I'll take your childishness as you admitting you can't formulate a response. The alternative is that you really can't speak english and for some reason found something in my post unclear.
You said you wanted to learn this stuff. I explained it to you, and your response was to be rude, play the victim and ignore all the information you were given
Commenting on your rudeness is not being un-civil. If you do not like people calling you out on your poor attitude, take some personal responsibility and behave yourself better instead of claiming victimhood and using that as an pretext to ignore the very information you claim to be trying to learn.
You have something to say? Let's see it. I've been waiting for someone to present a mathematical model of radiation sources and sinks. Apparently the people who really understand are happy to let the children play unsupervised.
I'm trying to construct a mental model of the process of warming by radiation. At the start of this particular discussion (weeks ago) I suggested that total radiation from a spherical shell around a star must equal the star's output. Albedo and the material composition of the shelll may determine the wavelength of emitted radiation, but the total energy must equal the star's output. Seems to me, anyway. If this is wrong, what am I missing?
NB. "You're just stupid" is not an informative response.
Anyway the answer is in WD clinger's post below, with the proviso that the greenhouse effect relies on the Earth NOT being a black body.
I'd stick to the very simple observations about the surface temperatures of Mercury, Venus, the Earth and the moon, and accept that these demonstrate how effective a greenhouse effect can be.
I am an engineer cum semiconductor device physicist, so am pretty happy with maths, but I don't have the time to become an expert on climate models - all I can do is perform sanity checks using simple calculations where any discrepancy is likely to be my problem rather than any climate scientists.
With that in mind I my sanity checks give results within an order of magnitude of the predictions of climate scientists.
You have something to say? Let's see it. I've been waiting for someone to present a mathematical model of radiation sources and sinks. Apparently the people who really understand are happy to let the children play unsupervised.
I would reverse that causation. A planet without atmosphere is usually a pretty good approximation of a black body. A planet with greenhouse gasses in its atmosphere will not behave as a black body. At a high level it's this property that makes them greenhouse gasses to begin with.
IOW It’s not that greenhouse gasses rely on the Earth not being a black body, rather, the Earth is not a black body because it has greenhouse gasses in its atmosphere. In the bigger scheme it’s still pretty close to a black body when compared to Venus.
Ok: A doubling of CO2 every decade!
ETA: More serously use the A1 scenerio which roughly 400 ppm of CO2 tday to 650 ppm of C02 in 2100. Your calculations based on this will be interesting .
a. Mass of atmosphere: 5.3 x 10 ^18 kg. http://hypertextbook.com/facts/1999/LouiseLiu.shtml
b. Total atmospheric CO2, by weight (percent): 0.046 % http://www.engineeringtoolbox.com/air-composition-d_212.html
c. CO2 emissions, 2011. 34 x 10^12 kg.yr^-1 http://www.pbl.nl/en/publications/2012/trends-in-global-co2-emissions-2012-report
Online calculator: http://web2.0calc.com/
Mass of atmospheric CO2= axb= (5.3 x 10 ^18 kg)x(4.6x10^-2)=2.438x10^17 kg.
Yearly CO2 emissions as a fraction of total atmospheric CO2 mass = (3.4x10^13 kg. yr^-1) /(2.438x10^17 kg.)=1.394538 x10^-4 yr^-1 or ~ 1.4x10^-4yr^-1
Number of years to double atmospheric CO2 = (1/1.4)x10^4yr.=0.7142857x10^4.. or about 7000 years.
That's without any natural biological sequestration.
Anybody want to check the work? Maybe I dropped couple powers of ten or multiplied when I should have divided.
I would reverse that causation. A planet without atmosphere is usually a pretty good approximation of a black body. A planet with greenhouse gasses in its atmosphere will not behave as a black body. At a high level it's this property that makes them greenhouse gasses to begin with.
IOW It’s not that greenhouse gasses rely on the Earth not being a black body, rather, the Earth is not a black body because it has greenhouse gasses in its atmosphere. In the bigger scheme it’s still pretty close to a black body when compared to Venus.
True, I should have said the greenhouse effect is a consequence of greenhouse gases allowing differential transmission of radiation depending on wavelength.
a. Mass of atmosphere: 5.3 x 10 ^18 kg. http://hypertextbook.com/facts/1999/LouiseLiu.shtml
b. Total atmospheric CO2, by weight (percent): 0.046 % http://www.engineeringtoolbox.com/air-composition-d_212.html
c. CO2 emissions, 2011. 34 x 10^12 kg.yr^-1 http://www.pbl.nl/en/publications/2012/trends-in-global-co2-emissions-2012-report
Online calculator: http://web2.0calc.com/
Mass of atmospheric CO2= axb= (5.3 x 10 ^18 kg)x(4.6x10^-2)=2.438x10^17 kg.
