Guest post by Ron House
As readers will know, I have been thinking about the hullabaloo about CO2 and global warming and I quickly concluded that CO2 is no threat, won’t do any significant warming (which would be good anyway), and is in fact 100% good for the planet. But someone said to me, if CO2 is no danger, that doesn’t mean that humans are not causing a danger in some other way. Of course I agreed with this, because there are lots of things humans are doing wrongly and thereby causing terrible damage to our world (and the CO2 storm in a teacup is distracting us all from fixing those real problems).
My friend then went on, however, to propose that the danger was still global warming and that the mechanism was, instead of CO2 greenhouse warming, the mere fact that human technology gives off heat. All the power used by all the machines and transport and so on eventually ends up as waste heat. Maybe that is in itself enough to cause us serious warming trouble? So I did some calculations.
According to the laws of thermodynamics, the process of doing useful work must necessarily lose some of the energy from the fuel in the form of waste heat; and that heat, well, heats. In other words, because of the huge extra amount of useful work we do, we create excess heat that would not have been here otherwise, and that heat has to either be dissipated somehow, or else raise the temperature.
The factors that have caused the ice ages, as we saw, are primarily small changes in insolation (heating) by the Sun. The changes can happen because the Sun’s energy output changes or because of cyclic changes in the Earth’s orbit and inclination, etc., changing the amount of heat that actually arrives on the surface. Changes in the Earth’s orbit are believed to be the triggers for the onset of ice ages, and the changes in heating caused by those changes are thought to be quite small compared to the total power output of the Sun. This might lead us to suspect that human-caused changes in the amount of heat at the surface might indeed have a significant effect on the climate.
To answer this question, we need to compare the amount of variation due to the Sun with the amount of heat emitted by industrial civilisation. if the latter is ‘in the same ballpark’ as the former, then human civilisation might be holding off the onset of a new ice age.
Although there is much dispute about the exact mechanism that causes the onset of ice ages, much of it doesn’t concern us right now because one basic fact is clear: somehow or other, the responsibility lies with changes in the amount of heat received from the Sun.
One theory is that the cause is Northern Hemisphere summer cooling. At our current stage in geological history, the North Pole is surrounded by land masses, which are snowed under every winter. If the summers became just a bit colder, then some of that winter snow would remain on the ground throughout summer, and would then turn to ice. The ice will reflect sunlight much better than green plants or dirt or even liquid water, so the cooling will accelerate and the next summer will be even colder and leave even more ice lying around. And so the planet falls into an ice age. Retained heat in the oceans slows down the changes and ‘smooths over’ short-term effects, but once the process starts, the killing ice eventually reclaims its deathly kingdom.
Dr David Archibald suggests that a key measure of this process is the amount of insolation at 65° north latitude. The power of the Sun at 65°N is about 476 Watts per square metre. That means that at midday in mid-summer at, say, Reykjavik (at 64°N, almost the only significant city anywhere close to 65°N), the Sun has about the power of five old-style incandescent light bulbs. When summer sun at this latitude is sufficient to melt the winter snowfall, all is well. Other factors in this calculation are the length of summer (because, for example, a longer, but slightly cooler summer might melt more ice than a shorter warmer one) and how high in the sky the Sun is in mid summer. And the higher it is in summer, the deeper and colder the long winter ‘night’ will be. The factors are complex and researchers disagree as to how exactly they should be combined in order to make good predictions, but some combination of these factors decides whether we bask in life-giving warmth or flee the deadly cold. We cannot hope to make predictions from the kind of short overview we are doing here, but we can get an idea of the magnitudes involved.
How much radiant energy the Sun has in the past or will in the future shine upon the Earth at this latitude can be reliably calculated from basic physical and astronomical properties of the way the Earth orbits the Sun and how that orbit changes with time. This is not an uncertain thing like the forecasts of climate models; it is not exactly easy to calculate, but it depends only upon the extremely well verified equations of Newtonian physics (or, if you prefer a few thousands of a percent more accuracy, relativity). If we didn’t know how to do these calculations, we could never have landed men on the Moon or flown discovery missions past Saturn and on to Uranus and Neptune. Yes, we do know how to make these calculations and we know it very reliably.
When the calculations are done, we find that at the depth of the last ice age, around 22,000 years ago, the Sun’s power (again at 65°N) was around 463Wm-2. On the other hand, at the height of our own interglacial, the Holocene, which occurred about 11,000 years ago (yes, we have been on the downward slope ever since—though you would never guess it from the hairy scary stories about warming in the media) the summer insolation at 65°N was about 527Wm-2. In other words, we have:
| What | When | Sun’s Power |
|---|---|---|
| Previous Ice Age | 22,000 years ago | 463Wm-2 |
| Holocene Peak | 11,000 years ago | 527Wm-2 |
| The Perfect Time | Now | 476Wm-2 |
From these figures, we may make the following inferences:
- The difference between peak warmth and deepest cold was around 55Wm-2;
- The current value, being only 13Wm-2 above the value at the depth of the ice age, is almost all the way back to ‘cold conditions’; it may be that only stored ocean heat is keeping us out of an ice age (for now).
