|
Post by poitsplace on Feb 6, 2009 1:57:40 GMT
We might already be ahead of the medieval warming period in terms of the last decade. As for the 1C warming, it's roughly what a doubling of co2 will provide directly. I have no problem with your 1C total on doubling...and you can take that meaning both ways. I have no problem with the figure and I have no problem with the warming. We've had the warming for 70 freaking years, we've had ice melt...temperatures seem perfectly able to drop again with the PDO and solar forcing. There's no evidence that this is happening Wrong numbers apparently. Smoothed numbers show an increase from about 307ppm in 1940 to about 337ppm in 1980, an increase of about 9.7%...then to a bit under 385 in 2007 (I'll give you the 14% on that one). It's a significant difference. [/quote]We've had 0.8C over the 20th century, [/quote] WOW, just...wow. Where to start? Ok, the starting point falls on a time of much lower solar activity, the bottom of the normal cooling cycle, and yet, overall (the period) was still considered to be coming out of the little ice age...oh and had a whole 12ppm increase in CO2. How is the 1900-1940 period REMOTELY relevant to anthropogenic global warming? Also, do you notice the ramp up from the bottom of that period is about the same as the 1980-2002 ramp? Shouldn't that be impossible? After all, if CO2 forcing MUST be necessary for such increases to occur now then it CAN'T be possible that it happened then. BTW, going back to the previous, smoothed, warm period peak in 1880 the total warming comes out to....6C speculation...we still aren't completly sure of the affects of clouds, much less a thick soup of chemicals Riiiight, the high tech energy sources will stay the exact same cost for the next 50+ years. Never mind the fact that the costs of all of them have been dropping non-stop for all of their history. No, we should EXPECT that the cost/performance improvements we've seen for all of human civilization (increasing exponentially, I might add) to simply stop dead right now. Once again you're stuck with the reality of the observed data...we have no evidence that there will be anything but CO2's expected (and not remotely dangerous) warming. Indeed, the last 70 years seems to indicate that's the most we'll get.
|
|
|
Post by woodstove on Feb 6, 2009 2:06:46 GMT
Hi Steve. You write: "On the other, the oceans have not yet caught up with the relatively rapid warming."
At best -- at best -- you are parroting something you read on Real Climate. You will need to cite a study showing that the oceans absorb significant energy from the atmosphere. As I'm sure you'll allow, after you've thought about it a little more, it is the other way around.
Your line of reasoning suggests that El Ninos are caused by a warm atmosphere! Gore says things like this from time to time.
|
|
|
Post by crakar24 on Feb 6, 2009 2:33:09 GMT
The basic science behind AGW is as proven as gravity -- rises in CO2 levels will increase the amount of energy trapped in the system. If the system lacks negative feedbacks, the temperature will rise and the temperature will stabilize based on increased radiation back into space.
Just a small point: To FurryCatHerder refer to above cut and paste. I dont recall the basic science behind gravity using the word "IF".
|
|
|
Post by dontgetoutmuch on Feb 6, 2009 4:55:34 GMT
Steve, oh man that is a nasty self inflicted wound ya got there... When you wrote:
"Other evidence of positive feedbacks is the large swings in climate that have occurred in the past such as during the ice age cycle. The changes in greenhouse gas levels, the albedo and the Milankovitch cycles are nowhere near enough to explain the ice ages."
Let me see, your argument is that C02 is going to kill us all, just like... well albedo can't, uhhh how about Milankovitch cycles... no? Well it must be those pesky greenhouse gasses, I don't know, dinosaurs breaking wind while driving their very large SUVs or something. NO??? Wait a minute what was your position again?
Steve's take on AGW -> C02 can't cause climate change even though it does.
Dude, get a band aid on that thing. :-)
|
|
|
Post by FurryCatHerder on Feb 6, 2009 7:03:52 GMT
FurryCatHerder... "The basic science behind AGW is as proven as gravity -- rises in CO2 levels will increase the amount of energy trapped in the system." You are right, and so what. The amount of extra heat trapped in the system is trivial... WITHOUT A POSITIVE FEEDBACK MECHANISM!!! AGW requires that the trace amount of heat trapped by the added C02 cause an out of control water vapor feedback loop. This has never happened. Period. Even at much greater concentrations of C02 and warmer temperatures. Why. Because it is fantasy. The only place this sort of positive feedback loop has EVER been seen is inside a computer instructed by its programmer in a kind of what if scenario. NONE of these models has EVER been validated to model the real world. NOT ONE. I don't know any actual climatologists who say there is going to be some "out of control water vapor feedback loop". And I beg to differ -- the positive feedback cycles are also just as proven as the fact that increasing CO2 causes more heat to be trapped by the atmosphere. And seriously, if you don't know the difference between a HYPOTHESIS and a THEORY, don't use the words. Too many people here use "theory" to refer to their own ideas when the correct word is "guess", as in "probably incorrect guess because I never studied the sciences needed to understand the concepts." I reject the warmies fixation on "ZOMG! IT'LL BE SO HOTZ!" because it's been hotter, and it's been colder, and life on Planet Earth keeps on going. I'm much more concerned with "there is so much coal!" foolishness from people who don't grasp that the easy coal has all been mined and some of the techniques (like, cutting off the tops of mountains ...) are so destructive to the environment and so expensive to use that people will quit using fossil fuels long before the run out.
