I have a question about CO2

[Asilomar]

I have a question about CO2. Numbers in Global Warming are thrown about all over the place. P&T's show ******** says that humans contribute only 3% of CO2 of the total a year. I had heard another statement that it was around 14% (I can not cite this ... it is a number that stuck with me, I am sorry).

I know that it is difficult to say exactly what percent due to all the factors - do you count cows that humans are holding for food sources as human contribution or natural, etc - but what percent of the green house gasses do humans contribute and how was that number figured out?

Thank you.

 

[Cuddles]

It depends a lot on context. To start with, there is a carbon cycle. CO₂ is constantly appearing and disappearing due to a variety of processes. Some just recycle the same carbon while others bring new carbon into play or trap existing carbon and take it out of the cycle. In terms of the total carbon in circulation, humans only contribute a relatively small amount. However, what is more important is that most of the carbon we release comes from prevously trapped carbon, and is added on top of the cycle that already exists. In the absence of a new carbon sink to remove this additional carbon from circulation, the amount of CO₂ will increase, until it reaches a new equilibrium.

As for the actual numbers, I can't say exactly what they are, but I'm sure others here can (I expect it's closer to the 3% mark). It's actually fairly easy to work out though. All you need to do is measure the amount of CO₂ that various processes create or absorb, and then see how much those processes actually happen. For example, we know how much CO₂ respiration produces and we know how much photosynthesis uses, so given a good estimate of the amount of plant life we can work out how much CO₂ plants contibute to each stage of the carbon cycle.

As for the human contribution, the important part is from burning fossil fuels, and the companies that sell them keep accurate records, so we know how much we burn.

 

[CapelDodger]

I have a question about CO2. Numbers in Global Warming are thrown about all over the place. P&T's show ******** says that humans contribute only 3% of CO2 of the total a year. I had heard another statement that it was around 14% (I can not cite this ... it is a number that stuck with me, I am sorry).

I know that it is difficult to say exactly what percent due to all the factors - do you count cows that humans are holding for food sources as human contribution or natural, etc - but what percent of the green house gasses do humans contribute and how was that number figured out?

Thank you.

The important figure is the accumulation of CO2, not the throughput of the entire system. Grass takes CO2 out of the atmosphere; cows eat the grass and breath it back out. Some goes into making more cow, which people then eat and they breathe it out. That's throughput.

On a much longer time-scale, CO2 is turned into shells, shells deposit on the sea-floor and become limestone, limestone is subducted, and the CO2 comes back out of volcanoes above the subduction zone.

Think of it as like a bank-account. Money comes in every month, money goes out every month, and the absolute amounts swamp the balance. But it's your balance you're interested in.

Atmospheric CO2-load is a third greater than pre-industrial levels, and all of that accumulation is down to the burning of fossil-fuels. Nothing else has changed.

 

[shadron]

Average CO2 concentration in the atmosphere is in the range of 387 PPM (that's parts per million), or about .04 percent by volume. That's up from 315 PPM as measured at Mauna Loa in 1960. It makes up a very small fraction of the atmosphere; that means that a relatively small quantity added makes a large difference. Animals begin showing signs of toxicity from CO2 are 10,000 PPM.

carbon dioxide^WP

 

[mhaze]

Average CO2 concentration in the atmosphere is in the range of 387 PPM (that's parts per million), or about .04 percent by volume. That's up from 315 PPM as measured at Mauna Loa in 1960. It makes up a very small fraction of the atmosphere; that means that a relatively small quantity added makes a large difference. Animals begin showing signs of toxicity from CO2 are 10,000 PPM.

carbon dioxide^WP

Won't those fossil fuels all run out before any detrimental effects occur, if any were going to occur? According to your logic if man's carbon outputs did not get back into the carbon cycle and we kept output at current rates, that little bit that makes a big difference will cause the animals will all start dying in or about the the year 8,674.

Is that how the little bit makes a big difference?

