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Post by icefisher on Apr 17, 2009 20:42:51 GMT
You can see the models are wrong, but they are close. But does that justify a "they don't work" argument? Can we ignore the climate they can reproduce just because there are other parts they don't? Probably every years precipitation graph looks similar. Minor deviations don't count. But we are not talking minor deviations. |
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Post by gridley on Apr 17, 2009 21:59:07 GMT
Perhaps CO2 does not exist, although unlike AGW, CO2 is widely (I would say all but universally) accepted to exist in MULTIPLE INDEPENDENT fields of HARD science and ENGINEERING. At least you admit the possibility that co2 does not exist. That's all we need, a small seed of doubt that can grow into a giant oak of a conspiracy theory. Oh of course multiple independant fields of hard science accept co2 exists. If they didn't they would lose their funding. Of course I'll admit the possibility that CO2 doesn't exist. I also admit the possibility that I don't exist. Ditto my wife, mother, father (well, he's dead to the best of my knowledge), sister... however I think you'd have a hard time finding any technically educated person (employed or not) who didn't believe in CO2, and I think most people who meet me would conclude that I exist. Um... funding. Funding as in "I work for Boeing, I get paid because people buy airplanes." is one thing. Funding as in "I got this government grant to research my theory." is something rather different. Hard scientists often get paid by corporations for R&D that produces real-world results that the company can make money off of. I will concede that as carbon becomes taxable there is, in fact, money to be made off of it. To be fair, I imagine it would be difficult to get funding for a study postulating the non-existence of CO2. OTOH, in particle physics you can get funding to look for things that no one is sure exist (yet). Unlike the GCMs, real-world experiments based on an assumption of the existence of CO2 continue to work with a high degree of reliability. |
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Post by socold on Apr 18, 2009 1:31:22 GMT
My "does co2 exist" was an extreme example. A realistic analogy to the scientific fact that co2 has increased from pre-industrial times would be the fact that the Earth is billions of years old.
I would be equally condenscending of a thread titled: "Is the Earth really older than 6000 years old?"
There's a line between realistic debate over science and silliness, and both "Has CO2 increased from pre-industrial times?" and "Is the Earth really older than 6000 years old?" cross well over that line.
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Post by gridley on Apr 20, 2009 15:24:02 GMT
My "does co2 exist" was an extreme example. A realistic analogy to the scientific fact that co2 has increased from pre-industrial times would be the fact that the Earth is billions of years old. I would be equally condenscending of a thread titled: "Is the Earth really older than 6000 years old?" There's a line between realistic debate over science and silliness, and both "Has CO2 increased from pre-industrial times?" and "Is the Earth really older than 6000 years old?" cross well over that line. So you believe atmospheric CO2 has never been higher than the present, and that this is an incontrovertible fact? |
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Post by socold on Apr 20, 2009 18:06:51 GMT
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Post by tacoman25 on Apr 20, 2009 18:18:54 GMT
It hasn't been higher than present for at least 800,000 years. Probably millions. Kind of weird that temperatures have likely been just as warm within the last 1000 years then... |
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Post by socold on Apr 20, 2009 18:29:04 GMT
It hasn't been higher than present for at least 800,000 years. Probably millions. Kind of weird that temperatures have likely been just as warm within the last 1000 years then... Such a swing in temperature from medieval warm period to little ice age suggest a strong net feedback in climate amplifying warming. Certainly it's very hard to explain such climate change if climate is self-regulating with net negative feedbacks. The same goes for interglacial - glacial cycles which show more warming than the orbital drivers alone can explain. It suggests temperature changes are being amplified. |
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Post by tacoman25 on Apr 20, 2009 18:38:11 GMT
Kind of weird that temperatures have likely been just as warm within the last 1000 years then... Such a swing in temperature from medieval warm period to little ice age suggest a strong net feedback in climate amplifying warming. Certainly it's very hard to explain such climate change if climate is self-regulating with net negative feedbacks. It's not hard at all. Neither the MWP or the LIA featured runaway climate change like what the IPCC and other have suggested will happen from AGW. The widespread existence of negative feedbacks does not mean that climate swings cannot occur, it merely means that an unstoppable positive feedback loop is highly unlikely. |
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Post by socold on Apr 20, 2009 18:53:20 GMT
Such a swing in temperature from medieval warm period to little ice age suggest a strong net feedback in climate amplifying warming. Certainly it's very hard to explain such climate change if climate is self-regulating with net negative feedbacks. It's not hard at all. Neither the MWP or the LIA featured runaway climate change like what the IPCC and other have suggested will happen from AGW. This isn't about runaway, it's about how much climate changes given a push. Mainstream science suggests that climate moves slightly more than it's pushed because feedbacks amplify the push somewhat, while skeptics claim that climate is works against being pushed. That means skeptics require a bigger push to explain climate changes in the past. So if the medieval -> little ice age temperature change is over 1C and we go with skeptics claims of a climate sensitivity less than 0.1C/wm-2 (which is compatible with recent claims by Roy Spencer and Richard Lindzen), therefore to get 1C temperature change requires a 10wm-2 forcing. Which is massive and very hard to justify occuring (It would tke a 5% increase in solar output to get that) With the mainstream consensus of about 0.75C/wm-2 climate sensitivity you only need a forcing of 1.3wm-2 to explain a 1C temperature rise. That's still a lot, but it's not as hard to imagine that occuring compared to a whooping 10wm-2 forcing. If we take the interglacial-glacial warming of 5-6C the problem is even worse for skeptics. It's not by accident that scientific studies that have tried to contrain climate sensitivity by looking at past temperature change find the very low climate sensitivities suggested by skeptics to be unfeasible. |
