1) By stable, I mean that for the last 600,000+ years or so we have seen cycles, where the max and min temperatures are similar (compared with the range over the 2.5 billion years before that). All the evidence I have seen points to us now tracking out of those cycles, thus we have the problem.
It hasn't been stable, in any terms. Actually, the global average temperautures for most of the last 550ma have been far more stable, for vastly longer periods of time than now. During the Cretaceous, the global average temperature remained at around 18 degrees (6 above now) for almost 100 million years!!!. 6-10 degree up and down fluctuations over a 600Ka period don't even count.
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2) The ecosystem arable stuff is quite a bit more complex than you point out and those same changes occurred when the world went from being primarily covered in forest to having large areas of grassland (also the grassland can't hold as much C, so if it had always been there we wouldn't have all the coal we are burning), changing agriculture techniques (no till etc.) means that bare soil is increasingly less common. But I don't disagree with your point.
Yes it is far more complex than what I wrote about there, I'd have had a much larger post if I went into the nitty gritty about it!!!!
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3) Temperature measurements are made at various levels in the atmosphere (and with various results), plus urban heat islands etc. are adjusted for in the models and the data interpretation, so I don't think that those factors negate the predictions for future climate.
They are now, and in the last 50 or so years, but what about the preceding 100 or so years...and they've only had the use of radiosondes for atmospheric measurements since the mid to late 40's. Satellites for even less time. The data isn't as good or as complete as it should be.
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4) I'll freely admit I know little if anything about the major controls on global temperature over the billion year timescales you are talking about (though I am fascinated). You appear to be suggesting that those controls are not well understood? Considering the differences that you have pointed out between then and now, and the relative recent stability (see my definition above!!!!), I would still say that making comparisons with the last million years or so was a much better option than looking at pre-cambrian times....
I'm not looking at the Pre-Cambrian for the most part. Only that geological processes have been relatively similar to now for the past 2500Ma. The climate has certainly changed, as has the atmosphere. Go far enough back and you've got an atmosphere that's mainly nitrogen, water vapour, some methane and ammonia, and over 100 atmospheres of CO2 content. Not my idea of a happy atmospheric mix!!!. What's more, it's a secondary atmosphere and not the one the planet originally outgassed.
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5) I agree totally with your paragraph on deforestation, I also agree absolutely that CO2 is not the only player in climate change. I don't think anyone would disagree, certainly not the modellers, who do include a whole raft of things.
The only way to know what the modellers have used in their models is to look at the algorithms used and the assumptions they've used in making the models. Some may have included deforestation, others may not. What interests me is though there are other factors which are contributing to climate change in just as important ways as CO2, why is there an almost religious belief in the cause being "only" CO2 emissions. That's how it appears to being played out.
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So in summary, the difference between you and me is that you consider CO2 increases to be a smaller impact than most models predict and that possibly the degree of warming is overestimated due to biased data?
My opinion is basically that all areas of biology are already seeing the effects of climate change (whatever the cause). Not being a climate scientist (but also not being totally ill informed) I have seen no convincing arguments that the basic assumptions of the "97%" http://www.iceinspace.com.au/forum/..../winking70.gif are incorrect and I don't have the background to judge whether any of the "3" have some wacked out idea that might just be correct. I'll exclude from that 3% all the jokers who are peddling disinformation for some end I don't understand.
Yes, nearly correct there...what I'm trying to get at is that the impact of the riding CO2 levels isn't the be all and end all of what's changing the climate. There are other factors just as important which are contributing but you hear very little about them. All you get is the CO2 bogey man and very little else. There's a lot more to the results being published than pure academic study and reporting and I think those leaked emails recently, have established that and don't believe for one minute it's only confined to those scientists involved. They have done the whole debate a complete disservice and science no favours either. If I was the chancellor of the university/ies they were at, I would have dragged them before an university council and made them explain themselves. If they didn't have a damn good answer to back themselves up (which they wouldn't), they'd have been charged with gross misconduct and had their tenures revoked. I'd have sacked them immediately and advised the governments not to take their studies on their word, or anyone else associated with their studies...that includes the IPCC, which they were a part of.
