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Global Warming / Climate Changes Pt. 22

Re: Global Warming / Climate Changes Pt. 22

Unread postby dohboi » Sat 21 Nov 2020, 17:08:02

Different molecules have different absorption spectrums because...they're...different...they have different molecular structures

N2 and O2, what almost all the earth's atmosphere is made up of, have very simple structures N=N, O=O

Not a lot of 'wiggle' room, so the bonds don't twist much. But CO2 and methane have structures that do allow for 'twist' of various sorts: methane even more than CO2, that's why it is an even more powerful greenhouse gas.

I realize Yon is not hear to learn, but if anyone is, here's a nice overview, and I'm sure folks like dis could give a much more refined and in depth explanation of the physics than may very simplified one, or even than what is presented at the link:

https://skepticalscience.com/print.php?r=35
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Re: Global Warming / Climate Changes Pt. 22

Unread postby diemos » Sat 21 Nov 2020, 17:13:00

Yonnipun wrote:Emissivity is a constant. It is the same for absorbing and emitting. It is a property of the body.


No, it's not.

When you change the mixture of gases in the atmosphere you change the emissivity.
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Re: Global Warming / Climate Changes Pt. 22

Unread postby dissident » Sat 21 Nov 2020, 18:54:48

dohboi wrote:Different molecules have different absorption spectrums because...they're...different...they have different molecular structures

N2 and O2, what almost all the earth's atmosphere is made up of, have very simple structures N=N, O=O

Not a lot of 'wiggle' room, so the bonds don't twist much. But CO2 and methane have structures that do allow for 'twist' of various sorts: methane even more than CO2, that's why it is an even more powerful greenhouse gas.

I realize Yon is not hear to learn, but if anyone is, here's a nice overview, and I'm sure folks like dis could give a much more refined and in depth explanation of the physics than may very simplified one, or even than what is presented at the link:

https://skepticalscience.com/print.php?r=35


Exactly. Both the H2O and CO2 are three atom molecules whereas N2 and O2 are two atom molecules. So they have vibrational modes that resonate in the IR bands. The covalent bonds in N2 and O2 are very strong so have a high frequency resonance. The dual covalent bonds in CO2 do not prevent it from bending and thus allow another degree of freedom for vibration. H2O does not have covalent bonds but hydrogen bonds and is also kinked so it has even more lower frequency vibrational modes than CO2. H2O is the premier greenhouse "gas" (really vapour) on Earth. But it would not be available in sufficient quantities to matter if not for dry greenhouse gases like CO2.

Molecular energy is not just kinetic energy of the whole molecule. It is the energy of the vibrational and rotational modes inside the molecule itself as well as the electron excitation energy which is not important under normal temperatures and solar radiation in the troposphere. In the stratosphere one gets excited atomic energy states, for example in atomic oxygen 1D state, O(1D) (*). This chemical species and its excited state do not exist in the stratosphere because there is a lack of hard UV to break down O2 and because the atmospheric density increases exponentially as one approaches the surface so excited atomic states are rapidly quenched through molecular collisions.

Boltzmann's Law gives the distribution of energy in thermodynamic equilibrium for both translational and internal kinetic energy states. Equilibrium here amounts to sufficiently rapid particle collisions to thermalize the internal atomic energy states. Above 80 km you get the appearance of so-called non-local thermodynamic equilibrium where the low density prevents a Gaussian distribution of internal energy states due to a lack of enough collisions over any relevant timescale. So excited atomic energy states (whether in single atom species or molecules) can persist.

(*) the presence O(3P) and O(1D) above 16 km is the key reason why NOx generates O3 in the troposphere and destroys it in the stratosphere.
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Re: Global Warming / Climate Changes Pt. 22

Unread postby dissident » Sat 21 Nov 2020, 18:57:59

diemos wrote:
Yonnipun wrote:Emissivity is a constant. It is the same for absorbing and emitting. It is a property of the body.