|
|
|
Post by Pooh on Feb 6, 2009 8:54:31 GMT
"Karl Popper and Global Warming"? Do you refer to the philosopher Karl Popper that George Soros studied under?
|
|
|
Post by icefisher on Feb 6, 2009 9:19:14 GMT
This has nothing to do with lines on a graph, it is simply that warming has effects that cause additional warming. For example warming causes ice to draw back and albedo reduces causing more warming. that's a positive feedback and so it amplifies any warming. Warming creates CO2 and CO2 creates warming, then add in your dropping albedo and who knows what else. Bottom line is this has happened before and it has gotten cooler after only a couple of hundred years of warming. First, natural forces causing cooling has to overcome the force causing it to get warmer and a couple of hundred years of strengthening feedbacks. . . .turn it all around and cool for a couple of hundred years and its feedbacks (dropping CO2 and increasing ice) and reverse again. It suggests a very powerful force. . . .and it suggests it reverses itself powerfully. So actually the more you argue for positive feedbacks the less likely it is CO2 can be powerful enough to be the driver. And when you move beyond CO2 is there anything to look at but the sun? As soon as you do you need to look at what the sun has been doing and how it corrolates with temperature. When that exercise is over not much is left for CO2. I hear AGW proponents sort of grudgingly acknowledging you get .1 to .2 in temperature variance between mins and maxs in solar cycles. Well they need to study these grand cycles then because they suggest decadal variations that cumulatively could equal virtually all the warming we have seen over the past 85 years.
|
|
|
Post by graywolf on Feb 6, 2009 10:35:20 GMT
From a quick squizz through the thread I suspect that deep ocean currents, and there warming ,have been neglected. Sure there are season variations to the upper 300m of ocean but the subduction of those waters into the global network of oceanic currents has yet to show it's hand. So along with the positive feedbacks we have already brought into being, be it dry soils inability to hold CO2, methane leakage from melting permafrost/cathrites, open dark water waters where once ice sat, ice shelf loss and it's impacts on temps up to 700km inland, oceanic CO2 sink reduction, ravaging of the rainforest's, desertification of sub-Saharan Africa due to overgrazing, increasing pollution from Indo-China etc.,etc. we have to face the prospect of the resurgence of warmer waters into the oceans as these 'deep currents' re-surface. Ever wondered at the time lag between temp rises and CO level increases?? See what occurs once the 'circle' is complete and we start insulating the planet further with an ocean that warms where it was once cooled.
This is all jolly fun (unless you have kids that is) but our time is growing short, soon enough the deniosphere will need to find even more excuses for the observations than the plethora they currently employ...
Me?, I'll stick to the one reason for the changes we see!
|
|
|
Post by glc on Feb 6, 2009 11:42:25 GMT
Re: Oceans
I'm with the sceptics on this one. It's highly improbable that a tiny increase in downward LWIR radiation has been responsible for bulk heating of the oceans over the past ~50 years (CO2 levels were only 315 ppm in 1958). Thermal emission from the atmosphere can only penetrate a few micron (about the thickness of a human hair) into liquid water. It is just (but only just) about conceivable that the additional CO2 effect *might* slow the rate of cooling but, in practice, this effect would be undetectable against a background of the huge variability (100+ w/m2) in the net radiative flux.
