2016 Global Temperatures

[PhillipS]

2 hours ago, heavy_wx said:

Energy is conserved only for a closed system; the Earth and its atmosphere are not a closed system because the sun transmits radiation to the Earth and its atmosphere and the Earth and its atmosphere transmit radiation to space. 

When the concentration of CO2 molecules increases in the atmosphere, more infrared radiation is absorbed by the atmosphere. This increased absorption occurs because CO2 molecules may become torqued by electromagnetic radiation at these wavelengths given the permanent dipole moment of CO2. The increased rotational energy of the CO2 molecules results in air molecules with higher kinetic energy (due to collisions) and thus warmer temperatures. These increased temperatures will also lead to an increase in infrared emission; however, this emission depends on the temperature and is therefore not, in general, the same as the absorption by these molecules.

If the CO2 concentration increased by a certain amount and then stayed constant, the temperature of the atmosphere would increase to a new equilibrium. This is of course ignoring the feedbacks of the climate system.

The bottom line is that with increased greenhouse gas concentrations, the total energy of the Earth system (the atmosphere, land, and ocean) increases. Energy is conserved in this scenario because the energy that would have been radiated to space without the greenhouse gases is instead stored in the Earth system. Once the new equilibrium is reached, the energy stored in the Earth system is constant.

Very clear and concise - thank you.

[lookingnorth]

The United States had its second warmest year on record in 2016. Only 2012 was warmer.

https://www.ncdc.noaa.gov/sotc/

[blizzard1024]

19 hours ago, heavy_wx said:

Energy is conserved only for a closed system; the Earth and its atmosphere are not a closed system because the sun transmits radiation to the Earth and its atmosphere and the Earth and its atmosphere transmit radiation to space. 

When the concentration of CO2 molecules increases in the atmosphere, more infrared radiation is absorbed by the atmosphere. This increased absorption occurs because CO2 molecules may become torqued by electromagnetic radiation at these wavelengths given the permanent dipole moment of CO2. The increased rotational energy of the CO2 molecules results in air molecules with higher kinetic energy (due to collisions) and thus warmer temperatures. These increased temperatures will also lead to an increase in infrared emission; however, this emission depends on the temperature and is therefore not, in general, the same as the absorption by these molecules.

If the CO2 concentration increased by a certain amount and then stayed constant, the temperature of the atmosphere would increase to a new equilibrium. This is of course ignoring the feedbacks of the climate system.

The bottom line is that with increased greenhouse gas concentrations, the total energy of the Earth system (the atmosphere, land, and ocean) increases. Energy is conserved in this scenario because the energy that would have been radiated to space without the greenhouse gases is instead stored in the Earth system. Once the new equilibrium is reached, the energy stored in the Earth system is constant.

Ok. So if the sun provides a certain amount of energy to the Earth system, by adding greenhouse gases, the entire Earth system warms? So that means that the total energy given off by the Earth system increases?  If you add greenhouse gases to the troposphere, you increase emission above this layer which leads to cooling above the troposphere. The increased emission is stronger than the absorption since there is less air up there. Like you said, if you increase CO2 for example, there is more absorption in the 15 micron band, this leads to more emission at this layer which is colder and hence the emission is lower so there is an imbalance. It warms and like you said the emission increases to restore balance. The balance that is restored is the tropospheric temperatures. With stronger emission, you cool the layers above and there is no net energy stored in the earth system from greenhouse gases.

Your quote:  "The bottom line is that with increased greenhouse gas concentrations, the total energy of the Earth system (the atmosphere, land, and ocean) increases. Energy is conserved in this scenario because the energy that would have been radiated to space without the greenhouse gases is instead stored in the Earth system. Once the new equilibrium is reached, the energy stored in the Earth system is constant."

How can this be true? If you continually store energy, you will continually heat the Earth up. This new "equilibrium" that is reached would emit more energy to space which would violate the 1st law of thermodynamics assuming no feedbacks as you state. Otherwise you are creating energy from greenhouse gases.  

I see you are a Penn State PHD student. Is Professor Bohren still around?  I had him for radiative transfer and he would be much better than me trying to explain this to you. Who is left in the dept that teaches rad tran?? I would ask them to explain this to you. I had Bohren for rad tran years ago and this was pretty basic stuff back then. 

[blizzard1024]

20 hours ago, heavy_wx said:

Energy is conserved only for a closed system; the Earth and its atmosphere are not a closed system because the sun transmits radiation to the Earth and its atmosphere and the Earth and its atmosphere transmit radiation to space. 

When the concentration of CO2 molecules increases in the atmosphere, more infrared radiation is absorbed by the atmosphere. This increased absorption occurs because CO2 molecules may become torqued by electromagnetic radiation at these wavelengths given the permanent dipole moment of CO2. The increased rotational energy of the CO2 molecules results in air molecules with higher kinetic energy (due to collisions) and thus warmer temperatures. These increased temperatures will also lead to an increase in infrared emission; however, this emission depends on the temperature and is therefore not, in general, the same as the absorption by these molecules.

