Air conditioning eventually reach the upper atmosphere. Once the refrigerant reaches the stratosphere, UV radiation from the Sun homolytically cleaves the chlorine-carbon bond, yielding a chlorine radical. These chlorine radicals catalyze the breakdown of ozone into diatomic oxygen, depleting the ozone layer that shields the Earth's surface from strong UV radiation. Each chlorine radical remains active as a catalyst until it binds with another radical, forming a stable molecule and quenching the chain reaction. Prior to 1994, most automotive air conditioning systems used R-12 as a refrigerant. It was replaced with R-134a refrigerant, which has no ozone depletion potential. Old R-12 systems
Stratosphere: Conquest of the Skies Stratosphere: Conquest of the Skies Stratosphere: Conquest of the Skies is a Vehicular combat game and also a real-time strategy PC game, developed by Kodiak Interactive and published by Ripcord Games in 1998. Stratosphere focuses on floating island battles which players control. Gameplay consist of the player controlling a single floating island which are called flying fortresses in the game. These fortresses float because they are built from 'floatstones' which can be collected from mountainsides and also from other fortresses after damaging them. There are three types of floatstones each used to build different structures on the fortress. Extra land