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
Future of Earth to slowly move inwards toward the Earth. If Earth is not destroyed by the expanding red giant Sun in 7.6 billion years, then on a time scale of 10 (10 quintillion) years the remaining planets in the Solar System will be ejected from the system by violent relaxation. If this does not occur to the Earth, the ultimate fate of the planet will be that it collides with the black dwarf Sun due to the decay of its orbit via gravitational radiation, in 10 years. On a time scale of 10 years, it is hypothesized that the Sun will collide