Moving on, how do these power figures compare with human energy output (mainly by burning fossil fuels)?
Human energy usage in 2006 was 491 exajoules. This translates to an average power usage of 15.56 terawatts each second (divide by the number of seconds in a year). To compare this with the Sun’s power as discussed above, we need to average this over the entire planet. The Earth’s surface area is 510 million sq. km., which gives 30,500 W per sq. km, or 0.03Wm-2. One final adjustment is needed to allow us to do the comparison: the Sun’s insolation given above was as received at noon, whereas this figure is an average over the whole planet. Since the planet’s area is four times the areas of a circle of the same radius, we must multiply by four, giving about 0.12Wm-2 as our final figure for comparison.
The human energy output of about 0.12Wm-2 is clearly overpowered by even the smallest of the numbers we have looked at so far. The 13Wm-2 difference between ice age conditions and today is at least a hundred times larger than human energy output. We might delay a killer ice age slightly, but our heating of the planet is nowhere near large enough to save us.
Are we heating the Earth too much – with heat?
As readers will know, I have been thinking about the hullabaloo about CO2 and global warming and I quickly concluded that CO2 is no threat, won’t do any significant warming (which would be good anyway), and is in fact 100% good for the planet. But someone said to me, if CO2 is no danger, that doesn’t mean that humans are not causing a danger in some other way. Of course I agreed with this, because there are lots of things humans are doing wrongly and thereby causing terrible damage to our world (and the CO2 storm in a teacup is distracting us all from fixing those real problems).
My friend then went on, however, to propose that the danger was still global warming and that the mechanism was, instead of CO2 greenhouse warming, the mere fact that human technology gives off heat. All the power used by all the machines and transport and so on eventually ends up as waste heat. Maybe that is in itself enough to cause us serious warming trouble? So I did some calculations.
According to the laws of thermodynamics, the process of doing useful work must necessarily lose some of the energy from the fuel in the form of waste heat; and that heat, well, heats. In other words, because of the huge extra amount of useful work we do, we create excess heat that would not have been here otherwise, and that heat has to either be dissipated somehow, or else raise the temperature.
The factors that have caused the ice ages, as we saw, are primarily small changes in insolation (heating) by the Sun. The changes can happen because the Sun’s energy output changes or because of cyclic changes in the Earth’s orbit and inclination, etc., changing the amount of heat that actually arrives on the surface. Changes in the Earth’s orbit are believed to be the triggers for the onset of ice ages, and the changes in heating caused by those changes are thought to be quite small compared to the total power output of the Sun. This might lead us to suspect that human-caused changes in the amount of heat at the surface might indeed have a significant effect on the climate.
To answer this question, we need to compare the amount of variation due to the Sun with the amount of heat emitted by industrial civilisation. if the latter is ‘in the same ballpark’ as the former, then human civilisation might be holding off the onset of a new ice age.
Although there is much dispute about the exact mechanism that causes the onset of ice ages, much of it doesn’t concern us right now because one basic fact is clear: somehow or other, the responsibility lies with changes in the amount of heat received from the Sun.
One theory is that the cause is Northern Hemisphere summer cooling. At our current stage in geological history, the North Pole is surrounded by land masses, which are snowed under every winter. If the summers became just a bit colder, then some of that winter snow would remain on the ground throughout summer, and would then turn to ice. The ice will reflect sunlight much better than green plants or dirt or even liquid water, so the cooling will accelerate and the next summer will be even colder and leave even more ice lying around. And so the planet falls into an ice age. Retained heat in the oceans slows down the changes and ‘smooths over’ short-term effects, but once the process starts, the killing ice eventually reclaims its deathly kingdom.
Dr David Archibald suggests that a key measure of this process is the amount of insolation at 65° north latitude. The power of the Sun at 65°N is about 476 Watts per square metre. That means that at midday in mid-summer at, say, Reykjavik (at 64°N, almost the only significant city anywhere close to 65°N), the Sun has about the power of five old-style incandescent light bulbs. When summer sun at this latitude is sufficient to melt the winter snowfall, all is well. Other factors in this calculation are the length of summer (because, for example, a longer, but slightly cooler summer might melt more ice than a shorter warmer one) and how high in the sky the Sun is in mid summer. And the higher it is in summer, the deeper and colder the long winter ‘night’ will be. The factors are complex and researchers disagree as to how exactly they should be combined in order to make good predictions, but some combination of these factors decides whether we bask in life-giving warmth or flee the deadly cold. We cannot hope to make predictions from the kind of short overview we are doing here, but we can get an idea of the magnitudes involved.