 

[shadron]

Ah, come on, mhaze, you know better than that; I've read some of your posts and I believe that you probably know more about the arguments for global warming than I do. I said nothing about CO2's role as a greenhouse gas, only what amount of it in the atmosphere will cause animal toxicity. I don't think anyone *at all* is saying we need to worry about CO2 building up to toxic levels in the atmosphere.

"Any detrimantal effects" takes in a whole lot more ground than toxicity; "obvious to the most casual observer", as they told me in Calculus.

 

[Asilomar]

I am not minimizing any of what has been said, but if we are only contributing, with all of our ... well, everything, 3% of the whole, I fail to see why we are getting so concerned with the contributes.

Wouldn't it be better to go the other way and, while yes, look for viable alternatives to fossil fuels, put research into CO2 sinks and negate the 3% we are adding?

I am looking for real discussion - I am a global warming believer, but the 3% ... well, that ... just darn, I thought we were producing numbers on the order of 25% of all CO2 or more.

 

[a_unique_person]

I am not minimizing any of what has been said, but if we are only contributing, with all of our ... well, everything, 3% of the whole, I fail to see why we are getting so concerned with the contributes.

Wouldn't it be better to go the other way and, while yes, look for viable alternatives to fossil fuels, put research into CO2 sinks and negate the 3% we are adding?

I am looking for real discussion - I am a global warming believer, but the 3% ... well, that ... just darn, I thought we were producing numbers on the order of 25% of all CO2 or more.

The result is the important thing. The concentration of CO2 is going to at least double, because of our actions. Without our actions, it would be staying pretty steady. 3% every year adds up, just ask any accountant.

 

[rjh01]

To add to the previous post. If you add a $1m into an account every year and take out a $1m a year every year and there is about $10 million dollars in the account, then I start to take out 3% of what you take out without putting in anything how long before the account is empty?

 

[shadron]

I am not minimizing any of what has been said, but if we are only contributing, with all of our ... well, everything, 3% of the whole, I fail to see why we are getting so concerned with the contributes.

Wouldn't it be better to go the other way and, while yes, look for viable alternatives to fossil fuels, put research into CO2 sinks and negate the 3% we are adding?

I am looking for real discussion - I am a global warming believer, but the 3% ... well, that ... just darn, I thought we were producing numbers on the order of 25% of all CO2 or more.

Not 3% - CO2 is at 378 PPM, or .0378% by volume. <---- Read this again, and understand: approximately 4 parts per 10,000 by volume. Much less than you thought. Nevertheless, an important very small fraction.

Think about your sinking, Asilomar: we are digging coal and pumping oil at a prodigious rate out of the earth. Coal is about 90% carbon, oil is about 92%. When we burn it, nearly all of it becomes, eventually, gaseous CO2. Now, to "sink" that amount we need to capture that same amount of carbon (and CO2 is only about 27% carbon by weight) and put it back or otherwise "destroy" it - perhaps turn it back into elemental carbon, releasing the oxygen and bury it in the mines we excavated. Or perhaps as dry ice, if we can keep it at -40 degrees or lower. That means dig out the coal, burn it to get energy, then "unburn" it to get the coal back and rebury it. Or we can shoot it into space. Do you see the ridiculousness of the concept of sinking it? The only free sink we have is the oceans, and they have finite capacity. There are some concepts that might work, but they're also expensive, and we have a huge backlog to service. Who's going to pay for i?

Why are we getting weirded out by that vanishingly small .04%? Well, mhaze will tell you a different story from me, but I would claim that CO2 is invisible to light and near-infrared radiation, but opaque to deeper infrared. Thus radiation from the sun as light can pass through the atmosphere to the ground, where it is converted to infrared, which in turn doesn't radiate back into space because the gas above it is relatively opaque to it. If there is a net increase in incoming radiation, then the earth warms up as a whole until the gases above the opaque layer can radiate sufficient infrared not from conversion of sunlight but rather form black-body warming. To do that, the whole atmosphere has to heat up, including me and thee.

Since it is only .04% it doesn't have an absolute effect of making the air totally opaque to infrared, only a slight increase in opacity. But with the magnitude of the incoming energy, even a small amount builds up, and an increase of a degree or two can have drastic effects.

