DOES BACK-RADIATION EXIST?

This article gives a very interesting discussion of this fundamental point. This author does not believe in the back-radiation theory.

Further reading below for those with time.
- http://www.tech-know.eu/uploads/IRabsW05122011.pdf argues that it does not. This article - http://earthobservatory.nasa.gov/Features/EnergyBalance/page5.php says it does.