If the CO2 concentration increased by a certain amount and then stayed constant, the temperature of the atmosphere would increase to a new equilibrium. This is of course ignoring the feedbacks of the climate system.

The bottom line is that with increased greenhouse gas concentrations, the total energy of the Earth system (the atmosphere, land, and ocean) increases. Energy is conserved in this scenario because the energy that would have been radiated to space without the greenhouse gases is instead stored in the Earth system. Once the new equilibrium is reached, the energy stored in the Earth system is constant.

read this...its from skeptical science...and tell all of us where they are wrong. https://skepticalscience.com/Stratospheric_Cooling.html

[drstuess]

1 hour ago, blizzard1024 said:

Your quote:  "The bottom line is that with increased greenhouse gas concentrations, the total energy of the Earth system (the atmosphere, land, and ocean) increases. Energy is conserved in this scenario because the energy that would have been radiated to space without the greenhouse gases is instead stored in the Earth system. Once the new equilibrium is reached, the energy stored in the Earth system is constant."

How can this be true? If you continually store energy, you will continually heat the Earth up. This new "equilibrium" that is reached would emit more energy to space which would violate the 1st law of thermodynamics assuming no feedbacks as you state. Otherwise you are creating energy from greenhouse gases.  

I'm not a meteorologist but I believe all he is saying is the following, which doesn't violate the first law. I may be missing something bit here goes.

 

Excuse the handwriting and it not being in latex.

You store energy and increase temperature which increases earth's radiation, however less of the suns solar radiation is absorbed. In equilibrium (at a higher temperature) they balance each other out. In the transient state where temperature hasn't risen enough, q in is greater than q out and earth's energy increases.

I don't believe he was making any statement about what happens above the layer emmissivity.

[BillT]

13 minutes ago, drstuess said:

I'm not a meteorologist but I believe all he is saying is the following, which doesn't violate the first law. I may be missing something bit here goes.

>

Excuse the handwriting and it not being in latex.

You store energy and increase temperature which increases earth's radiation, however less of the suns solar radiation is absorbed. In equilibrium (at a higher temperature) they balance each other out. In the transient state where temperature hasn't risen enough, q in is greater than q out and earth's energy increases.

I don't believe he was making any statement about what happens above the layer emmissivity.

please accept this simple fact folks there is NO "equilibrium" you folks keep insisting exists, there is NO BALANCE the factors involved constantly change = any point of equilibrium also constantly changes and cant ever be met and held steady because the factors keep on changing.....this is why we have thermodynamics the heat in systems is constantly moving towards colder bodies it always seeks to "balance" but can never find that balance because the factors at play always change and the balance point constantly MOVES...........i know i use laymans terms and also know i am CORRECT........show me the graph that shows our weather has ever had a point of balance? show me the period of balanced temps please?????

 

[heavy_wx]

59 minutes ago, blizzard1024 said:

Ok. So if the sun provides a certain amount of energy to the Earth system, by adding greenhouse gases, the entire Earth system warms? So that means that the total energy given off by the Earth system increases?  If you add greenhouse gases to the troposphere, you increase emission above this layer which leads to cooling above the troposphere. The increased emission is stronger than the absorption since there is less air up there. Like you said, if you increase CO2 for example, there is more absorption in the 15 micron band, this leads to more emission at this layer which is colder and hence the emission is lower so there is an imbalance. It warms and like you said the emission increases to restore balance. The balance that is restored is the tropospheric temperatures. With stronger emission, you cool the layers above and there is no net energy stored in the earth system from greenhouse gases.

Your quote:  "The bottom line is that with increased greenhouse gas concentrations, the total energy of the Earth system (the atmosphere, land, and ocean) increases. Energy is conserved in this scenario because the energy that would have been radiated to space without the greenhouse gases is instead stored in the Earth system. Once the new equilibrium is reached, the energy stored in the Earth system is constant."

How can this be true? If you continually store energy, you will continually heat the Earth up. This new "equilibrium" that is reached would emit more energy to space which would violate the 1st law of thermodynamics assuming no feedbacks as you state. Otherwise you are creating energy from greenhouse gases.

At equilibrium, the net flux of photons leaving the Earth system is the same as the net flux of photons entering the Earth system; I think we would agree on this point. If the CO2 concentration increases by a fixed amount, the net flux of photons entering the Earth system is constant but the net flow of photons leaving the Earth system decreases initially as CO2 absorbs LW radiation transmitted by the Earth. Because of the absorption by CO2, the air warms; this warming will continue until the increased emission by the warming CO2 causes the net flux of photons leaving the Earth system to be equal to the net flux of photons entering the Earth system; this point is of course a new equilibrium where the air temperature is warmer than the initial equilibrium before the increase in CO2 concentration.