 

[mhaze]

The relation between the temperature and heat storage of the oceans and the temperature of the atmosphere is not well understood, but the oceans contain about 2000x as much heat energy as the atmosphere. Typical "greenhouse gas theory" is strictly a radiative budget, and ignores the huge battery of energy in the oceans. (it ignores a lot of other things, also).

The unproven hypothesis is that slight increases in the trace gas CO2 have huge effects on the atmosphere's temperature due to positive feedback mechanisms operating on the basic logrythmic response of CO2 to radiation. The far extreme of that unproven hypothesis that you are asked to believe without any scientific proof, just arm waving and computer modeling studies, is that CO2 is responsible for all of the warming of the last 50 years (or last 100 years, depending on where you read).

This is "supported" by a variety of emotional and alarmist arguments including sea level rise, dramatic flooding, hurricanes (Katrina), melting ice caps (plural, really they mean the North Pole), polar bears, penquins, snake invasions of North America, cat population explosions, prophesies of drought....It's a regular cookbook of Biblical fears in one nice TV program, isn't it?

Once the simplistic and inaccurate "CO2 --> warming" premise is launched, then all of these fearful things are trotted out one after another as "consequences" of the "science".

 

[Cuddles]

The unproven hypothesis is that slight increases in the trace gas CO2 have huge effects on the atmosphere's temperature due to positive feedback mechanisms operating on the basic logrythmic response of CO2 to radiation.

No it isn't. The fundamental hypothesis is nothing to do with the atmosphere at all, it is simply that CO₂ transmits certain wavelengths while absorbing others, and that the Sun emits more of its energy in the transmitted region while the Earth emits more energy in the absorbed region. Except that that's not hypothesis, that's proven fact. The inevitable consequence of this is that more CO₂ in the atmosphere means more energy trapped underneath that CO₂. Again, not open to debate. Exactly where that energy is is not relevant to the question of whether global warming is happening. It could be in the atmosphere, in the sea, in the land, a mix of all three or, most likely, a dynamic system transfering between all three.

None of this is open to debate. What is open for debate is what the effects of trapping this extra energy actually are. We already know that your opinion is that the amount of energy is not significant. That's a perfectly valid stance, although not poorly supported by the evidence. What is odd is that you apaprently refuse to accept that your arguments actually agree that global warming is occuring. Arguing that the extra energy is trapped in a heat sink is not arguing that the energy is not there at all, and yet you consistently try to claim that global warming is not happening at the same time as claiming that you know where the extra heat is going. Weird.

 

[Ocelot]

is that CO2 is responsible for all of the warming of the last 50 years (or last 100 years, depending on where you read).

This straw man of yours, is it off to see the Wizard, the wonderful wizard of Oz.

I have never encountered anybody who claimed with certainty that 100% of the warming for the last 50 or 100 years was due to human CO₂ emissions.

The IPCC determined that there was a 90% probability that at least 50% of the recent warming was due to human emissions.

Of course there are other factors in play with natural climate variability. If you haven't got the stones to actually address the argument people are making then just naff off. Making up an argument that you can deal with is silly, pointless and makes you look foolish.

I find it insulting that you apaprently think anybody would be stupid enough to fall for this cheap trick, and dissapointing that your experience in this argument hasn't already demonstrated this to you.

When you and your straw man get to Oz don't forget to ask for a brain. At least one of you needs it.

 

[Lennart Hyland]

A swedish physics professor at Uppsala University, Kjell Aleklett also leading a reaserch-team in Global Energysystems, thinks that the global temperature will only 2 degrees but not more because of the limitation of fossil fuels as oil.

He thinks that the oil will run out before our global temperature has risen to high if you out thinks all feedback process.

A interview with him, (I hope you know swedish ):

http://www.youtube.com/watch?v=oRewPwTsLF0

What do you think about it?