How much radiant energy the Sun has in the past or will in the future shine upon the Earth at this latitude can be reliably calculated from basic physical and astronomical properties of the way the Earth orbits the Sun and how that orbit changes with time. This is not an uncertain thing like the forecasts of climate models; it is not exactly easy to calculate, but it depends only upon the extremely well verified equations of Newtonian physics (or, if you prefer a few thousands of a percent more accuracy, relativity). If we didn’t know how to do these calculations, we could never have landed men on the Moon or flown discovery missions past Saturn and on to Uranus and Neptune. Yes, we do know how to make these calculations and we know it very reliably.
When the calculations are done, we find that at the depth of the last ice age, around 22,000 years ago, the Sun’s power (again at 65°N) was around 463Wm-2. On the other hand, at the height of our own interglacial, the Holocene, which occurred about 11,000 years ago (yes, we have been on the downward slope ever since—though you would never guess it from the hairy scary stories about warming in the media) the summer insolation at 65°N was about 527Wm-2. In other words, we have:
| What | When | Sun’s Power |
|---|---|---|
| Previous Ice Age | 22,000 years ago | 463Wm-2 |
| Holocene Peak | 11,000 years ago | 527Wm-2 |
| The Perfect Time | Now | 476Wm-2 |
From these figures, we may make the following inferences:
-
- The difference between peak warmth and deepest cold was around 55Wm-2;
- The current value, being only 13Wm-2 above the value at the depth of the ice age, is almost all the way back to ‘cold conditions’; it may be that only stored ocean heat is keeping us out of an ice age (for now).
Moving on, how do these power figures compare with human energy output (mainly by burning fossil fuels)?
Human energy usage in 2006 was 491 exajoules. This translates to an average power usage of 15.56 terawatts each second (divide by the number of seconds in a year). To compare this with the Sun’s power as discussed above, we need to average this over the entire planet. The Earth’s surface area is 510 million sq. km., which gives 30,500 W per sq. km, or 0.03Wm-2. One final adjustment is needed to allow us to do the comparison: the Sun’s insolation given above was as received at noon, whereas this figure is an average over the whole planet. Since the planet’s area is four times the areas of a circle of the same radius, we must multiply by four, giving about 0.12Wm-2 as our final figure for comparison.
The human energy output of about 0.12Wm-2 is clearly overpowered by even the smallest of the numbers we have looked at so far. The 13Wm-2 difference between ice age conditions and today is at least a hundred times larger than human energy output. We might delay a killer ice age slightly, but our heating of the planet is nowhere near large enough to save us.
Are we heating the Earth too much – with heat?
Ron House June 3, 2010As readers will know, I have been thinking about the hullabaloo about CO2 and global warming and I quickly concluded that CO2 is no threat, won’t do any significant warming (which would be good anyway), and is in fact 100% good for the planet. But someone said to me, if CO2 is no danger, that doesn’t mean that humans are not causing a danger in some other way. Of course I agreed with this, because there are lots of things humans are doing wrongly and thereby causing terrible damage to our world (and the CO2 storm in a teacup is distracting us all from fixing those real problems).
My friend then went on, however, to propose that the danger was still global warming and that the mechanism was, instead of CO2 greenhouse warming, the mere fact that human technology gives off heat. All the power used by all the machines and transport and so on eventually ends up as waste heat. Maybe that is in itself enough to cause us serious warming trouble? So I did some calculations.
According to the laws of thermodynamics, the process of doing useful work must necessarily lose some of the energy from the fuel in the form of waste heat; and that heat, well, heats. In other words, because of the huge extra amount of useful work we do, we create excess heat that would not have been here otherwise, and that heat has to either be dissipated somehow, or else raise the temperature.
The factors that have caused the ice ages, as we saw, are primarily small changes in insolation (heating) by the Sun. The changes can happen because the Sun’s energy output changes or because of cyclic changes in the Earth’s orbit and inclination, etc., changing the amount of heat that actually arrives on the surface. Changes in the Earth’s orbit are believed to be the triggers for the onset of ice ages, and the changes in heating caused by those changes are thought to be quite small compared to the total power output of the Sun. This might lead us to suspect that human-caused changes in the amount of heat at the surface might indeed have a significant effect on the climate.
To answer this question, we need to compare the amount of variation due to the Sun with the amount of heat emitted by industrial civilisation. if the latter is ‘in the same ballpark’ as the former, then human civilisation might be holding off the onset of a new ice age.
Although there is much dispute about the exact mechanism that causes the onset of ice ages, much of it doesn’t concern us right now because one basic fact is clear: somehow or other, the responsibility lies with changes in the amount of heat received from the Sun.
One theory is that the cause is Northern Hemisphere summer cooling. At our current stage in geological history, the North Pole is surrounded by land masses, which are snowed under every winter. If the summers became just a bit colder, then some of that winter snow would remain on the ground throughout summer, and would then turn to ice. The ice will reflect sunlight much better than green plants or dirt or even liquid water, so the cooling will accelerate and the next summer will be even colder and leave even more ice lying around. And so the planet falls into an ice age. Retained heat in the oceans slows down the changes and ‘smooths over’ short-term effects, but once the process starts, the killing ice eventually reclaims its deathly kingdom.
