, completely baffling the scientists. |
| Blowing.Rock Master |
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According to every report I've ever found on polar bear populations, the population has been stable for about the last 40 years. This stable period followed one when the populations were growing as they rebounded from over-hunting. The AGW crowd likes to claim that global warming is killing polar bears, but there's no evidence to back that up. |