<p>Yes, you are right, the title says it all. The presence of greenhouse gases, of which there are several, allows radiant energy from the sun to pass through the atmosphere but hinders the longer wavelength, infra red, thermal radiation from getting back out again, thus acting like the glass in a greenhouse. CO2 is a less effective greenhouse gas than methane, but there is much more of it in the atmosphere and it stays there longer, so this is the one which causes most concern. There are natural processes which reduce the amount of CO2 and methane in the atmosphere as long as the input, mainly from human activity, is not more than they can deal with.</p>

CC BY-SA 4.0
2019-10-07T17:03:53.177Z
I think by "shorter wavelength" you actually meant "longer wavelength"?
Semidiurnal Simon
CC BY-SA 4.0
2019-10-07T17:54:47.207Z
You're right. How silly of me. It was the written equivalent of a slip of the tongue! I should have checked it more thoroughly.
Michael Walsby
CC BY-SA 4.0
2019-10-07T11:07:07.063Z
2019-10-07T18:01:29.817Z
2019-10-07T18:01:29.817Z
Michael Walsby
<p>I think the title says it all...</p>

CC BY-SA 4.0
2019-10-07T12:21:39.437Z
Hi Crom, did you have a look at the wikipedia page for greenhouse gases? At SE we value prior research, because nobody has time to answer a full out "explain the whole universe to me" questions. Thus, it would be nice of you to do some prior reading and then come back with the points you didn't understand.
AtmosphericPrisonEscape
CC BY-SA 4.0
2019-10-07T12:43:52.893Z
Nope, the title doesn't say it at all. What is the question here? Why is CO2 considered GHG? What is a GHG? How does the greenhouse effect work? Why does CO2 act as GHG? Please specify your question.
Erik
CC BY-SA 4.0
2019-10-07T17:06:02.513Z
Possible duplicate of [How do 'greenhouse gases' let heat in, but not let it out?](https://earthscience.stackexchange.com/questions/14706/how-do-greenhouse-gases-let-heat-in-but-not-let-it-out)
Semidiurnal Simon
CC BY-SA 4.0
2019-10-07T19:55:59.547Z
You are expected to show some effort to answer the question on your own. Honestly this should be closed as a homework question.
John
<atmosphere><atmospheric-radiation>
Why is CO2 considered a greenhouse gas? Can you explain the principles?
C_R_O_M________ C_R_O_M_______
# Why is CO2 considered a greenhouse gas? Can you explain the principles?

(Asked by: username_0 on 2019-10-07)

I think the title says it all...

**Tags:** atmosphere, atmospheric-radiation

> **Comments:**
> **username_1**: Hi Crom, did you have a look at the wikipedia page for greenhouse gases? At SE we value prior research, because nobody has time to answer a full out "explain the whole universe to me" questions. Thus, it would be nice of you to do some prior reading and then come back with the points you didn't understand.  
> **username_2**: Nope, the title doesn't say it at all. What is the question here? Why is CO2 considered GHG? What is a GHG? How does the greenhouse effect work? Why does CO2 act as GHG? Please specify your question.  
> **username_3**: Possible duplicate of [How do 'greenhouse gases' let heat in, but not let it out?](https://earthscience.stackexchange.com/questions/14706/how-do-greenhouse-gases-let-heat-in-but-not-let-it-out)  
> **username_4**: You are expected to show some effort to answer the question on your own. Honestly this should be closed as a homework question.  

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## 1 answers

### Answer by username_5 on 2019-10-07. Score: 2

Yes, you are right, the title says it all. The presence of greenhouse gases, of which there are several, allows radiant energy from the sun to pass through the atmosphere but hinders the longer wavelength, infra red, thermal radiation from getting back out again, thus acting like the glass in a greenhouse. CO2 is a less effective greenhouse gas than methane, but there is much more of it in the atmosphere and it stays there longer, so this is the one which causes most concern. There are natural processes which reduce the amount of CO2 and methane in the atmosphere as long as the input, mainly from human activity, is not more than they can deal with.

> **Comments:**
> **username_3**: I think by "shorter wavelength" you actually meant "longer wavelength"?  
> **username_5**: You're right. How silly of me. It was the written equivalent of a slip of the tongue! I should have checked it more thoroughly.  

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