questionposter Posted October 22, 2011 Posted October 22, 2011 (edited) Fossil-fuel carbon is devoid of C-14, and there are difference is the C-12/C-13 ratio for terrestrial vs oceanic sources. You can do isotopic analysis to find the dominant source of the increase in atmospheric carbon. Can you guess the answer? Carbon 12 occurs in fossil fuel but Carbon 12 is also the most abundant isotope of Carbon in the universe. http://skepticalscie...tural-cycle.htm Yep, I know that there's natural carbon cycles, I've seen the graphs for CO2 changes and ocean temperatures, and based on the giant exponentially increasing spikes near similar times, one event leads to another. However, recently Earth's global climate change has been happening at a faster rate than usual. This could be largely because of humans, or because of the fact that nature is most certainly not perfectly periodic and predictable. Either is likely, but regardless of whether humans or other aspects of nature caused it, it's still a problem. However, any factor of CO2 increases will make CO2, so if you eliminate any factor, it helps in some way no matter what. The other activities besides our own activities are hard to control. Edited October 22, 2011 by questionposter
swansont Posted October 22, 2011 Posted October 22, 2011 Carbon 12 occurs in fossil fuel but Carbon 12 is also the most abundant isotope of Carbon in the universe. Your point?
the asinine cretin Posted October 22, 2011 Posted October 22, 2011 This is significant. Berkeley Earth Releases Global Land Warming Analysis (PDF) Phil Plait's blog post on the subject If you aren't familiar with Richard Muller (the founder of Berkeley Earth, author of Physics for Future Presidents, among other things) this presentation may provide some interesting context.
questionposter Posted October 22, 2011 Posted October 22, 2011 Your point? My point is that your point about the isotopes having the specific ratios they do doesn't mean anything. If there use to be no carbon 14 in the atmosphere and then when humans started burning fossil fuel, a lot of carbon 14 was found in the atmosphere, then your point might mean something.
swansont Posted October 23, 2011 Posted October 23, 2011 My point is that your point about the isotopes having the specific ratios they do doesn't mean anything. If there use to be no carbon 14 in the atmosphere and then when humans started burning fossil fuel, a lot of carbon 14 was found in the atmosphere, then your point might mean something. There are ratios of the isotopes which are different for natural sources from terrestrial, oceanic and fossil fuels. We know what the ratio was in the past. It's different now. http://www.realclimate.org/index.php/archives/2004/12/how-do-we-know-that-recent-cosub2sub-increases-are-due-to-human-activities-updated/ http://brane-space.blogspot.com/2010/12/carbon-isotope-ratios-and-climate.html
John Cuthber Posted October 23, 2011 Posted October 23, 2011 (edited) My point is that your point about the isotopes having the specific ratios they do doesn't mean anything. If there use to be no carbon 14 in the atmosphere and then when humans started burning fossil fuel, a lot of carbon 14 was found in the atmosphere, then your point might mean something. The point does mean something; unfortunately you don't understand it. There was a lot of carbon 14 in the in the atmosphere. Then we started burning fossil fuel which has no carbon 14. We diluted that carbon 14. We can measure the extent of that effect. The extent of the dilution tallies with the rise in CO2 which shows that the CO2 rise is due to the release of ancient, i.e. fossil, carbon. We also have a fair idea of how much fossil fuel we burn (if for no other reason than that we get taxed on it) and so we can compare that to the rise in CO2 levels and to the dilution of the carbon 14. The numbers agree with the obvious suggestion that by burning a lot of coal and oil we have put a lot of CO2 into the air. We also know that the temperature of the earth has risen. So the "Anthropogenic global warning doesn't exist" supporters are saying "We know we put another blanket on the bed, and we know that we are now warmer; we just don't think there's a link between the two facts." Edited October 23, 2011 by John Cuthber 3
questionposter Posted October 23, 2011 Posted October 23, 2011 (edited) The point does mean something; unfortunately you don't understand it. There was a lot of carbon 14 in the in the atmosphere. Then we started burning fossil fuel which has no carbon 14. We diluted that carbon 14. We can measure the extent of that effect. The extent of the dilution tallies with the rise in CO2 which shows that the CO2 rise is due to the release of ancient, i.e. fossil, carbon. We also have a fair idea of how much fossil fuel we burn (if for no other reason than that we get taxed on it) and so we can compare that to the rise in CO2 levels and to the dilution of the carbon 14. The numbers agree with the obvious suggestion that by burning a lot of coal and oil we have put a lot of CO2 into the air. We also know that the temperature of the earth has risen. So the "Anthropogenic global warning doesn't exist" supporters are saying "We know we put another blanket on the bed, and we know that we are now warmer; we just don't think there's a link between the two facts." So your essentially saying that he said "there wasn't as much C-12, but now there is?". I can see how that works, but c-12 is still the most abundant form of carbon in the universe, I still have to consider that. Granted, what accelerated the acceleration of CO2 in the atmosphere could easily have been humans, bur right now after this much time, I just don't think over 75% of it can any longer be humans burning fossile fuels. Just as those graphs show exponential spikes, humans could easily be at the base of a spike that's now forming, only one event already lead to another. Human CO2 output on a yearly basis is pretty linear, but what's happening is an exponential or perhaps parabolic curve and the temperatures will also be well above where they would be if it was just a linear pattern. Edited October 23, 2011 by questionposter
iNow Posted October 23, 2011 Posted October 23, 2011 Personal incredulity is a terrible way to present an argument, questionposter. I strongly encourage you to better understand what your fellow posters are sharing with you prior to dismissing it. Your failure to understand is fairly plain to seemingly everyone but you.
