Is There Any Industry Making Use of the Greenhouse Effect?

Yes, it is a genuine question. And no, I do not want to hear about Al Gore / other politicians / greenies / lobbyists.

Is there any type of industry making use of the greenhouse effect? I understand that CO2 is added to actual greenhouses, but not because it is a GHG. Would be interesting to find out if such a world-changing phenomenon is or has been of practical use.