Why is the greenhouse effect only one way?

1.28K 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

Others made a good point about different types of radiation, which is true and a very important aspect of the greenhouse effect.

In addition, it’s also not so much a barrier as a filter or a sieve. If you look at it as a sieve than it isn’t really all that weird that it lets in more than it lets out. Let’s say 80% passes the sieve and 20% is filtered out. In that case 80% of sunlight comes into the earth, passing the sieve once. Going out it passes the sieve again and 20% is filtered out again, so only 64% leaves the earth.

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