Infrared Radiation: Bad or Good?

Infrared radiation is something which is seen as a positive function and negative function. The topic on the whole refers to the greenhouse affect and forms of radiation. Also infrared radiation deals with pollution which many don't know. Here's a link to read up a bit about: http://www.windows.ucar.edu/tour/link=/physical_science/magnetism/em_infrared.html

Below are my views on the trapping of infrared radiation.

How can trapping of infrared radiation by earth's atmosphere be a good thing?
A: Trapping of infrared radiation can be a good thing because the radiation keeps the earth's temperature relatively constant, warm, and a temperature which is livable for us as humans.

How can trapping of infrared radiation by earth's atmosphere be a bad thing?
A: Trapping of infrared radiation can be a bad thing because too much radiation can be trapped and over heats the earth. The thin layer of atmosphere is being swamped with pollution and more outgoing infrared radiation is trapped .