|
|
|
Post by steve on Feb 6, 2009 12:17:07 GMT
Hi Steve. You write: "On the other, the oceans have not yet caught up with the relatively rapid warming." At best -- at best -- you are parroting something you read on Real Climate. You will need to cite a study showing that the oceans absorb significant energy from the atmosphere. As I'm sure you'll allow, after you've thought about it a little more, it is the other way around. Your line of reasoning suggests that El Ninos are caused by a warm atmosphere! Gore says things like this from time to time. No. At *worst* I was parroting something from realclimate. But I wasn't (though it's obviously been said on realclimate as well). And I do not understand at all how you'd conclude that my line of reasoning says what you think it says . Perhaps it's just an excuse to bring up Gore the bogeyman. Clearly, if the atmosphere were the source of the ocean warming, then the oceans (having higher heat capacity) would lag behind. So the question is how far behind they are. Here's one paper that tries to estimate sensitivity based on ocean heat uptake and calculates a minimum (ie. most optimistic) value of 1.6C: Journal of Climate Article: pp. 3117–3121 An Observationally Based Estimate of the Climate Sensitivity J. M. Gregory et al ams.allenpress.com/perlserv/?request=get-abstract&issn=1520-0442&volume=15&page=3117&ct=1The "sceptic" view and the arguments against this view are probably encapsulated in the following paper and some of the replies to the paper: Heat capacity, time constant, and sensitivity of Earth’s climate system SE Schwartz - J. Geophys. Res, 2007
|
|
|
Post by steve on Feb 6, 2009 12:21:53 GMT
Steve, oh man that is a nasty self inflicted wound ya got there... When you wrote: "Other evidence of positive feedbacks is the large swings in climate that have occurred in the past such as during the ice age cycle. The changes in greenhouse gas levels, the albedo and the Milankovitch cycles are nowhere near enough to explain the ice ages." Let me see, your argument is that C02 is going to kill us all, just like... well albedo can't, uhhh how about Milankovitch cycles... no? Well it must be those pesky greenhouse gasses, I don't know, dinosaurs breaking wind while driving their very large SUVs or something. NO??? Wait a minute what was your position again? Steve's take on AGW -> C02 can't cause climate change even though it does. Dude, get a band aid on that thing. :-) No bandaid required. You've misunderstood. It was a discussion about feedbacks to an initial source of warming. Some of the feedbacks are probably independent of the inital cause of warming (be it solar, albedo changes or greenhouse gases). The fact that the climate was very sensitive to changes during the ice age is evidence that it may be very sensitive to changes due to CO2 warming.
|
|
|
Post by steve on Feb 6, 2009 12:46:18 GMT
Anyway, we're off topic.
The suggestion is that climate scientists are ignoring all the disproofs of the theory.
But most of the discussion here is about whether the evidence in support is sufficient. That is a completely different question.
Even so, I don't see any hard evidence that climate scientists are ignoring any incontrovertible disproofs of parts of the theory.
- cosmic ray theory is newish science with some weak evidence of correlation with some clouds, but no evidence that this affects climate. - PDO has some evidence of correlation based on numerology of PDO metrics. But it doesn't explain the mechanism for the warming or the reason for the numerology method used. - climate scientists rightly ignore the unreviewed pseudoscience and/or dodgy science of Gerlach and Tscheu-wotsisface and Miscolkzi plus bonkers ideas about CO2 saturation. Even my basic physics qualification was good enough to spot the flaws in these. - a lot of what is concluded by the layman as ignoring the obvious is either not obvious or not ignored. eg. the belief that feedbacks must mean ultimate planetary meltdown, or that climate scientists do not understand natural variability or that they ignore past evidence of "high CO2 and low temps". - that "prominent scientists" such as tv gardeners, weathermen and other celebrities repeat these misunderstandings is also justifiably ignored by climate scientists.
I see evidence that climate scientists are seriously taking into account many sources of uncertainty eg.: - between AR1 and AR2 a much better appreciation of aerosols reduced the warming predictions. - solar effects are being studied, and some warming is attributed to solar. - a huge effort is going into resolving the conflict between satellites and models which has mostly gone in favour of the models. - a lot of novel studies have been done to tease out UHI effects. - a huge effort is going into better comparing models with other satellite data. This should affect understanding of, for example, PDO/ENSO impacts. - effort is going into studies of proxy data. As yet, we do not have a proof of an MWP that was globally warmer than now. And even if we did it, in absence of knowledge of possible causes, it may not say anything about conditions today.
|
|
|
Post by jimcripwell on Feb 6, 2009 14:24:37 GMT
steve writes "- cosmic ray theory is newish science with some weak evidence of correlation with some clouds, but no evidence that this affects climate."
I think this is simply wrong. The point I make is that in AR4 Chapter 2.7, the IPCC argues that cosmic rays have no effect, but ignores and omits the data and publications that suggest that cosmic rays MAY have some effect; for example, Svensmark et al Proc. Roy. Soc. A October 2006, and The Chilling Stars, which was published BEFORE AR4. There is no firm conclusion in AR4 that cosmic rays have NO effect, yet their possible effect is ignored in Table SPM 2. If cosmic rays MAY effect climate, then the conclusion that the recent rise in world temperatures is very likely to have been caused by rising CO2 levels is simply not tenable.
