According to the World Meteorological Organization, the ozone layer will recover by 2060 on the entire planet. The ozone layer of the Earth has been recovering by 1-3 percent per decade since 2000 because of the implementation of the Montreal Protocol. This document prohibits the production of ozone-depleting compounds. According to WMO experts the ozone layer will fully recover by the 2030th year  in the northern hemisphere

Is the ozone layer dangerous or useful?
The level of ozone can be really dangerous for people in a hot foggy day in a gas-filled area. The ozone is highly dangerous, because this gas (triatomic oxygen) destroys the lungs. People walking in the streets breathing large amounts of ozone start to choke and feel chest pain.

But if the ozone is located in the places it should be - at a high altitude, then it is very good for health. Ozone absorbs ultraviolet rays.

Effect on the climate

But the most disturbing is that the depletion of the ozone layer can unpredictably change the climate. The ozone layer traps more heat from the sun inside. As the amount of ozone in the atmosphere decreases, the air temperature decreases, the direction of the prevailing winds changes and the weather changes. As the result there will be more droughts, crop failures, food insecurity and hungry. Some scientists have calculated that even if actions are taken and any activities destroying the ozone layer are stopped, it will take 100 years to restore it.

The best international project is strong cooperation between the countries

World leaders and Speed are matter for saving the Earth. From the first research about ozone in 1973, it took just 16 years for the world to discuss, agree and prepare the solution that reversed the trend. The earliest scientific warnings that carbon dioxide emissions could disrupt the climate date back to 1962. But despite differences international laws on the prevention of climate change since then (Rio 1992, Kyoto 1998, Copenhagen 2009, Paris 2015), emissions are still climbing.

Unfortunately, in the 80s, the environment change was not a part of the  global agenda. The polarising issue, business interests were the most important issues for global politics. Today the protectionism measures, representation of fossil fuel interests, denial of science and obstruction of international cooperation are part of international agenda. Still we live in the world where short-termism of the  protection the future health of the planet is under discussion.  

The following sources were used in writing the article:

http://conf.montreal-protocol.org/meeting/mop/mop30/presession/Background-documents/SAP-2018-Assessment-ES-October2018.pdf

https://www.theguardian.com/environment/2019/jan/20/how-to-stop-the-climate-crisis-six-lessons-from-the-campaign-that-saved-the-ozone