 

[bokonon]

Think about your sinking, Asilomar: we are digging coal and pumping oil at a prodigious rate out of the earth. Coal is about 90% carbon, oil is about 92%. When we burn it, nearly all of it becomes, eventually, gaseous CO2. Now, to "sink" that amount we need to capture that same amount of carbon (and CO2 is only about 27% carbon by weight) and put it back or otherwise "destroy" it - perhaps turn it back into elemental carbon, releasing the oxygen and bury it in the mines we excavated. Or perhaps as dry ice, if we can keep it at -40 degrees or lower. That means dig out the coal, burn it to get energy, then "unburn" it to get the coal back and rebury it. Or we can shoot it into space. Do you see the ridiculousness of the concept of sinking it?

A handful of ridiculous examples don't make the concept itself ridiculous. I can imagine a couple of sinks which would make more sense than dry ice or burying cans of carbonated beverages.

Suppose a process was developed which could split atmospheric CO2 into oxygen and carbon. The O2 could simply be released into the atmosphere, diluting the remaining CO2. The carbon could be used to make fine graphite particles, which could be released in the upper atmosphere to absorb the sun's energy in the "transmission" frequencies, where they would readily radiate most of the heat captured into space. Alternatively, the carbon could be used to make industrial quantities of carbon nanotubes, which could begin to replace wood and steel in construction and manufacturing.

Admittedly, I don't know if it's feasible to make carbon nanotubes in the same quantities as steel girders are manufactured today, or whether the energy to manufacture such quantities could be obtained from alternative (solar, wind, nuclear) sources so that net atmospheric CO2 would be guaranteed to decrease. I don't know if spraying graphite particles into the stratosphere is a bad idea for reasons that have nothing to do with global warming.

But I don't necessarily see the idea of carbon sinks as a bad idea. Suppose an industrial process was developed that would combine atmospheric CO2 with water to create hydrocarbons and release O2. Suppose the industrial process could run on solar power, and became our sole source of gasoline (or other fuels) once fossil fuels became prohibitively expensive. We'd essentially have reached a steady state, where what we burned was converted back into an energy storage medium (fuel) which would then be burned again. In such cases, any carbon removed to make plastic, or diamonds, or nanotube cable and girders, would be reducing the amount available to become CO2 in the atmosphere, and we could actually expect to see any greenhouse effect begin to diminish.

 

[mhaze]

Originally posted by mhaze
The unproven hypothesis is that slight increases in the trace gas CO2 have huge effects on the atmosphere's temperature due to positive feedback mechanisms operating on the basic logrythmic response of CO2 to radiation.

No it isn't. The fundamental hypothesis is nothing to do with the atmosphere at all, it is simply that CO₂ transmits certain wavelengths while absorbing others, and that the Sun emits more of its energy in the transmitted region while the Earth emits more energy in the absorbed region. Except that that's not hypothesis, that's proven fact. The inevitable consequence of this is that more CO₂ in the atmosphere means more energy trapped underneath that CO₂. Again, not open to debate. Exactly where that energy is is not relevant to the question of whether global warming is happening. It could be in the atmosphere, in the sea, in the land, a mix of all three or, most likely, a dynamic system transfering between all three.

None of this is open to debate. What is open for debate is what the effects of trapping this extra energy actually are. We already know that your opinion is that the amount of energy is not significant. That's a perfectly valid stance, although not poorly supported by the evidence. What is odd is that you apaprently refuse to accept that your arguments actually agree that global warming is occuring. Arguing that the extra energy is trapped in a heat sink is not arguing that the energy is not there at all, and yet you consistently try to claim that global warming is not happening at the same time as claiming that you know where the extra heat is going. Weird.

What is weird is that you have completely missed relevance and meaning of the phrases "feedback", "Logrhythmic response" and "far extreme" in the summary statement I made, thus your response is totally irrelevant as far as I can tell.

But thanks for telling everyone what was and was not open for debate according to your limits of view; re examine the three phrases that I have indicated and offer another analysis that is less weird.

 

[Spud1k]

I am not minimizing any of what has been said, but if we are only contributing, with all of our ... well, everything, 3% of the whole, I fail to see why we are getting so concerned with the contributes.

