Zorba
Lifer
- Oct 22, 1999
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If I'm reading the data in the link below correctly, nitrogen has 65.3% more thermal conductivity than CO2. Raws numbers are .026 for N and .017 for CO2. Oxygen is at .027, almost exactly the same as Nitrogen.
https://www.electronics-cooling.com/1998/09/the-thermal-conductivity-of-gases/#
Thermal conductivity isn't what causing the greenhouse effect. The greenhouse effect is caused by the radiative emissivity of the gas. In layman's terms, it is basically how much of the IR and Visible Light spectra the material absorbs. Nitrogen and Oxygen basically have 0 emissivity so they absorb/block no heat, while Carbon Dioxide and other greenhouse gases have a a non-zero number, which means they block some heat from leaving the earth at night (the Earth radiates to deep space at night).
Water vapor actually has by far the strongest greenhouse effect on Earth. You can observe this yourself by paying attention to clear nights vs cloudy nights. Cloudy nights will stay much warmer than clear nights, it is also why Phoenix doesn't cool off as much at night as it used to. Of course this works in the opposite way during the day, where a cloudy day blocks heat from the sun.
From my understanding, the current theory of global warming is that the additional non-water vapor greenhouse gases help retain enough heat that the atmosphere is in turn able to hold more water vapor (the warmer the air, the more moisture it can hold). This results in more cloud formation at night, which blocks heat from escaping at night. I'm not a climate researcher, but I have a masters in Heat Transfer and the basic premise is solid.
As for hard numbers, it is hard to say because it changes based on the amount in the atmosphere and the temperature.
This is the best link I could find quickly (for some reason Google was finding a bunch of anti-science websites): http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/grnhse.html