The above description is of course a simplification of the true response of the Earth system to an increase in the CO2 concentration, where we are essentially considering a single atmospheric layer with a homogenous temperature and CO2 distribution. We have not violated conservation of energy in this simplified model if we consider that the flux of photons entering the Earth system is always the same as the flux of photons leaving space and the flux of photons leaving the Earth system is always the same as the flux of photons entering space. As the solar radiance is constant for the Earth, we need consider only the flux of photons leaving the Earth system and entering space to show that space will necessarily cool to compensate for the warming of the Earth system in this model.

As I described earlier, the flux of photons leaving the Earth system decreases initially as the CO2 absorbs photons; this absorption leads the flux of photons leaving the Earth system and entering space to be initially less than the flux of photons entering the Earth system and leaving space, resulting in a net cooling of space and a net warming of the Earth system. This difference between the flux of photons entering and leaving the Earth system continually decreases as the atmosphere warms and emission increases, until reaching a new equilibrium where space is cooler, the Earth system is warmer, and the flux of photons leaving and entering the Earth system is the same.

Now what you alluded to is the phenomenon of stratospheric cooling resulting from increased CO2 concentration. This cooling has the net effect of decreasing the radiative forcing of increased CO2 concentration at TOA due to the cooling of the stratosphere. However, modeling studies (e.g., Hansen et al. 1997) suggest that this cooling does not balance out the warming of the troposphere and still allows CO2 to have a substantial forcing for warming surface temperatures. Also, the link you provided illustrates the mechanism for stratospheric cooling nicely but does not indicate that the cooling balances out the warming occurring in the troposphere.

One final thought: fully understanding the net radiative forcing that occurs given an increase in CO2 concentration (not even accounting for other climate system effects) requires us to consider the temperature, air density, and CO2 profiles throughout the atmosphere and is therefore difficult to assess without a radiative transfer model. If you have come across a modeling study showing stratospheric cooling offsetting tropospheric warming as a response to increased CO2 concentration, I would very much like to read it and hopefully increase my understanding of this process.

[Mallow]

2 hours ago, heavy_wx said:

At equilibrium, the net flux of photons leaving the Earth system is the same as the net flux of photons entering the Earth system; I think we would agree on this point. If the CO2 concentration increases by a fixed amount, the net flux of photons entering the Earth system is constant but the net flow of photons leaving the Earth system decreases initially as CO2 absorbs LW radiation transmitted by the Earth. Because of the absorption by CO2, the air warms; this warming will continue until the increased emission by the warming CO2 causes the net flux of photons leaving the Earth system to be equal to the net flux of photons entering the Earth system; this point is of course a new equilibrium where the air temperature is warmer than the initial equilibrium before the increase in CO2 concentration.

The above description is of course a simplification of the true response of the Earth system to an increase in the CO2 concentration, where we are essentially considering a single atmospheric layer with a homogenous temperature and CO2 distribution. We have not violated conservation of energy in this simplified model if we consider that the flux of photons entering the Earth system is always the same as the flux of photons leaving space and the flux of photons leaving the Earth system is always the same as the flux of photons entering space. As the solar radiance is constant for the Earth, we need consider only the flux of photons leaving the Earth system and entering space to show that space will necessarily cool to compensate for the warming of the Earth system in this model.

As I described earlier, the flux of photons leaving the Earth system decreases initially as the CO2 absorbs photons; this absorption leads the flux of photons leaving the Earth system and entering space to be initially less than the flux of photons entering the Earth system and leaving space, resulting in a net cooling of space and a net warming of the Earth system. This difference between the flux of photons entering and leaving the Earth system continually decreases as the atmosphere warms and emission increases, until reaching a new equilibrium where space is cooler, the Earth system is warmer, and the flux of photons leaving and entering the Earth system is the same.

Now what you alluded to is the phenomenon of stratospheric cooling resulting from increased CO2 concentration. This cooling has the net effect of decreasing the radiative forcing of increased CO2 concentration at TOA due to the cooling of the stratosphere. However, modeling studies (e.g., Hansen et al. 1997) suggest that this cooling does not balance out the warming of the troposphere and still allows CO2 to have a substantial forcing for warming surface temperatures. Also, the link you provided illustrates the mechanism for stratospheric cooling nicely but does not indicate that the cooling balances out the warming occurring in the troposphere.

One final thought: fully understanding the net radiative forcing that occurs given an increase in CO2 concentration (not even accounting for other climate system effects) requires us to consider the temperature, air density, and CO2 profiles throughout the atmosphere and is therefore difficult to assess without a radiative transfer model. If you have come across a modeling study showing stratospheric cooling offsetting tropospheric warming as a response to increased CO2 concentration, I would very much like to read it and hopefully increase my understanding of this process.

 

This is well-stated! I was thinking about a possible analogy that could help clarify things, and I think I've come up with one. This is to address the question of whether or not there is a "violation of conservation of energy" if the average temperature of the Earth warms even though the total incoming (and eventually outgoing) energy flux remained the same. Here is the analogy.