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Post by tacoman25 on Apr 20, 2009 19:03:36 GMT
It's not hard at all. Neither the MWP or the LIA featured runaway climate change like what the IPCC and other have suggested will happen from AGW. This isn't about runaway, it's about how much climate changes given a push. Mainstream science suggests that climate moves slightly more than it's pushed because feedbacks amplify the push somewhat, while skeptics claim that climate is works against being pushed. That means skeptics require a bigger push to explain climate changes in the past. So if the medieval -> little ice age temperature change is over 1C and we go with skeptics claims of a climate sensitivity less than 0.1C/wm-2 (which is compatible with recent claims by Roy Spencer and Richard Lindzen), therefore to get 1C temperature change requires a 10wm-2 forcing. Which is massive and very hard to justify occuring (It would tke a 5% increase in solar output to get that) With the mainstream consensus of about 0.75C/wm-2 climate sensitivity you only need a forcing of 1.3wm-2 to explain a 1C temperature rise. That's still a lot, but it's not as hard to imagine that occuring compared to a whooping 10wm-2 forcing. If we take the interglacial-glacial warming of 5-6C the problem is even worse for skeptics. It's not by accident that scientific studies that have tried to contrain climate sensitivity by looking at past temperature change find the very low climate sensitivities suggested by skeptics to be unfeasible. I don't know who you are referring to, but I am not suggesting very low climate sensitivities. I have always made the point about runaway warming being unlikely due to negative feedbacks...I think you are trying to turn this into something besides what I have said. The truth of the matter is that we still have so much to learn about climate forcing and sensitivity. Nobody knows for sure what caused the MWP, the LIA, or many other climate fluctuations...and we don't know what exact feedbacks enhanced or stunted those periods. Again though....a point I keep raising that no one can seem to account for is that if climate sensitivity is as high (to CO2) as mainstream climate theory suggests, then why is there still no sign of accelerating warming? What kind of feedbacks or other factors are possibly preventing this from occurring? |
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Post by socold on Apr 20, 2009 19:08:49 GMT
Negative feedbacks would cause a low climate sensitivity. If you suggest net negative feedbacks then you suggest a low climate sensitivity.
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Post by tacoman25 on Apr 20, 2009 19:18:48 GMT
Negative feedbacks would cause a low climate sensitivity. If you suggest net negative feedbacks then you suggest a low climate sensitivity. Low compared to IPCC estimates, yes. I don't believe the world is dominated by positive feedbacks that all lead to warming, as many AGWers seem to fear. |
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Post by gridley on Apr 21, 2009 14:33:18 GMT
Negative feedbacks would cause a low climate sensitivity. If you suggest net negative feedbacks then you suggest a low climate sensitivity. You've never studied feedback or taken a systems/controls class, I take it? Or does Climate Science have its own rules for positive and negative feedback that are not used by, say, mechanical engineers? If the earth didn't have negative feedback in its climate it would long since have turned into a hothouse like Venus. |
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Post by poitsplace on Apr 21, 2009 22:59:06 GMT
Negative feedbacks would cause a low climate sensitivity. If you suggest net negative feedbacks then you suggest a low climate sensitivity. You've never studied feedback or taken a systems/controls class, I take it? Or does Climate Science have its own rules for positive and negative feedback that are not used by, say, mechanical engineers? If the earth didn't have negative feedback in its climate it would long since have turned into a hothouse like Venus. Yeah, it's an annoying bit of ignorance on the AGW camp's part. We're expected to believe this world is dominated by very strong positive feedback but that temperatures stayed rock solid for about 1000 years...and that it somehow didn't get permanently locked into a hot or cold state in its early history. |
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Post by socold on Apr 22, 2009 0:05:11 GMT
Negative feedbacks would cause a low climate sensitivity. If you suggest net negative feedbacks then you suggest a low climate sensitivity. You've never studied feedback or taken a systems/controls class, I take it? Or does Climate Science have its own rules for positive and negative feedback that are not used by, say, mechanical engineers? If the earth didn't have negative feedback in its climate it would long since have turned into a hothouse like Venus. Yes climate feedbacks are not the same as feedbacks in say electronics. A climate feedback is one by which a change in temperature causes a change in forcing (which will thereby causing a further change in temperature). The unit for a climate feedback can be given in wm-2/C Ie A forcing is measured in wm-2 Climate sensitivity is measured in degrees C/wm-2 A feedback is measured in wm-2/degreeC A positive feedback is literally a feedback which is above zero (ie Xwm-2/C where X > 0) |
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