Ah, but we're not talking about correlations really are we? The models are much more sophisticated than that and based on the physics involved. I would have thought that an equation of: proportion of radiation not intercepted by other gases x fraction of radiation potentially absorbed by CO2 x CO2 concentration would give bounds on the CO2 effect both then and now (I realise that is a silly simplification, but you get my drift). I find it very hard to believe that those sort of calculations have not been done for the carboniferous and for the current climate. No doubt there are many factors that can be tweaked to give differing results, but it should give a range and it should allow sensitivity analysis to be done, giving probabilities. So I'm genuinely interested to know the likely explanations for the differences you point out.
The bottom line is though, that we're now talking about correlations rather than known physics and that is a risky basis in my opinion....
It's all about risk, and as I see it cutting CO2 emissions is the one thing most likely to help....
The climate models for those various periods are based on the physics of the climate, with variations taken into account for the obvious differences between each period of time. That's how they're able to make those correlations I have been talking about.
Oh, I'm with you. It's a risky thing to be pumping the CO2 into the atmosphere like we are. No matter which way it turns out, it's much better to err on the side of caution and look to decrease what we are pumping into the atmosphere. No matter what the overall factors are, adding to your already growing problem is not the smart way of going about doing things.
It hasn't been stable, in any terms. Actually, the global average temperautures for most of the last 550ma have been far more stable, for vastly longer periods of time than now. During the Cretaceous, the global average temperature remained at around 18 degrees (6 above now) for almost 100 million years!!!. 6-10 degree up and down fluctuations over a 600Ka period don't even count.
Ah but they do, obviously you are right about the long term stability and my use of the word is a poor choice, lets say "predictable" instead (though that has connotations I wouldn't use...), but if you have a steady up/down cycle (and on a gross scale it has been fairly steady for the last 4 ice ages at least) and then suddenly depart from it I would be worried. The fact that it varied in a different way much further back in time wouldn't make me feel any better about it.
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Originally Posted by renormalised
They are now, and in the last 50 or so years, but what about the preceding 100 or so years...and they've only had the use of radiosondes for atmospheric measurements since the mid to late 40's. Satellites for even less time. The data isn't as good or as complete as it should be.
Well, the data is as good as it can be and we can only work with what we can get. We can't get satellite or balloon measurements for the last million years, so we have to work with what we have and in my opinion the human inginuity used in estimating temperatures from many different fields in many different ways is remarkable. Especially as most (but by no means all) agree to quite a degree.
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Originally Posted by renormalised
The only way to know what the modellers have used in their models is to look at the algorithms used and the assumptions they've used in making the models. Some may have included deforestation, others may not. What interests me is though there are other factors which are contributing to climate change in just as important ways as CO2, why is there an almost religious belief in the cause being "only" CO2 emissions. That's how it appears to being played out.
Well, that is perhaps true of the media, I don't think it is true of the science. When i was working for the CRC for Greenhouse Accounting other gases were being looked at and the IPCC report has plenty on other gases too. The increasing concern about methane is an obvious part of that. Land use change is certainly a major factor in greenhouse accounting and a big sticking point right now in Copenhagen.
A lot of the algorithms used do get published in peer reviewed papers (dunno what proportion), it's just that by publication they tend to be somewhat behind the cutting edge.
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Originally Posted by renormalised
Yes, nearly correct there...what I'm trying to get at is that the impact of the riding CO2 levels isn't the be all and end all of what's changing the climate. There are other factors just as important which are contributing but you hear very little about them. All you get is the CO2 bogey man and very little else. There's a lot more to the results being published than pure academic study and reporting and I think those leaked emails recently, have established that and don't believe for one minute it's only confined to those scientists involved. They have done the whole debate a complete disservice and science no favours either. If I was the chancellor of the university/ies they were at, I would have dragged them before an university council and made them explain themselves. If they didn't have a damn good answer to back themselves up (which they wouldn't), they'd have been charged with gross misconduct and had their tenures revoked. I'd have sacked them immediately and advised the governments not to take their studies on their word, or anyone else associated with their studies...that includes the IPCC, which they were a part of.
I think the email leak is overplayed. It certainly isn't good and it has certainly done science a disfavour. But to some extent it just reflects reality. We scientists are people, personal politics, have dissagrements and have to fight over funding etc. We aren't a perfect science machine. I don't think there is anything there that casts doubt on the publicly released results.