Dr David Archibald suggests that a key measure of this process is the amount of insolation at 65° north latitude. The power of the Sun at 65°N is about 476 Watts per square metre. That means that at midday in mid-summer at, say, Reykjavik (at 64°N, almost the only significant city anywhere close to 65°N), the Sun has about the power of five old-style incandescent light bulbs. When summer sun at this latitude is sufficient to melt the winter snowfall, all is well. Other factors in this calculation are the length of summer (because, for example, a longer, but slightly cooler summer might melt more ice than a shorter warmer one) and how high in the sky the Sun is in mid summer. And the higher it is in summer, the deeper and colder the long winter ‘night’ will be. The factors are complex and researchers disagree as to how exactly they should be combined in order to make good predictions, but some combination of these factors decides whether we bask in life-giving warmth or flee the deadly cold. We cannot hope to make predictions from the kind of short overview we are doing here, but we can get an idea of the magnitudes involved.
How much radiant energy the Sun has in the past or will in the future shine upon the Earth at this latitude can be reliably calculated from basic physical and astronomical properties of the way the Earth orbits the Sun and how that orbit changes with time. This is not an uncertain thing like the forecasts of climate models; it is not exactly easy to calculate, but it depends only upon the extremely well verified equations of Newtonian physics (or, if you prefer a few thousands of a percent more accuracy, relativity). If we didn’t know how to do these calculations, we could never have landed men on the Moon or flown discovery missions past Saturn and on to Uranus and Neptune. Yes, we do know how to make these calculations and we know it very reliably.
When the calculations are done, we find that at the depth of the last ice age, around 22,000 years ago, the Sun’s power (again at 65°N) was around 463Wm-2. On the other hand, at the height of our own interglacial, the Holocene, which occurred about 11,000 years ago (yes, we have been on the downward slope ever since—though you would never guess it from the hairy scary stories about warming in the media) the summer insolation at 65°N was about 527Wm-2. In other words, we have:
| What | When | Sun’s Power |
|---|---|---|
| Previous Ice Age | 22,000 years ago | 463Wm-2 |
| Holocene Peak | 11,000 years ago | 527Wm-2 |
| The Perfect Time | Now | 476Wm-2 |
From these figures, we may make the following inferences:
-
- The difference between peak warmth and deepest cold was around 55Wm-2;
- The current value, being only 13Wm-2 above the value at the depth of the ice age, is almost all the way back to ‘cold conditions’; it may be that only stored ocean heat is keeping us out of an ice age (for now).
Moving on, how do these power figures compare with human energy output (mainly by burning fossil fuels)?
Human energy usage in 2006 was 491 exajoules. This translates to an average power usage of 15.56 terawatts each second (divide by the number of seconds in a year). To compare this with the Sun’s power as discussed above, we need to average this over the entire planet. The Earth’s surface area is 510 million sq. km., which gives 30,500 W per sq. km, or 0.03Wm-2. One final adjustment is needed to allow us to do the comparison: the Sun’s insolation given above was as received at noon, whereas this figure is an average over the whole planet. Since the planet’s area is four times the areas of a circle of the same radius, we must multiply by four, giving about 0.12Wm-2 as our final figure for comparison.
The human energy output of about 0.12Wm-2 is clearly overpowered by even the smallest of the numbers we have looked at so far. The 13Wm-2 difference between ice age conditions and today is at least a hundred times larger than human energy output. We might delay a killer ice age slightly, but our heating of the planet is nowhere near large enough to save us.
Interesting. We seem to have a whole lot of ideas on more ways in which humans might be making a difference. I have looked at raw heat emission, who wants to take on any of these other suggestions?
If human beings are responsible for any delay in the next glaciation in this ice age, the mechanism will be soot.
Nothing else makes sense. Heat pollution may have localized fleeting effects especially when local bodies of water in Northern regions are used for cooling. Once you flicked the switch the UHI would disappear almost instantly except where heat pushed the frost line up in the soil. Then you are talking days to normalize. Insignificant.
Younger Dryas is thought to have been caused by the rapid discharge of an ENORMOUS fresh water glacial lake into the Arctic Ocean over some months to a year. (Probably caused by the sudden collapse of an ice dam holding the water back.) It stopped ocean thermohaline circulation (eg. Gulf Stream) from transporting warm water to the arctic. Eventually the THC restarted and the Younger Dryas ended.
There was what seemed like a pretty conclusive research report published on this in the last few months. It’s buried somewhere in a pile of such reports in my den. There’s more to it than that, but I don’t recall the details.