Yearly CO2 emissions as a fraction of total atmospheric CO2 mass = (3.4x10^13 kg. yr^-1) /(2.438x10^17 kg.)=1.394538 x10^-4 yr^-1 or ~ 1.4x10^-4yr^-1
Number of years to double atmospheric CO2 = (1/1.4)x10^4yr.=0.7142857x10^4.. or about 7000 years.
That's without any natural biological sequestration.
Anybody want to check the work? Maybe I dropped couple powers of ten or multiplied when I should have divided.
I mentioned one, biological sequestration. I didn't forget others. I just provide a starting point with some solid numbers (if you trust the sources and my calculations). Bilolgical sequestration would have a damping effect on CO2 levels. Warming of ocean water has several effects in different directions (outgassing of dissolved CO2, water vapor, clouds, biomass increase).
There's something strange in the Vostok ice core record. It looks like atmospheric CO2 reaches a peak late in the interglacial, but not at the end.
A Venus style runaway greenhouse effect probably requires the wide scale breakdown of carbonate rock, which isn’t possible while there are still oceans moderating the earth’s temperature.
A year or two ago James Hansen wrote a paper that challenged that assumption and said that because the Sun is putting out ~10% more energy than it was the last time all the fossil carbon was in the atmosphere there is some possibility that burning it all could create a Venus style runaway but AFAIK that remains a minority position.
a. Mass of atmosphere: 5.3 x 10 ^18 kg. http://hypertextbook.com/facts/1999/LouiseLiu.shtml
b. Total atmospheric CO2, by weight (percent): 0.046 % http://www.engineeringtoolbox.com/air-composition-d_212.html
c. CO2 emissions, 2011. 34 x 10^12 kg.yr^-1 http://www.pbl.nl/en/publications/2012/trends-in-global-co2-emissions-2012-report
Online calculator: http://web2.0calc.com/
Mass of atmospheric CO2= axb= (5.3 x 10 ^18 kg)x(4.6x10^-2)=2.438x10^17 kg.
Yearly CO2 emissions as a fraction of total atmospheric CO2 mass = (3.4x10^13 kg. yr^-1) /(2.438x10^17 kg.)=1.394538 x10^-4 yr^-1 or ~ 1.4x10^-4yr^-1
Number of years to double atmospheric CO2 = (1/1.4)x10^4yr.=0.7142857x10^4.. or about 7000 years.
That's without any natural biological sequestration.
Anybody want to check the work? Maybe I dropped couple powers of ten or multiplied when I should have divided.
Math fail. You didn’t convert your % to a decimal. Your reference for % CO2 is in the atmosphere is also WELL out of date. They say 300ppm, but the current number is a little over 390ppm
The mass of CO2 in the Earths atmosphere is ~3000 GT or 3X10^15 Kg. Tt’s fraction of the atmosphere is increasing at ~2-3 ppm each year due to human activity. That represents ~46% of fossil CO2 emission, the rest ends up in the oceans
Math fail. You didn’t convert your % to a decimal. Your reference for % CO2 is in the atmosphere is also WELL out of date. They say 300ppm, but the current number is a little over 390ppm
The mass of CO2 in the Earths atmosphere is ~3000 GT or 3X10^15 Kg.
a. Mass of atmosphere: 5.3 x 10 ^18 kg. http://hypertextbook.com/facts/1999/LouiseLiu.shtml
b. Total atmospheric CO2, by weight (percent): 0.046 %0.06%http://www.engineeringtoolbox.com/air-composition-d_212.html
c. CO2 emissions, 2011. 34 x 10^12 kg.yr^-1 http://www.pbl.nl/en/publications/2012/trends-in-global-co2-emissions-2012-report
Online calculator: http://web2.0calc.com/
Mass of atmospheric CO2= axb= (5.3 x 10 ^18 kg)x(4.6x10^-2.06x10^(-2))=2.438x10^173.2x10^15 kg.
Yearly CO2 emissions as a fraction of total atmospheric CO2 mass = (3.4x10^13 kg. yr^-1) /(2.438x10^173.2x10^15 kg.)=1.394538 x10^-4 yr^-1 or ~ 1.4x10^-4yr^-1.01
Number of years to double atmospheric CO2 = (1/1.4)x10^4yr.=0.7142857x10^4..1/(.01) or about 7000100 years.
That's without any natural biological sequestration or feedbacks.
Anybody want to check the work? Maybe I dropped couple powers of ten or multiplied when I should have divided.
a. Mass of atmosphere: 5.3 x 10 ^18 kg. http://hypertextbook.com/facts/1999/LouiseLiu.shtml
b. Total atmospheric CO2, by weight (percent): 0.046 % http://www.engineeringtoolbox.com/air-composition-d_212.html
c. CO2 emissions, 2011. 34 x 10^12 kg.yr^-1 http://www.pbl.nl/en/publications/2012/trends-in-global-co2-emissions-2012-report
Online calculator: http://web2.0calc.com/
Mass of atmospheric CO2= axb= (5.3 x 10 ^18 kg)x(4.6x10^-2)=2.438x10^17 kg.