|
|
|
Post by duwayne on Feb 6, 2009 15:06:04 GMT
Anyway, we're off topic. The suggestion is that climate scientists are ignoring all the disproofs of the theory. But most of the discussion here is about whether the evidence in support is sufficient. That is a completely different question. Even so, I don't see any hard evidence that climate scientists are ignoring any incontrovertible disproofs of parts of the theory. - cosmic ray theory is newish science with some weak evidence of correlation with some clouds, but no evidence that this affects climate. - PDO has some evidence of correlation based on numerology of PDO metrics. But it doesn't explain the mechanism for the warming or the reason for the numerology method used. - climate scientists rightly ignore the unreviewed pseudoscience and/or dodgy science of Gerlach and Tscheu-wotsisface and Miscolkzi plus bonkers ideas about CO2 saturation. Even my basic physics qualification was good enough to spot the flaws in these. - a lot of what is concluded by the layman as ignoring the obvious is either not obvious or not ignored. eg. the belief that feedbacks must mean ultimate planetary meltdown, or that climate scientists do not understand natural variability or that they ignore past evidence of "high CO2 and low temps". - that "prominent scientists" such as tv gardeners, weathermen and other celebrities repeat these misunderstandings is also justifiably ignored by climate scientists. I see evidence that climate scientists are seriously taking into account many sources of uncertainty eg.: - between AR1 and AR2 a much better appreciation of aerosols reduced the warming predictions. - solar effects are being studied, and some warming is attributed to solar. - a huge effort is going into resolving the conflict between satellites and models which has mostly gone in favour of the models. - a lot of novel studies have been done to tease out UHI effects. - a huge effort is going into better comparing models with other satellite data. This should affect understanding of, for example, PDO/ENSO impacts. - effort is going into studies of proxy data. As yet, we do not have a proof of an MWP that was globally warmer than now. And even if we did it, in absence of knowledge of possible causes, it may not say anything about conditions today. Steve, You are saying that the models had major problems. This isn't news. The model skeptics were right. There's nothing to indicate that the modified models are any good even though their Global Warming predictions are dramatically lower. Just because changes have been made doesn't mean they are now accurate. The recent NOAA prediction is a warming of approximately 0.15C per decade from a combination of "model and empirical" sources . Why does this make sense when the warming was only about that much when the ocean currents were in a positive mode? The models should stay in the labs until they can at least replicate history. Then, given their complexity and propensity for failure, they should be treated with extreme caution, not touted as a the premier tool.
|
|
|
Post by dontgetoutmuch on Feb 6, 2009 17:28:50 GMT
FurryCatHerder--> I don't know any actual climatologists who say there is going to be some "out of control water vapor feedback loop".
My take--> AGW REQUIRES a runaway water vapor feedback loop to happen. All of their dire predictions are based up runaway catastrophic warming, caused by positive water vapor feedback loops. The position of AGW proponents is NOT “We know that human introduced C02 will cause a small positive change in global temperatures from what they would have been over the next century or two. We understand that we are not sure if this warming is significant to the planets environment in any way, and we are not sure if this is a good thing or a bad thing. Instead the IPCC has stated on the record that their climate MODELS project that the earth will be as much as 11.5 degrees F warmer by 2100. Of course the models say everything, warmer, yep, cooler, yep, wetter, yep, drier, yep. Well, what if it’s a nice day? Global warming for sure dude, got to stop it. It is fairly safe to say that at this point there is nothing that is incompatible AGW. Ice age? Why yes our models did predict that an ice age could occur, but after that it will be really hot. Now, give us our climate taxes, and our eco police and our one world government. NOW, or you are going to die.
FurryCatHerder--> And I beg to differ -- the positive feedback cycles are also just as proven as the fact that increasing CO2 causes more heat to be trapped by the atmosphere.
My take--> Positive feedback loops are proven?!? Whoa not so fast… did you forget a word? The one I’m thinking of is false. As in: Positive feedback loops have been proven false. Was that what you meant. If not, please help me understand how they are proven.
FurryCatHerde--> And seriously, if you don't know the difference between a HYPOTHESIS and a THEORY, don't use the words. Too many people here use "theory" to refer to their own ideas when the correct word is "guess", as in "probably incorrect guess because I never studied the sciences needed to understand the concepts."
My take--> Hmmm I don’t think I used those words in my post, but I think I know what they mean. Although I do need help coming up with a word: What do you call a THEORY or a HYPOTHESIS that has been falsified?
FurryCatHerder--> I reject the warmies fixation on "ZOMG! IT'LL BE SO HOTZ!" because it's been hotter, and it's been colder, and life on Planet Earth keeps on going. I'm much more concerned with "there is so much coal!" foolishness from people who don't grasp that the easy coal has all been mined and some of the techniques (like, cutting off the tops of mountains ...) are so destructive to the environment and so expensive to use that people will quit using fossil fuels long before the run out.
My take--> Wow! My take exactly. Well, I don’t have a problem with them getting the stuff out. With one condition. The folks doing the extraction need do it with the understanding that when the coal is out, the mountain needs to be put back. At least as good as it was before. (And no toxic runoff) Furthermore the costs of doing this should be included in determining whether or not getting the stuff out is economically feasible. We only have one petri-dish to play with, we need to stop urinating in it.
|
|