Why is the greenhouse effect only one way?

1.10K views

So what I’m reading is that these gas absorb the light from the sun and keeps it trapped on the earth.

What I don’t get is how is it letting the light and heat in from the sun in, but not the light and heat reflected from the Earth out? If it’s a barrier, shouldn’t it block both ways? If it’s not a barrier, how is it trapping the heat?

In: 950

42 Answers

Anonymous 0 Comments

Sunlight that comes in is largely in the visible spectrum of light.
The earth radiates heat out as light in the infrared spectrum.

Greenhouse gasses absorb a lot of infrared light, but little to no light in the visible spectrum, creating a one way mirror for heat. (methane for instance is completely transparent to our eyes, but is pitch black through an IR-camera)

You are viewing 1 out of 42 answers, click here to view all answers.