John Cuthber Posted October 23, 2011 Posted October 23, 2011 "I can see how that works, but c-12 is still the most abundant form of carbon in the universe, I still have to consider that. " Yes, it's very abundant. Massively more so than C14. So what? We can still measure it. We can measure changes in it, and we can do both of those accurately. So what's the issue?
swansont Posted October 23, 2011 Posted October 23, 2011 So your essentially saying that he said "there wasn't as much C-12, but now there is?". I can see how that works, but c-12 is still the most abundant form of carbon in the universe, I still have to consider that. Granted, what accelerated the acceleration of CO2 in the atmosphere could easily have been humans, bur right now after this much time, I just don't think over 75% of it can any longer be humans burning fossile fuels. Just as those graphs show exponential spikes, humans could easily be at the base of a spike that's now forming, only one event already lead to another. Human CO2 output on a yearly basis is pretty linear, but what's happening is an exponential or perhaps parabolic curve and the temperatures will also be well above where they would be if it was just a linear pattern. It's not just that C-12 increased. C-13 and C-14 did not increase in the proportion you would get if the sources were natural. The changes in the ratios is what you get from fossil fuel burning.
questionposter Posted October 24, 2011 Posted October 24, 2011 (edited) It's not just that C-12 increased. C-13 and C-14 did not increase in the proportion you would get if the sources were natural. The changes in the ratios is what you get from fossil fuel burning. So what your saying is that more C-12 was released recently, but the c-14/13 was not released at as fast a rate? And if so, that increase in CO2 can almost perfectly account for the amount of heat capacity increase in the atmosphere if you also consider the water vapor it chain-reactioned into the atmosphere? Personal incredulity is a terrible way to present an argument, questionposter. I strongly encourage you to better understand what your fellow posters are sharing with you prior to dismissing it. Your failure to understand is fairly plain to seemingly everyone but you. Wait...if I dismissed it, why would I keep commenting on it? Edited October 24, 2011 by questionposter
JohnB Posted October 24, 2011 Posted October 24, 2011 The changes in the ratios is what you get from fossil fuel burning. Not quite. The change in the ratios is what you get when you add a lot of very old CO2 to the atmosphere. I'm not out to be pedantic, simply as exact as possible. The change in ratios allows us to separate the sources of the CO2 into biological and geological categories and no more. After that we have to consider the sources of old CO2, which are of course the burning of fossil fuels and volcanoes (or other geological sources). The isotopic makeup of both of these is virtually identical due to age and as such are indistinguishable. Hence a change in vulcanism will result in a change in the ratios of C isotopes, just as burning fossil fuels does. From there we need to go to actual attribution which is based on the known amount of fossil fuels burnt and the estimate of volcanic gas output per year. The difficulty with this is that we have little more than guesses as to what the volcanics are. Most papers put the volcanic CO2 output at less than 500 million tonnes per year worldwide, however this seems unreasonably low when looking at the estimates for oceanic volcanoes. A rather good and fully referenced article on this can be found here. The bottom line is that to attribute the change in ratios wholly to anthropogenic causes requires you to assume that there is no change in geological processes during the time period in question. This position is logically untenable since the usual explanation for the cooling from 1880-1910 is attributed to an increase in vulcanism which must have led to an increase in naturally C14 deficient CO2. You simply cannot assume constancy on the one hand and variation on the other depending on what you want to argue. I notice that water vapour came up before. The simple fact is that this is perhaps the biggest unknown in climate modelling and estimation. There is a great argument going on ATM in the literature and on blogs between Dr. Andrew Dessler and Dr Roy Spencer on this very topic. The general GW theory is that clouds are a positive feedback and this is in all the models. Put simply, the more clouds there are, the less radiation escapes Earth and the atmosphere heats up, the clouds act as a blanket, so to speak. (This is Dr Desslers position) Dr Spencer takes the opposite view and thinks that the more clouds there are the cooler things will be due to the increased reflection from the tops of the clouds. (I'm keeping things very basic in this.) That clouds can both warm and cool is easily demonstrated by anyone. Cloudy nights are warmer than cloudless ones due to the clouds stopping the radiation from leaving the lower atmosphere, however, cloudy days are cooler than cloudless ones due to the clouds blocking the incoming radiation. this is most obvious