Yearly CO2 emissions as a fraction of total atmospheric CO2 mass = (3.4x10^13 kg. yr^-1) /(2.438x10^17 kg.)=1.394538 x10^-4 yr^-1 or ~ 1.4x10^-4yr^-1
Number of years to double atmospheric CO2 = (1/1.4)x10^4yr.=0.7142857x10^4.. or about 7000 years.
That's without any natural biological sequestration.
Anybody want to check the work? Maybe I dropped couple powers of ten or multiplied when I should have divided.
Math fail. You didn’t convert your % to a decimal. Your reference for % CO2 is in the atmosphere is also WELL out of date. They say 300ppm, but the current number is a little over 390ppm
The mass of CO2 in the Earths atmosphere is ~3000 GT or 3X10^15 Kg. Tt’s fraction of the atmosphere is increasing at ~2-3 ppm each year due to human activity. That represents ~46% of fossil CO2 emission, the rest ends up in the oceans
The atmosphere is about 5-Petatonnes so each year the emissions are about 27e9/5e15 tonnes, or about 5.6 ppm per year. In 2006 the CO2 levels were 381ppm according to the BBC.
The annual emissions are about 1% of the total level, which I'd regard as significant.
I am a semiconductor engineer, and some time ago, I decided to investigate this, and see whether the simple statistical tools I would use to assess how a process is running could be applied to the data from weather. These tools are used in what is called "Statistical Process Control", and a very good introduction can be found on this NIST website:
I have had a similar discussion on the badscience.net website about this, and on this website too:
My analysis and reasoning that led me to conclude that the climate in the region with the longest history of measurements is warmer than in any other period for which measurements exist (which is back to 1690).
You say deniers, I say alarmist. I see no data that shows that we change the climate any more so than it changed before people were around. We haven't made an ice age, or warmed to that extent.
I like the environment just as much as then next guy and conserve as I can.
People who speak of imminent doom are religious zealots wherever you find them. Period.
There is evidence that the climate is changing, and it is warming at an increasing rate. Your claims about global data isn't really valid for the longest running dataset: the Central England temperature series, that is based on measurements since 1690. It shows unequivocally that England is warmer now than it has been in the last three hundred years. It also says that it is getting still warmer.
I started looking at this data because I wanted to make my own mind up, and to see if the data was clear to me. I have used statistical process control techniques in my work, so I thought it would be interesting to analyse this data as if it were a device parameter running on a particular process. The signal is very strong, especially compared to the sort of data that I am used to in work.
Why does it matter if we are changing the climate or of it is natural variation?
Is the climate changing? The cusum says that England is getting warmer. It also says that the rate of change is increasing. The global data also supports this.
Is this bad? Well probably for crops, especially if repeated globally.
Is there a model that explains this? (well yes) but isn't this irrelevant?
Is CO2 a greenhouse gas? Well it absorbs IR, and atmospheric physicists say it is. They say that increasing CO2 woulld make the world warmer. Do we care if the warming is natural or artificial, if we can reduce it (or reduce our addition to it) and we accept that its effects would be bad?
If you want to know how to interpret the cusum, it is hidden in the spoiler below:
Cusums are used in certain types of statistical process control systems, and are very good at spotting when (noisy) processes are drifting from their target values. You decide on the target value (sometimes, but not always, the long term average) and then subtract this from each data point. This gives you the difference (or "Delta") above or below the target that each data point is. The cusum is the sum of all the deltas including the current data point. This is an integration and so removes noise from the signal.
To compare the process to the target, you then look at the gradients: horizontal will mean that it is running at target, upwards means above target, and downwards below target. An increase in steepness means that the process is moving further away from target, i.e. the process is still changing:
If the slope is such that there is an increase of 100 units in 100 readings, then the process is running at about 1 unit higher than the target, if it is 200 units lower in 100 readings then it is running at 2 units beow target etc.
Below I have annotated my cusum to show the different situations, and the increases in temperature:
Well, I'd like to understand why academic climatologists are so confident about 3. We plainly don't know the mechanisms so thoroughly that we can conclude it can't be anything else.
Does it matter where the CO2 is comming from, we are releasing several PPM per decade of CO2 so reducing that will reduce the rate iof increase of CO2, whatever the cause is.
EDIT:
According to wiki: the total emissions are 27,245,758 thousand metric tonnes per year, a quick sum is that this is about 27-Gigatonnes of CO2 per year.