You have a tank of water. In the bottom of the tank is a hole. The rate at which water drains out of this hole depends on the size of the hole, and on the water pressure, which is proportional to the depth of water in the tank. Additionally, you have a faucet adding water at a near-constant rate. Now, if the water level in the tank remains the same, it means that the faucet is adding water at the same rate at which the hole is draining it. I believe this is all relatively straightforward so far.

Now, at time t=0, we decrease the size of the hole in the bottom of the tank. Since the water level is initially unchanged, but the hole is smaller, we have less water flowing out the bottom than is being added at the top. This causes the water level in the tank to increase. Eventually, the water level in the tank will be high enough that the increased pressure at the bottom of the tank will counteract the effect of the decreased hole. This is the "new equilibrium" water level in the tank, the new level at which the incoming water balances the water draining out the bottom, and we will call the time at which this new equilibrium is reached t = t_e.

Even though the initial state and the final state exhibit the same rate of water coming into and flowing out of the system, the water level has changed as a response to the smaller hole in the bottom. The total amount of water stored in the tank has increased, even though the rate of water entering the tank remains the same, and no violation of conservation of mass was necessary to accomplish this. The total amount of water is analogous to the total amount of energy stored in the Earth system (which is directly related to the average temperature of the Earth). The size of the drain hole is analogous to the amount of GHGs in the atmosphere. The water pressure increases as the tank fills in the same way that the Earth radiates more as the emission temperature increases. It is these two factors (the smaller hole and the deeper water, i.e. the increased GHGs and the increased emission temperature) that determine the new water level/global energy storage.

I think this analogy is clean and illustrative. It demonstrates that it is indeed possible to adjust a system so that the total energy flux before t = 0 and after t = t_e is unchanged, but, due to a temporary imbalance that exists between t = 0 and t = t_e, the total energy stored in the system increases. Energy remains conserved. Obviously the climate system is much more complex than this (we can extend our analogy if we want), but this post is just addressing the question of whether energy conservation must be violated. I think it is now clear that that is not necessary.

[BillT]

deleted, as a waste of my time, but maybe not, for the water tank thing to be correct that means when i have a hose connected to the outlet and turn the water flow on and leave it constant then i go to the end of the hose a pinch it a bit, the hose starts backing up holding in more water until it explodes? or does the flow of water remain constant but my pinched end of the hose squirts the same amount out faster and further?

[blizzard1024]

3 hours ago, heavy_wx said:

At equilibrium, the net flux of photons leaving the Earth system is the same as the net flux of photons entering the Earth system; I think we would agree on this point. If the CO2 concentration increases by a fixed amount, the net flux of photons entering the Earth system is constant but the net flow of photons leaving the Earth system decreases initially as CO2 absorbs LW radiation transmitted by the Earth. Because of the absorption by CO2, the air warms; this warming will continue until the increased emission by the warming CO2 causes the net flux of photons leaving the Earth system to be equal to the net flux of photons entering the Earth system; this point is of course a new equilibrium where the air temperature is warmer than the initial equilibrium before the increase in CO2 concentration.

The above description is of course a simplification of the true response of the Earth system to an increase in the CO2 concentration, where we are essentially considering a single atmospheric layer with a homogenous temperature and CO2 distribution. We have not violated conservation of energy in this simplified model if we consider that the flux of photons entering the Earth system is always the same as the flux of photons leaving space and the flux of photons leaving the Earth system is always the same as the flux of photons entering space. As the solar radiance is constant for the Earth, we need consider only the flux of photons leaving the Earth system and entering space to show that space will necessarily cool to compensate for the warming of the Earth system in this model.

As I described earlier, the flux of photons leaving the Earth system decreases initially as the CO2 absorbs photons; this absorption leads the flux of photons leaving the Earth system and entering space to be initially less than the flux of photons entering the Earth system and leaving space, resulting in a net cooling of space and a net warming of the Earth system. This difference between the flux of photons entering and leaving the Earth system continually decreases as the atmosphere warms and emission increases, until reaching a new equilibrium where space is cooler, the Earth system is warmer, and the flux of photons leaving and entering the Earth system is the same.

Now what you alluded to is the phenomenon of stratospheric cooling resulting from increased CO2 concentration. This cooling has the net effect of decreasing the radiative forcing of increased CO2 concentration at TOA due to the cooling of the stratosphere. However, modeling studies (e.g., Hansen et al. 1997) suggest that this cooling does not balance out the warming of the troposphere and still allows CO2 to have a substantial forcing for warming surface temperatures. Also, the link you provided illustrates the mechanism for stratospheric cooling nicely but does not indicate that the cooling balances out the warming occurring in the troposphere.

One final thought: fully understanding the net radiative forcing that occurs given an increase in CO2 concentration (not even accounting for other climate system effects) requires us to consider the temperature, air density, and CO2 profiles throughout the atmosphere and is therefore difficult to assess without a radiative transfer model. If you have come across a modeling study showing stratospheric cooling offsetting tropospheric warming as a response to increased CO2 concentration, I would very much like to read it and hopefully increase my understanding of this process.

