Final answer:
The Montreal Protocol has successfully phased out CFCs, with most countries ceasing production by 1995 and developing nations by 2010. Less hazardous substances will be phased out by 2030, and signs of ozone layer recovery have been observed, with a full recovery expected by 2065.
Step-by-step explanation:
Chlorofluorocarbons (CFCs) have been largely phased out due to the Montreal Protocol on Substances that Deplete the Ozone Layer, an international treaty ratified in 1987. According to the protocol, CFCs have been mostly phased out since 1995, and while they were used in developing nations until 2010, the phase-out of less hazardous substances won't be complete until 2030.
The protocol reflects global cooperation in addressing the issue of ozone layer depletion, with both developed and developing countries working together to eliminate these substances.
The use of CFCs in global industries, such as refrigerants, air conditioning systems, and aerosols, had a significant impact on the ozone layer.
Since the protocol's enforcement, there have been signs of ozone recovery. It is hoped that the ozone layer will return to normal levels by around 2065 if the continued efforts under the protocol are maintained and emission of CFCs remains curtailed.
While developing countries have made significant strides in reducing CFC emissions, countries like China and India are notable for their contributions to CFC emissions. Additionally, the concern for 'CFC banks' where obsolete technologies slowly release stored CFCs into the atmosphere is an ongoing challenge for full recovery of the ozone layer.