Sabine Hossenfelder has a pretty good video on the details. Except for an error regarding the hydrostatic equation (which is not important to the topic of the video), she gets it correct. She goes into why stratospheric cooling and lower tropospheric warming occurs with increasing CO2.
Regarding why cloudy nights are warmer, more precisely the long wave is not reflected. It is actually absorbed and reemitted.
https://www.youtube.com/watch?v=oqu5DjzOBF8
Quote:
Originally Posted by blueash
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For those who want an explanation of how CO2 and methane DO act as greenhouse gases, and why there is a nice website from Columbia university with simple clear science. And you tube videos of how you can prove it to yourself. So Simple Even a sounding can do it.
How Exactly Does Carbon Dioxide Cause Global Warming? - You Asked
For those who don't click on links. The sun heats the earth in the visible light spectrum. The warm earth releases some of this heat back upwards into the atmosphere. Think how a dark rock is hot as it has trapped then released heat. That released heat is infrared heat. You have all likely used infrared heat lamps.
Infrared energy is invisible, just off the rainbow of colors we see, ultraviolet being just off the other side. Infrared energy waves come in contact with the molecules of the atmosphere as they travel from the warmed earth into the sky. Some molecules do not interact with infrared. The energy passes thru and continues into space. Oxygen ignores infrared. Nitrogen ignores infrared.
CO2 and other greenhouse gases do interact with infrared energy. They absorb some of it. Once the CO2 molecule absorbs the infrared heat, it then radiates it back out into the atmosphere, just like the dark rock absorbed it on the earth then radiated it out.
Some of the radiated energy goes up, back toward space, some goes down back toward the earth. That which is radiated back down to us warms us, and the planet.
Water vapor is also a greenhouse gas. It is an oversimplification but everyone here is 100% correct in noticing that cloudy nights are warmer than clear nights. Why? The amount of heat the warm earth is sending up toward space is the same whether cloudy or clear. But on cloudy nights that heat, infrared heat, cannot escape and is partially reflected back down keeping us warm. |