They are some papers that indicate that there has been cooling above the stratosphere. Of course ozone depletion clouds how much the stratosphere cools from CO2 increases below from ozone destruction. Here's another blog article that discusses cooling above the stratosphere.

https://www.wunderground.com/resources/climate/strato_cooling.asp

The papers that discuss cooling above the stratosphere from the above link are:  (Beig et al., 2006) and (Lastovicka et al., 2006).  Nothing more recent though. But each paper claims substantial cooling above the stratosphere. Beig et al states 5-10C cooling at 50-80 km up and Lastovicka et al claims 17C/decade cooling at 350 km. I have no access to these papers. If you read them please share what you find if you have time. thanks!  

 

 

 

[Mallow]

4 hours ago, BillT said:

deleted, as a waste of my time, but maybe not, for the water tank thing to be correct that means when i have a hose connected to the outlet and turn the water flow on and leave it constant then i go to the end of the hose a pinch it a bit, the hose starts backing up holding in more water until it explodes? or does the flow of water remain constant but my pinched end of the hose squirts the same amount out faster and further?

In that scenario, if you've decreased the area of the outlet by pinching the hose a bit, the hose would temporarily let out less water. During that time, more water would be flowing into the tank than out of it. The tank would fill until the water pressure at the hose end was high enough that the amount of water flowing out of the hose would again be equal to that entering the tank (meaning, at the point of constriction, the water must be flowing faster to compensate for the smaller aperture). In the end, you have a hose with a slightly smaller opening, water is again flowing into and out of the system at the same rate as it was initially, and the tank is now holding more total water. Does that make sense?

[BillT]

11 minutes ago, Mallow said:

In that scenario, if you've decreased the area of the outlet by pinching the hose a bit, the hose would temporarily let out less water. During that time, more water would be flowing into the tank than out of it. The tank would fill until the water pressure at the hose end was high enough that the amount of water flowing out of the hose would again be equal to that entering the tank (meaning, at the point of constriction, the water must be flowing faster to compensate for the smaller aperture). In the end, you have a hose with a slightly smaller opening, water is again flowing into and out of the system at the same rate as it was initially, and the tank is now holding more total water. Does that make sense?

on its face yes, but reality is the hose IMMEDIATELY starts spewing faster and further........the same would happen in the tank in my opinion...the narrowing of the aperture increases the relative pressure on the opening with the same amount of water in the tank....and the hose doesnt slow back down as long as the same narrowing at its end in in place with NO change in the amount of water flow.

[drstuess]

on its face yes, but reality is the hose IMMEDIATELY starts spewing faster and further........the same would happen in the tank in my opinion...the narrowing of the aperture increases the relative pressure on the opening with the same amount of water in the tank....and the hose doesnt slow back down as long as the same narrowing at its end in in place with NO change in the amount of water flow.

I don't think that the smaller hole would immediately flow faster and further. You might see the opposite in fact due to increase in friction to mass flow rate ratio.

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[BillT]

29 minutes ago, drstuess said:

I don't think that the smaller hole would immediately flow faster and further. You might see the opposite in fact due to increase in friction to mass flow rate ratio.

Sent from my SM-G930V using Tapatalk
 

please remember we are talking about a very TINY change in the size of the hole because that is the impact of co2 in the overall picture TINY.....and wouldnt a larger hole have more contact area and more friction?...also in the real world a hose indeed does instantly start squirting further when squeezed at its opening.

[drstuess]

please remember we are talking about a very TINY change in the size of the hole because that is the impact of co2 in the overall picture TINY.....and wouldnt a larger hole have more contact area and more friction?...also in the real world a hose indeed does instantly start squirting further when squeezed at its opening.

hose is different as the momentum of the water above makes it more about conservation of mass flow. Additionally more circumference has more griction, however more mass to affect, f=ma. As I said in my first post, friction to mass ratio. That's a simplification of all the boundary layer stuff which is what actually going on, but is more involved.

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[Mallow]

6 hours ago, BillT said:

on its face yes, but reality is the hose IMMEDIATELY starts spewing faster and further........the same would happen in the tank in my opinion...the narrowing of the aperture increases the relative pressure on the opening with the same amount of water in the tank....and the hose doesnt slow back down as long as the same narrowing at its end in in place with NO change in the amount of water flow.

I don't follow this post.

Additionally, I think making the opening a hose is an unnecessary complication. A simple hole with an adjustable aperture on the bottom of the tank is sufficient for this analogy. I would even suggest setting up this experiment if you're skeptical that it would produce the results I'm suggesting! I am quite confident that the initial and final flow into and out of the tank would be the same, and that the water level in the tank would rise, with no violation of conservation of mass. This is the point I am addressing with this analogy.

[chubbs]

7 hours ago, Mallow said:

I don't follow this post.