Jbar says:
June 4, 2010 at 7:39 pm
Younger Dryas is thought to have been caused by the rapid discharge of an ENORMOUS fresh water glacial lake into the Arctic Ocean over some months to a year. (Probably caused by the sudden collapse of an ice dam holding the water back.) It stopped ocean thermohaline circulation (eg. Gulf Stream) from transporting warm water to the arctic. Eventually the THC restarted and the Younger Dryas ended.
There was what seemed like a pretty conclusive research report published on this in the last few months. It’s buried somewhere in a pile of such reports in my den. There’s more to it than that, but I don’t recall the details.
___________________________________________________________________________
There seem to be alternative explanations. Actually the rapid discharge of fresh water AND the comet/what ever collision could both be correct. What a way to break an ice dam….
——————-
Willis Eschenbach says:
May 26, 2010 at 4:47 pm t
…..For an alternate explanation of the Younger Dryas event, we have, no kidding, diamonds …
Nanodiamonds in the Younger Dryas Boundary Sediment Layer
D. J. Kennett,1* J. P. Kennett,2 A. West,3 C. Mercer,4 S. S. Que Hee,5 L. Bement,6 T. E. Bunch,7 M. Sellers,7 W. S. Wolbach8
We report abundant nanodiamonds in sediments dating to 12.9 ± 0.1 thousand calendar years before the present at multiple locations across North America. Selected area electron diffraction patterns reveal two diamond allotropes in this boundary layer but not above or below that interval. Cubic diamonds form under high temperature-pressure regimes, and n-diamonds also require extraordinary conditions, well outside the range of Earth’s typical surficial processes but common to cosmic impacts. N-diamond concentrations range from 10 to 3700 parts per billion by weight, comparable to amounts found in known impact layers. These diamonds provide strong evidence for Earth’s collision with a rare swarm of carbonaceous chondrites or comets at the onset of the Younger Dryas cool interval, producing multiple airbursts and possible surface impacts, with severe repercussions for plants, animals, and humans in North America.
—————–
Duster says:
May 26, 2010 at 10:42 pm
Willis,
The “dip” following the “hump” actually marks the Younger Dryas. What your chart shows is that the onset of the Holocene was interrupted by the YD and actually delayed by about two thousand years. That period is problematic to paleontologists and archaeologists for several reasons. Massive extinctions are taking place. As Firestone and some others have observed there is a “nanodiamond” horizon marking the beginning of the event, but what is less commonly discussed is that the YD is also marked by an enormous C-14 anomaly which collapses near 2,000 years into an apparent 500 or so. So, in addition to Firestone’s possible extraterrestrial strike there is also a phenomenal radiation event with a large increase in cosmic rays to trigger the formation of excess C-14. The event was apparently very short in duration as well. I have yet to see any convincing hypothesis for the cause.
——————
Bruce of Newcastle says:
May 27, 2010 at 1:13 am
Concerning the Younger Dryas dip, there’s a good article on ‘Clovis culture’ in Wikipedia. Has the nanodiamonds and even “high levels of metal and magnetic spherules found deep inside the tusks and skulls of mammoths”.
Thing is though, most of the “human waste heat” is released in urban areas which of course contributes to the UHI effect, and hence may have a disproportionate influence on the thermometer record
Anna V-
Not sure I understand your questions.
How will we avoid the dip? If you mean “how will it stay warm for 50,000 years”? I think this is the paper that brought this to light: http://www.sciencemag.org/cgi/content/short/297/5585/1287 They point out that orbital eccentricity will be uncharacteristically low for the next 50kyr falling close to zero in 27kyr (which means that there’s less variation between summers and winters). They have a nice expanded plot of Milankovitch forcings from -200kyr to +200 kyr that more clearly shows 65N forcing than the plots covering MMs of years that you typically find on the web. 65N forcing will be above today’s value for the next 47kyr (with a small dip in around 15kyr). Using a climate model to predict ice, they came up with 50kyr interglacial. It ends in 50kyr EVEN IF we raise CO2 to 750 ppm. It ends earlier (in about 15 kyr at the little dip) for a case where they simulated 210ppm CO2.
There is also a precedent. One of the interglacials in the last 1MM years lasted almost 50kyr. Don’t remember which one. There’s a paper on that buried somewhere in a pile or disk folder. Those authors also indicated that the north pole went ice free during summer toward the end of that period. [Don’t ask how the polar bears survived it. Fossil and genetic data suggest that polar bears have only existed for less than 200,000 years. Very recent paper.]
Alex the skeptic-
AGW proponents are not suggesting that human energy production directly heats the planet through waste heat.
I think Ron House is simply answering a question that came up in a recent earlier thread on WUWT and illustrating how one can estimate these things for oneself. Also, he says that a friend of his posed this question.
anna v says:
June 4, 2010 at 1:08 am
???
From the black body formula and the 10K degree difference seen in the ice core anomalies ( and presumed to reflect world anomalies) the watts/m^2 now is the often quoted 390 ( assuming average temperature 15C). For 5C the radiation is 338.7 watts/m^2.
