Atmospheric Gases - absorption, reflection, and emission of radiation

[ExcessRed]

I'm going to be very careful to avoid the word "greenhouse" because of the indefinite ban on discussions about climate change - I want to be clear, this isn't a topic about that.

Part 1 - some gasses in the atmosphere absorb and emit radiation in the thermal infrared range. Gases like water vapor, carbon dioxide, methane, etc. I'm wondering if anyone can tell me what the measure of how much radiation the gas absorbs and emits is called?

Part 2 - some gasses are more effective at reflecting solar radiation away from the Earth than other gases. What is the measure of how "reflective" a gas is, in this context?

 

[darksociety]

I'm going to be very careful to avoid the word "greenhouse" because of the indefinite ban on discussions about climate change - I want to be clear, this isn't a topic about that.

Part 1 - some gasses in the atmosphere absorb and emit radiation in the thermal infrared range. Gases like water vapor, carbon dioxide, methane, etc. I'm wondering if anyone can tell me what the measure of how much radiation the gas absorbs and emits is called?

Part 2 - some gasses are more effective at reflecting solar radiation away from the Earth than other gases. What is the measure of how "reflective" a gas is, in this context?

1) The term you'll see a lot in the literature is 'radiative forcing' and its quantitative metric is watts per square metre (W/m^2).

2) Reflection in the general sense is qualified broadly as 'albedo', but I suspect you're after a more specific, physical mechanism. It's a tricky question, because there is more than one effect (e.g. resonance, dispersion) that requires a decent understanding of physics (which I'm afraid I don't have).