Additionally, I think making the opening a hose is an unnecessary complication. A simple hole with an adjustable aperture on the bottom of the tank is sufficient for this analogy. I would even suggest setting up this experiment if you're skeptical that it would produce the results I'm suggesting! I am quite confident that the initial and final flow into and out of the tank would be the same, and that the water level in the tank would rise, with no violation of conservation of mass. This is the point I am addressing with this analogy.

Your tub analogy is very good. To build. In the earth climate system there are really 4 interconnected tubs: atmosphere, earth (top 50m or so), ice sheets, and ocean. Each with different sizes of tub relative to the drain and different positions relative to each other. The oceans have a very large tub, 1000 times larger than the atmosphere, while ice sheets have a small drain and are downstream of the other tubs so it will take long time for these two to reach equilibrium. That is part of the reason climate change is such a difficult problem. Even though the drains have already been restricted its going to be a long time before all the tubs are full. Scientists can see the end state but many others can't.

[blizzard1024]

18 hours ago, Mallow said:

I think this analogy is clean and illustrative. It demonstrates that it is indeed possible to adjust a system so that the total energy flux before t = 0 and after t = t_e is unchanged, but, due to a temporary imbalance that exists between t = 0 and t = t_e, the total energy stored in the system increases. Energy remains conserved. Obviously the climate system is much more complex than this (we can extend our analogy if we want), but this post is just addressing the question of whether energy conservation must be violated. I think it is now clear that that is not necessary.

How can the total energy stored in a system increase, but energy remains conserved???  So your saying the water flow out of the faucet is constant and analogous to energy input from the sun. The level of the water in the tank is the amount of energy in our earth system defined as Oceans, Earth and entire atmosphere. The hole at the bottom of the tank are the greenhouse gases. You are dealing with flow rates here which is fine. So if you make the hole smaller, the increased pressure on the hole will increase the flow rate out of the bottom. If the flow rate out the bottom is not equal to the flow coming in the tank will overflow. The analogy is crude for the Earth system but if we work with it, the flow rate that increases out the hole would be analogous to the increased emissions into space of IR which cool the upper part of the atmosphere or the whole earth system would heat up. Just like the whole tank will overflow if the flow rate decreases out the drain.  

[drstuess]

How can the total energy stored in a system increase, but energy remains conserved???  So your saying the water flow out of the faucet is constant and analogous to energy input from the sun. The level of the water in the tank is the amount of energy in our earth system defined as Oceans, Earth and entire atmosphere. The hole at the bottom of the tank are the greenhouse gases. You are dealing with flow rates here which is fine. So if you make the hole smaller, the increased pressure on the hole will increase the flow rate out of the bottom. If the flow rate out the bottom is not equal to the flow coming in the tank will overflow. The analogy is crude for the Earth system but if we work with it, the flow rate that increases out the hole would be analogous to the increased emissions into space of IR which cool the upper part of the atmosphere or the whole earth system would heat up. Just like the whole tank will overflow if the flow rate decreases out the drain.  

Energy is conserved because it's not a closed system. As someone who throws out condescending remarks about people not getting conservation of energy, you really should read the first law of thermodynamics and sketch it out.

Also, the flow rate out the bottom changes as the pressure at the bottom changes. The pressure doesn't change as a direct result of the aperture, but indirectly as it causes the amount of water in the bucket to increase. It is a good analogy and explained quite well.

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[BillT]

54 minutes ago, drstuess said:

Energy is conserved because it's not a closed system. As someone who throws out condescending remarks about people not getting conservation of energy, you really should read the first law of thermodynamics and sketch it out.

Also, the flow rate out the bottom changes as the pressure at the bottom changes. The pressure doesn't change as a direct result of the aperture, but indirectly as it causes the amount of water in the bucket to increase. It is a good analogy and explained quite well.

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in the posters example the ONLY change is the size of the aperture THAT is the cause of the pressure increase, making it a bit smaller INCREASES to force of the water at that point.......my hose example is far better than these tank examples, because the water hose IS the experiment and shows in the real world making the aperture a tiny bit smaller does NOT cause any build up of pressure, it instantly increases the rate of flow through the bit smaller opening.....somebody suggested above i try the experiment, well my hose example IS that experiment, constant input into the hose being input at the same pressure, then make the opening a tiny bit smaller and the pressure inside increases immediately and forces the same flow of water through the smaller opening....the increase in pressure is caused by the aperture being a tiny bit smaller, NOT because it has to wait for more water to gather and increase the pressure.

[Mallow]

2 hours ago, blizzard1024 said:

How can the total energy stored in a system increase, but energy remains conserved???  So your saying the water flow out of the faucet is constant and analogous to energy input from the sun. The level of the water in the tank is the amount of energy in our earth system defined as Oceans, Earth and entire atmosphere. The hole at the bottom of the tank are the greenhouse gases. You are dealing with flow rates here which is fine. So if you make the hole smaller, the increased pressure on the hole will increase the flow rate out of the bottom. If the flow rate out the bottom is not equal to the flow coming in the tank will overflow. The analogy is crude for the Earth system but if we work with it, the flow rate that increases out the hole would be analogous to the increased emissions into space of IR which cool the upper part of the atmosphere or the whole earth system would heat up. Just like the whole tank will overflow if the flow rate decreases out the drain.  