Wouldn't it be better to go the other way and, while yes, look for viable alternatives to fossil fuels, put research into CO2 sinks and negate the 3% we are adding?

I am looking for real discussion - I am a global warming believer, but the 3% ... well, that ... just darn, I thought we were producing numbers on the order of 25% of all CO2 or more.

What you are talking about is the stuff relating to carbon sequestration. Only problem is, it's much easier putting CO2 into the atmosphere than taking it out. Fertilising nutrient-poor areas of the ocean to increase phytoplankton activity has been mooted more than once, as has making man-made chemical 'trees' that trap carbon dioxide. Unfortunately, when you do the sums, you'd struggle to get anywhere close to the 3% mark with the best of today's science.

The best theoretical solution anyone has come up with to date has been simply taking the flue gases from a coal-fired power plant and trapping it underground before it even gets into the atmosphere. Great, assuming none leaks out.

 

[CapelDodger]

To add to the previous post. If you add a $1m into an account every year and take out a $1m a year every year and there is about $10 million dollars in the account, then I start to take out 3% of what you take out without putting in anything how long before the account is empty?

"Income 20 shillings, outgoings nineteen shillings and sixpence, result : happiness. Income twenty shillings, outgoings twenty shillings and sixpence, result : misery".

Mr Micawber

 

[CapelDodger]

A swedish physics professor at Uppsala University, Kjell Aleklett also leading a reaserch-team in Global Energysystems, thinks that the global temperature will only 2 degrees but not more because of the limitation of fossil fuels as oil.

He thinks that the oil will run out before our global temperature has risen to high if you out thinks all feedback process.

A interview with him, (I hope you know swedish ):

http://www.youtube.com/watch?v=oRewPwTsLF0

What do you think about it?

Oil isn't the major fossil fuel, coal is, and that won't run out for a long time yet. Here in South Wales, coal-mines that were closed in the 80's because they couldn't compete with North Sea gas for electricity generation are being re-opened because the gas is running out (rapidly). Oil has been crucial for transport for less than a century, but that's a fraction of energy-consumption. Coal is the backbone of energy production; it has been for two centuries or more, and there's mountains of it left. Oil and gas came and will soon have gone, but coal is the old dependable.

 

[mhaze]

This straw man of yours, is it off to see the Wizard, the wonderful wizard of Oz.

I have never encountered anybody who claimed with certainty that 100% of the warming for the last 50 or 100 years was due to human CO₂ emissions.

The IPCC determined that there was a 90% probability that at least 50% of the recent warming was due to human emissions.

Of course there are other factors in play with natural climate variability. If you haven't got the stones to actually address the argument people are making then just naff off. Making up an argument that you can deal with is silly, pointless and makes you look foolish.

I find it insulting that you apaprently think anybody would be stupid enough to fall for this cheap trick, and dissapointing that your experience in this argument hasn't already demonstrated this to you.

When you and your straw man get to Oz don't forget to ask for a brain. At least one of you needs it.

Nonsense, go study a bit and come up with better stuff than silly analogies that don't work, based on poor understanding of the science, and enhanced by inaccurate reading of my statements.

I find it insulting that you would not carefully produce a response that is logical and persuasive.

1990 IPCC

“the observed (20th century temperature) increase could be largely due to ... natural variability” ​

IPCC 1995

“the balance of the evidence suggests a discernible human influence on climate”
​

IPCC 2001

“there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities”
​

IPCC 2007

“90% probable” that the recent warming is “due to the observed increase in anthropogenic greenhouse gas concentrations”
​

Ironic that while you scoff at my comments which were preceeded by the words "far extreme", in this very thread simultaneously the discussion is ongoing about carbon sequestration, which is prima facie evidence of a widespread belief that CO2 is in fact the culprit that must be placed under governmental control and regulation in order to save the planet.

By the way, (since I wasn't talking about IPCC but you are) be advised that when IPCC use words such as 90%, these are not statistical measures but relate in a circular logic fashion to phrases such as "very likely".