This is a difference over 50 in watts/m^2, overall average in the year and globe.
Quite – but you seem to be asuming that all 50 w/m2 can be attributable to solar forcing. Not so – if Ron House’s figures are to be believed. From the above table we have
Previous Ice Age 22,000 years ago 463Wm-2
The Perfect Time Now 476Wm-2
i.e. only 13 w/m2 difference at peak insolation on midsummers day (noon) . Averaged over a day it’s consideravble less – and over a year less still. The majority of the 50 w/m2 reduction you mention must have come from somewhere else. Fewer GHGs perhaps?
If one accepts the 3.7 watts/m^2 of the IPCC this is still less than 10%, and if one takes the effect without computer model feedbacks , much less.
Could you start by explaining how a -13 w/m2 solar forcing at peak insolation could kick start an ice age unless there were considerable feedbacks involved. As you rightly state ice age temperatures imply a 50 w/m2 reduction in energy emitted from the surface.
Ron House said “the air is opaque at a range of ten feet to a photon in the CO2 absorption band”
Whoa Ron, where did you get that data point from?? It is a VAST overstatement of the absorptive powers of CO2.
I just ran 3, 30, 300 and 3000 meters thickness of 389 ppm of CO2 on spectralcalc.com (which anyone can do, although they have made it obnoxiously difficult to get results out for free). Ten feet (3 meters) of atmosphere DOES completely absorb some wavelengths of infrared in the CO2 bands, but over an EXTREMELY NARROW range. Per Spectralcalc:
0-10% transmittance from 14.95 to 14.99 microns in 3 meters of atmosphere
0-10% transmittance from 4.19 to 4.35 microns in 3 meters of atmosphere
This is an extremely narrow window of complete absorption only 0.022 microns wide at 14.97 microns, the main absorption band! In 3 meters depth, most of CO2’s absorption spectrum has better than 98 or 99% transmittance. To see how this one 14.97 micron “curtain” of absorption broadens with atmospheric depth:
3 meters deep, 0.022 microns wide "complete" absorption 30 meters, 0.45 microns wide 300 meters, 1.59 microns wide 3000 meters, 2.75 microns wide (0.377 atmospheres, actual depth 0 to 3480 meters altitude)You can plainly see from that data that 10 feet of atmosphere absorbs very little of the full effect of the CO2 bands. It takes hundreds if not thousands of meters of atmosphere to feel the full effect of CO2.
You might argue that the effect of changes in the breadth of the 100% absorbance range will be felt within 10 feet of the ground, but the broadening of the absorption lines with increasing CO2 concentration (and the energy absorbed) will still be felt throughout the lower troposphere.
not exactly the formatting I expected.
I have said again and again: Global warming ad infinitum and global cooling as such, is impossible. If you have not figured out yet why, then go take a long bath, immerse yourself completely, come up out of the water, watch the water fall off from your skin and say to yourself: EUREKA
(Hints: 70% of surface is water, so at some stage earth must start acting like a giant water cooling plant & people are like ants – they just have to remove snow where ever they find it. Once they find out it is the cause of global cooling they will quickly do something about that too)
So now, everyone, please stop worrying about the carbon dioxide, we need more of it, not less. If you want to know why, ask me.
Anthony – Soot…
How much soot will we need to thaw some of the snow? The drawback is you will have to repeat the procedure every year.
Perhaps we should try it out now somewhere in siberia.
John Finn
June 5, 2010 at 5:52 am
All the IPCC numbers depend on using the black body formula.
The logic is that at a given temperature, energy input equals energy output for steady state. Energy input comes only from the sun ( if we ignore vulcanism and gravity). Energy output is black body radiation all said and done. Thus I do not have to trust anybody’s regional tables ( as the numbers you are quoting) if I am comparing global values, as the 3.9 watts/m^2 are global average for CO2 doubling.
The delay in releasing the energy that CO2 is supposed to induce, just affects the time from going from one steady state to the other, not the total energy inputted and outputted.
p.s.
I do not have a model for the start of the ice ages to compete with the suggestions of Archibald and House. The feedback of albedo is easy to cook up once the trend starts.
My calculation tries to put into context the global CO2 claim of IPCC with the global energetics of ice age versus holocene optimum.
anna v says:
June 5, 2010 at 12:01 pm
p.s.
I do not have a model for the start of the ice ages to compete with the suggestions of Archibald and House. The feedback of albedo is easy to cook up once the trend starts.
My calculation tries to put into context the global CO2 claim of IPCC with the global energetics of ice age versus holocene optimum
Ok – look again at the numbers in the article posted, i.e. 476 w/m2 NOW vs 463 w/m2 durng the LGM. This is a difference of ~13 w/m2 which represents a change of 2%-3%. If we assume that this change was uniform across the globe (day/night, winter/summer) then the average 240 w/m2 would be reduced by ~6.5 w/m2. This equates to a temperature (black body) decline of ~1.7 deg. Clearly, if these numbers are right (I am questioning them??) the feedback (albedo & ghgs) must have been at least twice that of the primary (solar) forcing.