No, it's not.

When you change the mixture of gases in the atmosphere you change the emissivity.


This poster is not serious about learning and is here just to piss on the thread.

Emissivity and absorptivity are well defined concepts and are fractions instead of being absolutes:

https://en.wikipedia.org/wiki/Kirchhoff ... _radiation

That poster couldn't even be bothered to do a simple Google search before pontificating here says it all.
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Re: Global Warming / Climate Changes Pt. 22

Unread postby jedrider » Sat 21 Nov 2020, 19:43:50

diemos wrote:
Yonnipun wrote:Emissivity is a constant. It is the same for absorbing and emitting. It is a property of the body.


No, it's not.

When you change the mixture of gases in the atmosphere you change the emissivity.


Well, in EQUILIBRIUM, Yon-Pun is correct. Unfortunately, we're far from equilibrium.

The Earth system is absorbing more than it is emitting. So, Yon-Pun likes to take half of science, leave out the other pertinent half and then claim something is impossible.

That MO is from the Denier's Handbook I'm sure.
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Re: Global Warming / Climate Changes Pt. 22

Unread postby yellowcanoe » Sat 21 Nov 2020, 20:05:29

jedrider wrote:Well, in EQUILIBRIUM, Yon-Pun is correct. Unfortunately, we're far from equilibrium.


Yes, which means that even if we were able to magically stop emitting CO2 tomorrow there would still be more warming before we return to equilibrium.
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Re: Global Warming / Climate Changes Pt. 22

Unread postby Newfie » Sat 21 Nov 2020, 20:47:04

yellowcanoe wrote:
jedrider wrote:Well, in EQUILIBRIUM, Yon-Pun is correct. Unfortunately, we're far from equilibrium.


Yes, which means that even if we were able to magically stop emitting CO2 tomorrow there would still be more warming before we return to equilibrium.


A fact which seems to be lost on most folks.
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Re: Global Warming / Climate Changes Pt. 22

Unread postby Yonnipun » Sat 21 Nov 2020, 21:04:52

yellowcanoe wrote:
jedrider wrote:Well, in EQUILIBRIUM, Yon-Pun is correct. Unfortunately, we're far from equilibrium.


Yes, which means that even if we were able to magically stop emitting CO2 tomorrow there would still be more warming before we return to equilibrium.


Do not worry. CO2 has no ability to heat up earth. You need additional energy for that. CO2 is simply a matter that itself needs energy to heat up.
Without the sun the earth would turn into giant ice ball in 24 hours. Oceans would freeze 2 meters thick in 48 hours. Just think about how powerful is the sun and how much energy it takes to keep the planet warm.
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Re: Global Warming / Climate Changes Pt. 22

Unread postby diemos » Sat 21 Nov 2020, 23:16:17

Huh. Looks like someone reset the bot to its initial state.
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Re: Global Warming / Climate Changes Pt. 22

Unread postby dissident » Sun 22 Nov 2020, 03:48:37

Equilibrium will not result in the same photon flux density with a different composition. The warming is not because the incoming radiation is not balanced with the outgoing radiation. It is actual accumulation of energy in the system which will remain after equilibrium is reached.

Considering that radiative damping in the atmosphere has a timescale of at most several weeks (it is a function of temperature with colder temperatures radiating less than warmer temperatures), any imbalance is dominated by slower processes such as change in surface albedo (e.g. land ice reduction), and the very long time scale for ocean heating to occur. Oceans do not warm up via direct radiation like the atmosphere and require circulation process to redistribute heat. Near the surface this is "fast" thanks to mixing by gyres (eddies) but deeper water is more laminar and takes a long time to respond. So most of the top of the atmosphere radiation imbalance is due to ocean lag.

The warming we are seeing is misleading since most of the thermal energy (90%) is being sequestered in the oceans. When equilibrium is reached (which is never and only approximately, since CO2 and other greenhouse gases will never be constant in time) things are going to be nasty.
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