The mental model that helps visualize why the sky is blue—blue photons flying in every direction—is also the mental model that helps understand the greenhouse effect.
Visible light passes through the atmosphere, gets absorbed by the ground, and then re-radiated at infrared (IR) wavelengths. Atmospheric gases like water vapor, methane, and CO2 cause a certain amount of that IR light to shoot in every direction. So a portion of inbound solar energy gets trapped bouncing around inside the atmosphere for a while before it finally makes it out.
Basically the greenhouse effect is the sky glowing in infrared in addition to blue. We can’t see infrared, but we can feel it with our skin. It feels like warmth.
Visible light passes through the atmosphere, gets absorbed by the ground, and then re-radiated at infrared (IR) wavelengths. Atmospheric gases like water vapor, methane, and CO2 cause a certain amount of that IR light to shoot in every direction. So a portion of inbound solar energy gets trapped bouncing around inside the atmosphere for a while before it finally makes it out.
Basically the greenhouse effect is the sky glowing in infrared in addition to blue. We can’t see infrared, but we can feel it with our skin. It feels like warmth.