All atmospheric <a href="https://en.wikipedia.org/wiki/Gas" class="extiw" title="en:Gas">gases</a> have a unique pattern of energy <a href="https://en.wikipedia.org/wiki/Absorption_(electromagnetic_radiation)" class="extiw" title="w:Absorption (electromagnetic radiation)">absorption</a>: they absorb some wavelengths of energy but are transparent to others. The absorption patterns of <a href="https://en.wikipedia.org/wiki/water_vapor" class="extiw" title="en:water vapor">water vapor</a> (blue peaks) and <a href="https://en.wikipedia.org/wiki/Carbon_dioxide" class="extiw" title="w:Carbon dioxide">carbon dioxide</a> (pink peaks) overlap in some <a href="https://en.wikipedia.org/wiki/wavelength" class="extiw" title="en:wavelength">wavelengths</a>. Carbon dioxide is not as strong a <a href="https://en.wikipedia.org/wiki/greenhouse_gas" class="extiw" title="en:greenhouse gas">greenhouse gas</a> as water vapor, but it absorbs energy in wavelengths (12-15 <a href="https://en.wikipedia.org/wiki/micrometers" class="extiw" title="en:micrometers">micrometers</a>) that water vapor does not, partially closing the “window” through which <a href="https://en.wikipedia.org/wiki/Heat" class="extiw" title="en:Heat">heat</a> radiated by the surface would normally escape to <a href="https://en.wikipedia.org/wiki/outer_space" class="extiw" title="en:outer space">space</a>. (Illustration adapted from Robert Rohde.)
<a href="https://en.wikipedia.org/wiki/NASA" class="extiw" title="en:NASA">NASA</a>, Robert Rohde
2014-04-20 19:20:16
<a rel="nofollow" class="external free" href="http://earthobservatory.nasa.gov/Features/EnergyBalance/page7.php">http://earthobservatory.nasa.gov/Features/EnergyBalance/page7.php</a> <a href="https://en.wikipedia.org/wiki/NASA_Earth_Observatory" class="extiw" title="en:NASA Earth Observatory">NASA Earth Observatory</a>