For most of Earth's history, the CO2 levels have been appreciably higher (much higher in most cases) than what they've been for the last 2.5 million years. How do you account for a CO2 level of 600-800ppm for most of the Tertiary/Quaternary Periods, and a high of 1200-1250ppm for the Palaeocene/Eocene epochs.
Carl, what will happen if CO2 levels go back up to 600ppm plus?
Peter, is the official climate science as unreliable as financial forecasts?
I think the email leak is overplayed. It certainly isn't good and it has certainly done science a disfavour. But to some extent it just reflects reality. We scientists are people, personal politics, have dissagrements and have to fight over funding etc. We aren't a perfect science machine. I don't think there is anything there that casts doubt on the publicly released results.
I haven't followed the email saga much at all but I think everyone has observed the timing and whos interests' it serves.
However I was taking to one of our academics who knows a researcher at East Anglica - though I'm not sure whether it was his emails that were leaked. Apparently the media picked up on the use of the word 'trick' to suggest that the scientists were pulling a swifty. It came up in the context of trying to put together a climate history over the past few millenia. There are multiple climate proxy records to consider and each one operates in a different way and has different spatial and temporal coverage and resolution. Then there is the instrumental record which also varies in quality and coverage. The comment was then something like .. "the trick is how to combine them..". So that bit, at least, is a storm in a tea-cup.
Climatology is really in its infancy by comparison, in general we don't know the causes of temperature change...
Infancy? After of decades of research nothing other than anthropogenic causes (ie the whole raft, plus 200 years of pumping CO2) has heen attributed to climate change.
I don't see any of the naysayers getting on a plane to Stockholm with any plausible natural mechanism to collect their Nobel's.
Lovelock (and many others) have shown that a species can and does have significant effect on its environment. The planet's atmosphere changed big time with the arrival of photosynthesis!
To suggest humans have not had an impact on our planet is lunacy IMHO. The science debate has moved on and most peer reviewed journals are simply agruing now about the degree of change.
Last edited by Peter Ward; 17-12-2009 at 05:20 PM.
Reason: spelling!
For most of Earth's history, the CO2 levels have been appreciably higher (much higher in most cases) than what they've been for the last 2.5 million years. How do you account for a CO2 level of 600-800ppm for most of the Tertiary/Quaternary Periods, and a high of 1200-1250ppm for the Palaeocene/Eocene epochs.
Carl, what will happen if CO2 levels go back up to 600ppm plus?
Peter, is the official climate science as unreliable as financial forecasts?
I think it will prove to be if we keep getting fed the "the end is nigh" human created CO2 GW alarmism. Many are now questioning the science behind this and rightly so. I still want someone to explain Henry's law to me in laymans terms and how it fits into all of this, seems this maybe a thorny one.
Future King Charlie said yesterday in Copenhagen that we have 7 years to get it right before we lose the controls forever - what at midnight on December 31 2016 that's it? Now where did he pull that one from, sounding more and more like a Y2K to me.
It is often suggested that oil companies and geologists associated with them are conspiring to fan the anti GW campaign for vested interests. Then of course the geologists cop a bagging (actually ridicule and personal attacks - very un scientific) as not being climate scientists - oh really, I suspect they have a better handle on what is happening based on billions of years of Earth's history.
Talk about not seeing the forest for the trees - a potentially huge tax burden on everyone in the form of an ETS that will pour billions from this country into a world fund to help "less fortunate nations" who have been happy to spend most of their income on arms, fighting with one another let alone feed themselves. Blimey if I were the president of kalamazoo I would saying anything at Copenhagen to get this through and reap the dollars.
Then of course we have people saying I am concerned for my grandkids - what? by imposing a huge make you feel good tax on them. Geez do the people questioning this quickly put together theory love their grandkids anyless, I think not. And all this based on a scientific theory that has grown its own legs, thank goodness there is now a growing chorus of doubters and questions being asked.
Anyways many islands were supposed to be under water by now -it is over 10 years since the first "frightening" reports were issued and I distinctly remember reading "within 10 yrs", maybe they refined the computer models and got another 10 or 20.
My comment was never meant to be an analogy, just used to point out how really bad an analogy of "97% of doctors" was. But then are financial forecasts really any different to the current dabate, maybe not - many financial experts who went to Uni to study economics, who use computer models to work out where to invest your money, they still have a job at the end of the day and get paid very well with your money whether they lose your money or not.
