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Tuesday, November 27, 2018

Greenhouse Effect Is About Infrared Light

“The greenhouse effect is a phenomenon of ‘radiative transfer” of heat, the process by which the energy of electromagnetic light waves (infrared and visible) is exchanged in matter. Radiative transfer dictates what energy is reflected, absorbed, and emitted.”
https://courses.lumenlearning.com/boundless-physics/chapter/global-warming/

When you stand in the sunlight, you feel warmer than when you are in shadow because you are being directly bathed in the radiant energy of long-waved infrared light and that produced by the short-waved visible light of the electromagnetic spectrum emitted from the sun. You are, also, being bathed in infrared energy (heat) being transferred from everything around you, as well as feeling the heat being conducted by the air around you.

“Although you usually cannot see it, all objects give off radiant energy and you can sometimes feel this energy. For example, if there is a pot of hot water on your stove, you can feel the radiant energy it gives off without touching it. You usually call what you feel “heat,” but it is more accurate to think of it as a kind of invisible light called “infrared radiation” that warms your skin... 
The amount of infrared radiation energy a warmed object gives off depends on its temperature—the higher the temperature, the more energy is given off. As you know, you can easily distinguish between a warm object and a hot object by holding your hand near the objects and feeling the difference in the heating effect on your hand.”
Note: If a material becomes hot enough, it becomes radiantly luminous. It emits the higher energy short-wave visible light as well as longer-waved infrared light.

Conduction, convection, radiation:
https://courses.lumenlearning.com/suny-ap2/chapter/energy-and-heat-balance/

http://alkisites.vansd.org/dgray/Assignments/conduction_convection_radiation_reading.pdf

https://www.energy.gov/energysaver/principles-heating-and-cooling

https://phys.libretexts.org/TextBooks_and_TextMaps/University_Physics/Book%3A_Physics_(Boundless)/13%3A_Heat_and_Heat_Transfer/13.5%3A_Global_Warming

https://www.acs.org/content/acs/en/climatescience/climatesciencenarratives/what-is-the-greenhouse-effect.html