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
I watched a great Carl Sagan video on this recently. Basically the light you see – visible light – comes from the sun and warms the Earth. The Earth absorbs this heat and radiates out infrared light. Now if we measure the ratio of visible in vs infrared out, the world would be around 20-30 degrees Celsius colder than it is now, all the water would freeze eventually.
But Carbon dioxide absorbs light at a specific wavelength. This is the infrared light because it’s at the right wavelength and that’s what warms the Earth up!
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