I am opposed to an ETS too, I think there are better ways to do it.
I think we need to reduce the risk of climate change first before we think about compensation.
Australia needs to replace coal powered electricity with gas, solar, wind, wave, nuclear etc.
Anyways many islands were supposed to be under water by now -it is over 10 years since the first "frightening" reports were issued and I distinctly remember reading "within 10 yrs", maybe they refined the computer models and got another 10 or 20.
PeterM.
This is misinformation.
They already are underwater.
The people of Tuvalu are being evacuated. Why do you say otherwise?
The people of Tuvalu are being evacuated. Why do you say otherwise?
Misinformation is right Pete.
Below pretty much says a lot in a small space about what may have contributed to their problems. http://www.skepticism.net/?p=62
Perhaps, as I noted in the kingdom of Kalamazoo - there maybe some opportunities for some good funding here, handouts, relocations to OZ and New Zealand and heck if the US helped create the problem during world war 2 by digging up the island for an airstrip and affecting the water table then I say allow them entry to the USA with heaps of money in their pockets. .
We are good at helping out small coutries and after all CO2 is mostly our fault right? Yet our hospitals are in crisis, kids are dying on our roads at an alarming rate, we have real problems alright.
75 per year being relocated to NZ, better employment and health etc etc, not bad. I would be first in line to leave.
And then from their own June 2008 report (below).
"The population tends to increase in the 4th quarter and decreases in the first quarter as students return to study"
Then you have returning labourers to Nauru.
So there are a lot of coming and goings in this small 1 meter above sea level island.
Many passengers on the Titanic also refused to believe the (unsinkable) ship was sinking.....it's well documented in the subsequent inquest.
BTW the article to which you refer acknowledges a (a dismissive "grand total") 7mm rise in sea level since 1993...which equates to around a 5 sq km loss of coastline for nations
like Tuvalu....as a recent ABC documentary showed....the poor buggers are underwater. Or are you suggesting they just imagining it?
Last edited by Peter Ward; 17-12-2009 at 08:03 PM.
Reason: clarification
Many passengers on the Titanic also refused to believe the (unsinkable) ship was sinking.....it's well documented in the subsequent inquest.
BTW the article to which you refer acknowledges a (a dismissive "grand total") 7mm rise in sea level since 1993...which equates to around a 5 sq km loss of coastline for nations
like Tuvalu....as a recent ABC documentary showed....the poor buggers are underwater. Or are you suggesting they just imagining it?
Coral Atolls - was it Darwin who suggested and was eventually proven correct that atolls are built on sinking volcanoes. Does that not then mean these atolls are actually sinking and not being swamped by the sea? That would explain the 7mm rise of water or actually the 7mm fall of land wouldn't it?
Depends on when the doco was made - there have been and continue to be tsunamis that no doubt have had some impact. I guess removing the cocunut trees doesn't help keep the land in place either, but lets blame it on CO2 man made global warming gets more votes that way. Pulls on the emotions a bit I guess. And what of digging up much of the island for an airstrip during WW2.
Nuff said, at least we kept it civil, thank you. I am going out supernova hunting. I will respect your views and your defence of them. I don't agree but I do respect them.
PeterM.
For most of Earth's history, the CO2 levels have been appreciably higher (much higher in most cases) than what they've been for the last 2.5 million years. How do you account for a CO2 level of 600-800ppm for most of the Tertiary/Quaternary Periods, and a high of 1200-1250ppm for the Palaeocene/Eocene epochs.
Carl, what will happen if CO2 levels go back up to 600ppm plus?
Peter, is the official climate science as unreliable as financial forecasts?
The higher levels during those epochs were due to several factors. One being as the Earth warmed up after the slight dip at the end of the Cretaceous, the oceans became less efficient at absorbing the CO2 that was building up. The ideal sea temp for the maximum absorption of CO2 is around 16 degrees. As the temp goes up it becomes less efficient at absorbing the CO2, but what the worrying things is this...if the CO2 levels go up appreciably, that make the oceans more acidic, through the formation of carbonic acid. This is disastrous for calciferous microorganisms such as forams, which absorb CO2 and calcium to make their carbonate shells. These little critters take a lot of the CO2 out of the air when they help the water to absorb it. If they can't make their shells, they die...you can see where this leads. Not only less CO2 absorption, but it stuffs the food chain as well.
