Final answer:
CFCs are proven to reach the atmosphere through scientific measurements and atmospheric studies. Chlorine atoms released from CFCs by UV radiation destroy ozone molecules, which has been confirmed by research and initiatives like the Montreal Protocol.
Step-by-step explanation:
The tests that prove that CFCs are getting into the atmosphere involve scientific measurements of atmospheric concentrations and studies of the chemistry of ozone depletion. When CFCs reach the stratosphere, they are broken down by ultraviolet (UV) radiation, releasing chlorine atoms that initiate a destructive cycle against ozone molecules. This understanding comes from extensive research and monitoring, such as the findings presented by the British Antarctic Survey and the work of scientists like Susan Solomon.
One significant piece of evidence was the discovery of the depletion of the ozone layer, now known as the ozone hole, over Antarctica. This discovery was made possible by continuous monitoring and the identification of CFCs and other ozone-depleting substances in the atmosphere. The impact of CFCs on the ozone layer is further confirmed by ongoing international efforts and agreements such as the Montreal Protocol.