The atmosphere is about 5-Petatonnes so each year the emissions are about 27e9/5e15 tonnes, or about 5.6 ppm per year. In 2006 the CO2 levels were 381ppm according to the BBC.
The annual emissions are about 1% of the total level, which I'd regard as significant.
You've got to watch your baseline though; using the graph's start time is artificial. If you say there's a permanent step change at 1600, or the period 1050-1600 is unusually high, then 1750 is a good takeff point and coincides with human emissions.
OK, I now found lake Vostok CO2 data (from here) and added that in, again on a log plot with the same scale. This might be dodgy, but they do tend to be similar at around -1k for the law dome data, and -2k for the vostok data. If this is the case,then this is outside the previous 400,000 years variation.
I am not an academic, like you I work as an engineer, and I tend to think like an engineer. I would like to have 95% confidence that a technical decision will be the right one before acting, but if the pros and cons are equal sometimes it is simply best to go with the course of action that is most probably correct.
If you then factor inrisks you might consider mitigation against unlikely events. I certainly consider what I can do to to mitigate the possible effects of something that has a 30% chance of occuring. (And far lower if the hazard is high enough)
Does it matter where the CO2 is comming from, we are releasing several PPM per decade of CO2 so reducing that will reduce the rate iof increase of CO2, whatever the cause is.
Ah well only possibly. If (for example) change in agriculture is changing vegetation types and so albido and water vapour levels, and CO2 is responding to the temperature rise, then we'll be spending money on the wrong thing and still have a disaster on our hands.
But martin, my fag-packet calculations confirm what I am told. I too can see lots of other potentially confounding factors, which are pretty complex and which is why there are departments of artmpospheric and climatological science.
In several situations the argument *seems* to me to be:
1) The simple model, based rough estimats and simple maths broadly agrees with the IPCC.
2) Ah, but that is only a simple model, what about more complex features which *might* change the story.
To which the answer is that they might indeed, which is why there are scientific papers discussing the features of the models or the data.
If the simplistic treatment disagreed with the acknowledged experts, then I might profitably try looking to see if I could understand why, and be a little more sceptical of their claims.
My simplistic analyses do broadly agree with the acknowledged experts, whilst the possible confounding factors are precisely the sort of confounding factors that I have seen acknowledged in discussing these models. This leads me to the conclusion that the experts aren't missing a trick, and they are probably correct, because they are already attempting to assess the magnitude and direction of these effects.
Remember I do not consider myself to have the ability to second guess the atmospheric physics departments of multiple universities (I have a day job already, and can only spend a few hours on this).
Because of this I can only do simple analyses, which I did, because I had heard there was a controversy.
When I did these simple sanity checks, they supported the IPCC statements and not the people who claimed that there was no problem.
This is not an argument from authority: Any moderately numerate person should be able to follow my reasoning, and I would like to know how this could come up with any other answer.
Of course it is possible to say that there might be confounding factors in such a complex system, but this is why you need proper models. We would have to be very lucky for all the confounding factors to be acting agaist there being anthropogenic global warming
And I am not acctually that interested if global warming is anthropogenic or natural.
CO2 emissions would add to the warming effect, and global warming will have many bad consequences, just due to changes in weather patterns and movement of fertile zones (especially across country boundries with the additional dnagers of war).
In such a situation, acting to militate against these effects is sound practice whether global warming is natural of artificial.
ETA: And my figures are in surprising agreement with Lolmiller's 46% getting into the atmosphere as this 5.6ppm per year is emissions, based on a really rough calculation where I did just use simple figures (I think I multiplied the surface area of the Earth by the mass of 32' (10m) of water over this area - to get the mass of the atmosphere because I could remember those figures, so didn't need to google.)
Math fail. You didn’t convert your % to a decimal. Your reference for % CO2 is in the atmosphere is also WELL out of date. They say 300ppm, but the current number is a little over 390ppm
The mass of CO2 in the Earths atmosphere is ~3000 GT or 3X10^15 Kg. Tt’s fraction of the atmosphere is increasing at ~2-3 ppm each year due to human activity. That represents ~46% of fossil CO2 emission, the rest ends up in the oceans
By this year it's common knowledge. You can arrive to that alone by taking the mass of the atmosphere (less than that 5.3 x 10 ^18 kg of yours, maybe 4.9 x 10 ^18 kg, ignore the tiny percentage of water vapour in that mass, multiply by CO2 concentration in volume (392 ppm in dry air) and then by the weight relation between CO2 and air (1.98/1.225) -remember CO2 is heavier than N2, O2 and Ar-, then reduce the value a little bit as CO2 concentration tends to diminish a bit with altitude and that gives some 3000 GT. I think the value was 2970 in the last fourth assessment report.
No, but something like that happened in the end-Devonian mass extinction, and did not result in a runaway. (But woe to us if we do that to the planet!)
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