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Originally Posted by onon
No co2 levels have been directly measured for 50 years, and the rise of human emissions during that time period have been more than enough to explain that increase.
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Oh, you wrote 10 years before. So, I guess I better change my argument, too.
In that case, so what? CO2 concentrations rose for 50 years. It's a blip on the geologic time scale. It means nothing to machinations which take thousands, even millions of years.
What do you think this proves, if anything?
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Rising temperatures don't cause co2 to rise as much as they have since pre-industrial times. co2 rises 100ppm from 10C warming in the ice core record (http://cdiac.ornl.gov/trends/co2/gra...vostok.co2.gif), and that's after thousands of years of increase. So 100ppm increase since preindustrial average (ie 280ppm to 380ppm) is not going to be caused by a <1C temperature rise in that time.
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Where did you get that idea? And what is the purpose of the graphic you provided? Did you think it showed a 100ppm CO2 increase for every 10C temperature increase?
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Plus the little ice age was at least 0.5C cooler than 1900 temperature, yet co2 levels were only about 10ppm lower. Temperature does dictate the equillibrium level of co2, but it isn't sensative enough to explain the 100ppm rise in the last 200 years.
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And your ability to actually juxtapose such a ridiculous claim and try to support it with this is really remarkable. Let's see, in your example .5C correlated with 10ppm of CO2. Ergo, 1C would be 20ppm, and 10C would be 200ppm. So, you claim that 10C correlates with 100ppm CO2, then give an example demonstrating that 10C correlates with 200ppm CO2. Which is it? Does 10C correlate with 100ppm CO2, or 200ppm CO2? Because, that's a pretty big error rate.
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They have been ruled out because nature is absorbing more co2 than it emits. So it cannot be the cause of the recent rise.
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How do you know this? Let me give you another example. There is a box. This box has between 650 and 750 million red marbles in it. There are holes all over the box, so some of the marbles are falling out. You don't know how many are falling out. It's somewhere between 100 and 200 million every minute. Also, someone keeps adding marbles to the box. You don't know how many they are adding, or even who they are. You can estimate they are adding between 200 and 300 million marbles every minute. Now, I'm going to add some marbles to the box. After one minute, there are between 675 and 775 marbles in the box. Can you figure out how many marbles I added to the box? Do the math and I'll tell you if you're right or wrong.
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It cannot be proven, but it's extremely unlikely that it would have risen this far this century without our contribution, and I cannot emphasize how unlikely it would be. Take the bottom graph on this page for context of the recent rise in the past 1000 years:
The Keeling curve and rise in CO2 in the atmosphere
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Yes, very dramatic. I'm sure it's quite effective at bringing in the contributions. Why is it so "extremely unlikely that it would have risen this far this century without our contribution"? Hasn't this happened before, naturally?
Ahh, yes, it has happened before - naturally. Your favorite graph shows this.
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You are confusing "equillibrium level" with the level co2 is actually is at. The actual level of co2 can be above or below the equillibrium level, and whether it is above or below determines whether nature will absorb more or emit more. The equillibrium level is determined by temperature. During the little ice age the equillibrium level was slightly lower (about 275ppm), and so co2 levels fell slowly to that level.
Currently co2 is far above the equillibrium level, which is why nature is currently a net absorber of co2.
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You're a riot, onon. Let me see if I understand this:
For every temperature, there is a concentration level of CO2 that at any amount over that level nature will begin to absorb more CO2 than it emits. You've also stated that the corollary is likewise true and at any amount under that level nature will begin to emit more CO2 than it absorbs. Do I have it right so far?
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Both. But currently co2 concentrations are rising primarily due to human emissions.
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Then it is not necessarily true that "nature removes more co2 from the atmosphere than it adds". Because nature does have a mechanism for removing more CO2 from the atmosphere than it adds. It is also not necessarily true that "without human co2 emissions the co2 levels in the atmosphere would start falling." Since nature has a mechanism for adding CO2 to the atmosphere. In both cases, this mechanism is temperature. Overly simplified, but I'm just playing by your rules.
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From the second image in the link I posted you can see they did "stop" during the past few hundred years and co2 levels were floating around 280ppm throughout with no significant change (even the little ice age only bought it down about 10ppm).
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These processes didn't stop, they just happened to even out. Judging by your favorite graph of the Vostok ice cores, an even level is an anomaly. Your "equilibrium" appears to have no other instance in the record. What do you think happened in the 18th century to make CO2 levels even out like that?
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What do you think happened in the 20th century which would have changed that trend if only humans hadn't emitted any co2?
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One, or many, of the forcings which drive CO2 levels up increased? One, or many of the forcings which drive CO2 levels down abated? I have no idea.
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Given the warming in the early 20th century occured naturally, without human emissions co2 would probably be today a bit higher than the pre-industrial baseline at about 285ppm. But not 380ppm which from the ice core records is an unprecedented level for co2 in at least the last 700,000 years.
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Then not all of the increase in CO2 is a result of Man.
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You say that in a joking way, but the climate has consistantly found this 280ppm level during interglacial periods:
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And then retreated, according to your graph. Ergo, there's no reason to believe CO2 levels would fall to 280ppm and remain there as you assert.
