Okay, didn't know that about glass, and still find it suspicious - if that were the case then you wouldn't need IR filters in cameras, etc, and would probably have proven problematic for Herschel's accidental accidental discovery of infrared. But okay, maybe for far infrared you'd need a special prism.
No need to remain suspicious. Simply look it up yourself. That's what google is for right? But I'll do it for you anyway.
Visible light is in the 390-700 nm wavelength.
Glass is transparent mostly in the 350 to 2500nm range, and is almost completely opaque outside of the 250 to 4000nm range
CO2 absorbsion occurs at 4257, 7204, 14992nm (more commonly notated as 667, 1388, and 2349 cm-1, in case you want to search to do your own verification)
So you can see there is a ton of IR in the 700-2500 range that glass is nearly completely transparent to. That's why you can have IR cameras. But CO2 is WAY out of range.