Saturday, March 24, 2018

Dear Judge Alsup: The TL:DR

Gingerbaker asked for the TL:DR for the good Judge Alsup.  Eli had already written it over at Real Climate, but deep in the comments so here it is

Eli Rabett explains it all about question 2, whether N2 and O2 play a role in the greenhouse effect.

A three parter with some TL:DRs below

A bit on observations and spectroscopy: showing that the collision free absorption of O2 and N2 can be ignored. Just too small

A discussion about the physics of molecular spectroscopy:  Shifts the balance from the qm selection rules to how molecules interact with electromagnetic radiation (e.g. IR or light). Discusses how changes in charge distributions during transitions determines whether photons are absorbed or emitted. Makes contact with electromagnetic antenna theory, eg electric dipole allowed transitions w. dipole antennas, etc. 

Eli figured the good Judge, having been a ham radio operator should grok that.

Collisional effects
Starting from the quantum interlude discusses (much paw-waving) how collisional induction of electric dipoles drives continuum absorptions for N2, O2, CO2 and H2O (by implication, need to add a paragraph, the water vapor continuum being an important part of the greenhouse effect, of course the concentration of water vapor in the atmosphere is dialed in on average by the non-condensible greenhouse gases.)

There were a couple of open questions in the discussion which the Bunny will get around to next week.  Hope that helps.


Russell Seitz said...

Does the Judge's hobby explain Monckers hamming it up on circuit theory & one dimensional feedback models ?

David B Benson said...

I would appreciate an estimate of the worldwide emissions of carbon from burning coal, oil, and natural gas since, say, 1750. Thank you.

EliRabett said...

Carbon or co2?

Tom said...

"From 1870 to 2014, cumulative carbon emissions totaled about 545 GtC. Emissions were partitioned among the atmosphere (approx. 230 GtC or 42%), ocean (approx. 155 GtC or 28%) and the land (approx. 160 GtC or 29%)."

David B Benson said...

Carbon, from 12/44 of the reported CO2.

David B Benson said...

Rectifying my calculation, yes, about 545 GtC.