You have the first two aspects of my analogy correct. The water entering the top from the faucet corresponds to the incoming radiative energy flux from the sun, and is nearly constant. The water level corresponds to the total energy stored in the earth system. The water exiting the hole in the bottom, however, does not in and itself correspond to greenhouse gases. It corresponds to the total radiative energy flux from the Earth. The reason I think this is a good analogy is that when the water level in the tank is higher (a higher global energy storage/global average temperature), the flow out the bottom increases due to higher water pressure (increased radiative energy flux from the Earth due to a higher emission temperature). Then, in this analogy, greenhouse gases control the size of the hole in the bottom--that is, increased GHGs decrease the radiative energy flux from Earth when the temperature hasn't changed yet. The accumulation of energy then warms the Earth, until the increase in radiative energy flux due to higher emission temperatures "compensates" for the GHG decrease in radiative energy flux.

"How can the total energy stored in a system increase, but energy remains conserved?" I would then turn this question around--how can the total water stored in the tank increase, but mass remains conserved? I think this analogy demonstrates exactly how. There is a time period during which there is an imbalance between the incoming water flow and the outgoing water flow, before the water level reaches a new equilibrium level. The key is that there are (at least) two processes that control the outgoing radiation/outflow of water from the tank. In the case of the water analogy, they're the size of the hole in the bottom of the tank, and the water level, which controls the water pressure at the bottom of the tank. The water flow rate at the bottom of the tank can match the constant flow rate from the faucet at the top via countless possible combinations of hole size/water level. The same can be said of the atmosphere--at least two processes control the radiative energy flux coming from the Earth, the emission temperature, and GHGs. Therefore, you can attain the same outgoing radiative energy flux via countless possible combinations of emission temperature and GHGs.
 

 

[Mallow]

11 minutes ago, BillT said:

in the posters example the ONLY change is the size of the aperture THAT is the cause of the pressure increase, making it a bit smaller INCREASES to force of the water at that point.......my hose example is far better than these tank examples, because the water hose IS the experiment and shows in the real world making the aperture a tiny bit smaller does NOT cause any build up of pressure, it instantly increases the rate of flow through the bit smaller opening.....somebody suggested above i try the experiment, well my hose example IS that experiment, constant input into the hose being input at the same pressure, then make the opening a tiny bit smaller and the pressure inside increases immediately and forces the same flow of water through the smaller opening....the increase in pressure is caused by the aperture being a tiny bit smaller, NOT because it has to wait for more water to gather and increase the pressure.

No, that is not accurate, and is certainly not what I mean. The change in the size of the aperture does not directly change the pressure of water at the bottom of the tank. The only thing that changes the water pressure at the bottom of the tank is the water level in the tank. This is basic physics and can be demonstrated very easily. Take two identical plastic bottles and fill both with water. Add a hole in both, one much bigger than the other. Cover the holes, and fill the water to the same level in the bottles. Now open both holes and time the emptying of the bottles. You will see that the bottle with the bigger hole does indeed empty more rapidly. If what you said above is correct, the water pressure through the smaller hole would instantly be higher, and perfectly compensate for the decreased size of the hole, to allow them to drain at the same rate. This is counterintuitive and demonstrably untrue.

I also don't understand what you mean by "my hose example IS that experiment"? Did you connect a hose to the bottom of a tank of water, allow a constant flow into the tank, and allow a constant flow out through the hose? Did you then squeeze the hose? That seems like a much more complicated setup than the one I've described, so if you've done it and taken the data, please share it!

[drstuess]

in the posters example the ONLY change is the size of the aperture THAT is the cause of the pressure increase, making it a bit smaller INCREASES to force of the water at that point.......my hose example is far better than these tank examples, because the water hose IS the experiment and shows in the real world making the aperture a tiny bit smaller does NOT cause any build up of pressure, it instantly increases the rate of flow through the bit smaller opening.....somebody suggested above i try the experiment, well my hose example IS that experiment, constant input into the hose being input at the same pressure, then make the opening a tiny bit smaller and the pressure inside increases immediately and forces the same flow of water through the smaller opening....the increase in pressure is caused by the aperture being a tiny bit smaller, NOT because it has to wait for more water to gather and increase the pressure.

As stated above, the hose example is a different system.

In the bucket and ignoring viscosity, water pressure is independent of aperture, and dependent only on the distance from the surface.

