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effects of Global Warming


Itoero

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24 minutes ago, Carrock said:

Nothing I'm aware of.

What structural property enables the absorption/emission of radiant energy in certain molecules (greenhouse  gas) and disables it in other molecules?

Edited by Itoero
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10 hours ago, Itoero said:

What structural property enables the absorption/emission of radiant energy in certain molecules (greenhouse  gas) and disables it in other molecules?

 

Quote

Carbon dioxide (CO2) is also an important greenhouse gas. It has a long lifetime in Earth's atmosphere. Carbon dioxide strongly absorbs energy with a wavelength of 15 μm (micrometers). This makes carbon dioxide a good absorber of wavelengths falling in the infrared radiation region of the spectrum.

http://www.ces.fau.edu/nasa/module-2/how-greenhouse-effect-works.php

Like water and microwaves, but here we have CO2 and IR.

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13 hours ago, Itoero said:

What structural property enables the absorption/emission of radiant energy ....

Tri-atomic molecules can stretch and bend, or waggle, in such a way (asymmetrically) as to "resonate" with infrared wavelengths.  Di-atomic molecules can't move in such a way, always constrained to move symmetrically.

Search: co2 vibrational modes animation.  I know there are you tubes of Prof. Denning, doing his 'waggle dance' showing how CO2 absorbs heat, using his head as the carbon and his upraised fists as the oxygen.

Or just search 'infrared CO2 waggle' online.

IRabsorption1.PNG.8d1abbcc8d0b130f2eef00b1db96e3b4.PNG  

The symmetric stretch is not infrared active, and so this vibration is not observed in the infrared spectrum of CO2.”

~

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13 hours ago, Essay said:

Tri-atomic molecules can stretch and bend, or waggle, in such a way (asymmetrically) as to "resonate" with infrared wavelengths.  Di-atomic molecules can't move in such a way, always constrained to move symmetrically.

Search: co2 vibrational modes animation.  I know there are you tubes of Prof. Denning, doing his 'waggle dance' showing how CO2 absorbs heat, using his head as the carbon and his upraised fists as the oxygen.

Or just search 'infrared CO2 waggle' online.

IRabsorption1.PNG.8d1abbcc8d0b130f2eef00b1db96e3b4.PNG  

The symmetric stretch is not infrared active, and so this vibration is not observed in the infrared spectrum of CO2.”

~

I've read CO absorbs infrared 3 times 'better' then CO2, how is that possible? Does the binding between C en O enable more radiant energy absorption because there is more 'vibrational space'? CH4 is also more potent then Co2...why?

Afbeeldingsresultaat voor CO

Is it correct to say that basically, vibrational nuclei are necessary  for absorption/emission infrared?

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10 hours ago, Itoero said:

I've read CO absorbs infrared 3 times 'better' then CO2, how is that possible? Does the binding between C en O enable more radiant energy absorption because there is more 'vibrational space'? CH4 is also more potent then Co2...why?

....

Is it correct to say that basically, vibrational nuclei are necessary  for absorption/emission infrared?

Absorption of energy is probably more easily thought of as occurring within the molecular bonds, rather than within “vibrational nuclei” as you suggest.  Methane, with four bonds, has many more opportunities to vibrate (waggle) in ways that absorbs IR, so that might be why it is stronger.  But whatever the reason, when the nuclei are different, then the bonds are different too.

For example, when the 4 hydrogen atoms of methane are substituted with chlorine or fluorine, you get an even stronger absorber for IR.  Methane (CH4), is about 100 times as powerful as carbon dioxide (~100 x CO2), but tetraflouro-methane (CF4) (~5000 x CO2) and dichloro-difluoro-methane (CCl2F2) (~11000 x CO2) both absorb more strongly than methane, even though the structure of all three molecules is about the same.  The one with twice the asymmetry (mixed Cl/F) as the other is about twice as strong too, but maybe that is just coincidence.

I’d never heard of CO being a greenhouse absorber, but I found it listed online as a "very weak" absorber!  Perhaps the unbound electrons at each end of the molecule can vibrate in a manner similar to (but much weaker than) how hydrogen bonds would vibrate, but that should probably be its own topic since CO doesn’t seem to be considered a significant ‘greenhouse’ gas.

“Carbon monoxide (CO) is only a very weak direct greenhouse gas, but has important indirect effects on global warming. Carbon monoxide reacts with hydroxyl (OH) radicals in the atmosphere, reducing their abundance.”

~

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14 hours ago, swansont said:

Where did you read that?

On Wikipedia but I can't rediscover it.

I just read this on quora: "Carbon monoxide (CO) is not considered a direct greenhouse gas, mostly because it does not absorb terrestrial thermal IR energy strongly enough. However, CO is able to modulate the production of methane and tropospheric ozone."

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  • 1 year later...

There have been methods that have been proposed known as "climate engineering" or "geoengineering."

Some proposals involve injecting reflective particles into the upper atmosphere to scatter and reflect sunlight back. Others involve seeding the oceans with iron to stimulate large-scale phytoplankton blooms. This is to draw down carbon dioxide out of the atmosphere through photosynthesis. But many climate scientists oppose to these methods as they do not know the possible side effects.

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