Also if a 6-7 w/m2 reduction in solar forcing brings on an ice age then a 3.7 w/m2 (CO2) increase could well be more significant than many of us are prepared to admit. Basically, this thread post by Ron House supports a strong positive feedback.
“It may be you are right that this is a post-wastage figure. If so, doubling it should fix the problem.”
Doubling isn’t close to correct. We burn a lot of stuff that never gets near the electricity grid or “energy supply”. Nor are any electricity plants close to 50% efficient.
Assume that no energy loss due to this is lost to space or oceans and you get the temp rise for one whole year. IT GETS TO A VERY LOW VALUE OF A FRACTION OF A DEGREE.
But even the warmists only reckon that we are warming at 0.02 degrees a year. An warming of 0.01°C is significant.
It’s no good saying that our efforts are insignificant if they are what tip the balance. You have to show that the system will cope, and I don’t reckon you can do that. Just as I don’t reckon the warmists can show that that CO2 is what is making the difference.
A company that makes a 1% profit and a company that makes a 1% loss a year only have a difference of 2% of the companies output. One will be soon gone though, because sometimes a small difference is all it takes sometimes.
Thanks for pulling those figures out. I have tried that site and I can’t even find the magic formula for running a calculation. That said, I think you are looking at this from a confusing viewpoint.
Absorption bands, theoretically, are narrow, and are widened by temperature and other factors. The point about your 30, 300, and 3000 metre figures is that these represent very minor amounts of the energy absorbed by the CO2. If you invert your figures in order to see absorption rate at a given line width, we see that in the centre of the band, absorption is as I said, and at 0.45 microns, absorption is already down to 1/10th of the absorption in the centre and at 1.59 microns it is down to 1%. For every band of every absorber, it will be possible to find widths that give any result you like for absorption rate, because the bands have no definite edges, the absorption just gets weaker and weaker.
The question is, what part of the complete effect is that responsible for? If CO2 only had, say 300-metre absorption in the centre of its absorption band, and if that were being reduced to 150 metres by a doubling, then even then, it would be very doubtful that this would have a significant effect on temperature because convective cells can easily be that big. I watched two eagles soaring on one just yesterday. So what we observe is that at least 99% of CO2’s greenhouse effectiveness occurs on a distance scale easily overwhelmed by convective effects. Doubling it merely tinkers with the left-over 1%. That is why I, for one, even entertain a doubt that the claimed logarithmic increase in temperature as CO2 increases is a small enough statement of the greenhouse effect.
John Finn says:
June 5, 2010 at 5:29 pm
Ok – look again at the numbers in the article posted, i.e. 476 w/m2 NOW vs 463 w/m2 durng the LGM. This is a difference of ~13 w/m2 which represents a change of 2%-3%. If we assume that this change was uniform across the globe (day/night, winter/summer) then the average 240 w/m2 would be reduced by ~6.5 w/m2. This equates to a temperature (black body) decline of ~1.7 deg. Clearly, if these numbers are right (I am questioning them??) the feedback (albedo & ghgs) must have been at least twice that of the primary (solar) forcing.
Well, I do not think that they assume that. The model examines this specific region with specific suppositions of available energy and that that is the region crucial for starting an ice age. Those are regional numbers and you would need to have sunlight inclination angles etc to integrate over the globe. One cannot just take percentages.
John Finn wondered – “If we assume that this change was uniform across the globe”
It’s not uniform. Most of this effect is due to precession of Earth’s axis, so when insolation is down at 65 deg N, it is up at 65 deg S latitude. The effect of insolation variation is dampened in the S hemisphere because the Antarctic land mass is permanently snow-covered. (Except for periods when it may get warm enough to destabilize the west Antarctic ice sheet, much of which is grounded below sea level.)
Mooloo said – “But even the warmists only reckon that we are warming at 0.02 degrees a year. An warming of 0.01°C [due to direct heating from energy production] is significant.”
Except that the warmist warming is every year, each one adding to the previous one over time, whereas the energy production warming is one-time-and-done. Once energy production raises the globe by 0.01C, the globe is radiatively in balance with that extra heat until we increase our annual energy use more.
Not sure what you’re trying to say. It’s not quite clicking.
Also, not sure that doubling CO2 will reduce the total-absorption depth by half. Would need to do a bit of math.
I will illustrate what I am trying to say with the following in more detail.
Radiation absorption is multiplicative (or “logarithmic”). Say you have an amount of CO2 that absorbs 50% at wavelength X. 100% going in, 50% coming out.
If you then add an equal amount of CO2, you could think of it like stacking one equal layer on top of the other. The first layer works like the above. The second layer absorbs 50% of the radiation coming into IT, and allows 25% of the source radiation to pass.