when a cloud passes in front of the Sun on a hot day, the temp drop is immediate and large. So the question becomes, "When averaged over the entire surface for 24 hours is the nett effect warming or cooling?". The models generate a prediction as to what will be the change in outgoing radiation due to the change in cloudiness WRT temperature changes and this can be tested against actual satellite measurements. Here's a preliminary figure from the upcoming paper comparing 14 climate models to observations; Some will of course argue that since a few of the models are somewhere within a bulls roar of the obs that then "proves" that the models are "consistent with" the obs. BS. Most of them aren't in the ballpark. I'll be very interested to see both the completed paper and Dr Desslers response as this is a major question. If the clouds are in fact a negative feedback then all the climate models have it wrong and are overestimating the warming. As to the OP and is global warming a "Crisis"? I would think that the onus of proof is on those who say it is. We've had lots of horror stories about what will happen in a warmer world but let's look at the historical facts. The world has warmed by nearly a degree in the last 150 years, even more than that according to the prelimnary BEST papers. So we should have seen some adverse effects already, shouldn't we? What are they? Winters and nights are warmer, growing seasons are longer, farm production is way up, non farm plant growth is up, there has been no discernable increase in "severe weather events" (in the Australian region cyclones are way down), rainfall is up in many places and down in others (which can be good or bad). So how about dropping the hand waving about unprovable futures and saying in what concrete, measurable fashion the climate is worse for a degree of warming.
iNow Posted October 24, 2011 Posted October 24, 2011 Wait...if I dismissed it, why would I keep commenting on it? Probably because you're used to being one of the smartest people in your circle of friends, and usually capable of explaining things better than a lot of people around you, but you also recognize that when posting here at SFN there are several smart people with a lot more experience and education from whom you can learn. To your credit, I suspect you keep commenting because you keep wanting to learn, improve, and fix any mistakes in your thinking. This is just a guess, though. Only you can accurately answer why you keep commenting. I'm no mind reader. 1
swansont Posted October 24, 2011 Posted October 24, 2011 So what your saying is that more C-12 was released recently, but the c-14/13 was not released at as fast a rate? And if so, that increase in CO2 can almost perfectly account for the amount of heat capacity increase in the atmosphere if you also consider the water vapor it chain-reactioned into the atmosphere? Yes, more carbon and not as much of it is C-13 or C-14 as you'd expect from biological sources. Heat capacity and water vapor were not part of this particular discussion. Not quite. The change in the ratios is what you get when you add a lot of very old CO2 to the atmosphere. I'm not out to be pedantic, simply as exact as possible. The change in ratios allows us to separate the sources of the CO2 into biological and geological categories and no more. After that we have to consider the sources of old CO2, which are of course the burning of fossil fuels and volcanoes (or other geological sources). The isotopic makeup of both of these is virtually identical due to age and as such are indistinguishable. Hence a change in vulcanism will result in a change in the ratios of C isotopes, just as burning fossil fuels does. From there we need to go to actual attribution which is based on the known amount of fossil fuels burnt and the estimate of volcanic gas output per year. The difficulty with this is that we have little more than guesses as to what the volcanics are. Most papers put the volcanic CO2 output at less than 500 million tonnes per year worldwide, however this seems unreasonably low when looking at the estimates for oceanic volcanoes. A rather good and fully referenced article on this can be found here. The bottom line is that to attribute the change in ratios wholly to anthropogenic causes requires you to assume that there is no change in geological processes during the time period in question. This position is logically untenable since the usual explanation for the cooling from 1880-1910 is attributed to an increase in vulcanism which must have led to an increase in naturally C14 deficient CO2. You simply cannot assume constancy on the one hand and variation on the other depending on what you want to argue. All you need is the average rate of vulcanism to be roughly constant. Any additional old carbon from 1880-1910 would have been cycled through biological systems in the next few years. There's no way it would have been detected when doing isotopic analysis decades later and, of course, could not affect analysis from earlier than the eruptions. For vulcanism to account for the increase, it needs to have been at a sustained higher (and increasing) rate all the way through to the present.