The second factor which had affected the CO2 levels was volcanic activity. The late Palaoecene-early Eocene was a fairly active period in time but not active enough to cause the whole warming episode. What they think was the main cause of the warming was a sudden release of the methane clathrates in the shallow seas and deep oceans. The CO2 built up to the levels (which were already fairly high...around 1000ppm) where it heated the atmosphere enough to trigger the widespread release of the clathrates. It was only about a 1-3 degree rise in the previous average temp. Once that happened, it was on for young and old.
The reason why the CO2 concentration dropped back down to 600-800ppm, was the cooling of the planet after Antarctica begin to freeze over, starting during the Oligocene, around 30Ma. That's when we see first evidence for a large scale glaciation on the continent. It, at first, occurred in the interior, on the high plateau and mountains and gradually spread outwards. What brought it down to the levels we saw pre-industrial and such was when the psychrosphere formed...the circumpolar oceanic current that effectively cut Antarctica off from the rest of the world's ocean currents, except for the deep ocean current, which is cold anyway. That finally happened when Sth America split off from Antarctica around 7-13Ma. Another event that also helped was the closing of the Panama Isthmus around 2.5Ma, which most likely helped trigger the Nth Hemisphere ice ages. However, throughout most of the Tertiary and the beginning of the Quaternary, the average global temps were higher than what they are now.
Another thing which probably didn't help, even though it pumped a fair bit of CO2 into the atmosphere was La Garita. Think Yellowstone was big...La Garita would've made the largest eruption at Yellowstone look like a dud firecracker. It was the largest volcanic eruption ever recorded in Earth history, as far as we know (maybe Siberia was larger but that's debatable). Enormously massive would be an understatement!!.
You also had continuing mountain building, especially with the Himalayas, the Rocky Mountains and the Alps (and associated ranges). Their erosion helped to scrub CO2 from the atmosphere, so what was initially a fairly high conc' of CO2 was gradually brought down to present levels.
If the CO2 went back up to 600ppm, it wouldn't be good. I would be worried about the clathrates. We're already seeing some sublimation due to an increase in the water temps surrounding the deposits. Given present oceanic conditions, 600ppm atmospheric CO2 might be a trigger point for a sustained sublimation of the clathrate. We don't know just yet, but I wouldn't want to risk it. If it was, as I've said before, we'd be in serious trouble.
I hope that's been of help
Oh, nearly forgot, here's a graph showing the temps during the Tertiary, right through to the Holocene (now).
Yep, gather all that hot air down in that big building in Canberra and use it to turnover turbines to generate the electricity. But don't let it escape...that'd be disastrous!!!!
Boucot, A, J., Xu, C, and Scotese, C. R., (2004). Phanerozoic climate zones and paleogeography with consideration of atmospheric CO2 levels. Paleotologicheskly Zhurnal, v2, pp 3 - 11.
Bashkirtsev, V, S. and Mashnich, G, P., (2003). Will we face global warming in the nearest future? Geomagnetism and Aeronomy 43: 124 - 127.
Soon, W., Baliunas, S, L, Robinson, A, B, Robinson, Z, W. (1999). Environmental effects of increased atmospheric carbon dioxide. Climate research. Vol 13, 149-164.
Hermann, A, D., Haupt, B, J., Patzkowsky, M, E Seldov, D, and Slingerland, R, L. (2004). Response of late ordovician paleooceannography to changes in sea level, continental drift and atmospheric pCO2: potential causes for long term cooling and glaciation. Paleogeog. Palaeoclimatol, Palaeoecol. 210: pp 385-481
Kaser , G., Hardy, D, R.,, Molg, T., Bradley, R, S., Hyera, T, M., (2004). Modern glacier retreat on kilimanjaro as evidence of climate change: observations and facts. international journal of climatology, v 24, pp 329 -339.
Lyman, J., Willis, J., and Johnson, G. (2006). Recent cooling of the upper ocean. Geophysical Research letters 33.
Thats enough, I cant be bothered typing any more. What do you make of these, there are quite a few more on the list.