If you triple the CO2, or “add a 3rd layer”, then the 3rd layer absorbs 50% of the 25% coming into it, letting only 12.5% of the source radiation to pass. And so on.
So in the end, the transmittance at ‘y’ ppm equals the transmittance at 1ppm raised to the ‘y’ power.
Now say you have a range of wavelengths each with a different transmittance. What happens when you double CO2?
1% –> 1% * 1% = 0.1%
10% –> 10% * 10% = 1%
20% –> 4%
31.6% –> 10%
50% –> 25%
70.7% –> 50%
86.6% — 75%
95% –> 90.25%
99% –> 98.01%
This illustrates that when you double CO2, the increase in the energy absorbed is distributed throughout the atmosphere, not just in the first 10 feet or 100 feet. However I agree generally that the greatest amount of increase in energy absorbed is closer to the surface than not. Calculating the function of energy absorbed vs altitude is beyond my time limit or perhaps ability, and we are already way off topic of the thread. (Don’t tell Willis!)
Your thread says that direct human contribution to warming via waste heat is too small to worry about. I’m convinced. Well done!
hi guys, going thru all what was mentioned all of the above, i have a small point of view to share which is back to the basics of human activity. not limited to oxygen consumption but resources consumption that generates heat, bi-products and toxicity. if we could only effectively consume natural sources which a relative amount of wastage close to zero (impossible!) together with recycling, i think nature wont fast forward this natural catastrophy “global warming” that has been everybody’s nightmare. technology speaks for itself the essence of the word is derived from the basic word consume (opinionwise).
howdee guys, going thru all what was mentioned all of the above, i have a small point of view to share which is back to the basics of human activity. not limited to oxygen consumption but resources consumption that generates heat, bi-products and toxicity. if we could only effectively consume natural sources which a relative amount of wastage close to zero (impossible!) together with recycling, i think nature wont fast forward this natural catastrophy “global warming” that has been everybody’s nightmare. technology speaks for itself the essence of the word is derived from the basic word consume (opinionwise).
OK, second point first. A photon is absorbed when it encounters a CO2 molecule (in the correct orientation, with the correct energy levels, etc etc.), which is the molecule’s cross-section. Absorption is ‘total’ (meaning to within some small amount of 100%) when enough molecules are present to reduce the probability of the photon’s having an uninterrupted path to sufficiently close to zero. From simple geometric considerations, if this happens at distance X for concentration C, then it must occur at distance X/2 for concentration 2C, since in both cases will a photon ‘run interference’ from the same number of CO2 molecules.
Your first point: You went on to show how the energy is distributed throughout the atmosphere, which is exactly correct (except the first line which should read 0.01%). Your explanation after that is pretty much what I was trying to get at, except you have explained it much better. Here is another attempt to say the same thing:
Imagine an absorption line in a spectrum. It has a characteristic shape like a little cutout from the spectrum with rounded edges. We can’t draw it here, but I am sure you know what I mean. Now the total greenhouse effect of that molecule is caused by the total energy absorption of that entire absorption line. It represents a ‘piece cut out’ of the transmitted energy. Now the claim is that greenhouse gases are responsible for about 30C of the Earth’s temperature. I am not sure what amount of that is expected to be CO2 alone, but let’s say all of it, to be on the safe side, even though we know H2O is a much greater absorber than CO2. Another conservative assumption I’ll make to keep things simple is to forget that the Stephan Boltzmann equations tell us that radiant flux is proportional to T^4, and simply regard a temperature drop as being proportional to the energy ‘cut out’. This is a stupendously huge assumption that makes my argument much harder to win.
(A note to non-scientific readers: anyone can get personal insight into scientific matters. The method is this: use your intuition to decide which way the truth lies, then simplify everything until you can see it plainly without the need for calculations. But every simplification you make must be ‘against’ your intuitive suspicion. Then, if the outcome is that your suspicion is confirmed, you can be very sure indeed that a detailed calculation would be even more in favour of your suspicion. If, on the other hand, your suspicion is not confirmed, then you know that a more in-depth investigation is needed. But if your intuition is good, you’ll often get a positive result that you have seen for yourself through your own insight, and not because you had to choose “whose climate science to buy” as one foolish warmist put it.)
So let’s now imagine that cutout shape of the absorption line. The energy absorbed is the area under the curve. The bulk of the energy and hence the temperature effect is due to the high central peak, and only very little is due to the extended edges. If we know that the entire central section from, say, 1/30th of maximum absorption on the left to the same point on the right is effectively ‘maxed out’, then it is only changes in the left and right tails of the absorption band that can have an effective influence on temperature. But by their very nature as the tiny tails, they are only a minor part of the total effect of CO2. Any change we make to them is a change in a very small proportion of the total temperature influence. And absorption bands do not get wider in proportion to concentration, they widen less the more CO2 there is. This would account for why a logarithmic effect, not a proportional one, is predicted by those who have done the complete calculation.