79% is gone.
The scientific progress first depleted the ozone. It is now replenishing it.
The ozone issue has changed with time. The use of CFC first depleted the ozone but now it is stable.
The "ozone layer" is roughly the same condition it has always been in. The amount of ozone in the upper atmosphere varies mainly due to variations in solar activity. UV radiation has serious affects on this layer. Holes form over the poles at the end of each winter due to a lack of sunlight. When the sun returns, the "holes" quickly disappear.
Ozone over the poles has been destroyed. It is due to the fact that ozone is susceptible to low weather.
Air pollution that was once blamed for global cooling is responsible for warming because it has depleted some ozone some pockets of the ozone layer which were responsible for preventing harmful UV rays from penetrating it.
See "What is the condition of the ozone layer now?"See "How large is the ozone hole now?"See "What is the condition of the ozone layer?"
do not now
Various measures are being taken now. The first measure was to try reduce the use of CFC's.
Ozone layer has many holes in it. However it has a considerable major hole in it above Antartica continent. It is formed due to CFC gas. Beacuse of the hole there is an increase in the temperature of earth.
Yes. After the Montreal Protocol, countries gradually phased out the production of CFCs. Chlorofluorocarbons (CFCs) that were used in refrigerators and aerosols were the main destroyers of the ozone layer. The ozone layer is now no longer depleting. Scientists hope that it will have completely restored itself by 2060.
The ozone hole was growing earlier but now due to the ban of ozone depleting susbtances, the ozone hole is replenishing.
Ozone layer was depleting earlier. Now it is being aided.