The process that occurs when sitting on the toilet while taking a dump that results in the odors or gases from ones poop to be rise up through their shirt, become momentarily trapped, then come out the collar of their shirt and into the dump-takers face. One can only choose to make things worse by then taking off their shirt after and releasing all the gas trapped under the shirt at once, creating a somewhat artificial fart. One can avoid The Green Blouse Effect by taking their shirt off PRIOR to taking a dump. It is similar to the Greenhouse Effect in the matter that both involved trapped gases.
Person 1:"Man, I took a dump then took my shirt off right after and there was like an explosion of poop odors that came out!"
Person 2:"You gotta watch out for that, it's called The Greenblouse Effect. We can do our part in preserving the welfare of our noses by taking our shirts off before we partake in the act of pooping."