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The mechanism for co2 emissions (from any source) causing co2 rises is pretty self explainatory. You just need the new emission source to tip the balance towards more in than out.
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Really? Is that all? Then say, changes in plant life, troposphere temperature, exosphere temperature, ocean temperature, ocean pH, etc. have nothing to do with it?
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If the absorption rate decreased then co2 levels would be rising far faster than they are, so we do know it's rising because the emission rate has increased.
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Unless inputs to the system aren't what you think they are.
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Take man's emissions out and there would be no rise because there would be less co2 entering the atmosphere than leaving it.
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You don't know that. In fact, you've already claimed this would not be true because temperature has risen and, according to you, rising temperatures result in greater CO2 levels.
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Nothing is provable but this stuff is certain to the point of 99.99%. A man could get fried on less evidence.
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Fine, believe in whatever helps you sleep. But you're not logically able to make the definite statements you've been making.
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Because it takes time for co2 to fall, a long time. The rate of absorption is proportional to how far co2 is above the equillibrium point. The measured co2 trends show that nature is absorbing co2 at a faster pace as the co2 levels in the atmosphere increase.
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Doesn't CO2 lead to a warmer planet?
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two of these are known - co2 rise, and human contribution. So the third can be calculated.
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Two of these are estimated, therefore the third is an estimate. What are the error rates of these estimates, onon?
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Not everything in climate is unknowable. Lots of things are well understood and known. The carbon cycle happens to be something better understood. But also in other cases - eg "If sun doubles in output, then earth warms" and "If el nino year, then warmer global temperatures" are very certain "if A, then B" statements to do with climate.
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The carbon cycle might be understood, but we are far from understanding how other parts of the system interact with it. You don't have to take my word for it. Just ask the IPCC.
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I don't know why, but almost with anything raised you try and find the smallest little detail to nit-pick over.
The Mauna Loa observatory has prominence only because it stretches back the furthest. But there are also global stations that measure co2 levels, and the trend from those match the Mauna Loa records well:
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This is not a small detail. The longest records you have are 50 years old. Fifty years is not nearly enough data for identifying, or eliminating for consideration, natural processes. They are from one observatory, measuring a very localized space of the troposphere. A space that might be downwind of any number of natural processes that would cause a steady rise in CO2 concentrations measurements. The other observations are likewise taken from very localized spaces and nowhere near indicative of world wide atmospheric CO2.
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But it isn't. A 10C rise was required to cause a 55% co2 rise.
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I know that you really want there to be some absolute math in here, but there's not. Show me the data points for all the CO2 levels and temperature. Show me where you're getting this, "It always has to change 10C before CO2 will change 100ppm." Then show me where it changed .5C and a relatively massive 10ppm in CO2.
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No that's not right at all. Humans are emitting 28 billion extra tons of co2 today. Not 15 tons.
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I thought you said the net effect was 15? My math was wrong by skipping the billion part, so let's redo it. 15 billion tons over 46 years means 690 gigatons of CO2. That's even more striking. I don't know where you got the 2300 gigatons of CO2 in the atmosphere, my sources show between 650 and 750 gigatons. I'll use that unless you want to show me your source for 2300.
So, we have the MLO telling us that CO2 concentrations increased 19%, but you're arguing that the net increase of anthropogenic should've been along the lines of somewhere between 90% and over 100%, depending on which estimate you use and how you want to calculate it. But clearly, the vast bulk of the CO2 in the atmosphere would have to have come from Man since 1957.
Unless you want to argue that Man's CO2 didn't all go into the atmosphere. Then we would have to look at the entire CO2 cycle. There's about 40,000 gigatons of carbon in the oceans, plus another 2000 gigatons of carbon in the biosphere. So, that's 42,000 gigatons of carbon, or roughly 155,400 gigatons of possible CO2. We'll go ahead and add the 750 gigatons of CO2 in the atmosphere for a grand total of about 156,150 gigatons of possible CO2. So, our additional 690 gigatons of CO2 contributed .004% to the total CO2 on the planet.
Something's not quite adding up, onon.
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Which part tells us the figures aren't even close to accurate?
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This part:
"Population estimates were not available to permit calculations of global
per capita estimates before 1950."
So, in other words, we have closer estimates for the past 50 years, but before that we don't really know.
Oh, I like that. Did you read it? So, they looked through some old "publications" (government? trade? personal?) on "historical energy statistics" (like how many people are burning fires, for how long, all over the world). Really, onon, how accurate do you think these estimates are?
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It's not true that everything in nature is chaotic and unpredictable. Certainly the seasons are a prime example of the most predictable aspects of climate. The carbon cycle is fairly simple at a macro level, and is fairly well understood. It's not true that we know nothing and cannot reach a good conclusion on this subject of the cause of co2 rise. It is beyond doubt that co2 levels are rising, and beyond doubt that human activity is the cause.
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Fine, fine. Whatever you want to believe. But your absolute statements like, "The net effect is that nature removes more co2 from the atmosphere than it adds." And, "Without human co2 emissions the co2 levels in the atmosphere would start falling." Are logical fallacies.