JohnB Posted October 24, 2011 Posted October 24, 2011 All you need is the average rate of vulcanism to be roughly constant. Any additional old carbon from 1880-1910 would have been cycled through biological systems in the next few years. There's no way it would have been detected when doing isotopic analysis decades later and, of course, could not affect analysis from earlier than the eruptions. For vulcanism to account for the increase, it needs to have been at a sustained higher (and increasing) rate all the way through to the present. Sorry swansont, I wasn't clear. I didn't mean to imply that all of the change in ratios since 1880 was due to vulcanism. I was pointing out that due to the similarities it is impossible to work what percentage of the change was due to vulcanism. (Within limits) Personally I would put the figure at only a few percentage points. If vulcanism outgassing of CO2 is roughly equal to man made emmissions, then a 2% change in vulcanism would result in a 1% change in ratios. The effect would not be significant (I don't think so anyway) but it must be there. Bringing up the 1880-1910 period was to illustrate that vulcanism waxes and wanes and so its contribution would wobble around a baseline period over shorter time scales.
questionposter Posted October 25, 2011 Posted October 25, 2011 (edited) Yes, more carbon and not as much of it is C-13 or C-14 as you'd expect from biological sources. Heat capacity and water vapor were not part of this particular discussion. But I mean, an increase in CO2 would raise global temperatures which would warm water up more, therefore putting more water in the atmosphere, therefore increasing the atmospheres capacity for heat even more and accelerating the heating process even more, that's what I was trying to say with the exponential increase rather than linear increase, is that it's not just CO2 output, its a whole chain of events. Probably because you're used to being one of the smartest people in your circle of friends, and usually capable of explaining things better than a lot of people around you, but you also recognize that when posting here at SFN there are several smart people with a lot more experience and education from whom you can learn. To your credit, I suspect you keep commenting because you keep wanting to learn, improve, and fix any mistakes in your thinking. This is just a guess, though. Only you can accurately answer why you keep commenting. I'm no mind reader. But if that whole "I'm use to being smart" thing or whatever you were saying is true, how do you explain this? http://www.sciencefo...ngs-wrong-here/ It's a relatively basic problem I should have learned about more in high school. Besides, if you look in the QM section I usually try to answer the basic questions to clear up confusing. Edited October 25, 2011 by questionposter
questionposter Posted October 25, 2011 Posted October 25, 2011 (edited) sorry double post, but I guess I might as well use it to say "what about Mt. S.t Helens"? Did that have any significant effect? I'd imagine it would cause cooling, but it's still green-house gases, so I'm up for whichever. Edited October 25, 2011 by questionposter
swansont Posted October 25, 2011 Posted October 25, 2011 But I mean, an increase in CO2 would raise global temperatures which would warm water up more, therefore putting more water in the atmosphere, therefore increasing the atmospheres capacity for heat even more and accelerating the heating process even more, that's what I was trying to say with the exponential increase rather than linear increase, is that it's not just CO2 output, its a whole chain of events. Yes, it is a chain of events. That's what goes in the models. But the trigger is CO2, and the evidence indicates it's anthropogenic. Water is a feedback term in the models, because it's caused by changes in temperature.
the asinine cretin Posted October 25, 2011 Posted October 25, 2011 More on what I posted about the other day.
JohnB Posted October 26, 2011 Posted October 26, 2011 Water is a feedback term in the models, because it's caused by changes in temperature. Water is a feedback term in the models, because all climate models are inbuilt with the false assumption that only temperature can change water vapour. (Fixed it for you. )
swansont Posted October 26, 2011 Posted October 26, 2011 Water is a feedback term in the models, because all climate models are inbuilt with the false assumption that only temperature can change water vapour. (Fixed it for you. ) Do you have some new thermodynamics you wish to share with us?
questionposter Posted October 26, 2011 Posted October 26, 2011 Do you have some new thermodynamics you wish to share with us? Pressure can also change water, so if there's large air-masses of low pressure, that will suck up water vapor more easily.
swansont Posted October 26, 2011 Posted October 26, 2011 Pressure can also change water, so if there's large air-masses of low pressure, that will suck up water vapor more easily. a) that's thermodynamics, and b) can you present evidence that the pressure of the atmosphere has been increasing over time, independent of the temperature?
questionposter Posted October 26, 2011 Posted October 26, 2011 a) that's thermodynamics, and b) can you present evidence that the pressure of the atmosphere has been increasing over time, independent of the temperature? Well, it's already been proven that Earth's atmosphere in general changes over time, but I don't know about pressure. I was thinking more like localized air masses sucking up more water vapor. Heat moves air, and moving air has less pressure, so it can suck up water vapor from liquid water more easily.
swansont Posted October 27, 2011 Posted October 27, 2011 I was thinking more like localized air masses sucking up more water vapor. Heat moves air, and moving air has less pressure, so it can suck up water vapor from liquid water more easily. Right. That's called weather. And it's driven by heat, which raises the temperature — we're looking for something long-term and not driven by temperature, which is in the models, and why this is a feedback term.
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