Here is someone who actually did the experiment, and as you can see the larger aperture hole caused greater velocity due to the existence of viscosity and friction.

http://physics.stackexchange.com/questions/12580/how-does-a-holes-size-affect-the-distance-that-water-will-squirt

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[Mallow]

20 minutes ago, BillT said:

in the posters example the ONLY change is the size of the aperture THAT is the cause of the pressure increase, making it a bit smaller INCREASES to force of the water at that point.......my hose example is far better than these tank examples, because the water hose IS the experiment and shows in the real world making the aperture a tiny bit smaller does NOT cause any build up of pressure, it instantly increases the rate of flow through the bit smaller opening.....somebody suggested above i try the experiment, well my hose example IS that experiment, constant input into the hose being input at the same pressure, then make the opening a tiny bit smaller and the pressure inside increases immediately and forces the same flow of water through the smaller opening....the increase in pressure is caused by the aperture being a tiny bit smaller, NOT because it has to wait for more water to gather and increase the pressure.

I think that I may understand where the confusion is coming from here. What you're discussing is a similar principle to the Bernoulli Effect, which states that all else being equal, fluid flowing faster exerts a lower pressure. In your hose example, this would correspond with the part of the hose with water flowing through the smaller aperture having lower water pressure, given the same rate of flow into and out of the hose. Of course, there are a lot more variables at play here, which is why I think the hose analogy is overcomplicated. Now you have to deal with the water flowing into the tank, the water level in the tank, the water flowing into the hose, the water flowing out of the hose, and the Bernoulli Effect. I do not think these additions are necessary, and they complicate the analogy. So I very much prefer to stick with my original analogy with just a hole in the bottom of the tank. I don't understand why this point is particularly controversial.

[Mallow]

7 minutes ago, drstuess said:

As stated above, the hose example is a different system.

In the bucket and ignoring viscosity, water pressure is independent of aperture, and dependent only on the distance from the surface.

Here is someone who actually did the experiment, and as you can see the larger aperture hole caused greater velocity due to the existence of viscosity and friction.

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I do not see the example you said you posted. Can you re-post the link? I am very curious to see the results!

[drstuess]

I do not see the example you said you posted. Can you re-post the link? I am very curious to see the results!

Added it in. It's just a discussion on stack exchange, but I am sure there's something on YouTube too.

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[BillT]

please people, in the tank example it is said the flow in and out are the SAME rate IF that is true then there would be NO extra water in the tank the water would just go right through the hole and the tank would hold no water.......the example says making the opening a tiny bit smaller would cause the tank to start filling and it wouldnt, the water would simply flow through the opening faster.........the example again claims an equilibrium between input and outflow which means the tank wouldnt have any water in it because it flows out as the same rate more comes in = NOTHING building up.

[Mallow]

11 minutes ago, BillT said:

please people, in the tank example it is said the flow in and out are the SAME rate IF that is true then there would be NO extra water in the tank the water would just go right through the hole and the tank would hold no water.......the example says making the opening a tiny bit smaller would cause the tank to start filling and it wouldnt, the water would simply flow through the opening faster.........the example again claims an equilibrium between input and outflow which means the tank wouldnt have any water in it because it flows out as the same rate more comes in = NOTHING building up.

There would be no fixed equilibrium water level in the tank if the flow rate out the bottom did not depend on the depth of the water in the tank. Because it does, there can be an equilibrium water level in the tank where the water flow in and out at the same rate. Indeed, this is a stable equilibrium--adding a large amount of water to the tank at one time without changing the flow rate at the top or the hole in the bottom will cause the water level to temporarily increase, but the increased water pressure at the bottom of the tank will allow water to flow out faster, until the water level is back down to the equilibrium level.

Additionally, if the flow rate out the bottom did not depend on the depth of water in the tank, it would not imply a zero water level in the tank, but would only imply a constant water level in the tank. If you have ten apples, and you repeatedly and simultaneously add one and take one away, you still have ten apples in the end.

[drstuess]

please people, in the tank example it is said the flow in and out are the SAME rate IF that is true then there would be NO extra water in the tank the water would just go right through the hole and the tank would hold no water.......the example says making the opening a tiny bit smaller would cause the tank to start filling and it wouldnt, the water would simply flow through the opening faster.........the example again claims an equilibrium between input and outflow which means the tank wouldnt have any water in it because it flows out as the same rate more comes in = NOTHING building up.

Here is some math... please read.
http://math.usu.edu/~powell/biomath/lb-02/lb-02.html

Notice the equation for hydrostatic pressure of water is Pressure=density of water x gravitational constant x height of column to surface.

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[Mallow]

17 minutes ago, drstuess said:

Here is some math... please read.
http://math.usu.edu/~powell/biomath/lb-02/lb-02.html

Notice the equation for hydrostatic pressure of water is Pressure=density of water x gravitational constant x height of column to surface.

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Yep, this is a pretty popular experiment that shows that the flow rate of water out of a hole in a reservoir (and thus the horizontal distance achieved by the exiting water stream) is driven by the depth of water above the hole (the water pressure at the hole). This illustrates half of my proposed analogy/experiment. I haven't found an example which incorporates the inflow/equilibrium level yet. If I can't, I may try to make my own example and post it in a video.