Final answer:
CFCs release chlorine atoms in the stratosphere, which catalyze ozone depletion. A single Cl atom can destroy thousands of O3 molecules, leading to increased UV radiation reaching the surface. The Montreal Protocol has contributed to phasing out CFCs and limiting further ozone layer damage.
Step-by-step explanation:
Chlorofluorocarbons (CFCs) interact with ozone in the stratosphere by breaking down under ultraviolet (UV) radiation, releasing chlorine atoms. These chlorine atoms act as a catalyst in the depletion of ozone. The reaction involves a chlorine atom (Cl) combining with an ozone molecule (O3) to form chlorine monoxide (ClO) and oxygen (O2). The ClO can react with another chlorine monoxide to regenerate the chlorine atom and produce more oxygen, while breaking down yet another ozone molecule. This destructive cycle means that a single chlorine atom can destroy thousands of ozone molecules, significantly depleting the ozone layer which shields the Earth from harmful UV radiation. The relationship between ClO- and ozone is central to this process, as ClO is a critical intermediate that enables the chlorine atom to continue the ozone destruction cycle.
Tackling ozone layer depletion has seen international cooperation through the establishment of the Montreal Protocol, which has phased out the production and emission of CFCs and other harmful chemicals. Actions like these have led to a reduction in the use of CFCs, with alternative substances such as hydrofluorocarbons (HFCs) and hydrochlorofluorocarbons (HCFCs) being more environmentally friendly by lacking chlorine or breaking down more readily before reaching the stratosphere.